A precision test system for a surgical navigation device

Abstract

The present invention discloses an accuracy test system for a surgical navigation device, which mainly realizes the accuracy measurement of the navigation device based on a laser tracker and a target ball matched therewith. Among them, the measurement method includes obtaining a conversion matrix from the scanning image coordinate system to the robotic arm coordinate system; controlling the movement of the robotic arm according to the starting point and the ending point on the scanning image according to the conversion matrix; and calculating the coordinates of the actual starting point and ending point reached by the robotic arm in the laser tracker coordinate system based on the target ball at the end of the robotic arm, and combining the coordinates of the starting point and the ending point in the accuracy test tooling actually measured by the laser tracker to obtain the device accuracy. The present invention does not depend on a specific optical measurement device, providing the possibility of accuracy testing for surgical navigation systems without optical measurement devices.

Description

Technical Field

[0001] The present invention relates to the technical field of surgical navigation robots, and more particularly to a system for testing the accuracy of a surgical navigation device. Background Art

[0002] Surgical navigation devices play an increasingly important role in the medical field, especially in puncture surgeries. Such devices can assist doctors in making precise surgical plans and guiding surgical tools to the target position through actuators such as robotic arms, thereby improving the accuracy and safety of surgeries.

[0003] System accuracy is one of the key indicators for evaluating the performance of surgical navigation devices, and it directly affects the success rate and safety of surgeries. Currently, for the system accuracy test of surgical navigation devices, a method based on optical measurement devices is mainly adopted.

[0004] This method uses an optical measurement device to measure the position where the actual robotic arm reaches, and takes the entry point and target point of the surgical path as the actual puncture measurement values. At the same time, the test entry point and target point on the test fixture are measured by the optical measurement device as the theoretical measurement values. Finally, the system accuracy of the surgical navigation device is evaluated by calculating the distance deviation and angle deviation between the actual entry point - target point and the theoretical entry point - target point.

[0005] However, not all surgical navigation systems are equipped with optical measurement devices. For systems that do not include optical measurement devices, the spatial position of the needle tip cannot be directly measured, so the above - mentioned method cannot be used for system accuracy testing. This limits the application scope of such surgical navigation systems and brings difficulties to their accuracy evaluation. Summary of the Invention

[0006] In view of this, to at least partially solve the above - mentioned technical problems, the present invention discloses a system for testing the accuracy of a surgical navigation device, aiming to break through the limitations of optical measurement devices and provide a method for testing the accuracy of a surgical navigation device based on laser tracking.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] On the one hand, the present invention provides a system for testing the accuracy of a surgical navigation device, which includes:

[0009] An accuracy test fixture, an image scanning device, a laser tracker, and a robotic arm, wherein target balls matching the laser tracker are provided at the end of the accuracy test fixture and the robotic arm;

[0010] The measurement method includes:

[0011] Obtain the transformation matrix from the scanned image coordinate system to the robotic arm coordinate system;

[0012] Control the movement of the robotic arm according to the starting point and the ending point on the scanned image according to the conversion matrix;

[0013] Based on the target ball at the end of the robotic arm, calculate the actual starting point and ending point coordinates of the robotic arm in the coordinate system of the laser tracker, and combine the coordinates of the starting point and the ending point in the precision test fixture actually measured by the laser tracker to obtain the equipment precision.

[0014] Preferably, obtaining the conversion matrix from the scanned image coordinate system to the robotic arm coordinate system includes:

[0015] Determine the first conversion relationship from the scanned image coordinate system to the laser tracker coordinate system based on the reference points on the precision test fixture;

[0016] Determine the second conversion relationship between the laser scanner coordinate system and the robotic arm coordinate system based on the test points at the end of the robotic arm;

[0017] And obtain the conversion relationship from the scanned image coordinate system to the robotic arm coordinate system according to the first conversion relationship and the second conversion relationship.

