CN1695565A - Extracorporeal lithotripter and its stone tracking and positioning device - Google Patents

Abstract

The invention discloses an external stone breaker and a stone tracking and positioning device thereof, comprising an X-ray machine, an ultrasonic scanner, a mobile platform, a monitor and a stone tracking and positioning device; wherein the X-ray machine is arranged on the machine table and can irradiate at 0 degree and 30 degrees to determine the calculus area in a three-dimensional way; the ultrasonic scanner is arranged at the lower end of the mobile platform, is positioned on the intersection line of the X-ray machine and the vibrating cup, displays the result on the monitor by moving along the axial direction of the calculus part of the patient, determines the movement position of the calculus by the calculus tracking and positioning device, and drives the mobile platform by matching with the motion controller to align the calculus part of the patient to the vibrating cup, so that the shock wave can accurately hit and crush the calculus.

Description

Extracorporeal lithotripter and its stone tracking and positioning device

technical field

The present invention relates to an extracorporeal lithotripsy machine and its calculus tracking and positioning device, in particular to an X-ray machine, an ultrasonic scanner, a mobile platform, a monitor and a calculus tracking and positioning device. The X-ray machine can be used as Stereoscopically determine the calculus area with 0 degree and 30 degree irradiation; scan with an ultrasonic scanner, and determine the moving position of the calculus through the calculus tracking and positioning device, and then cooperate with the motion controller to drive the mobile platform to align the position of the patient's calculus to the shock Cup, so that the shock wave can accurately hit and crush the stones.

Background technique

Due to the improvement of economic life, many people's eating habits tend to be refined and high in protein content; in addition, due to genetic or other unknown reasons, it is easy to cause kidney stones, which cause patients to have pain, nausea, vomiting, etc., which make individuals suffer health, Hazard to life, and loss to society.

In the past two decades, the method of treating human calculus has roughly changed from the traditional method of removing stones through surgery to extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripters are widely used in urology departments of medical institutions. Kidney stones, ureteral stones and bladder stones can all be treated by it.

The principle of extracorporeal shock wave lithotripsy is to use the shock wave generated by the detonation, through water and human tissue as the medium, the shock wave uses the principle of lens focusing to focus the shock wave on the stone, and crush it with instantaneous high pressure. Afterwards, the fragments can be excreted by human tissues to achieve the purpose of healing. It can be seen from this that there is a direct and significant relationship between the hit rate of the shock wave hitting the stone and the healing effect.

However, because the viscera in the abdominal cavity will move due to breathing, the stones will also move, and often the stones will move out of the shock wave focus area. Not only is the stone crushing ineffective, but it is more likely to accidentally hit the tissue and cause other sequelae.

Contents of the invention

The object of the present invention is to provide a kind of extracorporeal lithotripsy machine and its stone tracking and positioning device, which is a combination of X-ray machine, ultrasonic scanner, mobile platform, monitor and stone tracking and positioning device; use X-ray machine for three-dimensional irradiation Determine the calculus area, place the ultrasonic scanner on the intersection line of the X-ray machine and the shock cup on the machine table, move it axially along the patient's calculus area, and display the results on the monitor.

The second object of the present invention is to provide an extracorporeal lithotripter and its calculus tracking and positioning device. Through the steps of initial setting, image capture, calculus detection, image picture comparison, and calculus positioning, the moving position of the calculus can be fixed, so that Stones can be accurately crushed.

Another object of the present invention is to provide an extracorporeal lithotripter and its calculus tracking and positioning device, which is equipped with a calculus shadow auxiliary positioning device to assist in determining the exact position of the calculus, so as to improve the accuracy of calculus positioning.

Another object of the present invention is to provide an extracorporeal lithotripsy machine and its calculus tracking and positioning device, wherein the ultrasonic scanner is located on the intersection line of the X-ray machine and the shock cup to ensure overall focus positioning.

