Stepless variable collimator suitable for radiotherapy equipment

Abstract

The invention relates to the technical field of medical equipment, in particular to a stepless variable collimator suitable for radiotherapy equipment, which comprises a shell, a beam-shaped structure, a driving structure and a mounting hole, and can adjust the calibers of a collimator outlet and a collimator inlet under the action of the driving structure and the beam-shaped structure. Therefore, the most suitable radiation field size can be provided according to treatment requirements, the use flexibility is improved, the taper between the collimator inlet and the collimator outlet can be adjusted under the action of the driving structure and the beam-shaped structure, shielding of radiation field edge rays can be reduced as much as possible, and the treatment effect is improved. The intensity of rays at the edge can be equivalent to the intensity of rays at the central position, and the radiation treatment effect is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of medical equipment, in particular to a stepless variable collimator suitable for radiotherapy equipment. Background Art

[0002] In modern medicine, radiotherapy is an important means of treating malignant tumors. Radiotherapy refers to the use of high-energy radiation to kill tumors while protecting normal tissues from radiation damage as much as possible. The radiation sources of radiotherapy equipment generally include radioisotope radiation sources and accelerator radiation sources. Commonly used radioisotope radiation sources such as cobalt 60 sources use artificial isotopes to continuously produce gamma rays for radiotherapy. Medical linear accelerators produce high-energy X-rays, and the radiotherapy head is an important component of it, generally including radiation sources and field collimation systems. The rays of these two devices are emitted from a very small point and then expand outward. They need to be shaped by a collimator to obtain the desired radiation field. Modern gamma knife equipment usually uses multiple cobalt 60 radiation sources, each of which is equipped with several fixed-size collimators. The collimator holes are usually conical, and the size of the resulting radiation field is a number of fixed sizes and cannot be continuously and steplessly changed. Existing accelerators usually use three types: fixed collimators, multi-leaf collimators (MLCs), and variable collimators. Fixed-size collimators cannot adjust the size of the radiation field, and radiation fields of different shapes can only be obtained by replacing different collimators. MLC consists of multiple independently movable leaves, which are usually made of high-density metals (such as tungsten). By moving these leaves, various complex radiation beam shapes can be formed to adapt to irregular tumor shapes and treatment targets. Variable collimators usually use multiple leaves to move simultaneously to change the size of the collimator hole.

[0003] However, fixed collimator: radiation fields of different shapes can only be obtained by replacing different collimators; MLC: there is leakage between leaves, the complex structure leads to high cost but low reliability, and the large size and weight make it unsuitable for the compact development requirements of accelerator treatment heads. The inlet, outlet and middle cross-section shapes of existing variable collimators (US9406411, US20130294583A1) are consistent, resulting in partial blocking of the rays at the edge of the radiation field emitted from a small point, so the edge ray intensity of the radiation field is smaller than that of the center of the radiation field. Summary of the invention

[0004] In view of the problems in the prior art, the present invention provides a stepless variable collimator suitable for radiotherapy equipment.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a stepless variable collimator suitable for radiotherapy equipment, comprising a shell, a beam-shaped structure is provided on the shell, and a driving structure is provided on the beam-shaped structure;

[0006] The beam-shaped structure includes a connecting plate and a slider, one end of the shell is detachably mounted with one of the connecting plates, the other end of the shell is slidably connected with a slide cylinder, the end of the slide cylinder is fixedly connected with another connecting plate, a plurality of slide grooves are provided on the connecting plate, the inside of the slide grooves is slidably matched with a slider, a plurality of blades are provided inside the shell, two pin holes are provided at both ends of the blades, a blade pin is penetrated inside the pin hole, the blade pin passes through adjacent sliders, one end of the plurality of blades is closed to form a collimator inlet, the other end of the plurality of blades is closed to form a collimator outlet, and a driving structure is provided on the connecting plate.

[0007] Specifically, a plurality of guide posts are fixedly connected to the outside of the slide cylinder, and the inner wall of the shell is provided with guide grooves whose number is equal to the number of the guide posts, and the guide posts are slidably matched with adjacent guide grooves.

[0008] Specifically, at least three blades are provided, and a cavity formed by closing the plurality of blades presents a conical structure, and the diameter of the collimator inlet is smaller than or equal to the diameter of the collimator outlet.

[0009] Specifically, the centers of the collimator inlet and the collimator outlet are on the same straight line, and the center of the collimator inlet and the axis of the housing are on the same straight line.

