CN1286438C - Vision registering method for medical robot - Google Patents

Abstract

The invention discloses a visual registration method in an auxiliary stereotaxic neurosurgery robot, which uses a robot, a camera, a computer, a scanning imaging device and marking points to realize registration from a scanning image coordinate system to a robot coordinate system. In order to align the robot to the lesion according to the doctor's plan in the scanned image during the operation, it is necessary to establish the relationship between the scanned image coordinate system and the robot coordinate system, which is called the registration of the scanned image coordinate system to the robot coordinate system. During the operation, the computer determines the coordinates of the marking points attached to the patient's head in the scan image coordinate system, and at the same time uses the camera to measure the coordinates of the marking points in the robot coordinate system, thereby completing the registration. Compared with the contact measurement method, the registration method of the present invention has high positioning accuracy, and can automatically measure the position of the marking point in real time; compared with other non-contact methods, it is cheap, simple and convenient to operate, and has great advantages. Great advantage.

Description

Medical robot vision register method

Technical field

The present invention relates to a kind of process registration between the medical operating coordinate system that is used for, be meant a kind of vision register method that is used for auxiliary stereotactic neurosurgery robot particularly.

Background technology

Stereotactic neurosurgery is a subject branch of modern neurosurgery development, it is to utilize imaging localization and position finder guiding, small operating theater instruments such as microelectrode, puncture needle or endoscope are inserted appointment target spot in the brain, by writing down electric physiology, leave and take tissue specimen, producing methods such as damaging kitchen range, removal focus, diagnosis and treatment central nervous system's various diseases.Traditional stereotactic neurosurgery generally uses three-dimensional positioning framework that the focus point is positioned, before the operation beginning a three-dimensional positioning framework is fixed tightly in firmly patient's head, because three-dimensional positioning framework is a metal structure, so be visible in the image that scanned imagery device became, the pathological changes point in the image can be to determine its locus by frame coordinates just so.This method precision is higher relatively, but patient is had certain injury, belongs to damaging location.

Adopt the reference marker positioning mode to position in auxiliary stereotactic neurosurgery robot system, the fixed omniselector guiding of relative patient operation is adopted in the planning that undergos surgery in the scanogram space of computer.Traditional relatively have a framework directional operation, and it has eliminated framework to bring painful of patient and the inconvenience that brings to the doctor.

In order to make robot aim at the focus point according to the spatial surgery planning of computer scanning images, the scanning image coordinate system that need set up computer is called two registrations between the coordinate system with the relation between the robot coordinate system.The general reference marker point that uses is finished two registrations between the coordinate system.Need to obtain the coordinate of these gauge points in the robot coordinate system for this reason.In existing auxiliary stereotactic neurosurgery robot system, the locate mode of gauge point generally is divided into two classes, one class is a contact, and is arm-type as machinery, promptly uses the terminal contact mark point of mechanical arm to obtain the coordinate of gauge point in the robot coordinate system.This method advantage is to be easy to realize, the operation intuitive and convenient, and shortcoming is to need doctor's manual operation, certainty of measurement is subjected to artificial factor, and can not realize automatic measurement.Another kind of is contactless, as ultrasonic, electromagnetism and infrared etc., these modes can realize the automatic real-time positioning to gauge point, but deficiency is separately arranged again, be subjected to the influence of temperature, air-flow, humidity and propagation medium of environment bigger as ultrasonic power, electromagnetic mode is subjected to the electromagnetic effect of environment bigger, and infrared mode light path between photographic head and light emitting diode in operation process can not be kept off, and cost is higher.In these several modes, best mode is infrared locate mode, and it is the precision height not only, and sophisticated product is arranged and obtained widely and use, but it costs an arm and a leg and makes that domestic hospital is difficult to accept.