The extracorporeal lithotripsy machine and its stone tracking and positioning device that can realize the above-mentioned purpose of the invention include an X-ray machine, an ultrasonic scanner, a mobile platform, a monitor, and a stone tracking and positioning device; wherein, the X-ray machine is installed on the machine On the platform, it can be irradiated at 0 degrees and 30 degrees, and the calculus area can be determined in a three-dimensional manner; the ultrasonic scanner is installed at the lower end of the mobile platform, located on the intersection line of the X-ray machine and the shock cup, and passes through it along the patient's The stone part moves axially, and the results are displayed on the monitor, and then the moving position of the stone is determined by the stone tracking and positioning device, and the motion controller is used to drive the mobile platform to align the patient's stone part with the shock cup, so that the shock wave can be accurately hit and Crush the stones.

Description of drawings

Fig. 1 (A) is the structural stereogram of the present invention;

Fig. 1 (B) is the exploded schematic view of the electromagnetic shock wave generator module of the present invention;

Fig. 2 is another perspective view of the present invention;

Fig. 3 is a side view of the present invention;

Fig. 4 is the schematic diagram of rotation of the X-ray machine of the present invention;

Fig. 5 is a flow chart of calculus tracking and positioning in the present invention;

Fig. 5 (A) is the flow chart of stone detection step of the present invention;

FIG. 5(B) is a flow chart of the image frame comparison steps of the present invention;

Fig. 5 (C) is the flow chart of calculus shadow assisted positioning of the present invention;

Fig. 5 (D) is the flow chart of calculus tracking positioning and calculus shadow assisted positioning of the present invention;

Figure 6 is a block diagram of the present invention.

Explanation of reference signs: 1 X-ray machine; 11 rotating shaft arm; 2 ultrasonic scanner; 3 mobile platform; 4 monitor; 5 shock cup; 6 drive control device; 7 electromagnetic shock wave generator module; 71 fixed shock wave module Base; 72 shock wave lens fixing frame; 73 shock wave focusing double concave lens; 74 shock wave generating source assembly; 741 high voltage insulating ceramic base; 742 high voltage electromagnetic coil;

Detailed ways

Please refer to Fig. 1 (A) and the structural perspective view and another perspective view of the extracorporeal lithotripter and its calculus tracking and positioning device of the present invention shown in Fig. The device includes: X-ray machine 1, ultrasonic scanner 2, mobile platform 3, monitor 4, vibration cup 5 and drive control device 6; wherein, the X-ray machine 1 is installed on a rotating shaft arm 11, The rotating shaft arm 11 is in the shape of a semi-circular arc, and a shock cup 2 is arranged at an appropriate position at its lower end, and an ultrasonic scanner 2 is arranged at the lower end of the vertical line of the X-ray machine 1, and the ultrasonic scanner 2 can be driven and controlled. The device 6 is moved axially to scan along the stone site of the patient.

Please refer to FIG. 1(B), which is an exploded schematic diagram of the electromagnetic shock wave generator module of the extracorporeal lithotripter and its stone tracking and positioning device of the present invention. It can be seen from the figure that an electromagnetic shock wave generator module 7 is arranged inside the shock cup 5 The shock wave lens fixing frame 72 and the shock wave focusing double concave lens 73 are arranged inside the shock wave module fixed base 71, and the shock wave generation source assembly 74 is arranged at the lower end, and the shock wave generation source assembly 74 is composed of a high-voltage insulating ceramic base 741, a high-voltage electromagnetic coil 742, Teflon double-sided bonded film 743, metal film 744 and rubber film 745, the current passes through the high-voltage electromagnetic coil to generate a magnetic field, and the magnetic field is used to push the metal film to slap the water body in the fixed base of the shock wave module, and then generate shock waves to achieve shock The effect of crushing stones in human organs.

