Auxiliary positioning device for multi-layer parallel plate ionization chamber

Abstract

The utility model relates to a positioning auxiliary device of a multilayer parallel plate ionization chamber, which comprises a support, a rotating platform and a rotating shaft, the support is placed on a treatment bed, the rotating platform comprises a bottom plate and two side plates, the side plates are symmetrically and fixedly connected to the edges of the two sides of the bottom plate, the multilayer parallel plate ionization chamber is supported and installed on the bottom plate, and the rotating shaft is arranged on the bottom plate. The rotating platform is rotatably installed on the support through a rotating shaft, the rotating shaft comprises a driving shaft and a driven shaft which are rotatably installed on the two opposite sides of the support respectively, and the driving shaft and the driven shaft are connected with the two side plates respectively to drive the rotating platform. According to the positioning auxiliary device of the multi-layer parallel plate ionization chamber, the multi-layer parallel plate ionization chamber can rotate around the shaft, and the angle of the rotating platform is adjusted according to the angle of the rotating rack (beam incidence), so that the measurement of beams in different incidence directions is realized, the available scenes of the multi-layer ionization chamber are increased, and the measurement efficiency is improved.

Description

Technical Field

[0001] The utility model relates to proton beam detection, and more particularly to a positioning assistance device for a multi-layer parallel plate ionization chamber. Background Art

[0002] The current conventional cancer treatment methods mainly include surgery, chemotherapy and radiotherapy, etc. These three major methods are complementary and compatible with each other. For some patients, whether they have surgery or not, radiotherapy is required. Radiotherapy has become one of the indispensable means for treating cancer. The particle types currently used in radiotherapy include X-rays, γ-rays, electrons, protons, and heavy ions. To ensure the normal beam parameters, quality assurance is an essential part of proton therapy, including the depth-dose curve of the beam, which is an important parameter of the proton beam. Under monoenergetic conditions, by measuring the depth-dose distribution curve, the equivalent water depth at 80% of the distal maximum dose is the monoenergetic range.

[0003] In quality assurance, a multi-layer parallel plate ionization (also known as a multi-layer ionization chamber) is commonly used to detect the depth-dose distribution of the proton beam. The multi-layer ionization chamber is placed in a direction perpendicular to the beam. Through an independent ventilation plane parallel ionization chamber, particles can be detected within a range of sub-millimeter accuracy when the beam passes through the multi-layer ionization chamber plane, so as to measure the Bragg peak (BP), spread-out Bragg peak (SOBP) of the proton beam and determine the range.

[0004] The multi-layer ionization chamber has a cuboid appearance. During measurement, the multi-layer ionization chamber is usually placed horizontally on the treatment bed to ensure that the beam passes vertically through the multi-layer ionization chamber plane. This limits the incident angle of the beam that can be detected, that is, it can only receive proton beams from the horizontal direction, and can only measure the beam parameters at the horizontal angle, and cannot be applied to measure beams from other angular directions. That is to say, the existing multi-layer ionization chamber is only applicable to a horizontal beam treatment room (the treatment head is fixed and cannot rotate, and can only emit beams in the horizontal direction). For a rotating treatment room (the treatment head can rotate around the isocenter with the rotating gantry and can emit beams from different angles), since the multi-layer ionization chamber lacks the function of multi-angle positioning, it is impossible to detect non-horizontal beams. Summary of the Utility Model

[0005] In order to solve the positioning problem of the multi-layer ionization chamber when the gantry rotates to a non-horizontal angle, the utility model provides a positioning assistance device for a multi-layer parallel plate ionization chamber.

[0006] The positioning assistance device for a multi-layer parallel plate ionization chamber according to the present utility model comprises a bracket, a rotating platform and a rotating shaft. Among them, the bracket is placed on a treatment bed. The rotating platform includes a bottom plate and two side plates. The side plates are symmetrically and fixedly connected to the two side edges of the bottom plate. The multi-layer parallel plate ionization chamber is supported and installed on the bottom plate. The rotating platform is rotatably installed on the bracket through the rotating shaft. The rotating shaft includes a driving shaft and a driven shaft which are respectively rotatably installed on the opposite sides of the bracket. The driving shaft and the driven shaft are respectively connected to the two side plates to drive the rotating platform.

