CN100536770C - A surgical system and surgical navigation method guided by magnetic resonance images - Google Patents

Abstract

The present invention is surgical operation system under the guide of magnetic resonant image and the operation navigating method. The surgical operation system includes magnetic resonant imaging equipment, a tracking system, a surgical instrument, a sick bed, a control and display device, a computer with relevant software. It features the calibrating pin and calibrating mode, and the tracer with different coordinate systems for measuring pose and calibrating. The present invention can realize the precise location of the operational equipment relative to the magnetic resonant image and operation navigation.

Description

A surgical system and surgical navigation method guided by magnetic resonance images

technical field

The invention relates to a surgical system and a control method, in particular to a magnetic resonance image-guided surgical system and a surgical navigation method.

Background technique

Interventional surgery is a major development direction of modern surgery. The difference between interventional surgery or interventional therapy and traditional surgery is that it does not require surgery, and only requires a small incision to insert special catheters, cryo-needles, radiofrequency ablation needles, Surgical instruments such as guide wires penetrate into the lesion or surgical target in the human body, and then achieve the purpose of treatment through various physical/chemical effects, so as to solve the tumor resection, tissue biopsy, artificial equipment placement etc. Interventional surgery has the characteristics of no surgery, precise damage, small trauma, and fast recovery. It is considered to be an ideal alternative to many traditional open surgeries in the future.

During the interventional operation, doctors cannot directly observe the treatment site or lesion in the patient's body. In order to ensure the safety and effectiveness of the surgical process, an effective method is to use medical imaging methods for interventional surgery planning, navigation, treatment process observation, and treatment effect evaluation, so as to realize image guidance and monitoring of the entire surgical process. According to the characteristics of different diseases, different parts, and different types of interventional therapy, there are different image monitoring requirements. Among them, magnetic resonance imaging has become an ideal image-guided and imaging tool for interventional therapy because of its high image resolution, strong soft tissue imaging capabilities, free choice of image scanning orientation, ability to detect tissue temperature, and clear display of lesions occluded by bones. means of monitoring. Magnetic resonance-guided interventional surgery is also a hot research and development direction in international scientific research and clinical practice. And there is following problem in prior art:

1. In the process of magnetic resonance imaging, the nonlinearity of the gradient field will cause the geometric deformation of the image. The geometric deformation of the image is different on different magnetic resonance imaging equipment and in different fields of view of the same magnetic resonance imaging equipment. Therefore, it is necessary to correct the gradient deformation of the magnetic resonance image. The existing correction methods for the position offset can be divided into two types: one is to directly calculate the correction parameters through the method of image analysis based on the magnetic resonance imaging of the three-dimensional calibration model; One is to use the description function of the magnetic field—spherical harmonic function to calculate the offset of a limited number of control points in the imaging space. The calculation process of the former method is complex and the production cost of the calibration model is high, and it is necessary to repeatedly image and analyze the three-dimensional calibration model in different positions to obtain the position offset of the control point, which is difficult in practice. In the latter method, the design parameters of gradient coils are only a major factor of image deformation, and the influence of other hardware and software modules of the magnetic resonance system on image deformation is not considered, so the results of image correction often fail to meet the requirements.

2. When doctors perform magnetic resonance interventional therapy, they usually observe the magnetic resonance images of the lesion with the naked eye, and place the surgical instruments at the target position based on experience. This method cannot observe the interventional surgical instruments and the lesion site or location during the operation in real time. The actual error between the target points will affect the quality of the operation, making it difficult to guarantee the effect of the operation. Even if the error is large, the intervention operation must be repeated, causing the patient to suffer greater pain. Therefore, how to introduce a surgical instrument tracking system with high spatial positioning accuracy for three-dimensional space positioning of surgical instruments in the interventional therapy guided by magnetic resonance images, and how to accurately fuse the positioning information with magnetic resonance images must be solved. question.

3. Since the doctor is holding the surgical instrument, in the navigation mode of converting the surgical instrument and the lesion into the same coordinate system, the shaking of the hand will cause errors, so a device that can flexibly adjust the clamping position and direction of the surgical instrument is needed , and there is no off-the-shelf device in the prior art that can be used.

4. When changing the surgical instrument and lesion into the same system for observation, it is necessary to transform the relationship between the coordinate systems in the system, so it is necessary to provide a three-dimensional calibration model for calibration.

5. Since the feature point in the calibration model is a sphere, and the image formed by the magnetic resonance imaging equipment is obtained by integration, at the same time, due to the limitation of the imaging voxel size caused by the spatial resolution, and some other reasons such as volume effect, As a result, the image of the obtained feature points is distorted, so how to determine the center of the feature points is also a problem that needs to be solved.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a surgical system and a surgical navigation method that can be guided by magnetic resonance images in interventional surgery.

In order to achieve the above object, the present invention adopts the following technical solutions: a surgical system guided by magnetic resonance images, the hardware part includes magnetic resonance imaging equipment, a tracking system, surgical instruments, a hospital bed set on the magnetic resonance imaging equipment, control and a display device, as well as a computer and a control software part connected with each system; it is characterized in that: a calibration needle and a calibration module are also provided, and the pose of the magnetic resonance imaging equipment coordinate system can be measured by a tracking system; and the said The position of the magnetic resonance imaging equipment is correspondingly provided with at least one set of tracers constituting the world coordinate system, and the pose of the world coordinate system can be measured by the tracking system; An instrument tracker, the pose of the surgical instrument coordinate system can be measured by the tracking system; the bed tracker that constitutes the bed coordinate system is set on the hospital bed, and the hospital bed coordinate system can be measured by the tracking system; The calibration needle is composed of a needle with a certain length and a tracer. After the needle tip touches a certain point after calibration, the position of this point can be measured; the inside and surface of the calibration mold are respectively provided with a set of asymmetric Distributed feature point set I and feature point set II, the feature points of the feature point set I can be imaged by the magnetic resonance imaging device, and the feature points of the feature point set II can be measured by the tracking system; feature points The relative positional relationship between set I and feature point set II is known; after calibration, the lesion coordinates and surgical instrument coordinates can be transformed into the same coordinate system through the mutual transformation relationship between each coordinate system.

A surgical navigation method using the above-mentioned magnetic resonance image-guided surgical system, which includes the following steps: (1) in the system consisting of magnetic resonance imaging equipment, a tracking system, surgical instruments and a hospital bed, the magnetic resonance imaging equipment itself has magnetic The coordinate system of the resonance imaging equipment, the tracer is installed in the place where the position does not move to form the world coordinate system, and the surgical instrument tracer is set on the surgical instrument to form the coordinate system of the surgical instrument; (2) measuring and calibrating with the magnetic resonance imaging equipment The coordinates of the model feature point set I are measured by the tracking system, and the transformation relationship between the magnetic resonance imaging equipment coordinate system and the world coordinate system is calibrated through these two sets of coordinate data; (3) will carry the patient The hospital bed is pushed into the imaging area of the magnetic resonance imaging equipment, and the magnetic resonance imaging equipment provides the image data of the lesion and the pose of the coordinate system of the magnetic resonance imaging equipment, and the tracking system provides the pose of the coordinate system of the tracking system and the coordinate system of the surgical instrument. Combining the calibration results of step 2 to establish the transformation relationship between the coordinate systems; (4) using the transformation of the coordinate system, the lesion and the surgical instrument are placed in the same coordinate system for observation; (5) according to the relative position of the lesion and the surgical instrument image, move the surgical instrument, place it at the target position, and perform surgical treatment.

Another surgical navigation method using the above-mentioned magnetic resonance image-guided surgical system includes the following steps: (1) in the system consisting of magnetic resonance imaging equipment, tracking systems, surgical instruments and sick beds, the magnetic resonance imaging equipment itself has The magnetic resonance imaging equipment coordinate system, the tracer is installed in the place where the position does not move to form the world coordinate system, the surgical instrument tracer is set on the surgical instrument to form the surgical instrument coordinate system, on the hospital bed or opposite to the lesion Set the bed tracker at the same position to form the bed coordinate system; (2) Use the magnetic resonance imaging equipment to measure the coordinates of the feature point set I of the calibration model, and use the tracking system to measure the coordinates of the feature point set II, and use these two sets of coordinate data to calibrate The transformation relationship between the coordinate system of the magnetic resonance imaging equipment and the world coordinate system; (3) push the patient bed into the imaging area of the magnetic resonance imaging equipment, and the imaging data of the lesion will be provided by the magnetic resonance imaging equipment. Provide the pose information of the bed coordinate system; (4) drag the bed out of the imaging area of the MRI equipment and move it to the operation area, and the tracking system provides the pose of the tracking system coordinate system, the bed coordinate system and the surgical instrument coordinate system, The magnetic resonance imaging equipment coordinate system is provided by the magnetic resonance imaging equipment, and the transformation relationship between the coordinate systems is established in combination with the calibration results in step 2; (5) using the transformation of the coordinate system, the lesion and the surgical instrument are placed in the same coordinate system (6) According to the image of the relative position of the lesion and the surgical instrument, move the surgical instrument, place it at the target position, and perform surgical treatment.

(i＝1，2，...，n_ph)，由坐标

生成L个向量

这L个向量

分布在不同的方向；(b)利用跟踪系统2测量特征点集II各点在跟踪系统坐标系里的坐标，从而得到特征点集I各点在跟踪系统坐标系里的坐标

(i＝1，2，...，n_ph)，在跟踪系统坐标系生成和向量

一一对应的向量

(c)这两组向量满足变换关系为： $R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}});$ (d)由方程组 $R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}})$ 可解出旋转矩阵

然后将它代入方程组 $R_{\mathrm{scan}}^{\mathrm{track}}{X}_i^{\mathrm{scan}}+T_{\mathrm{scan}}^{\mathrm{track}}=X_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}}),$ 可解出

得到变换关系

进而得到磁共振成像设备坐标系和跟踪坐标系之间的变换关系 When each coordinate system is calibrated with the calibration module in the above-mentioned steps (2), the method of separately demarcating the rotation amount and the translation amount is adopted, and the steps are as follows: (a) Utilize the magnetic resonance imaging device 1 to measure each point of the feature point set I at Coordinates in the MRI equipment coordinate system

(i=1, 2, . . . , n _ph ), by coordinates

generate L vectors

The L vectors

distributed in different directions; (b) use tracking system 2 to measure the coordinates of each point of feature point set II in the tracking system coordinate system, so as to obtain the coordinates of each point of feature point set I in the tracking system coordinate system

(i=1, 2, ..., n _ph ), the sum vector is generated in the tracking system coordinate system

one-to-one vector

(c) These two sets of vectors satisfy the transformation relationship as follows: $R_{\mathrm{scan}}^{\mathrm{track}}{\mathrm{D.}}_i^{\mathrm{scan}}={\mathrm{D.}}_i^{\mathrm{track}}(i=\mathrm{1,2},...,{\mathrm{no}}_{\mathrm{pH}});$ (d) by the equation $R_{\mathrm{scan}}^{\mathrm{track}}{\mathrm{D.}}_i^{\mathrm{scan}}={\mathrm{D.}}_i^{\mathrm{track}}(i=\mathrm{1,2},...,{\mathrm{no}}_{\mathrm{pH}})$ The rotation matrix can be solved

and then substitute it into the equation $R_{\mathrm{scan}}^{\mathrm{track}}{x}_i^{\mathrm{scan}}+T_{\mathrm{scan}}^{\mathrm{track}}=x_i^{\mathrm{track}}(i=\mathrm{1,2},...,{\mathrm{no}}_{\mathrm{pH}}),$ Solvable

get transformation relationship

Then the transformation relationship between the MRI equipment coordinate system and the tracking coordinate system is obtained

Another surgical navigation method using the above-mentioned magnetic resonance image-guided surgery system, which includes the following steps: (1) setting at least three navigation marks on the patient's body surface on the hospital bed that have no relative movement with the lesion, and A surgical instrument tracer is set on the surgical instrument to form a surgical instrument coordinate system; (2) The patient bed is pushed into the imaging area of the magnetic resonance imaging equipment, and the magnetic resonance imaging equipment provides the image data of the lesion and the image data of the navigation marks (3) Drag the hospital bed out of the imaging area of the MRI equipment, move to the operation area, first use software to extract the coordinates of the navigation markers in the coordinate system of the MRI equipment from the lesion image, and then use the tracking system to measure the coordinates of the navigation markers in the MRI equipment coordinate system. The coordinates in the coordinate system of the tracking system, according to these two sets of data, the transformation relationship between the coordinate system of the magnetic resonance imaging equipment and the coordinate system of the tracking system is obtained; (4) the pose of the coordinate system of the tracking system and the coordinate system of the surgical instrument is provided by the tracking system , the pose and orientation of the coordinate system of the magnetic resonance imaging equipment is provided by the magnetic resonance imaging equipment, and the transformation relationship between the coordinate systems is established in combination with the calibration results in step 3; (5) using the transformation of the coordinate system, the focus and the surgical instrument are placed Observing in the same coordinate system; (6) According to the image of the relative position of the lesion and the surgical instrument, move the surgical instrument, place it at the target position, and perform surgical treatment.