Please refer to the side view of the extracorporeal lithotripter and its calculus tracking and positioning device of the present invention and the schematic diagram of the rotation of the X-ray machine shown in Figure 3 and Figure 4, it can be seen from the figure that the X-ray machine 1 can be driven by the drive control device 6 Rotate the shaft arm 11 to make 0° and 30° rotations to obtain the patient's correct calculus area in a two-dimensional manner; Target area for stones. After the calculus area is determined by the X-ray machine 1 , the ultrasonic scanner 2 is axially displaced through control, and the result is displayed on the monitor 4 .

In addition, a motion controller is used to connect the driver, motor and encoder, and the array of drivers, AC motors, encoders, reducers, decoders, etc. installed at the lower end of the mobile platform, so that the mobile platform can move in three-dimensional space, so that the The calculus area of the patient moves to the shock wave target area in due course.

Please refer to Fig. 5, which is a stone tracking and positioning flow chart of the extracorporeal lithotripsy machine and its stone tracking and positioning device of the present invention. It can be seen from the figure that the tracking and positioning process steps of the stone tracking and positioning device of the present invention include:

(A) Initial setup: Pre-configure the memory to provide the image buffer (Buffer) required for stone tracking and set the initial values of various parameters, and initialize the image capture card to wait for capture commands;

(B) Image grabbing: use multi-thread technology to capture images and store them in the buffer, and use the event-Driven architecture to process various requests from the graphical user interface. request, reduce the response time of each action of the user, and use double buffering technology (Double Buffering) to avoid image loss and ensure the effect of real-time tracking;

(C) Stone detection: The judgment of stones is carried out in the effective area (region of interest, ROI) defined by the user, and the effective area will move with the stone area determined later; in order to detect possible stones in the effective area (ROI) area, it is necessary to set an appropriate stone discrimination threshold (threshold value) and perform image binarization processing; if the image pixel (pixel) intensity in the effective area is greater than the set discrimination threshold, it is regarded as a stone candidate area ( stone region), all candidate regions in the effective region are marked and stored in the memory;

(D) Image frame matching (frame matching): After each image obtained from the image capture card is binarized according to the stone discrimination threshold, it is compared with the binary processing result of the previous image. The pixels in the overlapping part of the white area in the image are given a higher weighted value, and the pixels in the non-overlapping part are given a lower weighted value, and then the result of adding each weighted value is used as the matching value; the effective area ( ROI) moves in various directions, and calculates the matching value of each moving direction, and calculates the direction with the highest matching value (matching value) is the translation vector of the screen;

(E) Stone location: add the obtained screen movement vector to the previously determined stone position (stone position), and then determine the position of the stone after it has moved, and select the closest position in the current screen The stone candidate area (stone region), calculate the gray scale value center of mass of all pixels in this stone candidate area, and then obtain the new stone position, and define a new effective region (ROI) centered on this position.

Please refer to FIG. 5(A), which is a flow chart of the stone detection steps of the in vitro lithotripsy machine and its stone tracking and positioning device of the present invention. It can be seen from the figure that the stone detection steps of the present invention are as follows:

(A) stone image input;

(B) user participation;

(C) maximizing the entropy threshold;

(D) Appearance simplified processing procedures;

(E) area marking;

(F) stone test results;

(G) Calculate the stone center;

(H) Calculate the stone boundary.

Among them, the user only needs to mark the ROI with the mouse. After the ROI is defined, the gray scale value of all pixels in the ROI is calculated. According to clinical experience, the part with a higher gray scale value in the screen is more likely to be a stone. The gray scale value threshold for discriminating stones can be obtained by expression (1)

${\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; Arg</span>}}<span\; class="notranslate">\; \{</span>\underset{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="Max"\; filenames="A20041003786500121.png,A20041003786500141.png"\; state="\{\{state\}\}">Max</figure-callout></span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; \&psi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Based on this threshold value, the image in POI is binarized, and the white pixels are regarded as potential stone pixels. After simple morphollical processing, a smoother stone outline is obtained. There are many white areas in the ROI, and the one with the largest area that does not overlap with the ROI boundary is a stone. When the stone is detected, its center and boundary can be calculated.