[0007] Preferably, the bracket includes four vertical beams, four cross beams and two support beams. Among them, the two support beams extend in parallel. Each support beam is connected to two cross beams to form a U-shaped structure. The upper and lower U-shaped structures are connected by four vertical beams to form the main body of the bracket.

[0008] Preferably, the bracket further includes a plurality of horizontal adjustment mechanisms respectively located at the bottom of the lower U-shaped structure.

[0009] Preferably, each horizontal adjustment mechanism includes an adjustment handle, a base, a cushion plate, a screw rod and a nut. Among them, the cushion plate is connected to the bottom surface of the lower U-shaped structure. The screw rod sequentially passes through the base, the nut, the adjustment handle and the cushion plate from bottom to top. The nut is tightened with the screw rod to fix the base. The base is placed on the treatment bed.

[0010] Preferably, the rotating platform includes two pressing blocks and two connecting blocks. Among them, the connecting blocks are symmetrically and fixedly connected to the top surface of the bottom plate and pass through the openings on the substrate of the multi-layer parallel plate ionization chamber. The pressing blocks are buckled on the connecting blocks to clamp the substrate between the pressing blocks and the connecting blocks.

[0011] Preferably, the rotating platform further includes four locking handwheels. Among them, threaded openings are provided at the corresponding positions of the pressing blocks and the connecting blocks. The locking handwheels are screwed into the threaded openings to fix the pressing blocks to the connecting blocks, thereby installing and fixing the multi-layer parallel plate ionization chamber on the rotating platform.

[0012] Preferably, the rotating shaft further includes a driving shaft and a first cushion plate. Among them, the first cushion plate is fixedly connected to the first side of the bracket. The driving shaft is fixedly connected to the first cushion plate and connected to the driving shaft.

[0013] Preferably, the rotating shaft further includes two arched buckles and a second cushion plate. Among them, the second cushion plate is fixedly connected to the second side of the bracket. The two arched buckles for rotatably installing the driven shaft are fixedly connected to the second cushion plate.

[0014] Preferably, the rotating shaft further includes a protective cover which is installed above the second cushion plate and covers the driven shaft and the two arched buckles for protecting the driven shaft.

[0015] Preferably, the rotating shaft further includes a right-angle cushion block, and the lower part of the second backing plate is connected to the side surface of the bracket through two right-angle cushion blocks.

[0016] According to the positioning assistance device for a multi-layer parallel plate ionization chamber of the present invention, the multi-layer parallel plate ionization chamber can rotate around an axis, and the angle of the rotating platform is adjusted according to the angle of the rotating gantry (beam incident direction), so as to realize the measurement of beam currents in different incident directions, increase the available scenarios of the multi-layer ionization chamber, and improve the measurement efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. 1 is a schematic structural view of a positioning assistance device for a multi-layer parallel plate ionization chamber according to a preferred embodiment of the present invention.

[0018] Figure 2 FIG. 2 is a schematic structural view of a positioning assistance device for a multi-layer parallel plate ionization chamber according to a preferred embodiment of the present invention.

[0019] Figure 3 is Figure 1 the front view of the positioning assistance device.

[0020] Figure 4 is Figure 1 the right view of the positioning assistance device.

[0021] Figure 5 is Figure 1 the top view of the positioning assistance device.

[0022] Figure 6 is Figure 1 the schematic structural view of the bracket of the positioning assistance device.

[0023] Figure 7 shows Figure 6 the position of the horizontal adjustment mechanism of the bracket.

[0024] Figure 8 is Figure 6 the schematic structural view of the horizontal adjustment mechanism of the bracket.