When each coordinate system is demarcated with a calibration module in the above-mentioned steps (2), the software program of the navigation system is provided with a program for locating the center of the sphere to the feature point imaging result in the feature point set 1, which includes the following steps : (1) First assume that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinates of the cross-section in the scanning direction; (2) randomly scan three cross-sectional circle images at different positions along the same axis along the ball, or After scanning to obtain two cross-sectional circle images at different positions, fit the third cross-sectional circle image, and form a set of values by the area of the cross-sectional circle and the coordinate values of the cross-sectional circle in the scanning direction; (3) the three sets of obtained value, a Gaussian curve is fitted, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; Coordinate value, the combination of each axial coordinate value is the coordinate of the center of the sphere.

The present invention has the following advantages due to the adoption of the above technical scheme: 1. The present invention is provided with tracers for surgical instruments, sick beds, etc. in the magnetic resonance system, and also provided with calibration moulds, calibration needles and navigation marks for calibration, etc., Therefore, after calibration with the calibration model, whether it is during the imaging of the magnetic resonance imaging equipment, or moving or changing surgical instruments, or even moving the hospital bed to other positions, it can be performed online or offline or semi-automatically under the control of the navigation system of the present invention. Offline and other modes of interventional surgery, and ensure navigation accuracy. 2. The present invention aims at the problem that the position of the center of the sphere of the characteristic points on the calibration model is uncertain during the imaging process of the magnetic resonance imaging equipment, and a sphere center positioning program based on three-dimensional high-precision imaging is preset in the software imaging, so The precise center position of the sphere can be obtained from the magnetic resonance image when the calibration mode is calibrated, so that the navigation effect of the navigation system of the present invention is more accurate. 3. The present invention aims at the problem of the geometric deformation of the image caused by the nonlinearity of the gradient field in the process of magnetic resonance imaging, and reversely calculates the magnetic resonance correction parameters according to the actual image, which overcomes the disadvantage of the difference between the gradient coil design parameters and the real magnetic field gradient parameters , and in the process of reversing the magnetic field gradient parameters, the method of reversing the magnetic field gradient parameters in three directions is adopted in turn, which improves the convergence speed of the algorithm. 4. The present invention provides a surgical instrument guide for clamping surgical instruments, which can provide at least ten adjustable degrees of freedom, so it is very convenient and accurate to align the puncture needle at the lesion of the patient and insert it into the lesion conveniently On the one hand, it eliminates the influence of the operator's hand shake, and on the other hand, it reduces the bending phenomenon of surgical instruments during the puncture process. 5. In the present invention, since a linear laser is respectively arranged on the top and both sides of the examination and treatment space of the magnetic resonance imaging equipment, each linear laser can emit a fan-shaped plane laser to form protection in one direction, and the beams emitted by the three lasers are consistent with the The bed together forms a width and height restricted space, so that any object beyond the restricted space will trigger an alarm when it enters the magnetic resonance imaging equipment, thus effectively avoiding collisions between ultra-high and ultra-wide objects and the magnetic resonance imaging equipment. The danger and damage caused by the device protect the safety of the patient and the MRI equipment. The present invention can ensure the minimum damage to the patient while obtaining the maximum effect of interventional surgery. This method is applicable to various interventional treatment methods, including radio frequency, microwave, focused ultrasonic knife, particle implantation, etc.; the present invention can also It is suitable for various treatment targets such as needle biopsy and tumor/tissue ablation.

Description of drawings

Fig. 1 is a schematic diagram of the layout of the hardware part of the treatment system of the present invention

Fig. 2 is a schematic diagram of the navigation system of the present invention

Fig. 3 is a schematic diagram of the structure of the calibration model of the present invention

Fig. 4 is a schematic diagram of feature point setting on one surface of the calibration model of the present invention

Fig. 5 is a schematic diagram of the asymmetric distribution of feature points of the calibration model of the present invention

Figure 6 is a schematic diagram of images formed by magnetic resonance imaging equipment

Fig. 7 is a schematic diagram of three cross-sectional positions in Fig. 6

Fig. 8 is the Gaussian curve fitted by the present invention along the z-axis scanning in three-dimensional coordinates

Fig. 9 is a schematic diagram of the positioning geometric relationship of the center of the sphere in the present invention

Fig. 10 is a three-dimensional schematic diagram of the structure of the surgical instrument guiding device of the present invention

Fig. 11 is a schematic diagram of the structure of the lower bracket assembly of the present invention

Figure 12 Schematic diagram of the connection of the upper branch pipe, guide sleeve, shell, gear, etc. of the navigator of the present invention

Figure 13 is a schematic top view of Figure 12

Figure 14 is a schematic diagram of the structure of the upper beam of the navigator of the present invention

Figure 15 is a schematic diagram of the joint structure at the connection between the upper beam and the lower bracket of the navigator of the present invention

Figure 16 is a schematic diagram of the joint structure at the joint between the upper beam and the recliner of the navigator of the present invention

Fig. 17 is a three-dimensional schematic diagram of the recliner of the navigator of the present invention

Fig. 18 is a structural schematic diagram of the navigator angle adjuster of the present invention

Fig. 19 is a schematic cross-sectional view of the navigator recliner of the present invention

Fig. 20 is a side view sectional schematic view of Fig. 19

Figure 21 is a schematic diagram of the interventional guidance component of the navigator of the present invention

Figure 22 is a three-dimensional schematic diagram of the composition of the laser protector of the present invention

Fig. 23 is a schematic diagram of the positions of the lasers in the magnetic resonance imaging equipment according to the present invention

Fig. 24 is a logical block diagram of software part of the present invention

Figure 25 is a schematic diagram of the gradient correction program of the present invention

Figure 26 is a schematic diagram of the structure of the gradient correction module of the present invention

Fig. 27 is a side view sectional schematic view of Fig. 26

Fig. 28 is a schematic diagram of the change law of the magnetic field gradient on the X-axis of the present invention within ± 30cm

Fig. 29 is a schematic diagram of image changes of equidistant marker points in the present invention

Figure 30 is a schematic diagram of the gradient correction model marker points designed according to the distance between marker points and the calculation formula of diameter

Fig. 31 is a flow chart of searching and correcting parameters in the gradient correction of the present invention

Fig. 32 is a schematic diagram of marker points on the x-axis after gradient correction in the present invention

Figure 33 is a flow chart of surgical planning for the treatment method of the present invention

Figure 34 is a flow chart of the operation implementation of the treatment method of the present invention

Detailed ways

The present invention will be described in detail below through embodiments and in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, the present invention includes hardware and control software, wherein the hardware equipment mainly includes a magnetic resonance imaging device 1, a surgical instrument tracking system 2, a world coordinate system tracer 3, a surgical instrument 4 and a surgical instrument tracer device 5, hospital bed 6 and hospital bed tracer 7, calibration needle 8, calibration module 9, control and display equipment 10, etc. The control and display device 10 includes one or more consoles. For example, this embodiment includes a magnetic resonance console 11, an interventional treatment console 12, a surgical planning navigation system console 13, and an operating room video monitoring platform 14. The magnetic resonance compatible display screen 15 (such as liquid crystal display), etc., several consoles also can be combined into a total console. The hardware device of the present invention can also be provided with a life signal monitoring system 16 for monitoring patients, an interventional operation docking station 17 connected with the interventional treatment console 12, etc. according to the operation requirements.

The magnetic resonance imaging device 1 of the present invention adopts a horizontal open permanent magnet structure. This magnet structure avoids the limitation of the traditional barrel-shaped magnet structure on the angle and depth of the interventional surgical instrument 4 entering the human body, and the effective tracking area of the tracking system 2. The limitation ensures the realization of the real-time interventional surgery navigation mode, and ensures that the patient can perform interventional surgery on various parts of the human body while lying in the magnet. The magnetic resonance imaging device 1 is used to image the patient's lesions, the feature points in the calibration module 9, etc. The coordinate system of the magnetic resonance imaging device is the property of the magnetic resonance imaging device 1 itself, and it and other coordinates can be established through the calibration of the calibration module 9 Coordinate transformation relationship between systems.

Tracking system 2 of the present invention is made up of position sensor, work station and relevant circuit etc., and tracking system 2 can detect the coordinate of target point in the field of view of tracking system (the space area that keeps measuring precision), also can measure the position of target coordinate system and posture (referred to as pose) information, the tracking system 2 can be an optical tracking system, an electromagnetic tracking system, a robot, and the like. The tracking system 2 uses the position sensor on it to detect the world coordinate system tracer 3, the surgical instrument tracker 5, the hospital bed tracker 7, etc., and completes the positioning of the world coordinate system, the surgical instrument coordinate system and the hospital bed coordinate system. Attitude tracking measurement.

The world coordinate system tracer 3 of the present invention, the surgical instrument tracer 5 and the hospital bed tracer 7 all can adopt in the prior art by several (3 or more than 3) minimum tracer units (such as the surface has tracer balls of fluorescent material) to form a tracer, the position of the tracer unit can be directly observed by the position sensor in the tracking system 2, so that the tracers 3, 5, and 7 can be used as a coordinate system to provide the attached equipment pose information. The position of the world coordinate system is generally connected with the magnetic resonance imaging device 1 , and can also be set at other positions. The position of the world coordinate system does not move during treatment. The world coordinate system can be composed of one or more sets of trackers 3. If multiple sets of trackers 3 are placed in different positions, the position of the position sensor can be changed as needed during the navigation process to ensure that the position sensor can always detect it. A tracker of , so as to obtain the pose of the world coordinate system.

The surgical instrument 4 of the present invention includes precision instruments such as catheters and guide wires, which are introduced into the human body during the operation to diagnose and treat local lesions in the body. The surgical instrument 4 is connected with a surgical instrument tracer 5 as a surgical instrument coordinate system. The physical size and relative position of the surgical instrument 4 and the surgical instrument tracker 5 are determined, so the pose information of the surgical instrument 4 can be measured by the tracking system 2 .

The patient is placed on the hospital bed 6 of the present invention, and can move relative to the magnetic resonance imaging equipment 1 from the initial position to the imaging area or operation area, etc. After the bed tracker 7 serving as the bed coordinate system is fixed on the bed 6 , the pose information of the bed 6 can be measured by the tracking system 2 . In certain applications (for example neurosurgery of the brain), a support is fixed to the patient's body on the bed 6, and the bed tracker 7 can also be fixed to the support at this time. The purpose of placing the tracer 7 on the hospital bed 6 or the bracket is to accurately track the position of the lesion when the lesion moves. Place the tracer 7 on the bed 6, when the focus and the bed 6 have no relative movement, the movement of the bed 6 is the same as that of the focus; When moving, the movement of the stent is the same as that of the lesion. In the following description, the bed tracker 7 can also be understood as the tracker of the frame, and the pose of the bed can also be understood as the pose of the frame, and there is no obvious difference in mathematical symbols.

The calibration needle 8 of the present invention is composed of a needle with a certain length and a tracer. Since the physical size and relative position of the needle point and the tracer are determined, the position of the needle point can be tracked by the tracking system after calibration. 2 measurement, thereby utilizing the needle tip of the calibration pin 8 to touch a certain point, the position of this point can be measured.