[0010] Specifically, the shell is a cylindrical structure, the plurality of slide grooves are distributed in a circular array about the axis of the shell, and the plurality of sliders are distributed in a circular array about the axis of the shell.

[0011] Specifically, the cross section of the middle portion of the blade is a conical structure.

[0012] Specifically, the driving structure includes a motor and a first transmission member, the motor is installed on the connecting plate, the output shaft of the motor passes through the connecting plate, the first transmission member is fixedly connected to the output shaft of the motor, the second transmission member is rotatably connected to the connecting plate, the first transmission member is meshed with the second transmission member, the second transmission member is provided with a plurality of cam grooves, one end of the slider is fixedly connected to a cam, the cam extends to the inside of an adjacent cam groove and is slidably connected to the second transmission member.

[0013] Specifically, the rotation axis of the second transmission member and the axis of the housing are on the same straight line.

[0014] Specifically, the plurality of cams are distributed in a circular array about the rotation axis of the second transmission member, and the plurality of cam grooves are distributed in a circular array about the rotation axis of the second transmission member.

[0015] Specifically, the driving structure may also be driven by a motor, and different gear ratios are used to ensure that the taper of the collimator is always the same as the angle of the ray.

[0016] The beneficial effects of the present invention are:

[0017] (1) The stepless variable collimator suitable for radiotherapy equipment described in the present invention can adjust the aperture of the collimator outlet and the collimator entrance under the action of the driving structure and the beam structure, so as to provide the most suitable radiation field size according to the treatment needs, thereby improving the flexibility of use.

[0018] (2) The stepless variable collimator suitable for radiotherapy equipment described in the present invention can adjust the taper between the collimator entrance and the collimator exit under the action of the driving structure and the beam structure, thereby minimizing the shielding of the edge rays of the radiation field, so that the intensity of the rays at the edge can be equivalent to that at the center, thereby ensuring the effect of radiation therapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1 A schematic diagram of the overall structure of a preferred embodiment of a stepless variable collimator suitable for radiotherapy equipment provided by the present invention;

[0021] Figure 2 It is a schematic diagram of the connection structure between the slider and the slide groove of the present invention;

[0022] Figure 3 It is a schematic diagram of the connection structure between the slide cylinder and the guide groove of the present invention;

[0023] Figure 4 It is a schematic diagram of the connection structure between the slide cylinder and the slide post of the present invention;

[0024] Figure 5 It is a schematic diagram of the connection structure between the connection plate and the slider of the present invention;

[0025] Figure 6 It is a schematic diagram of the connection structure between the slider and the blade pin of the present invention;

[0026] Figure 7 It is a schematic diagram of the connection structure between the blade and the pin hole of the present invention;

[0027] Figure 8 It is a schematic diagram of the connection structure between the slider and the cam of the present invention.

[0028] In the figure: 1. shell; 2. beam structure; 201. connecting plate; 202. slider; 203. slide groove; 204. blade pin; 205. pin hole; 206. blade; 207. slide cylinder; 208. guide column; 209. guide groove; 3. driving structure; 301. motor; 302. first transmission member; 303. second transmission member; 304. cam groove; 305. cam; 4. mounting hole; 5. collimator inlet; 6. collimator outlet. DETAILED DESCRIPTION

[0029] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0030] like Figure 1 , Figure 3 and Figure 8 As shown, the stepless variable collimator suitable for radiotherapy equipment described in the present invention comprises a housing 1, a beam-forming structure 2 is provided on the housing 1, and a driving structure 3 is provided on the beam-forming structure 2;

[0031] The beam-shaped structure 2 includes a connecting plate 201 and a slider 202. One end of the shell 1 is detachably mounted with one of the connecting plates 201. The other end of the shell 1 is slidably connected with a slide cylinder 207. The end of the slide cylinder 207 is fixedly connected with another connecting plate 201. The connecting plate 201 is provided with a plurality of slide grooves 203. The inside of the slide grooves 203 is slidably matched with a slider 202. The inside of the shell 1 is provided with a plurality of blades 206. Two pin holes 205 are provided at both ends of the blades 206. The inside of the pin holes 205 is penetrated by a blade pin 204. The blade pin 204 penetrates the adjacent slider 202. One end of the plurality of blades 206 is closed to form a collimator inlet 5. The other end of the plurality of blades 206 is closed to form a collimator outlet 6. The connecting plate 201 is provided with a driving structure 3.

