Automatic positioning mechanism of reference ionization chamber and ray dose scanning analysis device thereof

Abstract

The utility model relates to the technical field of radiotherapy, in particular to an automatic positioning mechanism for a reference ionization chamber, and particularly relates to a ray dose scanning and analyzing device, a ball nut is placed at the bottom of a base, an adjusting screw rod is rotated to enable an arc-shaped clamping block to move downwards to clamp the ball nut, and then the ball nut is placed on the base. When a light field of an accelerator head irradiates a photosensitive element at one end of a hollow ball screw, a signal is transmitted to a motor, the motor works to drive a gear to rotate at the moment, then the gear cooperates with a gear ring to work to drive a ball nut to rotate, and meanwhile, the hollow ball screw in the ball nut does linear motion under the action of a connecting block and a limiting rod; while moving, the hollow ball screw is matched with the electric turntable to work to move along with the light field of the head of the accelerator all the time, so that the reference ionization chamber in the hollow ball screw is located in the irradiation range of the light field of the accelerator all the time, and the beam measurement efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of radiotherapy, in particular to an automatic positioning mechanism for a reference ionization chamber, and also to a radiation dose scanning and analyzing device. Background Art

[0002] Before clinical application, medical electron linear accelerators (hereinafter referred to as accelerators) require beam characteristics modeling to establish their physical models within treatment planning systems. This process involves measuring multiple parameters for different radiation types (electrons and photons) at various energies and field sizes, including percent depth dose, off-axis dose, maximum diagonal off-axis dose within the field, field wedge shape, field output factor, and transmission factor.

[0003] Currently, accelerator beam characteristics are primarily measured using a three-dimensional water-tank radiation detector with a scanning device. Because the X-rays or electron beams emitted by accelerators are pulsed radiation, the output dose rate is unstable. To reduce measurement fluctuations, improve the signal-to-noise ratio, and increase measurement accuracy, a reference ionization chamber is required in addition to the measurement ionization chamber. This reference ionization chamber can monitor and correct for fluctuations that may occur during the measurement process, ensuring the accuracy and consistency of the results. By continuously monitoring the reference ionization chamber readings, the measurement ionization chamber data can be corrected in real time to compensate for short-term fluctuations or other transient changes in the accelerator output. Using a reference ionization chamber can reduce systematic errors in measurements, improve overall measurement accuracy, and eliminate some common error sources. The reference ionization chamber should be located at the edge of the beam field or behind the measurement ionization chamber and should be fixed. Its placement should be carefully selected: placing it too close to the scan center may affect beam acquisition results, while placing it too far away may not effectively improve the signal-to-noise ratio.

[0004] Currently, the common method for securing the reference ionization chamber is to thread it through a hollow straight rod and secure one end to prevent it from falling. However, due to the numerous photon and electron energy levels in accelerators, the dosimetric parameters of various radiation fields of varying sizes must be measured for each energy level when modeling the treatment planning system. This means that when measuring radiation fields of varying sizes, medical physicists must frequently enter the equipment room to manually adjust the reference ionization chamber position, significantly increasing the complexity and inconvenience of the measurement process. Utility Model Content

[0005] To address the above problems, an automatic positioning mechanism for a reference ionization chamber and a radiation dose scanning and analysis device thereof are provided. When the light field of the accelerator head irradiates the photosensor at one end of the hollow ball screw, a signal is transmitted to the motor. At this time, the electric operation drives the gear to rotate, and the gear cooperates with the gear ring to drive the ball nut to rotate. At the same time, the hollow ball screw inside the ball nut will perform linear motion under the action of the connecting block and the limit rod. While moving, the hollow ball screw cooperates with the electric turntable to always follow the light field of the accelerator head, so that the reference ionization chamber inside the hollow ball screw is always within the irradiation range of the accelerator light field.