The present invention can also set a navigation mark 18 on the skin near the patient's lesion. The navigation mark 18 can be imaged in the magnetic resonance imaging device 1 and can also be measured by the tracking system 2. Through registration, the distance between the two coordinate systems can be calculated. coordinate transformation relationship. The navigation mark 18 has two purposes, one is to verify the tracking accuracy, and the other is to register the lesion image and align the image with the lesion entity. The above registration refers to the coordinate data of two sets of points. These two sets of points describe the same object, but the coordinates of the two sets of points are different due to the different coordinate systems. Through registration, the difference between the two coordinate systems can be calculated. The coordinate transformation relationship between them. Also called "registration" or "alignment".

Calibration module 9 of the present invention can adopt various structures, all is to provide two groups of characteristic point sets I and II in essence, and point set I can be imaged in imaging equipment, thereby obtains that each point in point set I is in magnetic resonance imaging equipment The coordinates in the coordinate system, the point set II can be measured by the tracking system, so as to obtain the coordinates of each point in the point set II in the tracking system coordinate system. The relative position relationship between the feature point set I and the feature point set II is known (called the geometric information of the calibration mode), that is, if the coordinates of each point of the feature point set I are known, each point of the feature point set II can be calculated. The coordinates of the points; if the coordinates of the points of the feature point set II are known, the coordinates of the points of the feature point set I can also be calculated. Below, only two examples of the calibration model will be given for illustration.

Embodiment 1: as shown in Fig. 3 and Fig. 4, the calibration mold 9 of the present embodiment comprises a rectangular calibration mold body 91 of 300mm * 240mm * 200mm made of plexiglass material, and the calibration mold body 91 has five other parts except the bottom surface. The surfaces are similar, and each surface has a characteristic layer 92 with a certain thickness, and the surfaces are sealed and connected by bonding or other methods. A group of spheres (such as cod liver oil spheres) as feature points 93 are arranged at intervals inside each feature layer 92 , and all the feature points 93 on the five surfaces together form the feature point set I. Corresponding to the position of each feature point 93 on the outer surface of each feature layer 92, a pit is set as a feature point 94, and the feature points 94 on the five outer surfaces together form the feature point set II. In calibration mold body 91 inside, promptly in the space that six wrap up is calibration mold solution 95, also can not have calibration mold solution. Calibration solution 95 can use sodium chloride solution, copper sulfate solution, etc., which have the effect of improving load and signal-to-noise ratio. The feature point 93 in the feature point set I can be imaged by the magnetic resonance imaging device 1, and its center can be calculated according to the obtained image; the feature point 94 of the feature point set II can be tracked by the tracking system 2 as long as it is clicked by the calibration needle 8. identify.

In the above-mentioned embodiment, if the feature points 93, 94 of each feature layer 92 are arranged symmetrically, but since the two back-to-back surfaces of the calibration mold body 1 are symmetrical, it is impossible to know whether a certain point is in the same position without prior knowledge. This face is still the face facing away from it, then when registering in the software, you must manually notify the software of the point correspondence between feature point sets I and II; if you set feature point 93 or feature point 94 on each face, choose asymmetric Spatial distribution (take feature point 93 as an example, as shown in Figure 5), that is, some positions are vacant, and the software can automatically find the corresponding relationship. In order to realize automatic matching during the registration operation in the present invention, the feature points 93 and 94 of the feature point set I and feature point set II set in the calibration module body 91 adopt asymmetric distribution. This asymmetric distribution includes the asymmetric distribution of each feature point 93 in the feature point set I, and also includes the asymmetric distribution of the feature points 94 in the feature point set II, and also includes the feature point 93 of the feature point set I and the feature point set II. There is no one-to-one correspondence between the feature points 94 in . Although these feature points 93,94 are asymmetrically distributed, once the calibration model is completed, the mutual positions between each feature point 93,94 are determined, and each feature point 93,94 label can be input into the computer to facilitate access at any time. use.

The above-mentioned calibration modules 9 are mainly used to calibrate and check the mutual positions between the coordinate systems. Since the feature point 93 of the feature point set I can be analyzed from the image formed by the magnetic resonance imaging device 1, the feature point set II’s The feature point 94 can be identified and measured by the tracking system 2, and the relationship between the feature point set I and the feature point set II is known (geometric information called calibration modulus), as long as the feature point 93 in the feature point set I ( Or the coordinates of the feature point 94) in the feature point set II), the coordinates of the feature point 94 in the feature point set II (or the feature point 93 in the feature point set I) can be calculated, and the magnetic resonance can be established by the relationship between them The transformation relationship between the coordinate system of the imaging device and the coordinate system of the tracking system.

However, according to the imaging characteristics of various imaging equipment (magnetic resonance imaging equipment, computed tomography equipment (CT), C-arm X-ray equipment, ultrasonic imaging system, etc.), when the magnetic resonance imaging equipment 1 pairs with the calibration model 9 When the feature point 93 is scanned (as shown in Figure 6), since the feature point 93 is not a point, but a sphere, the scanned image is obtained by integration, and the obtained image is irregular, especially the distance from the scanning center of the device The farther the position, the greater the deformation of the obtained image (as shown in a, b, and c in Figure 7), so the center of the sphere cannot be directly obtained from the image. For this reason, in the software program of the navigation system of the present invention, a kind of center-of-sphere positioning program based on high-precision imaging needs to be added, which is specifically described below:

As shown in Figure 8, in order to obtain the real center of the sphere of the feature point 93, the present invention first assumes that the area S of the circle on the cross-sectional view and the coordinate value of the cross-section in the scanning direction satisfy a normal distribution; scan with a magnetic resonance imaging device 1 feature point 93, and arbitrarily scan three cross-sectional circle images at different positions along the same axis, the area S of a certain cross-sectional circle in the scanning direction and the coordinate value of the cross-section in the scanning direction can form a set of values; It can be seen that as long as three sets of such values are obtained, a Gaussian curve can be fitted, and the coordinate value corresponding to the point with the largest area (peak point) on the curve is the coordinate value of the center of the sphere in the scanning direction. The curve reaches its peak at point 0 on the z-axis, indicating that this point is the coordinate value of the center of the sphere in the direction of the z-axis. In the same way, the coordinate values of the center of the sphere in the direction of the other two coordinate axes (x, y) can be obtained, and the coordinate values of the center of the sphere in this axis can be calculated by using three sections in each axis, and combined in The coordinates of the center of the sphere can be determined together.

During the scanning process, sometimes only two cross-sectional views may be obtained. At this time, it is first necessary to fit the third cross-sectional view through the center of the circle from these two pictures, and then use the above method to calculate the coordinate position of the center of the sphere. for example:

As shown in Figure 9, use a plane to cut a sphere (feature point 93), a circle will be obtained, in the figure (x, y, z) represents the coordinates of the center of the sphere, d represents the distance from the center of the sphere to the section circle, R ₀ Represents the radius of the ball, r represents the radius of the section circle, (a, b, c) represents the center of the section circle, and t1 represents the normal direction of the section circle. There is such a geometric relationship between them:

d ² +r ² =R ₀ ²

The approximate radius R ₀ of the known sphere is 3mm. By analyzing the image, the center coordinates (a, b, c) of the cross-section circle and the area S of the circle can be obtained. The radius r of the cross-section circle can be obtained by using the area S of the circle. Using the center of the sphere and The coordinates of the center of the circle can be used to obtain the distance d from the center of the sphere to the section circle, so that the coordinates (x, y, z) of the center of the sphere on the axis can be obtained by using the formula (1).

From the geometric relationship, we know that as long as the parameters of the two surfaces are known, the following simultaneous equations can be listed geometrically to solve the coordinates of the center of the sphere:

For the first face:

$\left\{\begin{array}{c}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="S"\; filenames="C200710064930E00381.png,C200710064930E00382.png"\; state="\{\{state\}\}">S</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \frac{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="t"\; filenames="C200710064930E00381.png,C200710064930E00382.png"\; state="\{\{state\}\}">t</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}\end{array}\right.$

In this way, two sets of values can be solved, geometrically speaking, one for the upper and lower.

For the second face:

$\left\{\begin{array}{c}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="S"\; filenames="C200710064930E00381.png,C200710064930E00382.png"\; state="\{\{state\}\}">S</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \frac{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="t"\; filenames="C200710064930E00381.png,C200710064930E00382.png"\; state="\{\{state\}\}">t</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}\end{array}\right.$

You can also solve two sets of values, one for the upper and lower.

Of the four centers solved above, two of them should actually be the same point (of course there must be errors). Let's find the distance between each two points, l ₁ , l ₂ , l ₃ , l ₄ , then the two points with the smallest distance should be the correct center of the sphere, so take the average of these two points to get the center of the sphere we want initial value.

With the initial value of the center of the sphere and the radius R ₀ of the sphere, the information of the cross-sectional circle passing through the center of the sphere is obtained, and the method of the present invention can be used to calculate the center of the sphere by combining the two existing information of the sectional circles. Since there are already three cross-sectional circle information (center, radius), the area of the circle can be calculated; since the coordinates of the center of the circle are known, three sets of values are obtained, and each set of values is determined by the area of a certain cross-sectional circle in the scanning direction and the coordinates of the cross section in the scanning direction, using these three sets of values as point coordinates on the Gaussian curve, a Gaussian curve can be fitted to obtain the coordinates of the center of the sphere in the scanning direction. Using the same method, the coordinate values of the center of the sphere in the other two directions can be obtained, thereby obtaining the position coordinates of the center of the sphere.

The essence of the navigation system of the present invention is to put the lesion picture and the virtual surgical instrument into the same coordinate system for observation, that is, to display them on the working screen (which can be a liquid crystal screen, a projection screen or other forms of display equipment) at the same time, and the screen The relative position of the above two is the same as that of the real lesion and the surgical instrument, so that the doctor can see both the lesion and the surgical instrument through the observation screen, and then accurately and quickly send the surgical instrument to the target position.

Adopt the navigation system of the present invention, the present invention can finish the operation of following two kinds of working modes (real-time and non-real-time):

Working mode 1: The patient lies on the hospital bed 6 , pushes the hospital bed 6 into the imaging area of the magnetic resonance imaging device 1 , and performs surgery in real time while scanning the lesion. Among them, the magnetic resonance imaging equipment 1 provides the image data of the lesion, and the tracking system 2 provides the pose information of the surgical instrument 4, and the lesion and the surgical instrument 4 are observed in the same coordinate system by coordinate transformation, and displayed on the screen at the same time, namely The relative position of the lesion and the surgical instrument 4 seen by the doctor on the screen is the actual relative position of the lesion and the surgical instrument 4 .

Working mode 2: The patient lies on the sickbed 6, pushes the sickbed 6 into the imaging area of the magnetic resonance imaging device 1, obtains the image of the lesion, and then drags the sickbed 6 out to a place for surgery (there is no interaction between the patient and the sickbed). mobile), perform surgery in non-real time. Among them, the magnetic resonance imaging equipment 1 provides the image data of the lesion, the tracking system 2 provides the position and posture information of the surgical instrument 3 and the hospital bed 6, and uses coordinate transformation to put the lesion and the surgical instrument 4 into the same coordinate system for observation, and simultaneously displays them on the screen , that is, the relative position of the lesion and the surgical instrument 4 seen by the doctor on the screen is the actual relative position of the lesion and the surgical instrument 4 .

In order to support the above two working modes, the system of the present invention supports the following three navigation modes. Before describing the navigation mode of the present invention in detail, the variables that appear in the description are defined as follows (as shown in Table 1):

Table 1: Definition of variables

Navigation mode A: In order to carry out the first working mode, the present invention adopts the tracer 3 as the world coordinate system (as shown in Figure 1), which is arranged on the magnetic resonance imaging device 1, so it is consistent with the magnetic resonance imaging device The relative position of 1 remains unchanged, and the surgical instrument tracker 5 is fixed on the surgical instrument 4 as the surgical instrument coordinate system. Through calibration modulo 9 calibration, the coordinate transformation relationship between the magnetic resonance imaging equipment coordinate system and the world coordinate system can be obtained, so that the lesion (the magnetic resonance imaging equipment 1 provides its image and pose information) can be transformed into the world coordinate system (here The calibration work only needs to be done once when the equipment is installed, as long as there is no relative movement between the tracer 3 and the magnetic resonance imaging equipment 1, the calibration results can be used directly in subsequent operations). At the same time, the pose of the surgical instrument 4 in the surgical instrument coordinate system is obtained through the calibration of the calibration module 9 (every operation must be calibrated, because the surgical instrument tracer 5 is generally fixed before the operation, and it is likely to be fixed during the operation. Separation and fixation of the surgical instrument 4 and the surgical instrument tracer 5 are carried out). During the operation, the tracking system 2 measures the pose of the world coordinate system, and obtains the conversion relationship between the own coordinate system of the tracking system 2 and the world coordinate system; at the same time, the tracking system 2 measures the pose of the surgical instrument coordinate system, and obtains the coordinates of the surgical instrument system and the world coordinate system, so that the surgical instrument 4 is also transformed to the world coordinate system for observation. In addition to uniformly transforming the lesion and surgical instruments 4 into the world coordinate system for observation, they can also be transformed into other coordinate systems for observation, such as the magnetic resonance imaging equipment coordinate system or the tracking system coordinate system.