[0025] Figure 9 is Figure 1 the schematic structural view of the rotating platform of the positioning assistance device.

[0026] Figure 10 is Figure 9 the partial schematic structural view of the rotating platform.

[0027] Figure 11 is Figure 1 the schematic structural view of the driven shaft of the positioning assistance device. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following will, in conjunction with the accompanying drawings, give the preferred embodiments of the present utility model and describe them in detail.

[0029] As Figures 1 - 5 shown, the positioning assistance device for a multi-layer parallel plate ionization chamber according to a preferred embodiment of the present utility model includes a bracket A, a rotating platform B, and a rotating shaft C. Among them, the bracket A is placed on the treatment bed, the multi-layer parallel plate ionization chamber is supported and installed on the rotating platform B, and the rotating platform B is rotatably installed on the bracket A through the rotating shaft C, so that the multi-layer parallel plate ionization chamber can follow the rotating platform B and rotate relative to the bracket A to any angle, thereby directly measuring the beam parameters at different angles of the rotating gantry using the multi-layer parallel plate ionization chamber and increasing the applicable scenarios of the multi-layer parallel plate ionization chamber.

[0030] As Figure 6 shown, the bracket A includes four vertical beams 17, four cross beams 18, and two support beams 19. Among them, the two support beams 19 extend in parallel, and each support beam 19 is connected to two cross beams 18 to form a U-shaped structure body. The upper and lower two U-shaped structure bodies are connected by four vertical beams 17 to form the main body of the bracket A. The length of the vertical beam 17 is less than the length of the cross beam 18 and also less than the length of the support beam 19. In this embodiment, the vertical beam 17, the cross beam 18, and the support beam 19 are in the shape of a cuboid. It should be understood that this cuboid shape is only an example rather than a limitation, and a cylindrical shape is also feasible.

[0031] As Figures 6 - 7 shown, the bracket A further includes four horizontal adjustment mechanisms A1 respectively located at the opposite ends of the bottoms of the two cross beams 18 of the lower U-shaped structure body. As Figures 7 - 8 shown, each horizontal adjustment mechanism A1 includes an adjustment handle 6, a base 15, a cushion plate 16, a screw 20, and a nut 21. Among them, the cushion plate 16 is connected to the bottom surface of the cross beam 18, and the screw 20 passes through the base 15, the nut 21, the adjustment handle 6, and the cushion plate 16 from bottom to top in sequence. The nut 21 is tightened with the screw 20 to fix the base 15, and the base 15 is placed on the treatment bed. In this embodiment, the nut 21 is a hexagonal nut, and the central hole of the adjustment handle 6 is hexagonal in shape and can just fit the nut 21. Therefore, rotating the adjustment handle 6 can drive the screw 20 to rotate together, thereby finely adjusting the vertical height by rotating the adjustment handle 6 to ensure that the bracket A is horizontally placed on the treatment bed. It should be understood that the installation quantity and position of the horizontal adjustment mechanism A1 are only examples rather than limitations. For example, it is also feasible to finely adjust the level with three horizontal adjustment mechanisms, and the third horizontal adjustment mechanism can be installed at the middle position of the support beam 19.

[0032] As Figures 9 - 10As shown in the figure, the rotating platform B includes two pressing blocks 1, a bottom plate 4, and two connecting blocks 9. Among them, the bottom plate 4 is the main part that provides support for the multi-layer parallel plate ionization chamber. The connecting blocks 9 are symmetrically and fixedly connected to the top surface of the bottom plate 4. When the multi-layer parallel plate ionization chamber is supported and installed on the rotating platform B, the connecting blocks 9 respectively pass through the left and right openings on the substrate of the multi-layer parallel plate ionization chamber, and the U-shaped pressing block 1 is buckled on the connecting blocks 9, so that the substrate of the multi-layer parallel plate ionization chamber is clamped between the pressing block 1 and the connecting blocks 9.

