A device and method for evaluating the accuracy of a collimator
By using test brackets, LED lamps and model boards on a multi-pinhole collimator to form light spots and measure the center deviation of the spot, the problem of time and resource waste in the mechanical performance evaluation of the collimator is solved, and accurate accuracy assessment is achieved to ensure accuracy The straightener performance meets the design requirements.
Patent Information
- Application Number
- CN202011154382.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-10-26
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2040-10-26
AI Technical Summary
After assembly of the multi-pinhole collimator, due to processing deviations or assembly errors, the mechanical properties may not meet the design requirements, resulting in a waste of time and resources for later performance evaluation.
Design a device to evaluate the accuracy of the collimator, including a test bracket, an LED lamp bracket, a model board and a porous collimator, and form a spot on the model board through an LED light source, measure the deviation between the spot center and the theoretical spot center, and evaluate the accuracy. Machine machining and assembly accuracy of straighteners.
In the early stages when the multi-pinhole collimator is put into use, it can effectively evaluate its machining and assembly accuracy, avoiding wasting time and resources, and ensuring that the collimator performance meets the requirements.
Smart Images
Figure CN112294348B_ABST
Abstract
Description
[0001] Technical field.
[0002] The invention relates to a collimator for a nuclear medicine image detector, in particular to a device for evaluating the accuracy of a multi-pinhole collimator.
[0003] Background technology.
[0004] The multi-pinhole collimator is composed of multiple pinhole heads with different inclination angles, which form an assembly with other structural components. After the multi-pinhole collimator is assembled, there is a certain assembly error. The actual angle of each pinhole head is the key point of the collimator. It is difficult to evaluate whether the inclination angle meets the use requirements of the collimator through conventional dimensional measurement methods. Usually, the assembled collimator is directly loaded into the detector equipment, and the image of the multi-pinhole collimator is acquired using a radiation source, an acquisition system and a processing system. The image acquisition results are used to evaluate whether the performance of the collimator meets the requirements. However, after the multi-pinhole collimator is assembled, the mechanical properties of the multi-pinhole collimator may not meet the early design requirements due to accumulated processing deviations or assembly errors. The performance of the collimator is evaluated through image acquisition at a later stage, resulting in a waste of time and resources.
[0005] Contents of the invention.
[0006] The present invention is to solve the above-mentioned shortcomings and is a device and method for evaluating the accuracy of a collimator. In the early stage of the multi-pinhole collimator being put into use, the method is used to evaluate the machining and assembly accuracy of the collimator.
[0007] In order to achieve the above object, the present invention adopts the following technical solutions.
[0008] The invention discloses a device for evaluating the accuracy of a collimator, comprising a test bracket, an LED lamp bracket, an LED lamp, a model plate, and a multi-hole collimator; the test bracket is fixed to the multi-hole collimator, and an LED bracket mounting hole is provided on the test bracket; the LED lamp bracket is fixedly mounted in the LED bracket mounting hole of the test bracket; the LED lamp is fixed on the LED lamp bracket and is placed at the focal center of a multi-pinhole head of the multi-pinhole collimator; the model plate is fixed on the rear surface of the multi-pinhole collimator, an adjustment gasket is placed between the rear surface of the multi-pinhole collimator and the model plate, and the position of the model plate is the theoretical position of the detector crystal surface.
[0009] Preferably, the collimator is a multi-pinhole collimator.
[0010] The test bracket and the multi-hole collimator are fixedly connected by screws.
[0011] The LED lamp is fixed on the LED lamp bracket by bonding with double-sided adhesive tape on the back.
[0012] A 1mm*1mm grid pattern is arranged on the model plate to determine the position of the projected light spot.
[0013] The model plate is made of translucent plastic material, and the projected light spot can be viewed on both sides of the model plate.
[0014] The model plate is fixed on the rear surface of the collimator by means of gluing or screws.