The specific derivation process of the coordinate transformation relationship in navigation mode A is as follows:

根据事先标定好的磁共振成像设备坐标系和世界坐标系之间的变换关系

可以将病灶的任意一点坐标从磁共振成像设备坐标系变换到世界坐标系中，得到此点在世界坐标系里的坐标Observing the lesion and the surgical instrument 4 in the world coordinate system, the magnetic resonance imaging device 1 scans the lesion to obtain its image data, including the coordinates of any point of the lesion in the magnetic resonance imaging equipment coordinate system

According to the transformation relationship between the coordinate system of the magnetic resonance imaging equipment calibrated in advance and the world coordinate system

The coordinates of any point of the lesion can be transformed from the MRI equipment coordinate system to the world coordinate system, and the coordinates of this point in the world coordinate system can be obtained

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

同时也测量世界坐标系的位姿

从而得到手术器械坐标系和世界坐标系之间的变换关系The tracking system 2 measures the pose information of the surgical instrument tracker 5

Also measure the pose of the world coordinate system

In order to obtain the transformation relationship between the surgical instrument coordinate system and the world coordinate system

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

The coordinates of any point T on the surgical instrument 4 in the surgical instrument coordinate system is known, transform it into the world coordinate system

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

So far, the lesion and the surgical instrument 4 have been observed in the same coordinate system (world coordinate system), and they can be displayed on the screen. The relative position of the lesion and the surgical instrument 4 seen by the doctor on the screen is the actual relative position of the lesion and the surgical instrument 4 .

In addition to the world coordinate system, the lesion and the surgical instrument 4 can also be transformed into other coordinate systems for observation, such as the magnetic resonance imaging equipment coordinate system or the tracking system coordinate system.

不需要进行变换，而只需变换手术器械4到磁共振成像设备坐标系Observation using the coordinate system of the magnetic resonance imaging equipment, since the lesion is already in the coordinate system of the magnetic resonance imaging equipment, the coordinates of any point are

No need to transform, but only need to transform the surgical instrument 4 to the magnetic resonance imaging equipment coordinate system

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Using the tracking system coordinate system to observe, the coordinates of any point of the lesion and any point of the surgical instrument 4 in the tracking system coordinate system are respectively

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Navigation mode B: In order to carry out the second working mode, it can be extended on the basis of the calibration method and tracking method of navigation mode A. Similarly, using the tracker 3 as the world coordinate system, its relative position with the magnetic resonance imaging device 1 remains unchanged, and the surgical instrument tracker 5 is fixed on the surgical instrument 4 . In addition, in order to adapt to the movement of the hospital bed 6 (patient), a bed tracker 7 fixed on the bed 6 relative to the patient's lesion (or a human body coordinate tracker set on the patient on the bed) is also required. During the operation, after the lesion is imaged in the magnetic resonance imaging device 1, as the patient bed 6 moves to the position where the operation is performed, the coordinate transformation relationship between the coordinate system of the magnetic resonance imaging device and the world coordinate system and the pose of the patient bed 6 are used Information, the lesion can be transformed into the world coordinate system for observation. The tracking method of the surgical instrument 4 is the same as that in the navigation mode A. In addition to uniformly transforming the lesion and surgical instruments 4 into the world coordinate system for observation, they can also be transformed into other coordinate systems, such as the magnetic resonance imaging equipment coordinate system, the tracking system coordinate system or the hospital bed coordinate system.

The specific derivation process of the coordinate transformation relationship in navigation mode B is as follows:

Observe the lesion and the surgical instrument 4 in the world coordinate system, and when the patient is pushed into the magnetic resonance imaging device 1 for imaging, the coordinates of any point of the lesion in the world coordinate system are described by formula (1)

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

被跟踪系统2探测，它在世界坐标系里的位姿为The subscript 0 indicates that the bed 6 is pushed into the MRI equipment 1, and the pose of the bed coordinate system is

Detected by tracking system 2, its pose in the world coordinate system is

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

From formulas (1) and (7), it can be known that the coordinates of any point of the lesion in the bed coordinate system at this time are

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

After the imaging is completed, the lesion (patient) moves to the operation position (indicated by subscript 1) along with the hospital bed 6 . Since there is no relative movement between the patient and the bed 6, the coordinates of the lesion on the bed 6 remain unchanged

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

被跟踪系统2探测，它在世界坐标系里的位姿为The pose of bed 6 at this time

Detected by tracking system 2, its pose in the world coordinate system is

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

From formulas (8) to (10), it can be concluded that the coordinates of the lesion in the world coordinate system at this time are

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

The coordinates of any point of the surgical instrument 4 in the world coordinate system are the same as those described by formula (3)

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

So far, the lesion and surgical instruments have been observed in the same coordinate system (world coordinate system).

In addition to the world coordinate system, lesions and surgical instruments can also be transformed into other coordinate systems for observation, such as the magnetic resonance imaging equipment coordinate system, tracking system coordinate system or hospital bed coordinate system.

Using the magnetic resonance imaging equipment coordinate system to observe, the coordinates of any point of the lesion and any point of the surgical instrument 4 in the magnetic resonance imaging equipment coordinate system are respectively

$V_{\mathrm{lesion},1}^{\mathrm{scan}}=C_{\mathrm{the\; world}}^{\mathrm{scan}}{V}_{\mathrm{lesion},1}^{\mathrm{the\; world}}=C_{\mathrm{the\; world}}^{\mathrm{scan}}{\left(C_{\mathrm{the\; world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}{\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{the\; world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{the\; world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}$ (12)

${<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; work</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Using the tracking system coordinate system to observe, the coordinates of any point of the lesion and any point of the surgical instrument 4 in the tracking system coordinate system are respectively

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Using the sick bed coordinate system to observe, the coordinates of any point of the lesion and any point of the surgical instrument 4 in the sick bed coordinate system are respectively

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 14</span>}<span\; class="notranslate">\; )</span>$

Navigation mode C: In order to carry out the second working mode, different calibration methods and tracking methods from navigation mode B can be used. It is fixed on the patient's body surface with navigation markers 18 (the number is not less than 3) that can be imaged in the magnetic resonance imaging device 1, and is imaged in the magnetic resonance imaging device 1. During the operation, between the navigation markers 18 and the lesion No relative movement. After the hospital bed 6 (patient) is pulled out and reaches the operation area, extract the coordinates of the navigation marker 18 in the magnetic resonance imaging equipment coordinate system on the lesion image, and use the tracking system 2 to measure the navigation marker 18 on the patient's body surface in the tracking system coordinate system The coordinates in , register these two sets of data, so that the lesion image and the real lesion position are superposed together in a certain coordinate system (such as the tracking system coordinate system), because the surgical instrument 4 is also transformed to this coordinate system at this time (for example, the tracking system coordinate system), so the joint observation of the lesion and the surgical instrument 4 can be realized, and then the operation can be started.

The specific derivation process of the C coordinate transformation relationship in the navigation mode is as follows:

(i＝1，2，...，n_nav)；使用跟踪系统2测量导航标志点18，得到它们在跟踪系统坐标系里的坐标

病灶和手术器械坐标之间的变换关系为：After the hospital bed 6 is in place, extract n _nav navigation marks 18 (n _nav ≥ 3, generally n _nav is equal to 4) on the lesion image, and obtain the three-dimensional coordinates of the navigation marks 18 in the magnetic resonance imaging equipment coordinate system

(i=1, 2, ..., n _nav ); use the tracking system 2 to measure the navigation marker points 18, and obtain their coordinates in the tracking system coordinate system

The transformation relationship between the coordinates of the lesion and the surgical instrument is:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 15</span>}<span\; class="notranslate">\; )</span>$

为磁共振成像设备坐标系在跟踪系统坐标系里的位姿。通过式(15)可得到n_nav个方程，并解出从而病灶的任意一点在磁共振成像设备坐标系里的坐标

可变换到跟踪系统坐标系in

is the pose of the magnetic resonance imaging equipment coordinate system in the tracking system coordinate system. Through formula (15), n _nav equations can be obtained, and the solution Therefore, the coordinates of any point of the lesion in the coordinate system of the magnetic resonance imaging equipment

Transformable to tracking system coordinate system

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span>$

是已知的，将其变换到跟踪系统坐标系里The coordinates of any point T on the surgical instrument 4 in the surgical instrument coordinate system

is known, transform it into the tracking system coordinate system

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

So far, the lesion and the surgical instrument 4 have been observed in the same coordinate system (tracking system coordinate system), and they can be displayed on the screen. The relative position of the lesion and the surgical instrument 4 seen by the doctor on the screen is the actual The relative position of the lesion and the surgical instrument 4 .

In order to make the doctor not need to use the tracking system 2 to measure the navigation sign 18 again, a tracker can be added as the world coordinate system, and its pose Measured by tracking system 2. This world coordinate system is different from the world coordinate systems of navigation modes A and B. It is not fixed on the magnetic resonance imaging device 1, but keeps the relative position of the lesion unchanged. For example, when the lesion is the head, it can be moved to Tracer and head fixed.

The subscript 0 is used to indicate the initial calibration position, and 1 indicates that the position sensor of the tracking system 2 has moved to a new position. Transform any point of the lesion from the tracking system coordinate system to the world coordinate system

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 17</span>}<span\; class="notranslate">\; )</span>$

Transform any point of the surgical instrument 4 to the world coordinate system

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 18</span>}<span\; class="notranslate">\; )</span>$

更新，通过式(17)和(18)的变换保证病灶和手术器械的定位准确。In this way, we put the lesion and surgical instrument 4 into the world coordinate system for observation. When the position sensor moves, the world coordinate system is at the position of the position sensor

Update, through the transformation of formulas (17) and (18) to ensure accurate positioning of the lesion and surgical instruments.

Lesions and surgical instruments can also be observed in the tracking system

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 19</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 20</span>}<span\; class="notranslate">\; )</span>$

In the above-mentioned calibration of the magnetic resonance imaging equipment coordinate system, the magnetic resonance imaging equipment 1 scans an object to obtain an image, and the space coordinate system used is the magnetic resonance imaging equipment coordinate system. In order to transform the image from the magnetic resonance imaging equipment coordinate system to other coordinates system (such as the world coordinate system), calibration work is required to obtain the transformation relationship between the imaging coordinate system and a certain coordinate system R (such as the world coordinate system or tracking system coordinate system, etc.) With this relationship, the lesion can be transformed into this coordinate system for observation. If the relationship between other coordinate systems (such as the tracking system coordinate system) and the world coordinate system is known, the lesion can also be transformed into other coordinate systems.

The present invention uses the calibration module 9 and the tracking system 2 to calibrate the transformation relationship between the magnetic resonance imaging equipment coordinate system and the world coordinate system

(i＝1，2，...，n_ph)；跟踪系统2测量标定模9，得到特征点集II的每一特征点94的坐标，也就得到了特征点集II的每一点在跟踪系统坐标系里的坐标

(i＝1，2，...，n_ph)。这两组坐标满足方程According to the description of the structure of the above-mentioned calibration module 9, it can be known that the magnetic resonance imaging device scans the calibration module 9 to obtain the coordinates of each feature point 93 of the feature point set 1 in the coordinate system of the magnetic resonance imaging device

(i=1, 2 _, . coordinates in the system coordinate system

(i=1, 2, . . . , n _ph ). These two sets of coordinates satisfy the equation

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; pH</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; one</span>}<span\; class="notranslate">\; )</span>$

From the solutions of these equations, the transformation relationship between the MRI equipment coordinate system and the tracking coordinate system can be solved Then the transformation relationship between the MRI equipment coordinate system and the world coordinate system is obtained

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}<span\; class="notranslate">\; )</span>$

由跟踪系统2测量世界坐标系得到。in

It is obtained by measuring the world coordinate system by tracking system 2.