[0006] In order to solve the problems of the prior art, the utility model provides an automatic positioning mechanism for a reference ionization chamber, comprising a three-dimensional water tank, wherein the side walls of the three-dimensional water tank are movably provided with a mounting bracket, the top of the mounting bracket is rotatably provided with an electric turntable, the top of the electric turntable is provided with a U-shaped frame and a mounting block, the interior of the U-shaped frame is rotatably provided with a ball nut, the interior of the ball nut is rotatably provided with a hollow ball screw, one end of the hollow ball screw is provided with a photosensitive element, the interior of the hollow ball screw is provided with a reference ionization chamber, the exterior of the ball nut is provided with a gear ring, the interior of the U-shaped frame is provided with a motor, and the output shaft of the motor is provided with a gear meshing with the gear ring.

[0007] Preferably, a threaded hole for installing a fastening screw is provided inside the mounting bracket, and an extrusion block for fixing the mounting bracket is provided at one end of the fastening screw.

[0008] Preferably, a connecting block is provided on the outside of the hollow ball screw, a limiting rod is further provided on the outer wall of the connecting block, and a through hole for the limiting rod to move is provided inside the mounting block.

[0009] Preferably, a base for placing a ball nut is provided inside the U-shaped frame, and an arc-shaped clamping block is also movably provided inside the U-shaped frame. An adjusting screw is rotatably provided on the top of the arc-shaped clamping block, and one end of the adjusting screw extends to the outside of the U-shaped frame. A through hole for the guide rod to move is opened on the top of the U-shaped frame, and the bottom of the guide rod is connected to the top of the arc-shaped clamping block.

[0010] Preferably, a plurality of rollers are provided on the top of the base and the bottom of the arc-shaped clamping block, and an annular groove for the rollers to move is provided on the outside of the ball nut.

[0011] Preferably, a radiation dose scanning and analysis device includes the aforementioned automatic positioning mechanism for a reference ionization chamber.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The mounting bracket can be installed on the side wall of the three-dimensional water tank by tightening the screw in conjunction with the extrusion block, and then the ball nut is placed at the bottom of the base, and the adjusting screw is turned to move the arc clamp downward to clamp the ball nut. When the light field of the accelerator head is irradiated to the photosensor at one end of the hollow ball screw, a signal is transmitted to the motor. At this time, the electric work drives the gear to rotate, and the gear cooperates with the gear ring to drive the ball nut to rotate. At the same time, the hollow ball screw inside the ball nut will make a linear motion under the action of the connecting block and the limit rod, and the hollow ball screw will always follow the light field of the accelerator head in conjunction with the electric turntable while moving, so that the reference ionization chamber inside the hollow ball screw is always within the irradiation range of the accelerator light field, avoiding the tedious steps of medical physicists entering the accelerator room to manually adjust the position of the reference ionization chamber when measuring different field sizes, thereby greatly improving the efficiency of beam measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a schematic diagram of the overall structure of an automatic positioning mechanism of a reference ionization chamber and a radiation dose scanning and analysis device thereof.

[0015] Figure 2 The present invention is a structural schematic diagram of an automatic positioning mechanism of a reference ionization chamber and an electric turntable in a radiation dose scanning and analysis device.

[0016] Figure 3 It is an automatic positioning mechanism for a reference ionization chamber and a radiation dose scanning and analysis device. Figure 2 Schematic diagram of the enlarged structure at point A in the middle.

[0017] Figure 4 The present invention is a structural diagram of a limit rod and a connecting block in an automatic positioning mechanism of a reference ionization chamber and a radiation dose scanning and analyzing device thereof.

[0018] Figure 5 The present invention is a structural diagram of a ball nut in an automatic positioning mechanism of a reference ionization chamber and a radiation dose scanning and analyzing device thereof.

[0019] Figure 6 The present invention is a schematic diagram of the structure of a base and roller in an automatic positioning mechanism of a reference ionization chamber and a radiation dose scanning and analysis device thereof.