Summary of the invention

The objective of the invention is to propose the vision register method in a kind of auxiliary stereotactic neurosurgery robot, be to adopt the coordinate of technique of binocular stereoscopic vision measurement markers point in the robot coordinate system, thereby finish the registration of scanning image coordinate system to the robot coordinate system.This method only needs two camera heads can determine the coordinate of gauge point in the robot coordinate system.Compare with contact measurement method, its setting accuracy height, and can be automatically the position of measurement markers point in real time; Compare with other non-contact method, it cheap, simple to operation, tool has an enormous advantage.

Vision register method in a kind of auxiliary stereotactic neurosurgery of the present invention robot, this method is by containing robot, camera head, computer, the coordinate of scanned imagery device execution vision technique measurement markers point in the robot coordinate system, thereby finish the registration of scanning image coordinate system to the robot coordinate system, this method comprises the following steps:

(a) at patient head labelling point;

(b) determine the coordinate of gauge point in scanning image coordinate system:

Scan patient head with scanned imagery device, become image to be input to computer institute, the surgery planning software processes in the machine is determined the coordinate of gauge point in image coordinate system as calculated;

(c) determine the coordinate of gauge point in the robot coordinate system:

The patient head image that camera head is obtained is input to computer, and the positioning software in the machine is handled as calculated, determines the coordinate of gauge point in the robot coordinate system, and sends this coordinate to surgery planning software;

The coordinate of described gauge point in the robot coordinate system comprises that robot coordinate system OXYZ, camera head coordinate system O ' X ' Y ' Z ', undistorted image coordinates are that o ' u ' v ', distorted image coordinates are o " u " v " with computer screen coordinate system o _cFive coordinate systems of uv, the conversion simultaneous between described five coordinate systems obtains the coordinate of gauge point on computer screen;

(d) surgery planning software is finished the registration of scanning image coordinate system to the robot coordinate system.

Described vision register method, the number of its gauge point can have 4.

Described vision register method, its camera head are finished the coordinate of measurement markers point in the robot coordinate system.

Described vision register method, its scanned imagery device can be CT or MRI.

Advantage of the present invention: this vision register method is compared with the contact register method, its setting accuracy height, and can be automatically the position of measurement markers point in real time; Compare with other noncontact register method, it cheap, simple to operation, tool has an enormous advantage.

Description of drawings

Fig. 1 is the FB(flow block) of vision register method of the present invention.

Fig. 2 is scanogram of the present invention space, robot space and patient head sketch map.

Fig. 3 is the flow chart that the present invention determines the coordinate of gauge point in scanning image coordinate system.

Fig. 4 concerns sketch map between each coordinate system in the vision register method of the present invention.

The specific embodiment

The present invention is described in further detail below in conjunction with drawings and Examples.

In the auxiliary stereotactic neurosurgery of robot, patient head is behind the scanning imagery device scan, and its image is input to " the surgery planning software " of computer, and the doctor sketches the contours the focus point by software in scanogram, and definite target spot and puncture path." surgery planning software " is converted into the object pose of robot among the robot coordinate system with doctor's the planning in scanogram, and the control robot undergos surgery with the guiding doctor according to the path alignment target spot of planning.Finish the conversion from the scanning image coordinate system to robot coordinate system, need set up the mapping relations of scanning image coordinate system, promptly finish two registrations between the coordinate system to the robot coordinate system.

The present invention is the vision register method in a kind of auxiliary stereotactic neurosurgery robot, use the gauge point of robot, camera head, computer, scanned imagery device and patient head, finish the registration of scanning image coordinate system, so that the focus point can be aimed at according to the planning of doctor in scanogram by robot in the operation process to the robot coordinate system.Registration process as shown in Figure 1,

Specific practice is:

(a) paste four gauge points in patient head, then patient head is carried out CT or MRI scanning, obtain the image of patient head surface and internal structure thereof, and be entered in " the surgery planning software " of computer;

(b) doctor goes up at " the surgery planning software " of computer and determines the position of gauge point on scanogram, calculates the coordinate of gauge point in scanning image coordinate system by " surgery planning software ";

(c) camera head is demarcated in the robot coordinate system, use camera head collection patient head image then and it is imported " the vision localization software " of computer, calculate the coordinate of gauge point in the robot coordinate system, and these coordinates are passed to " surgery planning software ";

(d) " surgery planning software " calculates the relation between scanning image coordinate system and the robot coordinate system according to the coordinate of gauge point in scanning image coordinate system and robot coordinate system, promptly finishes two registrations between the coordinate system.The target coordinate in scanning image coordinate system, determined of doctor and the puncture path pose that promptly can be exchanged into robot afterwards, thus the control robot arrives the desired position.

