Six-dimensional bed precision testing device

Abstract

The utility model relates to a precision testing device for a six-dimensional bed. The device comprises a test bottom plate and a film installation assembly, the film installation assembly is arranged on the test bottom plate, the film installation assembly comprises a U-shaped support, a fixed box assembly, a connecting shaft, a locking pin and a base, the U-shaped support is provided with a plurality of groups of installation holes, the fixed box assembly is connected with the U-shaped support through the connecting shaft and the installation holes, and the U-shaped support is arranged on the base. According to the utility model, the motion precision of the rotation of the six-dimensional bed is verified through a method of analyzing the deviation of a positioning reference point based on a nuclear physical film, and the motion precision of the motion of the six-dimensional bed is obtained through analyzing test data.

Description

Technical Field

[0001] The utility model relates to the field of testing, in particular to a six-dimensional bed accuracy testing device. Background Art

[0002] The current Gamma Knife is a large medical device that integrates stereotactic technology and radiosurgery technology, and is mainly used to treat cranial and brain diseases and body tumors. Its treatment principle is similar to the focusing process of a magnifying glass. The radiation beams are cross-superimposed so that the lesion area receives a high dose, while the normal tissue around the lesion receives a lower dose, thereby reducing the damage of radiotherapy to normal tissue. In order to improve the treatment accuracy of radiotherapy equipment, most Gamma Knives are equipped with a dedicated treatment bed.

[0003] In order to avoid damage to the patient's important tissues and organs, the treatment bed should have six-dimensional movement. On the basis of translational movement along the three linear axes of X, Y, and Z, it should also have three rotations around the linear axes of Xt, Yt, and Zt. In this way, the rays can focus on the lesion while bypassing the important tissues and organs at the lesion site, thereby effectively reducing and avoiding damage to the patient and improving the treatment effect. However, the current measurement of the rotation accuracy of the six-dimensional bed is mostly tested using binocular cameras and 3D structured light cameras. Such methods have complex calibration and complex data processing algorithms, and the test method cannot guarantee that it can correctly reflect the rotation accuracy of the six-dimensional bed.

[0004] Therefore, it is necessary to provide a new testing device to measure and compensate for the accuracy of the six-dimensional bed, so as to improve the accuracy of the six-dimensional bed and thus enhance the treatment effect. Utility Model Content

[0005] In order to solve the above-mentioned technical problems existing in the background technology, the utility model provides a six-dimensional bed accuracy testing device. By using a set of special testing devices, the motion accuracy of the six-dimensional bed rotation is verified by a method based on nuclear physics film analysis and positioning reference point deviation. By analyzing the test data, the motion accuracy of the six-dimensional bed movement is obtained.

[0006] The technical solution of the utility model is: the utility model is a six-dimensional bed precision testing device, which is special in that: the six-dimensional bed precision testing device includes a testing base plate and a film mounting assembly, the film mounting assembly is arranged on the testing base plate, the film mounting assembly includes a U-shaped bracket, a fixing box assembly, a connecting shaft, a locking pin and a base, a plurality of groups of mounting holes are arranged on the U-shaped bracket, the fixing box assembly is connected to the U-shaped bracket through the connecting shaft and the mounting holes, and the U-shaped bracket is arranged on the base.

[0007] Furthermore, the fixed box assembly includes a fixed box, a film box and a rotating shaft. The film box is arranged in the fixed box. The rotating shafts are respectively arranged at both ends of the fixed box. The fixed box is connected to the connecting shaft through the rotating shaft.

[0008] Furthermore, four groups of mounting holes are arranged on the U-shaped bracket at the use height of the six-dimensional bed in the Z direction, and each group of mounting holes is symmetrical in pairs.

[0009] Furthermore, a pin hole is provided at the bottom of each mounting hole in the vertical direction and the horizontal direction, so as to rotate the fixing box assembly to two working positions of 0° and 90° on each group of mounting holes and fix them.