[0018] Preferably, determining the first conversion relationship from the scanned image coordinate system to the laser tracker coordinate system based on the reference points on the precision test fixture includes:

[0019] Determine the first coordinates of the reference points on the precision test fixture;

[0020] Use the image scanning device to scan the reference points to obtain the second coordinates of the reference points in the scanned image;

[0021] Use the laser tracker to measure the reference points on the precision test fixture to obtain the third coordinates of the reference points;

[0022] Determine the first conversion relationship according to the first coordinates and the second coordinates, and the first coordinates and the third coordinates in sequence.

[0023] Preferably, determining the second conversion relationship between the laser scanner coordinate system and the robotic arm coordinate system based on the test points at the end of the robotic arm includes:

[0024] Determine the coordinates of the test points in the robotic arm coordinate system, and at the same time, through measurement by the laser tracker, obtain the coordinates of the test points in the laser tracker coordinate system;

[0025] According to the coordinates of the test points in the robotic arm coordinate system and the coordinates in the laser tracker coordinate system, obtain the second conversion relationship.

[0026] Preferably, calculating the actual starting point and ending point coordinates of the robotic arm in the coordinate system of the laser tracker based on the target ball at the end of the robotic arm includes:

[0027] Construct a target ball coordinate system based on the target ball at the end of the robotic arm, and determine the coordinates of the actual starting point and ending point in the target ball coordinate system;

[0028] Obtain the transformation matrix from the target ball coordinate system to the laser tracker coordinate system, and obtain the coordinates of the actual starting point and ending point in the laser tracker coordinate system according to the transformation matrix.

[0029] Preferably, constructing a target ball coordinate system based on the target ball at the end of the robotic arm includes:

[0030] S1. There are 3 target balls at the end of the robotic arm, and their coordinates are defined as R1(x1, y1, z1), R2(x2, y2, z2), R3(x3, y3, z3);

[0031] S2. Taking the target ball R2 as the origin of the coordinate system, we get:

[0032] The direction vector of the x-axis is:

[0033] ;

[0034] The direction vector of the y-axis is:

[0035] ;

[0036] The direction vector of the z-axis is:

[0037] ;

[0038] S3. Normalize the direction vectors of the x, y, and z axes respectively, and we get:

[0039]

[0040] In the formula, , , are the normalized direction vectors of the x, y, and z axes respectively.

[0041] Preferably, determining the coordinates of the actual starting point and ending point in the target ball coordinate system includes:

[0042] According to the size of the calibration positioning tooling, the coordinates of the starting point in the target ball coordinate system are:

[0043]

[0044] Among them, is the starting point coordinate.

[0045] The coordinates of the ending point in the target ball coordinate system are obtained according to the following formulaThe coordinates are:

[0046]

[0047] Wherein, is the path length between the starting point and the ending point in the target ball coordinate system.

[0048] Preferably, the transformation matrix from the target ball coordinate system to the laser tracker coordinate system is:

[0049]

[0050] Wherein, is the coordinate of the origin R2 in the laser tracker coordinate system.

[0051] Preferably, the device accuracy includes an angular deviation and a distance deviation;

[0052] Define the path formed by the actual starting point and ending point coordinates of the robotic arm in the laser tracker coordinate system as the first path, and the path formed by the starting point and ending point coordinates in the accuracy test tooling actually measured by the laser tracker as the second path;

[0053] The angular deviation is the included angle between the first path and the second path;

[0054] The distance deviation includes the distance from the starting point coordinate in the accuracy test tooling actually measured by the laser tracker to the first path, the distance from the ending point coordinate in the accuracy test tooling actually measured by the laser tracker to the first path, and the Euclidean distance between the actual ending point coordinate of the robotic arm in the laser tracker coordinate system and the ending point coordinate in the accuracy test tooling actually measured by the laser tracker.

[0055] As can be seen from the above technical solutions, the surgical navigation device accuracy test system disclosed by the present invention has universality, which not only provides the possibility of accuracy testing for surgical navigation systems without optical measurement devices, but also, since the present invention does not rely on specific optical measurement devices, it can be implemented on more types of surgical navigation systems, thereby expanding the application scope of surgical navigation systems.