[0033] As Figures 9 - 10 shown in the figure, the rotating platform B further includes four locking handwheels 2 and two side plates 10. Among them, the side plates 10 are symmetrically and fixedly connected to the two side edges of the bottom plate 4. Threaded openings are provided at the corresponding positions of the pressing block 1 and the connecting blocks 9. After the locking handwheels 2 pass through the inner flanges of the side plates 10, they are respectively screwed into the threaded openings to fix the pressing block 1 to the connecting blocks 9, so as to install and fix the multi-layer parallel plate ionization chamber on the rotating platform B, so that the multi-layer parallel plate ionization chamber will not have relative displacement relative to the rotating platform B, but will rotate together with the rotating platform B. It should be understood that the locking handwheel 2 is actually equivalent to a large screw. The pressing block 1 buckled on the connecting blocks 9 only clamps the substrate of the multi-layer parallel plate ionization chamber between the pressing block 1 and the bottom plate 4 and aligns the threaded openings on the pressing block 1 and the connecting blocks 9, which does not play a fixing role. Inserting the locking handwheel 2 into the threaded opening and tightening it can play a role in fixing the multi-layer parallel plate ionization chamber. In this embodiment, the shape of the locking handwheel 2 is cylindrical. It should be understood that this cylindrical shape is only an example rather than a limitation, and a cuboid locking column or fixing by screws is also feasible. It should be understood that the method of fixing the multi-layer parallel plate ionization chamber by the pressing block 1 and the locking handwheel 2 is only an example rather than a limitation. For example, it is also feasible to fix the multi-layer parallel plate ionization chamber to the bottom plate 4 of the rotating platform B through designs such as ropes.

[0034] As Figures 1 - 2 shown in the figure, the rotating shaft C includes a driving shaft 5, a main rotating shaft 8, and a first cushion plate 12 located on the right side. Among them, the first cushion plate 12 is fixedly connected to the top surface of the cross beam 18 on the right side of the upper U-shaped structure of the bracket A. The driving shaft 5 is fixedly connected to the first cushion plate 12 and is connected to the driving shaft 8. The main rotating shaft 8 is fixedly connected to the side plate 10 on the right side of the rotating platform B, so that the rotating platform B can be rotated to a corresponding angle through the driving shaft 5. In this embodiment, the driving shaft 5 is a manually rotating shaft. It should be understood that the manually rotating shaft here is only an example rather than a limitation, and it is also feasible to achieve rotation by installing a motor.

[0035] As Figures 1 - 2 and Figure 11As shown, the rotating shaft C further includes a driven shaft 7 located on the left side, two arched fasteners 11, and a second backing plate 13. Among them, the second backing plate 13 is fixedly connected to the top surface of the cross beam 18 on the left side of the upper U-shaped structure of the bracket A. The two arched fasteners 11 for rotatably mounting the driven shaft 7 are fixedly connected to the second backing plate 13, and the driven shaft 7 is fixedly connected to the side plate 10 on the left side of the rotating platform B. In addition, the rotating shaft C further includes a protective cover 3 and a right-angle spacer 14. Among them, the protective cover 3 for protecting the driven shaft 7 covers the driven shaft 7 and the two arched fasteners 11 above the second backing plate 13. Since the width of the protective cover 3 exceeds the width of the cross beam 18, the lower part of the second backing plate 13 is connected to the side surface of the cross beam 18 through two right-angle spacers 14.

[0036] By rotating the drive shaft 5 clockwise or counterclockwise, the rotating platform B can be rotated to the corresponding angle. In this embodiment, the driven shaft 7 and the main rotating shaft 8 are two stepping motors. When the stepping motor stops rotating, the self-locking characteristic of the motor keeps the rotating platform B and the multi-layer parallel plate ionization chamber in a fixed position. After rotating in place, an inclinometer can be used to measure the current angle. The accuracy of the inclinometer is 0.01°, and the positioning error is generally controlled within 0.1°. Define the angle of the beam current incident vertically from top to bottom as 0° (or 360°), which increases as the gantry rotates clockwise. The beam current incident angle of 180° refers to the direction of the beam current incident vertically from bottom to top. The rotatable range of the rotating platform B is 180°, that is, it solves the technical problem of measuring the beam current performance in any angular direction with a multi-layer ionization chamber, and greatly increases the applicable scenarios of using a multi-layer ionization chamber to measure the beam current.