[0015] The position of the model plate is the theoretical position of the detector crystal surface. The distance between the detector crystal surface and the rear surface of the collimator is determined by the theoretical design value. Adjustment gaskets of equal thickness are placed at the four corners between the rear surface of the collimator and the model plate. This does not affect the LED light projection and can ensure that the position of the model plate is the same as that of the crystal surface.
[0016] A method for evaluating the accuracy of a collimator according to the present invention comprises the following steps:
[0017] 1) Assemble a device to evaluate the accuracy of the collimator;
[0018] 2) The LED light source passes through the pinhole head of the multi-pinhole collimator and forms a light spot on the model plate placed behind the collimator;
[0019] 3) Obtain the projection spot center and theoretical spot center;
[0020] 4) Compare the center of the projected light spot with the center of the theoretical projected light spot on the model plate, and measure the distance between the two light spot centers through the grid on the model plate to obtain the deviation between the actual projected light spot and the theoretical light spot;
[0021] 5) The machining and assembly accuracy of the collimator is evaluated by distance. The distance has a theoretical value. If the measured distance is less than the theoretical value, the accuracy meets the requirement; otherwise, it does not meet the requirement.
[0022] The beneficial effects of the present invention are as follows: the present invention can evaluate the machining and assembly accuracy of the multi-pinhole collimator before the collimator is put into use, thereby avoiding waste of time and resources.
[0023] Description of the drawings.
[0024] Figure 1 : Structural diagram of the device of the present invention.
[0025] Figure 2 : Schematic diagram of model plate of the present invention.
[0026] Figure 3 : Schematic diagram of light spot collection of the present invention.
[0027] Figure 4 : Schematic diagram of deviation measurement of the present invention.
[0028] In the figure: a test bracket (1), an LED lamp bracket (2), an LED lamp (3), a model plate (4), and a multi-hole collimator (5).
[0029] Specific implementation method.
[0030] Specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0031] like Figure 1 As shown, a device and method for evaluating the accuracy of a collimator of the present invention comprises a test bracket (1), an LED lamp bracket (2), an LED lamp (3), and a model plate (4); the test bracket (1) is fixed to a multi-hole collimator (5), and an LED bracket mounting hole is provided on the test bracket (1); the LED lamp bracket (2) is fixedly mounted in the LED bracket mounting hole of the test bracket; the LED lamp (3) is fixed to the LED lamp bracket (2) and is placed at the focal center of the multi-pinhole head of the multi-pinhole collimator; the model plate (4) is fixed to the rear surface of the multi-pinhole collimator, and an adjustment gasket is placed between the rear surface of the multi-pinhole collimator and the model plate (4), and the position of the model plate (4) is the theoretical position of the detector crystal surface; the test bracket (1) and the multi-hole collimator (5) are fixedly connected by screws. The LED lamp is fixed to the LED lamp bracket by means of bonding with double-sided adhesive tape on the back; the model plate is fixed to the rear surface of the collimator by means of bonding or screws; the position of the model plate (4) is the theoretical position of the detector crystal surface, and the distance between the detector crystal surface and the rear surface of the collimator is determined by the theoretical design value. Adjustment gaskets of equal thickness are placed at the four corners between the rear surface of the collimator and the model plate, which does not affect the projection of the LED light and can ensure that the position of the model plate is the same as the position of the crystal surface.
[0032] like Figure 2 As shown in the figure, a 1mm*1mm grid is arranged on the model board to determine the position of the projected light spot. The model board is made of translucent plastic material, and the projected light spot can be viewed on both sides of the model board.
[0033] like Figure 3 As shown, the LED lamp (3) emits light that passes through the collimator to form a light spot on the model plate (4).
[0034] like Figure 4 As shown, the outer ring is the theoretical projection spot, and the inner ring is the actual projection spot of the LED lamp (3). The center positions of the two rings are obtained respectively, and the distance between the centers of the two spots is measured to obtain the deviation between the actual projection spot and the theoretical spot. Through the measured deviation value, it is evaluated whether the processing and assembly accuracy of the multi-pinhole collimator meets the use requirements. If the measured distance is less than the theoretical value, the accuracy meets the requirements; otherwise, it does not meet the requirements.