[0056] In addition, the present application can accurately obtain the transformation matrix from the scanned image coordinate system to the robotic arm coordinate system, ensuring that the surgical navigation system can accurately map and locate during actual operation;

[0057] In addition, by calculating the deviation between the actual position and the theoretical position of the target ball at the end of the robotic arm, the system accuracy of the surgical navigation device can be accurately evaluated. Description of the Drawings

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0059] Figure 1 Schematic structural diagram of the surgical navigation device accuracy test system provided by the present invention;

[0060] Figure 2 To obtain the actual starting point reached by the robotic arm provided by the present invention and the end point Schematic diagram of the coordinates in the target ball coordinate system. Specific implementation manners

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0062] Embodiment 1:

[0063] The present invention provides a surgical navigation device accuracy test system, which provides a new and effective method for the field of surgical navigation device accuracy testing. It not only solves the problem that it is difficult to perform accuracy testing for some systems due to the lack of optical measurement equipment, but also improves the accuracy and convenience of testing, and has important significance for improving the overall level of medical surgical navigation technology.

[0064] In this embodiment, the test system includes:

[0065] An accuracy test tooling for providing test points for accuracy testing. In this embodiment, the reference points or test points on the accuracy test tooling are made of materials with clear imaging in medical images;

[0066] An image scanning device for scanning the accuracy test tooling to obtain a scanned image containing test points;

[0067] A robotic arm for moving according to the target points in the scanned image;

[0068] A laser tracker for measuring the test points on the accuracy test tooling and the target positions where the robotic arm moves. Among them, target balls matching the laser tracker are provided at the accuracy test tooling and the end of the robotic arm.

[0069] In this application, for a system without an optical measurement device, a laser tracker measurement tool is used to test the system accuracy. In this embodiment, the measurement method includes:

[0070] Obtain the transformation matrix from the scanned image coordinate system to the robotic arm coordinate system;

[0071] Control the movement of the robotic arm according to the starting point and the ending point on the scanned image according to the transformation matrix;

[0072] Based on the target ball at the end of the robotic arm, calculate the actual starting point and ending point coordinates of the robotic arm in the laser tracker coordinate system, and combine with the coordinates of the starting point and the ending point in the accuracy test fixture actually measured by the laser tracker to obtain the equipment accuracy.

[0073] For ease of implementation, as Figure 1 shown, in this embodiment, a coordinate transformation unit, a robotic arm driving unit, and an accuracy detection unit are respectively set for the above steps.

[0074] Furthermore, in one embodiment,

[0075] Obtaining the transformation matrix from the scanned image coordinate system to the robotic arm coordinate system includes:

[0076] (1) Determine the first transformation relationship from the scanned image coordinate system to the laser tracker coordinate system based on the reference points on the accuracy test fixture; including:

[0077] Determine the first coordinates of the reference points on the accuracy test fixture;

[0078] In this embodiment, after the third-party institution calibrates the accuracy test fixture, the measurement results are given. According to the spatial positions between the calibrated points, a coordinate system is established, so as to obtain the first coordinates of the reference points on the accuracy test fixture in this coordinate system.

[0079] Use the image scanning device to scan the reference points to obtain the second coordinates of the reference points in the scanned image; Note: The reference point coordinates can be directly read on the image.

[0080] Then obtain the transformation matrix from the accuracy test fixture to the scanned image according to the first coordinates and the second coordinates:

[0081]

[0082] Furthermore, use the laser tracker to measure the reference points on the accuracy test fixture to obtain the third coordinates of the reference points;

[0083] In the present invention, the laser tracker is matched with corresponding software, and the reference point coordinates of the points can be directly read from the software.