[0037] The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Various changes can be made to the above embodiments of the present invention. That is, all simple, equivalent changes and modifications made according to the claims and the content of the specification of the present invention application fall within the scope of the claims of the present invention patent. Those not described in detail in the present invention are all conventional technical contents.

Claims

1. A positioning assistance device for a multi-layer parallel plate ionization chamber, characterized in that, The positioning assistance device includes a bracket, a rotating platform and a rotating shaft. Among them, the bracket is placed on the treatment bed. The rotating platform includes a bottom plate and two side plates. The side plates are symmetrically and fixedly connected to the two side edges of the bottom plate. The multi-layer parallel plate ionization chamber is supported and installed on the bottom plate. The rotating platform is rotatably installed on the bracket through the rotating shaft. The rotating shaft includes a driving shaft and a driven shaft that are respectively rotatably installed on the opposite sides of the bracket. The driving shaft and the driven shaft are respectively connected to the two side plates to drive the rotating platform.

2. The positioning assistance device according to claim 1, wherein The bracket includes four vertical beams, four cross beams and two support beams. Among them, the two support beams extend in parallel. Each support beam is connected to two cross beams to form a U-shaped structure. The upper and lower U-shaped structures are connected by four vertical beams to form the main body of the bracket.

3. The positioning assistance device according to claim 2, wherein The bracket further includes a plurality of horizontal adjustment mechanisms respectively located at the bottom of the lower U-shaped structure.

4. The positioning assistance device according to claim 3, wherein, Each horizontal adjustment mechanism includes an adjustment handle, a base, a cushion plate, a screw rod and a nut. Among them, the cushion plate is connected to the bottom surface of the lower U-shaped structure. The screw rod sequentially passes through the base, the nut, the adjustment handle and the cushion plate from bottom to top. The nut is tightened with the screw rod to fix the base. The base is placed on the treatment bed.

5. The positioning assistance device according to claim 1, characterized in that The rotating platform includes two pressing blocks and two connecting blocks. Among them, the connecting blocks are symmetrically and fixedly connected to the top surface of the bottom plate and pass through the openings on the substrate of the multi-layer parallel plate ionization chamber. The pressing blocks are buckled on the connecting blocks to clamp the substrate between the pressing blocks and the connecting blocks.

6. The positioning assistance device according to claim 5, characterized in that, The rotating platform further includes four locking handwheels. Among them, threaded openings are provided at the corresponding positions of the pressing blocks and the connecting blocks. The locking handwheels are screwed into the threaded openings to fix the pressing blocks to the connecting blocks, thereby installing and fixing the multi-layer parallel plate ionization chamber on the rotating platform.

7. The positioning assistance device according to claim 1, wherein The rotating shaft further includes a driving shaft and a first cushion plate. Among them, the first cushion plate is fixedly connected to the first side of the bracket. The driving shaft is fixedly connected to the first cushion plate and connected to the driving shaft.

8. The positioning assistance device according to claim 7, wherein The rotating shaft further includes two arched buckles and a second cushion plate. Among them, the second cushion plate is fixedly connected to the second side of the bracket. The two arched buckles for rotatably installing the driven shaft are fixedly connected to the second cushion plate.

9. The positioning assistance device according to claim 8, wherein The rotating shaft further includes a protective cover, which is installed above the second cushion plate and covers the driven shaft and the two arched buckles for protecting the driven shaft.

10. The positioning assistance device according to claim 9, wherein The rotating shaft further includes right-angle pads. The lower part of the second cushion plate is connected to the side surface of the bracket through two right-angle pads.

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