The coordinate of image calculation gauge point in the robot coordinate system that " vision localization software " is gathered by camera head in the present invention." surgery planning software " is used for determining the coordinate of gauge point in scanning image coordinate system in the present invention, and receive the coordinate of gauge point in the robot coordinate system that " vision localization software " is imported, finish the registration from the scanning image coordinate system to robot coordinate system.

(1) coordinate of gauge point in scanning image coordinate system

The process of determining the coordinate of gauge point in scanning image coordinate system as shown in Figure 3.Scanogram is input to " surgery planning software " in the computer, searches the image of underlined point and make marks with the distal point of mouse at gauge point, planning software is noted the figure layer at gauge point place and residing position on this figure layer.All scanograms are carried out the interlayer interpolation arithmetic, the residing figure layer of gauge point sequence number can be converted into the w coordinate in the scanning image coordinate system shown in the accompanying drawing 2, the position of gauge point in the figure layer promptly is u, the v coordinate in the scanning image coordinate system, can obtain the three-dimensional coordinate of gauge point in scanning image coordinate system thus.

(2) determine the coordinate of gauge point in the robot coordinate system

The present invention uses the coordinate of method measurement markers point in the robot coordinate system of vision localization.Be the formulation of this method below.

In the method, have five coordinate systems, as shown in Figure 4, wherein coordinate system OXYZ is the robot coordinate system, and O ' X ' Y ' Z ' is the camera head coordinate system, and o ' u ' v ' is undistorted image coordinates system, o " u " v " is distorted image coordinates system, o _cUv is the computer screen coordinate system.Can set up computer screen coordinate system o by coordinate transform _cRelation between uv and the robot coordinate system OXYZ.Vision localization in this method is exactly to put at computer screen coordinate system o by certain _cCoordinate among the uv calculates this coordinate in machine x people coordinate system OXYZ.

(1) coordinate system transformational relation

(a) robot coordinate system → camera head coordinate system

$\left[\begin{array}{c}{X}^{\′}\\ Y^{\′}\\ Z^{\′}\end{array}\right]=\left[\begin{array}{cccc}{r}_{11}& r_{12}& r_{13}& t_x\\ r_{21}& r_{22}& r_{23}& t_y\\ r_{31}& r_{32}& r_{33}& t_z\end{array}\right]\left[\begin{array}{c}X\\ Y\\ Z\\ 1\end{array}\right]---\left(1\right)$

(t _x, t _y, t _z) be translational component, (α, beta, gamma, t _x, t _y, t _z) be 6 external parameters of camera head. $R=\left[\begin{array}{ccc}{r}_{11}& r_{12}& r_{13}\\ r_{21}& r_{22}& r_{23}\\ r_{31}& r_{32}& r_{33}\end{array}\right]$ Be spin matrix, comprise three parameters (α, beta, gamma), α, β, γ be respectively around X,

The corner of Y, Z axle then has:

$R=\left[\begin{array}{ccc}\cos \mathrm{\β}\cos \mathrm{\γ}& \sin \mathrm{\α}\sin \mathrm{\β}\cos \mathrm{\γ}+\cos \mathrm{\α}\sin \mathrm{\γ}& -\cos \mathrm{\α}\sin \mathrm{\β}\cos \mathrm{\γ}+\sin \mathrm{\α}\sin \mathrm{\γ}\\ -\cos \mathrm{\β}\sin \mathrm{\γ}& -\sin \mathrm{\α}\sin \mathrm{\β}\sin \mathrm{\γ}+\cos \mathrm{\α}\cos \mathrm{\γ}& \cos \mathrm{\α}\sin \mathrm{\β}\sin \mathrm{\γ}+\sin \mathrm{\α}\cos \mathrm{\γ}\\ \sin \mathrm{\β}& -\sin \mathrm{\α}\cos \mathrm{\β}& \cos \mathrm{\α}\cos \mathrm{\β}\end{array}\right]$

(b) camera head coordinate system → undistorted picture coordinate system

Perspective projection relation according to imaging

$u^{\′}=f\·s_x\·\frac{X^{\′}}{Z^{\′}}---\left(2\right)$

$v^{\′}=f\·s_y\·\frac{Y^{\′}}{Z^{\′}}---\left(3\right)$

F is the camera head focal length, s _x, s _yBe the camera head scale factor, unit (pixel/mm).

(c) undistorted picture coordinate system → distortion is as coordinate system

There are two class distortions in camera head lens: radial distortion and tangential distortion.Wherein radial distortion is the main cause that causes the imaging point skew, generally only considers radial distortion.

u″＝u′-R _u (4)

v″＝v′-R _v (5)

R _u＝u×(k ₁r ²+k ₂r ⁴+…)≈u×(k ₁r ²+k ₂r ⁴) (6)

R _v＝v×(k ₁r ²+k ₂r ⁴+…)≈v×(k ₁r ²+k ₂r ⁴) (7)

$r=\sqrt{u^2+v^2}---\left(8\right)$

The radial distortion of camera head is the even multinomial of r, and high order can be ignored.k ₁, k ₂Be the coefficient relevant with radial distortion.

(d) distortion is as coordinate system → computer screen coordinate system

u＝u″+u ₀ (9)

v＝v″+v ₀ (10)

u ₀, v ₀Side-play amount for the relative computer picture coordinate system of image coordinates initial point.(f, s _x, s _y, k ₁, k ₂, u ₀, v ₀) be the inner parameter of camera.

(2) camera head is demarcated

Because camera head and target range are closer in using, and the distortion of camera head itself is also little, thereby in native system, do not consider distortion.Above-mentioned each coordinate system transformational relation simultaneous can be got, be tied to the transformation relation of computer screen coordinate system from robot coordinate

$\left[\begin{array}{c}{X}^{\&prime;}\\ Y^{\&prime;}\\ Z^{\&prime;}\end{array}\right]=\left[\begin{array}{cccc}{r}_{11}& r_{12}& r_{13}& t_x\\ r_{21}& r_{22}& r_{23}& t_y\\ r_{31}& r_{32}& r_{33}& t_z\end{array}\right]\left[\begin{array}{c}X\\ Y\\ Z\\ 1\end{array}\right],\left[\begin{array}{c}u\\ v\\ 1\end{array}\right]=\frac{1}{z}\left[\begin{array}{ccc}{k}_1& 0& {\mathrm{<figure-callout\; id="0"\; label="u"\; filenames="C20031012249500121.png,C20031012249500131.png"\; state="\{\{state\}\}">u</figure-callout>}}_0\\ 0& k_2& {\mathrm{<figure-callout\; id="0"\; label="v"\; filenames="C20031012249500121.png,C20031012249500131.png"\; state="\{\{state\}\}">v</figure-callout>}}_0\\ 0& 0& 1\end{array}\right]\left[\begin{array}{c}{X}^{\&prime;}\\ Y^{\&prime;}\\ Z^{\&prime;}\end{array}\right]---\left(11\right)$

K wherein ₁=fs _x, k ₂=fs _yThen

$u=k_1\frac{r_{11}X+r_{12}Y+r_{13}Z+t_x}{r_{31}X+r_{32}Y+r_{33}Z+t_z}+{\mathrm{<figure-callout\; id="0"\; label="u"\; filenames="C20031012249500121.png,C20031012249500131.png"\; state="\{\{state\}\}">u</figure-callout>}}_0$