[0035] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.
Claims
1. A device for evaluating the accuracy of a collimator, comprising a test bracket, an LED lamp bracket, an LED lamp, and a model plate; characterized in that: The test bracket is fixed to the multi-pinhole collimator, and an LED bracket mounting hole is provided on the test bracket; the LED lamp bracket is fixedly installed in the LED bracket mounting hole; the LED lamp is fixed on the LED lamp bracket and placed at the focal center of the multi-pinhole head of the multi-pinhole collimator; the model plate is fixed on the rear surface of the multi-pinhole collimator, the position of the model plate is the theoretical position of the detector crystal surface, the distance between the detector crystal surface and the rear surface of the multi-pinhole collimator is determined by the theoretical design value, and adjustment gaskets of equal thickness are placed at the four corners between the rear surface of the multi-pinhole collimator and the model plate, which does not affect the LED light projection and can ensure that the position of the model plate is the same as the position of the crystal surface; a grid diagram is arranged on the model plate, and the distance between the actual projection spot center and the theoretical spot center can be measured through the grid on the model plate, and the machining and assembly accuracy of the multi-pinhole collimator can be evaluated through this distance.
2. The device for evaluating the accuracy of a collimator according to claim 1, characterized in that: The test bracket and the multi-pinhole collimator are fixedly connected by screws.
3. The device for evaluating the accuracy of a collimator according to claim 1, characterized in that: The LED lamp is fixed on the LED lamp bracket by bonding with double-sided adhesive tape on the back.
4. The device for evaluating the accuracy of a collimator according to claim 1, characterized in that: The grid pattern arranged on the model plate is a 1mm*1mm grid pattern, which is used to determine the position of the projection spot.
5. The device for evaluating the accuracy of a collimator according to claim 1, characterized in that: The model plate is made of translucent plastic material, and the projected light spot can be viewed on both sides of the model plate.
6. The device for evaluating the accuracy of a collimator according to claim 1, characterized in that: The model plate is fixed on the rear surface of the multi-pinhole collimator by means of gluing or screws.
7. A method for evaluating the accuracy of a collimator, the method comprising the following steps: 1) Assemble a device for evaluating the accuracy of a multi-pinhole collimator; the device for evaluating the accuracy of a multi-pinhole collimator comprises a test bracket, an LED lamp bracket, an LED lamp, and a model plate; the test bracket is fixed to the multi-pinhole collimator, and an LED bracket mounting hole is provided on the test bracket; the LED lamp bracket is fixedly installed in the LED bracket mounting hole; the LED lamp is fixed on the LED lamp bracket and placed at the focal center of the multi-pinhole head of the multi-pinhole collimator; the model plate is fixed on the rear surface of the multi-pinhole collimator, the position of the model plate is the theoretical position of the detector crystal surface, the distance between the detector crystal surface and the rear surface of the multi-pinhole collimator is determined by the theoretical design value, and adjustment gaskets of equal thickness are placed at the four corners between the rear surface of the multi-pinhole collimator and the model plate, which does not affect the projection of the LED light and can ensure that the position of the model plate is the same as the position of the crystal surface; a grid pattern is arranged on the model plate; 2) The LED light source passes through the multi-pinhole collimator and the multi-pinhole head, forming a light spot on the model plate placed behind the multi-pinhole collimator; 3) Obtain the actual projection spot center and the theoretical spot center; 4) Compare the center of the actual projected light spot with the center of the theoretical light spot on the model plate, and measure the distance between the two light spot centers through the grid on the model plate to obtain the deviation between the actual projected light spot and the theoretical light spot; 5) The machining and assembly accuracy of the multi-pinhole collimator is evaluated by distance. The distance has a theoretical value. If the measured distance is less than the theoretical value, the accuracy meets the requirement; otherwise, it does not meet the requirement.