In order to improve the calibration accuracy in navigation mode A and navigation mode B, the present invention adopts a separate calibration method for the rotation amount and the translation amount when the calibration module 9 is used for calibration

包括旋转矩阵(3×3矩阵)和平移向量(3×1矩阵)，即

Including rotation matrix (3×3 matrix) and translation vector (3×1 matrix), namely

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>\left(\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}& {\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right)<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}<span\; class="notranslate">\; )</span>$

point coordinates

V = (X 1) ^T = (x y z 1) ^T

and formula (23) into (21) to get

${\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; four</span>}<span\; class="notranslate">\; )</span>$

(i＝1，2，...，n_ph)，通过方程式(24)同时解出旋转矩阵

和平移向量

The general calibration method is to utilize the magnetic resonance imaging equipment 1 to measure the coordinates of each point of the feature point set I in the magnetic resonance imaging equipment coordinate system (i=1, 2 _, . , so as to obtain the coordinates of each point in the feature point set I in the tracking system coordinate system

(i=1, 2, ..., n _ph ), solve the rotation matrix simultaneously by equation (24)

and translation vector

In this way, good local calibration results can be obtained in the area near the feature point sets I and II, but because the field of view is relatively large, and the feature point 93 of the calibration model is only a small part of the point in the field of view, so in the magnetic resonance imaging equipment The accuracy of the calibration within the entire field of view of 1 is affected by the rotation matrix The influence of the error is large, so that only the area near the feature point 93 is accurately positioned, while the error in the area far away from the feature point 93 is large. Calibrating the rotation matrix and the translation matrix separately can ensure that the rotation matrix has the best calibration result. Although the minimum calibration error near the feature points 93 and 94 is sacrificed in this way, good calibration results can be obtained in the entire field of view. The specific process of separate calibration is as follows:

(i＝1，2，...，n_ph)，由坐标

生成L个向量

原则是使向量尽量分布在视场的各个方向(最理想的是从视场中心向各个方向发出的向量集)。然后，利用跟踪系统2测量特征点集II各点在跟踪系统坐标系里的坐标，从而得到特征点集I各点在跟踪系统坐标系里的坐标

(i＝1，2，...，n_ph)，在跟踪系统坐标系生成和向量

一一对应的向量

(一一对应的意思是如果向量

由特征点和特征点

生成，那么向量

也由同样的特征点

和特征点

生成)。First, utilize the magnetic resonance imaging equipment 1 to measure the coordinates of each feature point 93 of the feature point set I in the magnetic resonance imaging equipment coordinate system

(i=1, 2, . . . , n _ph ), by coordinates

generate L vectors

The principle is to make the vectors distributed in all directions of the field of view as much as possible (the ideal is the set of vectors sent from the center of the field of view to all directions). Then, use the tracking system 2 to measure the coordinates of each point of the feature point set II in the tracking system coordinate system, thereby obtaining the coordinates of each point of the feature point set I in the tracking system coordinate system

(i=1, 2, ..., n _ph ), the sum vector is generated in the tracking system coordinate system

one-to-one vector

(One-to-one correspondence means that if the vector

by feature point and feature points

generate, then the vector

also by the same feature points

and feature points

generate).

These two sets of vectors satisfy the transformation relation

${\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; pH</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 25</span>}<span\; class="notranslate">\; )</span>$

然后将它代入方程组(24)可解出

得到变换关系

进而得到磁共振成像设备坐标系和跟踪坐标系之间的变换关系 $C_{\mathrm{scan}}^{\mathrm{track}}.$ The rotation matrix can be solved by equations (25)

Then substituting it into the equation system (24) can be solved

get transformation relationship

Then the transformation relationship between the MRI equipment coordinate system and the tracking coordinate system is obtained $C_{\mathrm{scan}}^{\mathrm{track}}.$

In the process of implementing the above three navigation modes A, B, and C, in order to increase the field of view of the tracking system 2, multiple trackers 3 can be used to form a world coordinate system, and these trackers 3 are distributed in different positions (each The coordinate transformation relationship between the trackers 3 has been measured), and the tracker 3 with the best detection effect of the position sensor is selected as the world coordinate system during navigation. Therefore, the position sensor of the tracking system 2 is allowed to move to multiple positions to track the position of the surgical instrument 4, and the working area of the position sensor is expanded. At this time, the lesion and surgical instruments can still be calculated by the previous formula.

The improvement of the present invention to the hardware part also includes the following content:

1. In addition to placing the magnetic resonance image and the surgical instrument in the same coordinate system for observation and performing surgery through the transformation of the coordinate system, the present invention also provides a surgical instrument guide 40 for the surgical instrument 4, using the surgical instrument guide 40, on the one hand, can eliminate the influence of the operator's hand shake, and on the other hand, reduce the bending phenomenon of the surgical instrument 4 during the puncturing process, so as to ensure that the interventional surgical instrument is placed in place accurately.

As shown in FIG. 10 , the surgical instrument guide 40 of the present invention includes a lower bracket assembly 410 , an upper beam assembly 430 , a recliner assembly 450 and an intervention guide assembly 470 .

As shown in FIGS. 11-13 , the lower bracket assembly 410 of the present invention includes a base 411 with a certain weight, and four rollers 412 are arranged on the bottom of the base 411 for supporting and conveniently pushing and pulling the entire device. A standpipe 413 is fixedly connected to the top of the base 411 , and an outer cover 414 fixedly connected to the base 411 is arranged outside the standpipe 413 . A guide sleeve 415 , 416 is respectively arranged in the middle of the standpipe 413 and the uppermost part of the outer cover 414 , and an upper branch pipe 417 is inserted in the two guide sleeves 415 , 416 . One side of the upper branch pipe 417 is provided with a rack 418 . A gear 419 meshed with the rack 418 is set in the outer cover 414 on the standpipe 413 top, a sprocket 420 is arranged coaxially with the gear 419, another sprocket 421 is set at the bottom of the standpipe 413, and two sprockets 420, 421 is surrounded by a chain 422 , a counterweight 423 is fixedly connected to the outer chain 422 , and the inner chain 422 passes through the other side of the counterweight 423 . The setting principle of the counterweight 423 is: the weight of the upper branch pipe 417 and the above parts forms a dynamic balance with the counterweight 423. Like this, if there is an external force to lift the upper branch pipe 417 upwards or press the upper branch pipe 417 downward, the rack on the upper branch pipe 417 will 418 just can drive gear 419, and sprocket wheel 420,421 and chain 422 rotate, and counterweight 423 is moved up and down, reaches the dynamic balance of another position; 418, so whether the operator lifts or presses down the upper branch pipe 417, it will be very light and labor-saving. In order to prevent the upper branch pipe 417 from accidentally touching and causing movement, a handle 424 passing through the outer cover 414 is provided on the outer cover 414 to facilitate locking and positioning after the upper branch pipe 417 and the lower bracket assembly 410 are adjusted.

As shown in Fig. 14 and Fig. 15, the upper beam assembly 430 of the present invention includes an adapter column 431, a wedge sleeve 432 arranged in the middle of the adapter column 431, a T-shaped joint 433 arranged outside the wedge sleeve 432, and a wedge The sleeve 432 and the T-shaped joint 433 are fixedly connected into one body by a plurality of screws. The two wedges 434 , 435 respectively penetrate into the wedge sleeve 432 from both sides of the adapter column 431 , and the two baffles 436 , 437 are respectively fixed on the adapter column 431 by a plurality of screws from both ends. A limit nut 438 is screwed in the central screw hole of the baffle plate 437, the end of the limit nut 438 is supported on the wedge 435, and a screw rod 440 with a rotating handle 439 is connected to the center of the two wedges 434,435 In the screw holes, and the central screw holes of the two wedges 434, 435 are left-handed and the other right-handed, so when the screw 440 corresponding to the two rotates, the two wedges 434, 435 can move relatively, and then lock or loosen the wedges. A sleeve 432 and a T-shaped joint 433 fixed on the wedge sleeve 432 . The bottom of the adapter column 431 is fixedly connected to the top of the upper branch pipe 417 through a common locking nut 441 and a nylon sleeve 442 .

As shown in Fig. 14 and Fig. 16, a beam 443 is pierced in the T-shaped sleeve 433, and the two ends of the T-shaped sleeve 442 are fixedly connected with the beam 443 by common lock nuts and nylon sleeves. An elbow 444 is provided at the end where the upper beam 430 is connected to the recliner 450, and a transition shaft 446 is connected in the elbow 444 through the cooperation of the key and the keyway 445, and an adjustment sleeve 447 is connected to the transition shaft 446 by threads. The outside of the shaft 446 passes through a group of three-lobe sleeves 448, and connects the elbow 444 and one end of the adjustment sleeve 447 at the same time. A screw sleeve 449 is fixedly connected to the end of the beam 443, and the screw sleeve 449 and the beam 443 are inserted in the adjustment sleeve 447. The beam 443 can fix the screw sleeve 449 on the transition shaft 446 .

As shown in Figures 17-20, the recliner assembly 450 of the present invention includes a housing 451, a connecting shaft 452 is arranged at one end of the housing 451, and a connecting shaft 452 is arranged in the housing 451 relative to the axis of the connecting shaft 452. Integrated upper and lower ball seats 453,454, a ball head of a ball shaft 455 is set in the upper and lower ball seats 453,454, and a ball head driven by a fine-tuning nut 456,457 is respectively set on the top and side of the housing 451. Depress the screw rod 458 and the side push screw rod 459, and the bottoms of the depress screw rod 458 and the side push screw rod 459 are respectively provided with a swing sleeve 460, 461 connected to the ball shaft 455. A transition shaft 462 is connected to the end of the ball shaft 455, a hand wheel 463 and a transition plate 464 rotated by the hand wheel 463 are connected to the transition shaft 462, and the transition plate 464 is connected to the intervention guide assembly 470 through a rotating handle. The recliner 450 is used to adjust the deflection angle of the interventional guide assembly 470 and the direction of needle insertion. Adjusting the fine-tuning nuts 456 and 457 can respectively make the ball shaft 455 swing up, down, left, and right with the ball head as the axis, and adjust the angle of the hand. The wheels 463 can move the interventional guide assembly 470 axially along the ball axis 455 .

As shown in Figure 17 and Figure 21, the intervention guide assembly 470 of the present invention includes two outer needle cards 471, 472 hinged together, and two inner needle cards 473, 474 are arranged inside the two outer needle cards 471, 472, The puncture needle 475 is pierced in the two inner needle cards 473,474. The outer needle card 471 and the inner needle card 473 on one side are fixedly connected with the transition plate 464 as a whole, and the outer needle card 72 on the other side can be opened relative to the outer needle card 71 to put in another inner needle card 474 and puncture Needle 475, after closing the outer needle clamp 472, two outer needle clamps 471, 472 can be fixed together by a screw 476, the tightness of the two fixing depends on the puncture needle 475, so that it can be used under the action of external force. The needle cards 471, 472 slide inside.

When the surgical instrument guide 40 of the present invention is in use, the base 411 can be pushed to move to any position, the upper branch pipe 417 can be moved up and down by the rotating handle 424, the crossbeam 443 can be rotated by rotating the handle 439, and the fine-tuning nuts 456, 457 can be rotated And the handwheel 463 can adjust the direction of the puncture needle, so as to aim at the focus of the patient; once the operation is completed, the doctor can easily and accurately guide the puncture needle into the predetermined focus.