In most cases, the device can correctly identify stones in the ROI. However, since stones move with the internal organs of the human body, the size of stones in the image changes constantly, making stone tracking extremely important. After the stone area has been correctly identified in the ROI of the first picture, the next goal is to perform "image-screen comparison" in addition to identifying all possible stone candidate areas with "stone detection" in subsequent pictures To find out where the stones are after they move.

Please refer to FIG. 5(B), which is a flow chart of the image comparison steps of the in vitro lithotripter and its stone tracking and positioning device of the present invention. It can be seen from the figure that the image comparison steps of the present invention are as follows:

(A) Obtain the ROI binary image of the previous frame;

(B) Move the ROI in either direction;

(C) Obtain the binary image of the current picture with the displaced ROI;

(D) comparing the ROI binary image of the current picture with the ROI binary image of the previous picture;

(E) After repeatedly calculating the figure of merit (FOM, Figure of merit) in each direction, the direction with the largest figure of merit is the direction of stone movement, and the vector in this direction is used to exclude large bright areas that may cause misjudgment.

The process is described in detail as follows: First, the figure of merit (FOM) is used as the basis for judging the comparison and matching in the picture. When the pixels in the calculus area in the previous picture match the pixels in the largest area in the current picture, the highest figure of merit (FOM) is given. The calculation equation of is shown in (2), wherein, P represents the previous frame, C represents the current frame, and W represents the weight value.

$\mathrm{<span\; class="notranslate">\; FOM</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; for\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; yandi</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j\; wherdP\; andC\; overlap</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; AND</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

When calculating, move the ROI in all directions in the current screen to obtain binary images, then compare the binary images in each direction with the binary images in the previous screen, and calculate each direction with (2) After the figure of merit (FOM), the direction with the highest figure of merit is the direction of screen movement.

Add the obtained moving vector to the previously determined stone position to determine the position of the stone after movement, and select the stone closest to this position from all the marked stone candidate areas in the current screen For the candidate area, the new calculus position can be obtained by calculating the mass center of gray scale values of all pixels in the calculus area.

It can be seen that, through the above-mentioned steps of image comparison, the moving direction and position of the stones in the human body can be accurately obtained, thereby overcoming the problem of stones being displaced due to the movement of internal organs, and making the stone crushing action more accurate. Accurate, can also avoid the situation that other visceral tissues are inadvertently shaken.

In order to increase the accuracy of calculus position judgment, the present invention also develops another set of calculus shadow auxiliary positioning device, that is, to use shadow to detect calculus. The so-called "shadow detection" is based on the fact that ultrasonic waves cannot pass through stones and bones. When scanning, there will be long strips of shadows behind the stones. detection. When the operator locks kidney stones, the shadow can be used as an important basis for judging whether the area with a high gray scale value is a stone. If the area has a high gray scale value and there is a shadow behind it, this area can be Determined as a stone; in other words, if the area has only high grayscale values but no shading it will not be considered a stone.

Please refer to FIG. 5(C), which is a flow chart of the stone shadow auxiliary positioning of the extracorporeal lithotripter and its stone tracking and positioning device of the present invention. It can be seen from the figure that the stone shadow auxiliary positioning steps of the present invention are as follows:

(A) Determine the search path according to the outline of the fan-shaped picture;

(B) obtaining candidate samples;

(C) Candidate samples compared;

(D) selected shadow path;

(E) Determine the location of the stone.

During implementation, the search path is first defined, and if the stone shadow matches the search line, it is the best comparison result. Because the calculus shadow sample has two features, one is the calculus part, and the other is the shadow part, the present invention uses two steps to distinguish the comparison process. The first step is to find out the possible position of the calculus. The second step is to simulate stone shadows at the points where these stones may exist.