[0084] Using the existing registration algorithm with the first coordinate and the third coordinate, determine the transformation matrix from the laser tracker to the coordinate system of the accuracy test tooling:

[0085]

[0086] Finally, obtain the first transformation relationship from the scanned image to the laser tracker, which is:

[0087]

[0088] (2) Based on the test points at the end of the robotic arm, determine the second transformation relationship between the coordinate system of the laser scanner and the coordinate system of the robotic arm;

[0089] Install a target ball at the end of the robotic arm. When the robot is in the starting position, use the laser tracker to measure the spatial position of the test point at the end of the robotic arm based on the installed target ball at the end of the robotic arm;

[0090] Note: Three target balls can be installed simultaneously. If there is only one target ball, the positions of the three target balls can be measured sequentially by installing them one by one.

[0091] Meanwhile, determine the coordinates of the test point in the coordinate system of the robotic arm;

[0092] In this application, according to the body parameters of the robotic arm and the joint angle values, the common forward kinematics method is used to determine the coordinate values of the test point in the coordinate system of the robotic arm.

[0093] Used to obtain the second transformation relationship based on the coordinates of the test point in the coordinate system of the robotic arm and the coordinates in the coordinate system of the laser tracker, that is:

[0094]

[0095] Note: The calculation process refers to Patent 202310101952.1.

[0096] (3) According to the first transformation relationship and the second transformation relationship, obtain the transformation relationship from the scanned image coordinate system to the robotic arm coordinate system:

[0097]

[0098] After obtaining the transformation between the image and the robotic arm coordinate system, when selecting points from the tooling image, the robotic arm will move to the corresponding position on the accuracy test tooling.

[0099] In the present invention, this process can be realized by the robotic arm drive unit.

[0100] When the robotic arm reaches the specified target position, the accuracy measurement of the navigation device can be carried out.

[0101] In one embodiment,

[0102] Perform precision measurement on the surgical navigation device, including:

[0103] First, calculate the actual starting and ending coordinates of the robotic arm in the coordinate system of the laser tracker based on the target balls at the end of the robotic arm;

[0104] The following is illustrated by a specific embodiment. In this embodiment, the starting point selected in the scanned image is A, and the ending point is B. After the robotic arm moves to the corresponding points A and B respectively, the positions of the 3 target balls R1, R2, and R3 at the end of the robot are measured by the laser tracker;

[0105] Then, based on the positions of the 3 target balls and the calibrated calibration positioning tooling, deduce the points of the actual needle insertion point and the lesion point reached by the robot 、 。

[0106] The specific steps include:

[0107] 1) Construct a target ball coordinate system based on the 3 target balls at the end of the robotic arm; Refer to Figure 2 in (a), the steps are:

[0108] S1. There are 3 target balls at the end of the robotic arm, with positions R1(x1, y1, z1), R2(x2, y2, z2), and R3(x3, y3, z3) (obtained by measurement with the laser tracker);

[0109] S2. Take target ball R2 as the origin of the coordinate system, and the path between target ball R1 and target ball R2 as the x-axis direction vector:

[0110]

[0111] The path between target ball R2 and target ball R3 is a vector on the XZ plane:

[0112]

[0113] According to the vector and multiply to obtain the y-axis direction vector:

[0114]

[0115] Finally, according to the vector and multiply to obtain the z-axis direction vector:

[0116]

[0117] S3. Normalize the x, y, and z-axis direction vectors respectively to obtain:

[0118]

[0119] In the formula, , , are respectively the normalized x, y, and z-axis direction vectors.

[0120] Obtain the transformation matrix from the target ball coordinate system to the laser tracker coordinate system, which is:

[0121]

[0122] In the formula, is the coordinate of the origin R2 in the laser tracker coordinate system.

[0123] 2) Determine the actual starting point and the ending point coordinates in the target ball coordinate system;

[0124] In this embodiment, referring to Figure 2 in (b), according to the calibrated dimensions of the calibration positioning tooling, the position of the needle insertion point relative to the target ball coordinate system can be known, and the representation of the needle insertion point in the target ball coordinate system is obtained as:

[0125]

[0126] Because the direction of the needle insertion point and the lesion point designed by the tooling is parallel to the direction from the target ball R2 to R3, the direction of the needle insertion point and the lesion point is the z-axis direction of the target ball coordinate system. According to the planned path length , the representation of the lesion point in the target ball coordinate system is obtained:

[0127]

[0128] 4) And obtain the coordinates of the actual starting point and ending point in the laser tracker coordinate system according to the transformation matrix:

[0129]

[0130] P 入针点 , P 病灶点 are the positions of the needle insertion point and the lesion point in the laser tracker coordinate system.