[0010] Furthermore, a groove is provided on one side of each group of mounting holes, and the groove facilitates the rotating shaft to access the mounting hole.

[0011] Furthermore, a plurality of groups of fixing holes for film mounting components are arranged on the test base plate according to the use area of ​​the six-dimensional bed in the XOY plane.

[0012] Furthermore, the shape of the fixed box is a cuboid, a sphere or a cube.

[0013] Furthermore, a pressing piece is provided on the test base plate, and the pressing piece is used to press the test base plate onto the six-dimensional bed.

[0014] The utility model provides a six-dimensional bed accuracy testing device, which establishes a mathematical model of rotational joint motion compensation according to the principle of mechanical forward kinematics, and uses a set of special testing devices to verify the accuracy of the mathematical model and the rotational motion accuracy through a method of positioning reference point deviation based on nuclear physics film analysis, and obtains a compensation model for the six-dimensional bed motion by analyzing the test data, thereby improving the six-dimensional bed motion accuracy and improving the accuracy of clinical treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model;

[0016] Figure 2 It is a schematic diagram of the structure of the film installation assembly of the utility model;

[0017] Figure 3 It is a structural schematic diagram of a fixed box assembly of the utility model;

[0018] Figure 4 It is a schematic diagram of the test base plate structure of the utility model.

[0019] Figure 5 It is a schematic diagram of the installation holes of the film installation assembly of the utility model.

[0020] The following are the descriptions of the reference numerals:

[0021] 1. Test base plate; 2. Film installation assembly; 3. Pressing parts;

[0022] 1.1,Fixing hole;

[0023] 2.1. U-shaped bracket; 2.2. Fixed box assembly; 2.3. Connecting shaft; 2.4. Locking pin; 2.5. Base; 2.6. Mounting hole; 2.7. Groove; 2.8. Pin hole.

[0024] 2.2.1, fixed box; 2.2.2, film box; 2.2.3, rotating axis. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

[0026] See also Figures 1 to 5 The structure of a specific embodiment of the utility model includes a test base plate 1, a film mounting assembly 2, and a clamping piece 3. The film mounting assembly 2 is fixed on the test base plate 1. A clamping piece 3 is provided on the test base plate 1, and the clamping piece 3 is used to press the test base plate 1 onto the six-dimensional bed. A plurality of groups of fixing holes 1.1 of the film mounting assembly 2 are arranged on the test base plate 1, so that the test of the film mounting assembly 2 at different positions can be realized. The fixing hole 1.1 is a fixing hole of one group of the film mounting assembly 2 on the test base plate 1. A plurality of groups of fixing holes 1.1 of the film mounting assembly 2 are arranged on the test base plate 1 according to the use area of ​​the six-dimensional bed in the XOY plane. By fixing the film mounting assembly 2 at different positions of the test base plate 1, multi-point measurement in the XOY plane is completed;

[0027] The film mounting assembly 2 is composed of a U-shaped bracket 2.1, a fixing box assembly 2.2, a connecting shaft 2.3, a locking pin 2.4, a base 2.5, a mounting hole 2.6, a groove 2.7, and a pin hole 2.8. The fixing box assembly 2.2 is mounted on the U-shaped bracket 2.1. The fixing box assembly 2.2 is connected to the U-shaped bracket 2.1 through the connecting shaft 2.3 and the mounting hole 2.6. Four groups of mounting holes 2.6 are arranged on the U-shaped bracket 2.1 according to the use height of the six-dimensional bed in the Z direction. Each group of mounting holes 2.6 is symmetrical in pairs. A groove 2.7 is provided on one side of each group of mounting holes 2.6. The groove 2.7 facilitates the rotation axis 2.2.3 to access the mounting hole. The U-shaped bracket 2.1 is set on the base 2.5. A pin hole 2.8 is provided in the vertical direction and the horizontal direction at the bottom of each mounting hole 2.6, which is used to rotate the fixing box assembly 2.2 to two working positions of 0° and 90° on each group of mounting holes 2.6 and fix it. The fixed box assembly 2.2 can rotate around the axis of the mounting hole 2.6 by ±10° at the same group of mounting holes 2.6, and ±10° is the angle by which the fixed box assembly 2.2 can rotate, so as to complete multi-point measurement in the Z direction under the same X and Y coordinates;