When the pixel with the largest grayscale value is found along the search path, the pixel with the largest grayscale value may be a stone, or it may be an internal organ tissue located above the stone instead of a stone. In order to avoid high gray scale values caused by the tissue being too close to the probe or the upper end of the calculus, when the search line starts from a position far away from the probe, the present invention judges the results of shadow samples along the search path.

The comparison rule for shadow samples is to find the maximum gray scale value in each candidate sample, that is, the gray scale peak value, then calculate the gray scale average value of the interval, and find out the difference between the gray scale peak value and the gray scale average value. The sample with the largest difference is selected as the sample that best matches the shadow and shadow characteristics, and the position of the stone in this sample can be used as the basis for "stone discrimination".

Please refer to Fig. 5(D), which is a flow chart of stone tracking and positioning and stone shadow auxiliary positioning of the extracorporeal lithotripsy machine and its stone tracking and positioning device of the present invention. It can be seen from the figure that the stone shadow auxiliary positioning of the present invention can be combined with continuous video images The comparison is performed synchronously to judge the calculus, making the determination of the correct area of the calculus more accurate. Therefore, when the image is defined by the user after the ROI, the correct calculus position can be obtained through the "stone detection" and then can be followed by "image comparison". And "stone shadow assisted positioning" and other processes to accurately locate moving stones.

Please refer to Fig. 6, which is a block diagram of an extracorporeal lithotripter and its calculus tracking and positioning device of the present invention. It can be seen from the figure that at the beginning of implementation, the power supply is first activated, the power supply is driven by the controller, and the I/O module Drive the high-voltage circuit to make the rotating shaft arm of the X-ray machine rotate 0 degrees and 30 degrees to obtain the correct stone area of the patient; at the same time, drive the ultrasonic scanner to scan the patient by driving the controller and servo motor to measure After knowing the depth of the stone, the ultrasonic stone image positioning program and the ultrasonic stone image real-time tracking and positioning program are carried out. The stone area is firstly marked by the user, and then through the positioning program, the current image is compared with the previous image to determine After correcting the calculus area and its moving vector, synchronously drive the controller and servo motor to drive the mobile bed to align the patient’s calculus area to the target area. Shake the cup to crush the stones.

The above detailed description is a specific description of a feasible embodiment of the present invention. This embodiment is not used to limit the scope of the present invention. All equivalent implementations or changes that do not depart from the spirit of the present invention should be included in the present invention within the scope of protection.

Claims (12)