[0131] Furthermore, combined with the coordinates of the starting point and the ending point in the accuracy test tooling actually measured by the laser tracker, the equipment accuracy is obtained. In the present invention, the theoretical path measures the positions of the target balls at points A and B on the laser tracker measurement tooling, and the positions of points A and B on the tooling , . According to A, B, , the navigation equipment accuracy can be calculated.

[0132] In one embodiment,

[0133] The device accuracy includes an angular deviation and a distance deviation;

[0134] Define the path formed by the actual starting and ending coordinates of the robotic arm in the coordinate system of the laser tracker as the first path, and the path formed by the starting and ending coordinates in the accuracy test tooling actually measured by the laser tracker as the second path;

[0135] The angular deviation is the included angle between the first path and the second path;

[0136] The distance deviation includes the distance from the starting coordinate in the accuracy test tooling actually measured by the laser tracker to the first path, the distance from the ending coordinate in the accuracy test tooling actually measured by the laser tracker to the first path, and the Euclidean distance between the actual ending coordinate of the robotic arm in the coordinate system of the laser tracker and the ending coordinate in the accuracy test tooling actually measured by the laser tracker.

[0137] According to an embodiment of the present invention,

[0138] The included angle deviation is:

[0139]

[0140] The distances from points A and B to the straight line are 、 :

[0141]

[0142] In the formula:

[0143] ----The distance from point A to the straight line ;

[0144] ----The vector formed by coordinate A and coordinate ;

[0145] ----The distance from point B to the straight line ;

[0146] ---The vector formed by coordinate B and coordinate ;

[0147] The distance deviation of the lesion point :

[0148]

[0149] Wherein, is the actual end point reached by the robotic arm in the coordinate system of the laser tracker The coordinates of are the coordinates of end point B in the precision test fixture actually measured by the laser tracker.

[0150] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts among the various embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For related parts, reference can be made to the description in the method section.

[0151] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surgical navigation equipment accuracy testing system, characterized in that: include: Precision testing tooling, image scanning equipment, laser tracker and robotic arm, wherein the precision testing tooling and the end of the robotic arm are provided with a target ball matching the laser tracker; Measurement methods include: Obtaining a transformation matrix from the scanning image coordinate system to the robot arm coordinate system; determining a first transformation relationship from the scanning image coordinate system to the laser tracker coordinate system based on a reference point on the precision test fixture; including: Determine the first coordinate of the reference point on the precision test fixture; Scanning the reference point using an image scanning device to obtain a second coordinate of the reference point in the scanned image; Use a laser tracker to measure the reference point on the precision test fixture to obtain the third coordinate of the reference point; Determine a first conversion relationship according to the first coordinate and the second coordinate, and the first coordinate and the third coordinate in sequence; Controlling the movement of the robot arm according to the transformation matrix based on the starting point and the end point on the scanned image; The starting and ending coordinates of the robot arm in the laser tracker coordinate system are calculated based on the target ball at the end of the robot arm, and the starting and ending coordinates of the precision test fixture measured by the laser tracker are combined to obtain the equipment accuracy. The actual starting and ending coordinates of the robot arm in the laser tracker coordinate system are calculated based on the target ball at the end of the robot arm, including: Construct a target ball coordinate system based on the target ball at the end of the robotic arm, and determine the coordinates of the actual starting point and end point in the target ball coordinate system; The conversion matrix from the target sphere coordinate system to the laser tracker coordinate system is obtained, and the coordinates of the actual starting point and end point in the laser tracker coordinate system are obtained according to the conversion matrix from the target sphere coordinate system to the laser tracker coordinate system.