[0020] The numbers in the figure are: 1. Three-dimensional water tank; 2. Mounting bracket; 3. Hollow ball screw; 4. Reference ionization chamber; 5. Limit rod; 6. Fastening screw; 7. Extrusion block; 8. Mounting block; 9. Connecting block; 10. U-shaped frame; 11. Motor; 12. Gear; 13. Gear ring; 14. Ball nut; 15. Guide rod; 16. Adjusting screw; 17. Photosensitive element; 18. Electric turntable; 19. Base; 20. Arc clamping block; 21. Roller. DETAILED DESCRIPTION

[0021] In order to further understand the features, technical means, specific objectives and functions achieved by the present invention, the present invention is described in further detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] like Figures 1 to 6 As shown, the utility model provides:

[0023] A reference ionization chamber automatic positioning mechanism includes a three-dimensional water tank 1, a mounting bracket 2 is movably provided on the side wall of the three-dimensional water tank 1, an electric turntable 18 is rotatably provided on the top of the mounting bracket 2, a U-shaped frame 10 and a mounting block 8 are provided on the top of the electric turntable 18, a ball nut 14 is rotatably provided inside the U-shaped frame 10, a hollow ball screw 3 is rotatably provided inside the ball nut 14, a photosensitive element 17 is provided at one end of the hollow ball screw 3, a reference ionization chamber 4 is provided inside the hollow ball screw 3, a gear ring 13 is provided outside the ball nut 14, a motor 11 is provided inside the U-shaped frame 10, and a gear 12 meshingly connected to the gear ring 13 is provided on the output shaft of the motor 11.

[0024] When the light beam from the accelerator head strikes the photosensitive element 17 at one end of the hollow ball screw 3, the photosensitive element 17 immediately captures the signal and transmits it to the motor 11. At this point, the motor 11 starts operating, driving the gear 12 to rotate. The gear 12 and the gear ring 13 work in close coordination, thereby driving the ball nut 14 to rotate. Under the combined action of the connecting block 9 and the limiting rod 5, the hollow ball screw 3 inside the ball nut 14 moves in a straight line. Simultaneously, during its movement, the hollow ball screw 3 closely cooperates with the electric turntable 18, continuously following the movement of the light beam from the accelerator head. This ensures that the reference ionization chamber 4 inside the hollow ball screw 3 remains within the irradiation range of the accelerator's light beam. This process eliminates the tedious step of medical physicists entering the accelerator room to manually adjust the position of the reference ionization chamber 4 when measuring different beam sizes. This greatly improves the efficiency of beam measurement, making the entire measurement process more efficient and convenient.

[0025] like Figure 2 As shown, a threaded hole for installing a fastening screw 6 is provided inside the mounting bracket 2 , and an extrusion block 7 for fixing the mounting bracket 2 is provided at one end of the fastening screw 6 .

[0026] By using the tight fit of the fastening screws and the extrusion block 7, the mounting bracket 2 can be effectively fixed to the side wall of the three-dimensional water tank 1. This installation method is not only simple, but also convenient for subsequent disassembly work, greatly improving the efficiency of installation and maintenance.

[0027] like Figure 2 and Figure 6As shown, a connecting block 9 is provided on the outside of the hollow ball screw 3 , a limiting rod 5 is further provided on the outer wall of the connecting block 9 , and a through hole for the limiting rod 5 to move is opened inside the mounting block 8 .

[0028] The movement of the limiting rod 5 within the through hole effectively prevents the hollow ball screw 3 from positional deviation during movement. The limiting rod 5 precisely moves within the through hole, ensuring that the hollow ball screw 3 does not deviate from its predetermined trajectory under any circumstances, thereby avoiding mechanical failure or loss of precision that may be caused by positional deviation.

[0029] like Figure 6 As shown, a base 19 for placing the ball nut 14 is provided inside the U-shaped frame 10, and an arc-shaped clamping block 20 is also movably provided inside the U-shaped frame 10. An adjusting screw 16 is rotatably provided on the top of the arc-shaped clamping block 20, and one end of the adjusting screw 16 extends to the outside of the U-shaped frame 10. A through hole for the guide rod 15 to move is opened at the top of the U-shaped frame 10, and the bottom of the guide rod 15 is connected to the top of the arc-shaped clamping block 20.