2. In order to avoid the collision between ultra-high and ultra-wide objects and the magnetic resonance imaging equipment, and to protect the safety of the patient and the magnetic resonance imaging equipment 1, a set of laser protection device 50 is provided on the magnetic resonance imaging equipment 1 in the present invention. As shown in Fig. 22 and Fig. 23, the present invention sets a commercially available linear laser 51, 52, 53 respectively on the top and both sides of the imaging space of the magnetic resonance imaging device 1, and connects the lasers 51, 52, 53. The alarm device (not shown in the figure), the information of each laser 51 , 52 , 53 is also input into the control device of the magnetic resonance imaging equipment 1 at the same time. In this way, the laser light emitted by each linear laser 51, 52, 53 is a fan-shaped plane, and the laser light emitted by the three beam lasers 51, 52, 53 can just cover the top surface and both sides, forming a rectangular extension with the position of the sick bed 9. Space, ie the space into which the magnetic resonance imaging device 1 is allowed to enter. Once any part of the patient's body exceeds the working space formed by the three lasers 51, 52, 53, or the surgical instruments on the patient's body exceed or other pipelines inserted exceed, the alarm device will sound an alarm to remind the surgeon, After the motion control system of the imaging device 1 receives the information that the laser beam is blocked, the software will automatically stop the next operation step, and the hospital bed 9 will also be stopped and continue to move forward, thus effectively avoiding ultra-high and ultra-wide objects and magnetic resonance The collision of the imaging equipment protects the patient and the magnetic resonance imaging equipment.

3. The present invention adopts a plurality of surgical cantilevers, which are respectively used to fix the tracking system 2 and the display screen 15, etc. These cantilevers can maintain a smooth and large-scale movement, ensuring that the three-dimensional azimuth tracking system 2 can detect the operation in various postures. Instrument 4; at the same time, ensure that the doctor can observe the surgical navigation interface on the display screen at the best angle and the best distance during the intervention operation.

As shown in Figure 24, the software part of the present invention includes a main control module, which contains three processing modules: a process control module, a system setting and log module, and a database management module (including medical image archiving and communication); an operation planning navigation module It contains two support modules: image/data analysis module and system navigation calibration module; graphic user interface control module and interactive control module. The software part defines general multiple types of application programming interfaces for the three types of external equipment that need to be controlled and connects them with corresponding equipment; that is, the general tracking system control application programming interface, the general imaging equipment application programming interface, and the general treatment system control application programming interface . The main control module is the core part of the software, which coordinates all module calls and mutual information transmission in the software. The process control module manages all application-related processes, such as system calibration, surgical planning, real-time navigation, etc.; the system setting and log module is responsible for setting system configuration and system-related database information (such as equipment database), and this module also maintains System log; the database management module manages all data, including images, equipment (treatment) models, imaging equipment, process protocols, system logs and system configuration. For the management of images, the database management module uses the medical image archiving and communication system (PACS) way of working. The image/data analysis module provides image processing and data analysis functions, and the system navigation calibration module provides equipment position tracking functions and the relationship between different equipment coordinate systems. The graphical user interface control module and the interactive control module display all control and image information for the user, and have user operation functions.

In the software, the present invention aims at the problem that the image formed by the magnetic resonance imaging device 1 in the prior art causes the geometric deformation of the image due to the nonlinearity of the gradient field, and proposes a method of calculating every The three-dimensional offset of a pixel, and the offset is compensated to the image coordinates of the pixel in the magnetic resonance image gradient deformation correction program based on the spherical harmonic function, the correction program is preset in this software as a software In the Image/Data Analysis module of the Invention Software section. As shown in Fig. 24 and Fig. 25, the gradient correction program of the present invention includes three parts: calculation of space offset, image offset compensation and correction, and search for correction parameters, which are respectively described below:

A. The steps to calculate the space offset are as follows:

The magnetic field strength B _{z(r, θ, φ)} of the magnetic resonance system can be expressed by the following formula (1) in the spherical coordinate system

B _{r(n, m)} (r, θ, φ) = r ⁿ [a _{v(n, m)} cos(mφ)+b _{v(n, m)} sin(mφ)]×P _{(n, m)} ( cosθ) (1)

where B _{r(n, m)} (r, θ, φ) is the nth-order m-level term after the spherical harmonic function expansion of B _z . a _{v(n, m)} and b _{v(n, m)} are constants, a _{v(n, m)} and b _{v(n, m)} are the coefficients of the n-order m-level expansion term in the v direction, and they are the nonlinear gradient of the magnetic field Intrinsic characteristics of , r is the distance from the sought point to the center of the sphere. P _{(n, m)} (cosθ) is a Legendre polynomial, and the sum of the finite terms B _{r(n, m)} (r, θ, φ) can approximate the magnetic field strength B _{z(r, θ, φ)} .

After establishing the expression of Bz _{(r, θ, φ)} , the gradient function of the magnetic field can be obtained:

${\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&equiv;</span>\frac{{<span\; class="notranslate">\; \&PartialD;</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; zv</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>}}{<span\; class="notranslate">\; \&PartialD;</span>\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; \&equiv;</span>\frac{{<span\; class="notranslate">\; \&PartialD;</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; zv</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; L</span>}}}{<span\; class="notranslate">\; \&PartialD;</span>\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; +</span>\frac{<span\; class="notranslate">\; \&PartialD;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; zv</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; N</span>}}}{<span\; class="notranslate">\; \&PartialD;</span>\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; \&equiv;</span>{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

是梯度场线性部分，即球谐函数展开的一阶项，

是可以由球谐函数展开的高阶项计算的非线性部分，所以：where v represents the (x, y or z) direction in the Cartesian coordinate system, B _zv(r) is the total strength of the gradient field,

is the linear part of the gradient field, that is, the first-order term of the spherical harmonic expansion,

is the nonlinear part that can be computed by the higher-order terms of the spherical harmonic expansion, so:

definition

in:

Formula (4) describes the degree of nonlinearity of the gradient in the direction of v (x, y or z) in the Cartesian coordinate system, which can be used to calculate the coordinate offset of the point V (x, y, z) in the Cartesian space A calculation interval of an appropriate size can be selected according to the imaging space of the magnetic resonance equipment 1, and the control points V _ci (x, y, z) are uniformly distributed in this interval, and the offset of each control point is calculated according to formula (4) and save it in the control point offset file.

B. The steps of offset compensation correction are as follows:

The correction of the image to be corrected is realized by image offset compensation correction, which is completed by changing the image coordinates of each pixel in the image coordinate system, so the process of image correction for each pixel, that is: firstly, the pixel The image coordinates ( _{u, v) of p (u} , v) are converted into coordinates (x, y, z) in the imaging space. Then use the interpolation algorithm to calculate the space of the pixel according to the offset η _{c (1-8) of the 8 control points V c ( 1-8} ) adjacent to the pixel saved in the control point offset file Offset _ηp . The spatial offset of the pixel is converted into the offset σ _p in the image coordinate system again; finally, the offset is compensated to the image coordinate of the pixel. The specific formula is described as follows:

其磁共振空间坐标为V₀，图像的分辨率为Res，图像的视野为Fov。则任意象素p_i(u，v)的磁共振空间坐标为V_i。Assume that in the magnetic resonance imaging space, the vector corresponding to the row of the image to be corrected is v _r , and the vector corresponding to the column is v _c . The first pixel is

The magnetic resonance space coordinate is V ₀ , the resolution of the image is Res, and the field of view of the image is Fov. Then the magnetic resonance space coordinate of any pixel p _{i (u, v)} is V _i .

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\frac{\mathrm{<span\; class="notranslate">\; Fov</span>}}{\mathrm{<span\; class="notranslate">\; Res</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Assume that the offsets of the 8 control points adjacent to the pixel are:

${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; .</span>$

的偏移量可以表示为：but

The offset of can be expressed as:

${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>$

${+\mathrm{\&eta;}}_{(x_0,+1{\mathrm{the\; y}}_0,z_0)}*(x_i-x_0)*({\mathrm{the\; y}}_0+1-{\mathrm{the\; y}}_i)*(z_0+1-z_i)$

${+\mathrm{\&eta;}}_{(x_0,{\mathrm{the\; y}}_0+1,z_0)}*(x_0+1-x_i)*({\mathrm{the\; y}}_i-{\mathrm{the\; y}}_0)*(z_0+1-z_i)$

${+\mathrm{\&eta;}}_{(x_0,{\mathrm{the\; y}}_0,z_0+1)}*(x_0+1-x_i)*({\mathrm{the\; y}}_0+1-{\mathrm{the\; y}}_i)*(z_i-z_0)$

${+\mathrm{\&eta;}}_{(x_0+1,{\mathrm{the\; y}}_0,z_0+1)}*(x_i-x_0)*({\mathrm{the\; y}}_0+1-{\mathrm{the\; y}}_i)*(z_i-z_0)$

${+\mathrm{\&eta;}}_{(x_0,{\mathrm{the\; y}}_0+1,z_0+1)}*(x_0+1-x_i)*({\mathrm{the\; y}}_i-{\mathrm{the\; y}}_0)*(z_i-z_0)$

${+\mathrm{\&eta;}}_{(x_0+1,{\mathrm{the\; y}}_0+1,z_0)}*(x_i-x_0)*({\mathrm{the\; y}}_i-{\mathrm{the\; y}}_0)*(z_0+1-z_i)$

${+\mathrm{\&eta;}}_{(x_0+1,{\mathrm{the\; y}}_0+1,z_0+1)}*(x_i-x_0)*({\mathrm{the\; y}}_i-{\mathrm{the\; y}}_0)*(z_i-z_0)---\left(6\right)$

the spatial offset of the pixel Converted to the offset σ _{p(u, v)} in the image coordinate system.

σ _{p(u, v)} = (Δu, Δv)

$\mathrm{<span\; class="notranslate">\; \&Delta;u</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; *</span>\frac{\mathrm{<span\; class="notranslate">\; Res</span>}}{\mathrm{<span\; class="notranslate">\; Fov</span>}}$

$\mathrm{<span\; class="notranslate">\; \&Delta;v</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; *</span>\frac{\mathrm{<span\; class="notranslate">\; Res</span>}}{\mathrm{<span\; class="notranslate">\; Fov</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

Compensate the offset to the pixel's image coordinates, the pixel's new image coordinates (u', v').

u'=u+Δu;

v'=v+Δv;

By performing the above operations on each pixel in the image to be corrected, the correction of the entire image can be completed.

C. The steps to search for calibration parameters are as follows:

The module for searching correction parameters obtains correction parameters by analyzing the magnetic resonance images of the gradient correction modulus 60 multiple times. The following describes the design method of the gradient correction modulus 60 and the steps of searching for the correction parameters. For the sake of accuracy and calculation amount, the calculation of the gradient field is based on 5-stage expansion.

(1) Gradient correction mode

As shown in Fig. 26 and Fig. 27, the gradient correction modulus 60 is a tool for gradient correction, which is used not only for searching system parameters, but also for measuring corrected errors. The gradient correction mold 60 is a square box body 61, and cylinders 62 arranged in a square array in a square array with unequal spacing are arranged in the box body 61, and the cylinder 62 is filled with copper sulfate solution, which can be imaged in a magnetic resonance imaging device . The cylinders 62 in the gradient correction module are arranged according to the gradient distribution rule expressed by the formula (2), and the cylinders 62 are used as marking points in the calibration module, so that the parameter values of the gradient distribution can be calculated more accurately.

As shown in Figure 28, it shows the change law of the magnetic field gradient of the cylinder 62 on the X axis within ±30cm. Due to the nonlinearity of the magnetic field gradient, taking the marker points in the X direction as an example, if the marker points are equidistant, then As the X-coordinate gets larger, the image X-coordinate difference between adjacent marker points first becomes larger and then decreases sharply (as shown in FIG. 29 ). Therefore, in order to ensure the calculation accuracy of the image coordinates of the marker points, the present invention adopts the distribution of marker points with unequal intervals and marker points with different sizes according to the law of the magnetic field gradient change. The following takes the X direction as an example to give the calculation method of the marker point spacing and size:

According to formula (3) and estimated values of a _{x(n, m)} and b _{x(n, m)} :

a _x(3,1) =10 ^-4 , a _x(5,1) =10 ^-7 ,

The fifth-order expansion of the gradient field magnetic induction B _z at v _{(x, y=0, z=0)} can be written:

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; 16</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; 5</span>}}$

The gradient at v _(x,y=0,z=0) is:

${\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; 32</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}$

Assume that the distance between the mark points at the center of the magnetic field is l ₀ , and the diameter of the mark points is d ₀ . Then the marker point spacing at v _{(x, y=0, z=0)} point is:

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; G</span>}}<span\; class="notranslate">\; ;</span>$

The diameter of the marker point at point v _{(x, y=0, z=0)} is:

$\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; )</span>}$

Similarly, the expression G _z of the magnetic induction gradient of the gradient field in the z-axis direction can be obtained according to the formula (3) and the estimated values of a _{z(n, m)} and b _{z(n, m)} . Then calculate the point distance and the size of the marker point in the other direction of the plane calibration module according to _Gz . Generally speaking, the design parameters of the magnetic resonance gradient field in the x and y directions are basically the same, so only one of the x and y directions can be calculated. A typical gradient correction model can be made using the distribution data in the x and z directions. The gradient correction module 60 of the present invention (as shown in FIG. 30 ) is redesigned according to the calculation formula of the spacing and diameter of the marker points.