1. An extracorporeal lithotripsy machine, including an X-ray machine, an ultrasonic scanner and a mobile platform; wherein, the X-ray machine is installed on a machine platform, which can be used for 0-degree and 30-degree irradiation, and can be used in a three-dimensional manner Determine the calculus area; the ultrasonic scanner is set at the lower end of the mobile platform, on the intersection line of the X-ray machine and the shock cup on the machine table, and the result is displayed on the imaging device by moving it axially along the patient's calculus area , and cooperate with the motion controller to drive the mobile platform to align the position of the patient's stone to the shock cup, so that the shock wave can accurately hit and crush the stone. 2. The extracorporeal lithotripter and its calculus tracking and positioning device as claimed in claim 1, wherein an electromagnetic shock wave generator module is arranged inside the shock cup, and a shock wave lens fixing frame and a shock wave focusing dual are arranged on the inside of the shock wave module fixing base. Concave lens, the lower end is equipped with a shock wave generating source component, the current passes through a high-voltage electromagnetic coil to generate a magnetic field, and the magnetic field is used to push the metal film to slap the water body in the fixed base of the shock wave module, and then generate shock waves to crush the stones in human organs. 3. The extracorporeal lithotripter and its calculus tracking and positioning device as claimed in claim 2, wherein the shock wave generating source component is composed of an insulating ceramic base, a high-voltage electromagnetic coil, Teflon double-sided bonding film, a metal film and a rubber film . 4. A tracking and positioning method for a stone tracking and positioning device of an extracorporeal lithotripter, comprising the following steps: (A) Initial setting, setting the initial value of each parameter, and initializing the image capture card to wait for the capture command; (B) Image capture, capture images in a multi-stream manner and store them in the buffer; (C) Calculus detection, the judgment of stones is in the effective area defined by the user, and an appropriate threshold value for stone judgment is set and image binarization is performed; (D) Image frame comparison, after each image obtained from the image capture card is binarized according to the stone discrimination threshold, compared with the binary processing result of the previous image, and the overlapped part Different weighting values are given to pixels or non-overlapping pixels to obtain screen motion vectors; (E) Calculus positioning, adding the obtained image movement vector to the previously determined calculus position to determine the calculus moving position. 5. The extracorporeal lithotripter and its calculus tracking and positioning device according to claim 4, wherein in the image capture step, the event-triggered framework is used to process various requests from the graphical user interface, reducing the response to each action of the user time. 6. The extracorporeal lithotripter and its calculus tracking and positioning device according to claim 4, wherein in the image capturing step, a double buffer mode is adopted to avoid image loss and ensure real-time tracking. 7. The extracorporeal lithotripter and its calculus tracking and positioning device as claimed in claim 4, wherein in the calculus detection step, the gray scale value threshold of the calculus is calculated by the following equation (1): ${\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; Arg</span>}}<span\; class="notranslate">\; \{</span>\underset{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; Max</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; \&Psi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$ 8. The extracorporeal lithotripsy machine and its stone tracking and positioning device according to claim 4, wherein in the image picture comparison step, the merit value is used as the basis for judging the comparison and matching in the picture, when the pixels of the stone area in the previous picture When matching the pixels in the largest area in the current picture, the highest merit value is given. The calculation formula of the merit value is as shown in (2), where P represents the previous picture, C represents the current picture, and W represents the weight value: $\mathrm{<span\; class="notranslate">\; FOM</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; forx</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; yandi</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; jwherePandCoverlap</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; AND</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$ 9. The extracorporeal lithotripter and its calculus tracking and positioning device according to claim 8, wherein in the image image comparison step, the effective area in the current image is moved in various directions to obtain binary images, and then each The binarized image of the direction is compared with the binarized image of the previous frame, and after calculating the merit value of each direction, the direction with the highest merit value is the direction of the screen movement. 10. A tracking and positioning method for a stone tracking and positioning device of an extracorporeal lithotripter, comprising the following steps: (A) Initial setting, setting the initial value of each parameter, and initializing the image capture card to wait for the capture command; (B) Image capture, capture images in a multi-stream manner and store them in the buffer; (C) Calculus detection, using the judgment of stones in the effective area defined by the user, setting an appropriate threshold for stone discrimination and performing image binary processing; (D) Image frame comparison: After each image obtained from the image capture card is binarized according to the stone discrimination threshold, it is compared with the binarized processing result of the previous image, and the overlapping parts are compared. Different weighting values are given to pixels or non-overlapping pixels to obtain screen motion vectors; (E) Calculus positioning, adding the obtained picture movement vector to the previously determined calculus position, to determine the calculus movement position; (F) Calculus shadow assisted positioning. After the stone detection step, simultaneously determine the search path, obtain candidate samples, compare candidate samples, select the shadow path, and determine the location of the stone according to the outline of the fan-shaped picture. 11. The method according to claim 10, wherein the stone shadow assisted positioning process is to first define the search path, and use the coincidence of the stone shadow and the search line as the best comparison result, first find out the possible location of the stone, and then At the point where the stone may exist, the stone shadow simulation is performed. 12. The method according to claim 11, wherein the search path starts from an appropriate distance from the ultrasonic probe, obtains candidate samples along the back of the search path, calculates the average value of each gray scale in the candidate samples, and finds out The largest gray scale value (gray scale peak value) among the candidate samples, and the stone with the largest difference between the gray scale peak value and the gray scale average value.

Images