$v=k_2\frac{r_{21}X+r_{22}Y+r_{23}Z+t_y}{r_{31}X+r_{32}Y+r_{33}Z+t_z}+{\mathrm{<figure-callout\; id="0"\; label="v"\; filenames="C20031012249500121.png,C20031012249500131.png"\; state="\{\{state\}\}">v</figure-callout>}}_0$

Promptly

$u=\frac{X(k_1{r}_{11}+r_{31}{u}_0)+Y(k_1{r}_{12}+u_0{r}_{32})+Z(k_1{r}_{13}+u_0{r}_{33})+(k_1{t}_x+u_0{t}_z)}{r_{31}X+r_{32}Y+r_{33}Z+t_z}$

$v=\frac{X(k_2{r}_{21}+r_{31}{v}_0)+Y(k_2{r}_{22}+v_0{r}_{32})+Z(k_2{r}_{23}+v_0{r}_{33})+(k_2{t}_y+v_0{t}_z)}{r_{31}X+r_{32}Y+r_{33}Z+t_z}$

Order

$A_1=\frac{k_1{r}_{11}+r_{31}{u}_0}{t_z},A_2=\frac{k_1{r}_{12}+u_0{r}_{32}}{t_z},A_3=\frac{k_1{r}_{13}+u_0{r}_{33}}{t_z},A_4=\frac{k_1{t}_x+u_0{t}_z}{t_z}$

$A_5=\frac{r_{31}}{t_z},A_6=\frac{r_{32}}{t_z},A_7=\frac{r_{33}}{t_z}$

$A_8=\frac{k_2{r}_{21}+r_{31}{v}_0}{t_z},A_9=\frac{k_2{r}_{22}+v_0{r}_{32}}{t_z},A_{10}=\frac{k_2{r}_{23}+v_0{r}_{33}}{t_z},A_{11}=\frac{k_2{t}_y+v_0{t}_z}{t_z}$

Then

$u=\frac{A_{1}X+A_{2}Y+A_{3}Z+A_4}{A_{5}X+A_{6}Y+A_{7}Z+1},v=\frac{A_{8}X+A_{9}Y+A_{10}Z+A_{11}}{A_{5}X+A_{6}Y+A_{7}Z+1}$

Therefore have

A ₁X+A ₂Y+A ₃Z+A ₄-A ₅Xu-A ₆Yu-A ₇Zu＝u (12)

A ₈X+A ₉Y+A ₁₀Z+A ₁₁-A ₅Xv-A ₆Yv-A ₇Zv＝v (13)

More than two equations comprise 11 parameters to be asked, given n (n 〉=6) group reference point (u _n, v _n, X _n, Y _n, Z _n), order

$E=\left[\begin{array}{ccccccccccc}{X}_1& Y_1& Z_1& 1& -X_1{u}_1& -Y_1{u}_1& -Z_1{u}_1& 0& 0& 0& 0\\ & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \\ & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \\ & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \\ X_n& Y_n& Z_n& 1& -X_n{u}_n& -Y_n{u}_n& -Z_{\mathrm{<figure-callout\; id="0"\; label="n\; u\; n"\; filenames="C20031012249500121.png,C20031012249500131.png"\; state="\{\{state\}\}">n</figure-callout>}}{u}_n{}_{}& 0& 0& 0& 0\\ 0& 0& 0& 0& -X_1{v}_1& -Y_1{v}_1& -Z_1{v}_1& X_1& Y_1& Z_1& 1\\ & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \\ & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \\ & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \&CenterDot;& & & \&CenterDot;& \\ 0& 0& 0& 0& -X_n{v}_n& -Y_n{v}_n& -Z_n{v}_n& X_n& Y_n& Z_n& 1\end{array}\right]$