2. The accuracy testing system according to claim 1, characterized in that: Get the transformation matrix from the scanned image coordinate system to the robot arm coordinate system, including: Determine a first transformation relationship from a scanning image coordinate system to a laser tracker coordinate system based on a reference point on the precision test fixture; Determine a second conversion relationship between the laser scanner coordinate system and the robotic arm coordinate system based on a test point at the end of the robotic arm; And a conversion relationship from the scanning image coordinate system to the robot arm coordinate system is obtained according to the first conversion relationship and the second conversion relationship.

3. The accuracy testing system according to claim 2, characterized in that: Determining a second transformation relationship between the laser scanner coordinate system and the robotic arm coordinate system based on the robotic arm end test point includes: Determine the coordinates of the test point in the robot arm coordinate system, and simultaneously measure the test point in the laser tracker coordinate system using a laser tracker; A second conversion relationship is obtained according to the coordinates of the test point in the robot arm coordinate system and the coordinates of the test point in the laser tracker coordinate system.

4. The accuracy testing system according to claim 1, characterized in that: The target ball coordinate system is constructed based on the target ball at the end of the robotic arm, including: S1. There are three target balls at the end of the robot arm, with coordinates defined as R1 (x1, y1, z1), R2 (x2, y2, z2), and R3 (x3, y3, z3); S2, taking the target ball R2 as the origin of the coordinate system, we get: x-axis direction vector x axis for: x axis =R1-R2=(x1-x2,y1–y2,z1-z2); y-axis direction vector y axis for: <h2 style=";text-align:left;direction:ltr">y<h2 style=";text-align:left;direction:ltr"> axis <h2 style=";text-align:left;direction:ltr"> =R<h2 style=";text-align:left;direction:ltr"> xz <h2 style=";text-align:left;direction:ltr"> *x<h2 style=";text-align:left;direction:ltr"> axis <h2 style=";text-align:left;direction:ltr"> R<h2 style=";text-align:left;direction:ltr"> xz <h2 style=";text-align:left;direction:ltr"> (R2-R3)(x2-x3,y2-y3,z2-z3) The z-axis direction vector Z axis for: z axis =x axis *y axis ; S3. Normalize the x, y and z axis direction vectors respectively to obtain: X axis =x axis / |x axis | AND axis =and axis / |and axis | WITH axis =from axis / |from axis | Where, X axis , Y axis , Z axis are the normalized x, y and z axis direction vectors respectively.

5. The accuracy testing system according to claim 1, characterized in that: Determine the coordinates of the actual starting point and end point in the target sphere coordinate system, including: According to the calibration positioning tool size, the starting point p in the target sphere coordinate system is obtained. entry The coordinates are: p entry =[x en ,y en ,z en ] Among them, [x en ,y en , z en ] is the starting point coordinate; The end point p in the target sphere coordinate system is obtained according to the following formula target The coordinates are: p target =(x en ,y en ,from en +only) Where len is the path length between the starting point and the end point in the target sphere coordinate system.

6. The accuracy testing system according to claim 1, characterized in that: The transformation matrix from the target sphere coordinate system to the laser tracker coordinate system is: Wherein, R2′(x2′, y2′, z2′) is the coordinate of the origin R2 in the laser tracker coordinate system.

7. The accuracy testing system according to claim 1, characterized in that: Equipment accuracy includes angle deviation and distance deviation; Define the path formed by the starting point and end point coordinates actually reached by the robot arm in the laser tracker coordinate system as the first path, and the path formed by the starting point and end point coordinates actually measured by the laser tracker in the precision test fixture as the second path; Angular deviation, which is the angle between the first path and the second path; The distance deviation includes the distance from the starting point coordinates in the precision test fixture actually measured by the laser tracker to the first path, the distance from the end point coordinates in the precision test fixture actually measured by the laser tracker to the first path, and the Euclidean distance between the end point coordinates actually reached by the robot arm in the laser tracker coordinate system and the end point coordinates in the precision test fixture actually measured by the laser tracker.

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