[0028] The fixed box assembly 2.2 includes a fixed box 2.2.1, a film box 2.2.2 and a rotating shaft 2.2.3. The film box 2.2.2 is arranged in the fixed box 2.2.1, and the rotating shafts 2.2.3 are arranged at both ends of the fixed box 2.2.1. The fixed box 2.2.1 is connected to the connecting shaft 2.3 through the rotating shaft 2.2.3 passing through the mounting hole 2.6.

[0029] Figure 4 In this embodiment, the test base plate 1 is provided with 47 fixing holes 1.1 for fixing the film mounting assembly 2 at different positions of the test base plate 1.

[0030] The utility model is based on the mathematical model of rotation joint motion compensation: according to the principle of mechanical forward kinematics, the target control point position is obtained by rotating the joint angle.

[0031] The mathematical model of rotational joint motion compensation first establishes a coordinate system. According to the left-hand rule, the fulcrum 1 is used as the origin as coordinate system 1, and the fulcrum 2 is used as the origin as coordinate system 2. Specifically, the following steps are included:

[0032] 1) Establish the basic coordinate system of the model;

[0033] 1.1) According to the left-hand coordinate system rule, take the fulcrum 1 as the origin as coordinate system 1, defined as Axis1, and take the fulcrum 2 as the origin as coordinate system 2, defined as Axis2;

[0034] 1.2) According to the right-hand screw rule, the counterclockwise rotation around the X-axis of Axis1 is the positive direction. Similarly, the counterclockwise rotation around the Y-axis is the positive direction, and the counterclockwise rotation around the Z-axis of Axis2 is the positive direction.

[0035] 2) Based on the forward kinematics algorithm, the test point rotates around the rotation axis by an angle θ and a rotation direction to calculate the position of the target control point;

[0036] 2.1) The center of the ball model is used as the test point in the Axis2 coordinate system and rotates θ in the positive and negative directions around the Z axis respectively. 1 and θ 2 Angle, according to the homogeneous coordinate system conversion order to get Axis2(z) θ , θ={θ 1 ,θ 2}; The transformation matrices in different directions are:

[0037]

[0038] The above matrices are multiplied by the relative initial position to obtain the rotational motion position Pz(θ 1 ) and Pz(θ 2 ):

[0039]

[0040] 2.2) Similarly, in the relative Axis1 coordinate, rotate θ in the positive and negative directions around the X axis respectively. 1 and θ 2 Angle, you can get Axis1(x) θ Coordinate system, θ = {θ 1 ,θ 2}, the transformation matrix in different directions can be expressed as:

[0041]

[0042] Multiply the above matrices by the initial position of Axis1 to obtain the rotational motion positions Px(θ1) and Px(θ2):

[0043]

[0044] 2.3) Further, under the relative Axis1 coordinate, rotate θ1 and θ2 around the positive and negative directions of the Y axis to obtain Axis1(y) θ Coordinate system, where θ = {θ 1 ,θ 2}, the transformation matrix in different directions is:

[0045]

[0046] Multiply the above matrices by the initial position of Axis1 to obtain the rotation position Py(θ 1 ) and Py(θ 2 )for:

[0047]

[0048] 3) When rotating around a certain axis, the offset is calculated based on the target position and relative initial position of the ball center of the ball mold to determine the compensation amount in the direction of the axis;

[0049] 3.1) According to the movement position after rotation around the Zt axis and the initial relative position, the offset in the X, Y, and Z directions is solved and expressed as:

[0050]

[0051] Similarly, the offset in the X, Y, and Z directions after rotation around the Yt axis is expressed as:

[0052]

[0053] After rotating around the Xt axis, the offset in the X, Y, and Z directions is expressed as:

[0054]