(2) The steps to search for calibration parameters are as follows:

The correction parameter search module needs to search for the correction parameters in the X, Y and Z directions three times, and the implementation steps are described below by taking the search for the correction parameters in the X direction as an example (as shown in Figure 31):

a) Gradient field linear calibration: Assuming that within a field of view of 5 cm, the gradient magnetic field strength is a linear function, by scanning a calibration module of known size, the scaling factor between the physical size and the image coordinates is obtained;

b) Set the initial system parameter C _f : set the initial parameter C _xf of the X direction a _x(5,1) and a _x(3,1) :

c) Calculate the spatial position offset η _x : bring the set initial parameter C _xf into the formula

, calculate the spatial position offset η _x , and store it in the offset lookup table.

d) Place the gradient correction calibration module near the center of the magnetic field, and ensure that the row direction of the calibration module cylinder is consistent with the X direction, and the column direction is consistent with the Y or Z direction.

e) Set the scanning parameters of the magnetic resonance instrument, including the field of view, scanning direction, and the position of the image center, set the scanning layer (slice) in the x, y plane, the image center is located at the center of the magnetic field, and the field of view is the range that is expected to be corrected, and The original MRI image Mo of the gradient-corrected calibration mode can be obtained.

f) Use the image offset compensation correction module to correct the original image to obtain the corrected calibration mode image Mc.

g) Take an image containing marker points p _{1, 2,} 3 .

h) Calculate the world coordinates Xi corresponding to the marker points p _{1, 2, 3} . . . according to the scale factor obtained in step a).

i) Calculate the sum S of the squares of the position errors of the marker points p _{1, 2, 3} . . .

j) Determine whether S meets the requirements or whether the number of iterations n exceeds the set value, if "Yes", exit the iteration, and use the current system parameter value as the program output; if "No", change the initial value to continue searching.

Using the correction method mentioned above, the gradient can ensure that the linearity error is about 4‰ within the field of view of the gradient coil within 5cm.

In the operation process of the present invention, the following steps are generally included: patient preparation, operation planning, operation navigation, treatment process monitoring and treatment effect evaluation, which are explained respectively below:

Patient selection:

First of all, it is necessary to select patients who are suitable for magnetic resonance navigation interventional surgery. The selection criteria include: the patient can undergo magnetic resonance scanning (there is no magnetic resonance incompatible device such as a cardiac pacemaker in the body), and the patient's body shape can adapt to the magnetic resonance scanning coil. The size of the patient's lesion can be observed by magnetic resonance during the interventional operation; the patient's lesion can be touched by the interventional surgical instrument.

Surgical Planning:

As shown in FIG. 33 , firstly, the patient’s medical images need to be imported into the system. These medical images can be scanned by the magnetic resonance imaging device 1 of the present invention, or obtained from other magnetic resonance systems, or from other types of medical imaging. Obtained by instruments (such as CT, ultrasound, etc.). According to the imported patient's medical image, it is necessary to locate the lesion and image location and segmentation of key tissues. Combining the above information to plan the operation together, on the one hand, it can ensure the best effect of interventional therapy, and on the other hand, it can minimize the damage to normal tissues, especially vital tissues. It is also necessary to import the information of the surgical instrument 4 to be used in the interventional operation, including geometric shape and treatment effect, etc.

Next, use human-computer interaction means such as a mouse to correctly place the position of the interventional surgical instrument 4 on the console 13 of the surgical planning and navigation system, so as to ensure that the relationship between the surgical instrument 4 and the position of the lesion displayed on the medical image is more appropriate; At the same time, the surgical instrument 4 will not pass through or damage important tissues (such as large blood vessels, important organs, etc.) on the way from the body surface to the lesion point. After the simulation of surgical instrument 4 is in place, the simulation of the treatment effect can be carried out. If the result is not good, you can choose to increase the surgical instrument 4 (such as increasing the number of frozen needles in interventional cryotherapy) or switch to surgical instruments with different parameters and therapeutic effects 4. Until a satisfactory simulation treatment effect is achieved.

Surgical Navigation:

As shown in Figure 34, after necessary patient and equipment preparations for surgery, the surgical navigation phase is entered, and surgical instruments are inserted into the patient's body one by one according to the route and target location determined in the surgical plan. During the insertion process, the high-precision spatial positioning of the instrument is maintained and combined and displayed on the patient's magnetic resonance image, and the image is simultaneously output to the display screen 15 in the shielded room for the doctor to navigate the surgical instrument 4 .

Treatment process monitoring:

After the surgical instrument 4 is in place, the interventional treatment can be performed. During the entire interventional treatment process, the magnetic resonance imaging device 1 maintains a cycle of rapid image scanning, and immediately transmits the image to the surgical planning navigation system console 13 after each scanning On the other hand, monitor the surgical treatment process (such as monitoring the growth of the frozen area and the process of covering the tumor during cryotherapy).

Evaluation of treatment effect:

After the interventional treatment, it is necessary to evaluate the treatment results on-site through magnetic resonance images or other means. Based on the evaluation of the interventional treatment results, the site decides whether to immediately supplement the interventional surgery to achieve the desired therapeutic effect. If necessary, return to the initial operation step , and then execute in sequence.

ending:

After confirming the end of the interventional operation, output the interventional operation report, and complete the postoperative cleaning work: including patient evacuation, interventional treatment equipment inspection, surgical site cleaning, etc., and the entire operation process is over.

Claims (28)

1. A surgical system guided by magnetic resonance images, the hardware part including magnetic resonance imaging equipment, a tracking system, surgical instruments, a hospital bed set on the magnetic resonance imaging equipment, control and display equipment, and connections with various systems The computer and control software part; it is characterized in that: a calibration pin and a calibration mold are also provided, and the pose of the magnetic resonance imaging equipment coordinate system can be measured by a tracking system; at least one is provided corresponding to the position of the magnetic resonance imaging equipment A set of tracers constituting the world coordinate system, the pose of the world coordinate system can be measured by the tracking system; the surgical instrument is provided with a surgical instrument tracer as the surgical instrument coordinate system, and the surgical instrument coordinate The pose of the system can be measured by the tracking system; the bed is provided with a bed tracer that constitutes the bed coordinate system, and the bed coordinate system can be measured by the tracking system; the calibration needle is composed of a certain length The needle and the tracer are jointly composed, and the calibrated needle tip touches a certain point to measure the position of this point; a set of asymmetrically distributed feature point sets I and feature point sets are set on the inside and surface of the calibration mold II, the feature points of the feature point set I can be imaged by the magnetic resonance imaging device, and the feature points of the feature point set II can be measured by the tracking system; the relative positions of the feature point set I and the feature point set II The relationship is known; after calibration, the lesion coordinates and surgical instrument coordinates are transformed into the same coordinate system through the mutual transformation relationship between the coordinate systems. 2. The magnetic resonance image-guided surgery system according to claim 1, wherein a navigation mark corresponding to the position of the lesion is set on the skin surface of the patient on the hospital bed, and the navigation mark can be selected by the patient. can be imaged by the magnetic resonance imaging device and can be measured by the tracking system. 3. A magnetic resonance image-guided surgical system according to claim 1, wherein the calibration mold includes a calibration mold body, and the other five surfaces of the calibration mold body except the bottom surface, each Each surface has a feature layer with a certain thickness, and a set of spheres forming a feature point set I is arranged inside each feature layer, and another set of pits forming a feature point set II is set on the surface of each feature layer. Calibration mold body is filled with calibration mold solution in the space that six wrapping up. 4. A magnetic resonance image-guided surgery system according to claim 2, characterized in that: said calibration mold includes a calibration mold body, and the other five surfaces of said calibration mold body except the bottom surface, each Each surface has a feature layer with a certain thickness, and a set of spheres forming a feature point set I is arranged inside each feature layer, and another set of pits forming a feature point set II is set on the surface of each feature layer. Calibration mold body is filled with calibration mold solution in the space that six wrapping up. 5. A magnetic resonance image-guided surgery system according to claim 1, 2, 3 or 4, characterized in that it also includes a surgical instrument guide, and the surgical instrument guide includes a lower bracket assembly, an upper beam assembly, a recliner assembly and an interventional guide assembly; the lower bracket assembly includes a base, a riser arranged on the base, and an upper branch pipe sleeved and locked in the riser; the The upper crossbeam assembly includes a T-shaped joint sleeved and locked outside the upper branch pipe, a crossbeam passing through the T-shaped joint and a connecting head arranged at one end of the crossbeam; the recliner assembly includes a connection A housing of the connecting head, a ball shaft arranged in the housing, a depressing screw and a side pushing screw respectively connected to the ball shaft vertically and laterally, are arranged on the top and side of the housing The fine-tuning nuts respectively connected to the depressing screw and the side pushing screw; the hand wheel and the transition plate arranged at the protruding end of the ball shaft; the intervention guide assembly includes an outer clamp connected to the transition plate, locked The inner clamping bracket is arranged in the outer clamping bracket, and the surgical instrument is locked and arranged in the inner clamping bracket. 6. A magnetic resonance image-guided surgery system according to claim 1, 2, 3 or 4, characterized in that three linear lasers and An alarm, each of the lasers emits a fan-shaped plane laser beam, the three laser beams and the position of the hospital bed together form a width and height limited space suitable for the inspection and treatment space of the magnetic resonance imaging equipment, the alarm The detector is connected with the motion control system of the magnetic resonance imaging equipment, and gives an alarm when any one of the laser beams is blocked. 7. A magnetic resonance image-guided surgical system according to claim 5, characterized in that: three linear lasers and one alarm are arranged on the top and both sides of the imaging space of the magnetic resonance imaging equipment, each The laser emits a fan-shaped plane laser beam. The three laser beams and the position of the hospital bed together form a width and height limited space suitable for the examination and treatment space of the magnetic resonance imaging equipment. The alarm and the magnetic resonance imaging equipment The motion control system is connected and an alarm is given when any of the laser beams is blocked. 8. A magnetic resonance image-guided surgical system as claimed in claim 1, 2, 3, or 4, wherein a program for correcting gradient deformation of magnetic resonance images is preset in the software part, which includes a calculation space The three steps of offset, image offset compensation and correction and search for correction parameters are to calculate the three-dimensional offset of each pixel on the image in three-dimensional space according to the spherical harmonic function of the magnetic induction intensity, and use the The offset is compensated into the image coordinates of the pixel. 9. A magnetic resonance image-guided surgical system as claimed in claim 5, characterized in that: a program for correcting gradient deformation of magnetic resonance images is preset in the software part, which includes calculating spatial offset, image offset The three steps of displacement compensation correction and search for correction parameters are to calculate the three-dimensional offset of each pixel on the image in three-dimensional space according to the spherical harmonic function of the magnetic induction intensity, and compensate the offset to the The pixel's image coordinates. 10. A magnetic resonance image-guided surgical system according to claim 6, characterized in that: the software part is preset with a program for correcting the gradient deformation of the magnetic resonance image, which includes calculating the spatial offset, image offset The three steps of displacement compensation correction and search for correction parameters are to calculate the three-dimensional offset of each pixel on the image in three-dimensional space according to the spherical harmonic function of the magnetic induction intensity, and compensate the offset to the The pixel's image coordinates. 11. A magnetic resonance image-guided surgical system according to claim 1, 2, 3, or 4, characterized in that: in the world coordinate system, Any point coordinates of the lesion

The coordinates of this point in the MRI equipment

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ in

is the transformation relationship between the pre-calibrated magnetic resonance imaging equipment coordinate system and the world coordinate system; The coordinates of any point of the surgical instrument The coordinates of this point in the surgical instrument coordinate system can be

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}$ ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; reack</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}$ in,

The transformation relationship between the world coordinate system measured by the tracking system and the tracking system coordinate system,