A＝[A ₁?A ₂?A ₃?A ₄?A ₅?A ₆?A ₇?A ₈?A ₉?A ₁₀?A ₁₁] ^T

C＝[u ₁?u ₂?…?u _n?v ₁?v ₂?…?v _n] ^T

Then have

E·A＝C

A＝E ⁺·C (14)

If the undetermined parameter of two camera heads is respectively:

A _l＝[A _1l?A _2l?A _3l?A _4l?A _5l?A _6l?A _7l?A _8l?A _9l?A _10l?A _11l] ^T

A _r＝[A _1r?A _2r?A _3r?A _4r?A _5r?A _6r?A _7r?A _8r?A _9r?A _10r?A _11r] ^T

Given n within two common field ranges of camera head (n 〉=6) individual known in the robot coordinate system reference point of coordinate, can calibrate all undetermined parameters of two camera heads respectively by (14).Timing signal can be got on the mechanical arm terminal needle point point as with reference to point, allows mechanical arm move to the individual different position of n (n 〉=6) respectively, with obtain n individual known in the robot coordinate system reference point of coordinate.

(3) coordinate Calculation of gauge point

Get by equation (12), (13):

(A ₁-A ₅u)X+(A ₂-A ₆u)Y+(A ₃-A ₇u)Z＝u-A ₄ (15)

(A ₈-A ₅v)X+(A ₉-A ₆v)Y+(A ₁₀-A ₇v)Z＝v-A ₁₁ (16)

If the coordinate to be asked of certain point is that (Z), it is respectively (u through the coordinate in the computer screen coordinate system after two camera head imagings for X, Y in the robot coordinate system _l, v _l) and (u _r, v _r), then have:

$\left[\begin{array}{ccc}{A}_{1l}-A_{5l}{u}_l& A_{2l}-A_{6l}{u}_l& A_{3l}-A_{7l}{u}_l\\ A_{8l}-A_{5l}{v}_l& A_{9l}-A_{6l}{v}_l& A_{10l}-A_{7l}{v}_l\\ A_{1r}-A_{5r}{u}_r& A_{2r}-A_{6r}{u}_r& A_{3r}-A_{7r}{u}_r\\ A_{8r}-A_{5r}{v}_r& A_{9r}-A_{6r}{v}_r& A_{10r}-A_{7r}{v}_r\end{array}\right]\left[\begin{array}{c}X\\ Y\\ Z\end{array}\right]\left[\begin{array}{c}{u}_l-A_{4l}\\ v_l-A_{11l}\\ u_r-A_{4r}\\ v_r-A_{11r}\end{array}\right]---\left(17\right)$

Can obtain the coordinate of gauge point in the robot coordinate system by (17):

$\left[\begin{array}{c}X\\ Y\\ Z\end{array}\right]={\left[\begin{array}{ccc}{A}_{1l}-A_{5l}{u}_l& A_{2l}-A_{6l}{u}_l& A_{3l}-A_{7l}{u}_l\\ A_{8l}-A_{5l}{v}_l& A_{9l}-A_{6l}{v}_l& A_{10l}-A_{7l}{v}_l\\ A_{1r}-A_{5r}{u}_r& A_{2r}-A_{6r}{u}_r& A_{3r}-A_{7r}{u}_r\\ A_{8r}-A_{5r}{v}_r& A_{9r}-A_{6r}{v}_r& A_{10r}-A_{7r}{v}_r\end{array}\right]}^{+}\left[\begin{array}{c}{u}_l-A_{4l}\\ v_l-A_{11l}\\ u_r-A_{4r}\\ v_r-A_{11r}\end{array}\right]---\left(18\right)$

(3) registration from the scanning image coordinate system to robot coordinate system

As shown in Figure 2, establishing the coordinate of four gauge points in the robot coordinate system is respectively

(X ₁, Y ₁, Z ₁), (X ₂, Y ₂, Z ₂), (X ₃, Y ₃, Z ₃), (X ₄, Y ₄, Z ₄), the coordinate in scanning image coordinate system is respectively