[0030] By placing the ball nut 14 at the bottom of the base 19 and then rotating the adjusting screw 16 to move the arc-shaped clamping block 20 downward, the ball nut 14 is precisely clamped. This clamping method ensures that the ball nut 14 remains stable during operation and avoids unnecessary shaking. In addition, a roller 21 is designed at the top of the base 19, and a roller 21 is also equipped at the bottom of the arc-shaped clamping block 20. These two rollers 21 cooperate with each other to provide additional support and guidance for the ball nut 14 when it rotates, making the rotation of the ball nut 14 smoother and greatly reducing the wear and tear that may occur on the ball nut 14 during long-term use. This design not only improves the service life of the ball nut 14, but also ensures the stability and reliability of the entire mechanical system.

[0031] like Figure 5 As shown, a plurality of rollers 21 are provided on the top of the base 19 and the bottom of the arc-shaped clamping block 20 , and an annular groove for the rollers 21 to move is provided on the outside of the ball nut 14 .

[0032] The annular groove effectively allows the roller 21 to rotate freely within it, preventing the ball nut 14 from shifting during rotation. This prevents the ball nut 14 from falling out during operation due to incorrect positioning, thereby ensuring the stability and reliability of the entire radiation dose scanning and analysis device. The annular groove design not only increases the lifespan of the device but also reduces potential failures and repair costs caused by part loss.

[0033] Specifically, a radiation dose scanning and analysis device includes the aforementioned reference ionization chamber automatic positioning mechanism.

[0034] The above embodiments merely illustrate one or several implementations of the reference ionization chamber automatic positioning mechanism and its radiation dose scanning and analysis device of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art will be able to devise various variations and improvements without departing from the spirit of the present invention, and these variations and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A reference ionization chamber automatic positioning mechanism, characterized in that: The invention comprises a three-dimensional water tank (1), wherein a mounting bracket (2) is movably provided on the side wall of the three-dimensional water tank (1), an electric turntable (18) is rotatably provided on the top of the mounting bracket (2), a U-shaped frame (10) and a mounting block (8) are provided on the top of the electric turntable (18), a ball nut (14) is rotatably provided inside the U-shaped frame (10), a hollow ball screw (3) is rotatably provided inside the ball nut (14), a photosensitive element (17) is provided at one end of the hollow ball screw (3), a reference ionization chamber (4) is provided inside the hollow ball screw (3), a gear ring (13) is provided outside the ball nut (14), a motor (11) is provided inside the U-shaped frame (10), and an output shaft of the motor (11) is provided with a gear (12) meshed with the gear ring (13).

2. The automatic positioning mechanism for a reference ionization chamber according to claim 1, characterized in that: A threaded hole for installing a fastening screw (6) is provided inside the mounting bracket (2), and an extrusion block (7) for fixing the mounting bracket (2) is provided at one end of the fastening screw (6).

3. The automatic positioning mechanism for a reference ionization chamber according to claim 2, characterized in that: A connecting block (9) is provided on the outside of the hollow ball screw (3), a limiting rod (5) is further provided on the outer wall of the connecting block (9), and a through hole for the limiting rod (5) to move is provided inside the mounting block (8).

4. The automatic positioning mechanism for a reference ionization chamber according to claim 1, characterized in that: A base (19) for placing a ball nut (14) is provided inside the U-shaped frame (10), and an arc-shaped clamping block (20) is also movably provided inside the U-shaped frame (10). An adjusting screw (16) is rotatably provided on the top of the arc-shaped clamping block (20), and one end of the adjusting screw (16) extends to the outside of the U-shaped frame (10). A through hole for the guide rod (15) to move is opened on the top of the U-shaped frame (10), and the bottom of the guide rod (15) is connected to the top of the arc-shaped clamping block (20).

5. The automatic positioning mechanism for a reference ionization chamber according to claim 4, characterized in that: A plurality of rollers (21) are provided on the top of the base (19) and the bottom of the arc-shaped clamping block (20), and an annular groove for the rollers (21) to move is provided on the outside of the ball nut (14).

6. A radiation dose scanning and analysis device, characterized in that: It comprises an automatic positioning mechanism for a reference ionization chamber as described in any one of claims 1-5.

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