The transformation relationship between the coordinate system of the surgical instrument measured for the tracking system and the coordinate system of the tracking system. 12. A surgical system guided by magnetic resonance images according to claim 5, characterized in that: in the world coordinate system, Any point coordinates of the lesion

The coordinates of this point in the MRI equipment

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ in

is the transformation relationship between the pre-calibrated magnetic resonance imaging equipment coordinate system and the world coordinate system; The coordinates of any point of the surgical instrument The coordinates of this point in the surgical instrument coordinate system can be

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}$ ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; reack</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}$ in,

The transformation relationship between the world coordinate system measured by the tracking system and the tracking system coordinate system, The transformation relationship between the coordinate system of the surgical instrument measured for the tracking system and the coordinate system of the tracking system. 13. A surgical system guided by magnetic resonance images according to claim 6, characterized in that: in the world coordinate system, Any point coordinates of the lesion

The coordinates of this point in the MRI equipment

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ in

is the transformation relationship between the pre-calibrated magnetic resonance imaging equipment coordinate system and the world coordinate system; The coordinates of any point of the surgical instrument

The coordinates of this point in the surgical instrument coordinate system can be

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}$ ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; reack</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}$ in,

The transformation relationship between the world coordinate system measured by the tracking system and the tracking system coordinate system,

The transformation relationship between the coordinate system of the surgical instrument measured for the tracking system and the coordinate system of the tracking system. 14. A surgical system guided by magnetic resonance images according to claim 8, characterized in that: in the world coordinate system, Any point coordinates of the lesion

The coordinates of this point in the MRI equipment

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ in is the transformation relationship between the pre-calibrated magnetic resonance imaging equipment coordinate system and the world coordinate system; The coordinates of any point of the surgical instrument

The coordinates of this point in the surgical instrument coordinate system can be

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}$ ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; reack</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}$ in,

The transformation relationship between the world coordinate system measured by the tracking system and the tracking system coordinate system,

The transformation relationship between the coordinate system of the surgical instrument measured for the tracking system and the coordinate system of the tracking system. 15. A magnetic resonance image-guided surgery system according to claim 1, 2, 3, or 4, characterized in that: when the lesion is on the bed, in the world coordinate system, The coordinates of any point of the lesion The coordinates of this point in the fixed imaging device

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ in

is the transformation relationship between the coordinate system of the fixed imaging equipment calibrated in advance and the world coordinate system; where the subscript 0 indicates that the bed is pushed into the imaging equipment, and the pose of the coordinate system of the bed at this time

Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ From the above two formulas, it can be known that the pose of the lesion in the bed coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ When the imaging is completed, the lesion moves to the surgical position with the bed, which is represented by subscript 1. Since the lesion and the bed do not move relative to each other, the pose of the lesion on the bed remains unchanged: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$ The position of the bed at this time Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$ From formulas (3) to (5), it can be concluded that the pose of the lesion in the world coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ The pose of the surgical instrument in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; .</span>$ 16. The magnetic resonance image-guided surgical system according to claim 5, characterized in that: when the lesion is on the bed, in the world coordinate system, The coordinates of any point of the lesion The coordinates of this point in the fixed imaging device transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ in

is the transformation relationship between the coordinate system of the fixed imaging equipment calibrated in advance and the world coordinate system; where the subscript 0 indicates that the bed is pushed into the imaging equipment, and the pose of the coordinate system of the bed at this time

Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ From the above two formulas, it can be known that the pose of the lesion in the bed coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ When the imaging is completed, the lesion moves to the surgical position with the bed, which is represented by subscript 1. Since the lesion and the bed do not move relative to each other, the pose of the lesion on the bed remains unchanged: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$ The position of the bed at this time Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$ From formulas (3) to (5), it can be concluded that the pose of the lesion in the world coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ The pose of the surgical instrument in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; .</span>$ 17. The magnetic resonance image-guided surgical system according to claim 6, characterized in that: when the lesion is on the bed, in the world coordinate system, The coordinates of any point of the lesion

The coordinates of this point in the fixed imaging device

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ in

is the transformation relationship between the fixed imaging equipment coordinate system and the world coordinate system calibrated in advance; the subscript 0 indicates that the bed is pushed into the imaging equipment, and the coordinate system pose of the hospital bed at this time

Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ From the above two formulas, it can be known that the pose of the lesion in the bed coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ When the imaging is completed, the lesion moves to the surgical position with the bed, which is represented by subscript 1. Since the lesion and the bed do not move relative to each other, the pose of the lesion on the bed remains unchanged: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$ The position of the bed at this time

Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$ From formulas (3) to (5), it can be concluded that the pose of the lesion in the world coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ The pose of the surgical instrument in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; .</span>$ 18. The magnetic resonance image-guided surgical system according to claim 8, characterized in that: when the lesion is on the bed, in the world coordinate system, The coordinates of any point of the lesion

The coordinates of this point in the fixed imaging device transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ in is the transformation relationship between the fixed imaging equipment coordinate system and the world coordinate system calibrated in advance; the subscript 0 indicates that the bed is pushed into the imaging equipment, and the coordinate system pose of the hospital bed at this time

Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ From the above two formulas, it can be known that the pose of the lesion in the bed coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ When the imaging is completed, the lesion moves to the surgical position with the bed, which is represented by subscript 1. Since the lesion and the bed do not move relative to each other, the pose of the lesion on the bed remains unchanged: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$ The position of the bed at this time Detected by the tracking system, its pose in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$ From formulas (3) to (5), it can be concluded that the pose of the lesion in the world coordinate system at this time is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; scan</span>}}$ The pose of the surgical instrument in the world coordinate system is: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; .</span>$ 19. A surgical system guided by magnetic resonance images according to claim 2 or 4, wherein the coordinates of the navigation marks in the coordinate system of the magnetic resonance imaging equipment are

Wherein i=1, 2,..., n _nav , n _nav is the quantity of navigation marks; The coordinates of said navigation marks in the tracking system coordinate system are

The transformation relationship between the coordinates of the lesion and the surgical instrument is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ in

is the pose of the magnetic resonance imaging equipment coordinate system in the tracking system coordinate system, n _nav equations can be obtained through formula (1), and the solution

Any point of the lesion image

Transformable to tracking system coordinate system: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ The coordinates of a point T on the surgical instrument in the surgical instrument coordinate system

is known, transform it to the tracking system coordinate system: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}$ in

The transformation relationship between the coordinate system of the surgical instrument measured for the tracking system and the coordinate system of the tracking system. 20. A magnetic resonance image-guided surgical system according to claim 19, characterized in that: a tracer that remains unchanged relative to the lesion position is added as a new world coordinate system, and its pose Measured by the tracking system, the subscript 0 indicates that the position sensor of the tracking system is in the initial calibration position, and 1 indicates that the position sensor of the tracking system moves to a new position; the coordinates of any point of the lesion in the world coordinate system

The coordinates of this point in the magnetic resonance imaging equipment coordinate system

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; img</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lesion</span>}}^{\mathrm{<span\; class="notranslate">\; img</span>}}$ in

is the transformation relationship between the world coordinate system and the tracking system coordinate system at the initial position, The transformation relationship between the world coordinate system and the tracking system coordinate system on the new position 1,

The transformation relationship between the magnetic resonance imaging equipment coordinate system and the tracking system coordinate system at the initial position 0; The coordinates of any point of the surgical instrument

The coordinates of this point in the surgical instrument coordinate system

transformed into: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; the\; world</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; world</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tools</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; tools</span>}}$ in,

is the transformation relationship between the world coordinate system and the tracking system coordinate system at the new position 1,

is the transformation relationship between the surgical instrument coordinate system and the tracking system coordinate system. 21. A magnetic resonance image-guided surgical system according to claim 1, 2, 3, or 4, characterized in that: when calibrating each coordinate system with a calibration module, set in the software program of the navigation system There is a program for locating the center of the sphere through the imaging results of the feature points in the feature point set I, and the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 22. A magnetic resonance image-guided surgical system according to claim 5, characterized in that: when using the calibration model to calibrate each coordinate system, the software program of the navigation system is provided with a feature point set The procedure for the positioning of the center of the sphere as a result of the feature point imaging in I, the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 23. A magnetic resonance image-guided surgery system according to claim 6, characterized in that: when using the calibration model to calibrate each coordinate system, the software program of the navigation system is provided with a feature point set The procedure for the positioning of the center of the sphere as a result of the feature point imaging in I, the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 24. A magnetic resonance image-guided surgical system according to claim 8, characterized in that: when using the calibration model to calibrate each coordinate system, the software program of the navigation system is provided with a feature point set The procedure for the positioning of the center of the sphere as a result of the feature point imaging in I, the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 25. A magnetic resonance image-guided surgery system according to claim 11, characterized in that: when using the calibration model to calibrate each coordinate system, the software program of the navigation system is provided with a feature point set The procedure for the positioning of the center of the sphere as a result of the feature point imaging in I, the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 26. A magnetic resonance image-guided surgery system according to claim 15, characterized in that: when using the calibration model to calibrate each coordinate system, the software program of the navigation system is provided with a feature point set The procedure for the positioning of the center of the sphere as a result of the feature point imaging in I, the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 27. A magnetic resonance image-guided surgical system according to claim 19, characterized in that: when calibrating each coordinate system with a calibration module, a feature point set is set in the software program of the navigation system The procedure for the positioning of the center of the sphere as a result of the feature point imaging in I, the process is as follows: (1) First, it is assumed that the area S of the circle on the cross-sectional view satisfies a normal distribution with the coordinate value of the cross-section in the scanning direction; (2) Randomly scan three cross-sectional circle images at different positions along the same axis of the ball, or after scanning two cross-sectional circle images at different positions, fit the third cross-sectional circle image passing through the center of the circle. The area of the circle and the coordinate values of the section circle in the scanning direction form a set of values; (3) Fit a Gaussian curve with the obtained three sets of values, and the coordinate value corresponding to the point with the largest area on the curve is the coordinate value of the center of the sphere in the scanning direction; (4) According to the same method, the coordinate values of the center of the sphere in the direction of the other two coordinate axes are obtained, and the coordinate values of each axis are combined together to obtain the coordinates of the center of the sphere. 28. A method for calibrating a magnetic resonance image-guided surgical system according to any one of claims 1 to 18, characterized in that: when calibrating each coordinate system with a calibration module, the rotation amount and the translation amount are separated Calibration method, the steps are as follows: (a) Utilize the magnetic resonance imaging equipment 1 to measure the coordinates of each point of the feature point set I in the magnetic resonance imaging equipment coordinate system

where n _ph is the total number of points in the feature point set I, which is determined by the coordinates

generate L vectors

The L vectors distributed in different directions; (b) Utilize tracking system 2 to measure the coordinates of each point of feature point set II in the tracking system coordinate system, so as to obtain the coordinates of each point of feature point set I in the tracking system coordinate system

Generate and vector in tracking system coordinate system one-to-one vector

(c) These two sets of vectors satisfy the transformation relationship as follows: $R_{\mathrm{scan}}^{\mathrm{track}}{\mathrm{D.}}_i^{\mathrm{scan}}={\mathrm{D.}}_i^{\mathrm{track}}(i=\mathrm{1,2},...,{\mathrm{no}}_{\mathrm{pH}});$ (d) by the equation $R_{\mathrm{scan}}^{\mathrm{track}}{\mathrm{D.}}_i^{\mathrm{scan}}={\mathrm{D.}}_i^{\mathrm{track}}(i=\mathrm{1,2},...,{\mathrm{no}}_{\mathrm{pH}})$ The rotation matrix can be solved

and then substitute it into the equation $R_{\mathrm{scan}}^{\mathrm{track}}{x}_i^{\mathrm{scan}}+T_{\mathrm{scan}}^{\mathrm{track}}=x_i^{\mathrm{track}}(i=\mathrm{1,2},...,{\mathrm{no}}_{\mathrm{pH}}),$ The translation vector can be solved

get transformation relationship

Then the transformation relationship between the MRI equipment coordinate system and the tracking coordinate system is obtained

in

Include the rotation matrix and translation vector

Right now ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}<span\; class="notranslate">\; =</span>\left(\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}& {\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; scan</span>}}^{\mathrm{<span\; class="notranslate">\; track</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right)<span\; class="notranslate">\; .</span>$

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