(u ₁, v ₁, w ₁), (u ₂, v ₂, w ₂), (u ₃, v ₃, w ₃), (u ₄, v ₄, w ₄), scanning image coordinate system is T to robot coordinate system's transformation matrix, then

$\left[\begin{array}{cccc}{X}_4-X_1& X_3-X_1& X_2-X_1& X_1\\ Y_4-Y_1& Y_3-Y_1& Y_2-Y_1& Y_1\\ Z_4-Z_1& Z_3-Z_1& Z_2-Z_1& Z_1\\ 0& 0& 0& 1\end{array}\right]=T\left[\begin{array}{cccc}{u}_4-u_1& u_3-u_1& u_2-u_1& u_1\\ v_4-v_1& v_3-v_1& v_2-v_1& v_1\\ w_4-w_1& w_3-w_1& w_2-w_1& w_1\\ 0& 0& 0& 1\end{array}\right]$

Try to achieve

$T=\left[\begin{array}{cccc}{X}_4-X_1& X_3-X_1& X_2-X_1& X_1\\ Y_4-Y_1& Y_3-Y_1& Y_2-Y_1& Y_1\\ Z_4-Z_1& Z_3-Z_1& Z_2-Z_1& Z_1\\ 0& 0& 0& 1\end{array}\right]{\left[\begin{array}{cccc}{u}_4-u_1& u_3-u_1& u_2-u_1& u_1\\ v_4-v_1& v_3-v_1& v_2-v_1& v_1\\ w_4-w_1& w_3-w_1& w_2-w_1& w_1\\ 0& 0& 0& 1\end{array}\right]}^{-1}$

Can finish the registration of scanning image coordinate system accurately by the sign of above-mentioned mathematical way to the robot coordinate system.This method only needs two camera heads can determine the coordinate of gauge point in the robot coordinate system.Compare with contact measurement method, its setting accuracy height, and can be automatically the position of measurement markers point in real time; Compare with other non-contact method, it cheap, simple to operation, tool has an enormous advantage.

Medical robot vision register method of the present invention also can be used for Wicresoft thoracic cavity, abdominal operation, and its register method is identical with the auxiliary stereotactic neurosurgery of robot with gauge point.

Claims (4)

1, the vision register method in a kind of auxiliary stereotactic neurosurgery robot, this method is carried out the coordinate of gauge point in the robot coordinate system that the vision technique measurement is attached to patient head by containing robot, camera head, computer, scanned imagery device, thereby finish the registration of scanning image coordinate system to the robot coordinate system, this method comprises the following steps:

(a) at patient head labelling point;

(b) determine the coordinate of gauge point in scanning image coordinate system:

Scan patient head with scanned imagery device, become image to be input to computer institute, the surgery planning software processes in the machine is determined the coordinate of gauge point in scanning image coordinate system as calculated;

(c) determine the coordinate of gauge point in the robot coordinate system:

The coordinate of gauge point in the robot coordinate system comprises that robot coordinate system OXYZ, camera head coordinate system O ' X ' Y ' Z ', undistorted image coordinates are that o ' u ' v ', distorted image coordinates are o " u " v " and five coordinate systems of computer screen coordinate system ocuv; the conversion simultaneous between described five coordinate systems calibrates the undetermined parameter of camera head; by the coordinate of gauge point in the robot coordinate system, tries to achieve the coordinate of gauge point on computer screen;

The patient head image that camera head is obtained is input to computer, and the positioning software in the machine is handled as calculated, determines the coordinate of gauge point in the robot coordinate system, and sends this coordinate to surgery planning software;

(d) surgery planning software is finished the registration of scanning image coordinate system to the robot coordinate system.

2, vision register method according to claim 1 is characterized in that: the number of gauge point is 4.

3, vision register method according to claim 1 is characterized in that: camera head is finished the coordinate of measurement markers point in the robot coordinate system.

4, vision register method according to claim 1 is characterized in that: scanned imagery device can be CT or MRI.

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