[0055] The test process of this utility model is as follows:

[0056] 1) During the test, the film mounting assembly 2 is fixed to the test base plate 1 through the fixing holes 1.1 on the test base plate 1, and the test base plate 1 is mounted on the positioning bed plate of the six-dimensional bed through the clamping member 3;

[0057] 2) Film box 2.2.2 for loading films;

[0058] 3) Drill a needle hole in the center of the film box;

[0059] 4) Install the film box 2.2.2 into the fixed box 2.2.1;

[0060] 5) Turn the U-shaped bracket 2.1 to the working angle (0° or 90°);

[0061] 6) Rotate the fixed box assembly 2.2 by an angle;

[0062] 7) Send the film mounting assembly 2 to the gamma knife center via the six-dimensional bed;

[0063] 8) Move the six-dimensional bed rotation axis to adjust the fixed box 2.2 to be parallel to the drum axis surface;

[0064] 9) According to the theoretical compensation amounts Δx, Δy, Δz calculated by the mathematical model of the rotational joint motion compensation in step 1), the six-dimensional bed is moved according to the theoretical compensation amounts Δx, Δy, Δz;

[0065] 10) The gamma knife beam hits the film;

[0066] 11) Take out the film for analysis, use a scanning device to scan the film to generate a two-dimensional image, input it into ImageJ software to obtain the outer contour of the film, and calculate the pixel coordinates of the center of the circle as the center point;

[0067] 12) Compare the center point coordinate value with the initial state to calculate the center deviation value.

[0068] Combining the above two installation positions, multi-point measurements can be completed in the space within the six-dimensional bed use area, thereby truly reflecting the correctness of the motion model and the motion accuracy of the six-dimensional bed. The shape of the fixing box 2.2.1 is not limited to a rectangular parallelepiped, but can also be a sphere, a cube, etc.

[0069] The technical contents not specifically described in the present utility model and the above embodiments are the same as the prior art.

[0070] The above are only specific implementation methods disclosed in the present utility model, but the protection scope of the present utility model is not limited thereto. The protection scope of the present utility model shall be based on the protection scope of the claims.

Claims

1. A six-dimensional bed accuracy testing device, characterized in that: The six-dimensional bed precision testing device includes a test base plate and a film mounting assembly, the film mounting assembly is arranged on the test base plate, the film mounting assembly includes a U-shaped bracket, a fixing box assembly, a connecting shaft, a locking pin and a base, a plurality of groups of mounting holes are arranged on the U-shaped bracket, the fixing box assembly is connected to the U-shaped bracket through the connecting shaft and the mounting holes, and the U-shaped bracket is arranged on the base.

2. The six-dimensional bed accuracy testing device according to claim 1 is characterized in that: The fixed box assembly comprises a fixed box, a film box and a rotating shaft. The film box is arranged in the fixed box. The two ends of the fixed box are respectively provided with rotating shafts. The fixed box is connected to the connecting shaft through the rotating shaft.

3. The six-dimensional bed accuracy testing device according to claim 2 is characterized in that: The U-shaped bracket is provided with four groups of mounting holes at the use height in the Z direction of the six-dimensional bed, and each group of mounting holes is symmetrical in pairs.

4. The six-dimensional bed accuracy testing device according to claim 3 is characterized in that: A pin hole is provided in the bottom vertically and horizontally of each mounting hole.

5. The six-dimensional bed accuracy testing device according to claim 4 is characterized in that: A groove is arranged on one side of each group of mounting holes.

6. The six-dimensional bed accuracy testing device according to claim 5 is characterized in that: A plurality of groups of fixing holes for film mounting components are arranged on the test base plate according to the use area of ​​the six-dimensional bed in the XOY plane.

7. The six-dimensional bed accuracy testing device according to any one of claims 1 to 6, characterized in that: The shape of the fixing box is a cuboid, a sphere or a cube.

8. The six-dimensional bed accuracy testing device according to claim 7, characterized in that: A pressing piece is arranged on the test bottom plate.

Images