[0032] Specifically, the outside of the slide 207 is fixedly connected with a plurality of guide posts 208, and the inner wall of the shell 1 is provided with guide grooves 209 whose number is equal to the guide posts 208. The guide posts 208 are slidably matched with adjacent guide grooves 209, so that the movement of the slide 207 can be guided by the guide posts 208 sliding inside the guide grooves 209.

[0033] Specifically, at least three blades 206 are provided, and the cavity formed when the multiple blades 206 are closed has a conical structure. The diameter of the collimator entrance 5 is less than or equal to the diameter of the collimator exit 6. The centers of the collimator entrance 5 and the collimator exit 6 are on the same straight line, and the center of the collimator entrance 5 and the axis of the housing 1 are on the same straight line. Therefore, the diameters of the collimator entrance 5 and the collimator exit 6 can be adjusted by changing the positions of the two ends of the multiple blades 206.

[0034] Specifically, the shell 1 is a cylindrical structure, the plurality of slide grooves 203 are distributed in a circular array about the axis of the shell 1, and the plurality of sliders 202 are distributed in a circular array about the axis of the shell 1, so that the slide grooves 203 can guide the sliders 202 in motion.

[0035] Specifically, the cross section of the middle portion of the blade 206 is a conical structure, so the movement of the two sliders 202 can drive the blade 206 to move, thereby achieving adjustment of the position of the blade 206.

[0036] Specifically, the driving structure 3 includes a motor 301 and a first transmission member 302. The motor 301 is installed on the connecting plate 201. The output shaft of the motor 301 passes through the connecting plate 201. The first transmission member 302 is fixedly connected to the output shaft of the motor 301. The second transmission member 303 is rotatably connected to the connecting plate 201. The first transmission member 302 is meshed with the second transmission member 303. The second transmission member 303 is provided with a plurality of cam grooves 304. A cam 305 is fixedly connected to one end of the slider 202. The cam 305 extends to the inside of the adjacent cam groove 304 and is slidably connected to the second transmission member 303. The rotation axis of the second transmission member 303 and the axis of the housing 1 are on the same straight line. The plurality of cams 305 are distributed in a circular array about the rotation axis of the second transmission member 303. The plurality of cam grooves 304 are distributed in a circular array about the rotation axis of the second transmission member 303. Therefore, the plurality of sliders 202 can be driven to move at the same time.

[0037] Specifically, the driving structure 3 may also be driven by a motor, and different gear ratios are used to ensure that the taper of the collimator is always the same as the angle of the ray.

[0038] When the present invention is in use, when it is necessary to adjust the caliber of the collimator entrance 5, one of the motors 301 can be started, and the output shaft of the motor 301 rotates to drive the first transmission member 302 to rotate, and the first transmission member 302 rotates to drive the second transmission member 303 to rotate (the transmission member is preferably a gear, and can also be a belt or a connecting rod), and the rotation of the second transmission member 303 will drive the movement of multiple cam grooves 304 (the shape of the cam groove 304 can be an arc or a straight line), and when the cam groove 304 moves, the cam 305 will move inside the cam groove 304, and the movement of the cam 305 will drive the slider 202 slides inside the slide groove 203. Since the slider 202 is connected to one end of the blade 206 through the blade pin 204, when the slider 202 moves, it will drive one end of the blade 206 to move. Since multiple sliders 202 move at the same time, one end of multiple blades 206 will move at the same time. The simultaneous movement of the ends of multiple blades 206 will change the diameter of the collimator entrance 5 formed by the closing of multiple blades 206. (In order to ensure that the through hole formed after the blades 206 are closed is close to a circle, the number of blades 206 should be no less than 3.) Adjacent blades 206 are not close to each other. A small gap is left to ensure the movement of the mechanism. Since the two ends of the blade 206 move independently, the distance between the pin holes 205 at the two ends of the blade 206 along the axial direction of the shell 1 is variable. Therefore, when adjusting the position of the blade 206, the slide 207 will slide inside the shell 1. By setting the sliding fit between the guide column 208 and the guide groove 209, the slide 207 can be guided for movement. By sliding the slide 207 on the shell 1, the phenomenon of the blade 206 being stuck during the position adjustment process can be avoided, so that the position of the blade 206 can be smoothly adjusted. When the collimator needs to be adjusted, When adjusting the position of the outlet 6, it is only necessary to start another motor 301. Therefore, the sizes of the apertures of the collimator entrance 5 and the collimator exit 6 can be controlled respectively by the two motors 301, thereby realizing stepless changes in the sizes of the collimator entrance 5 and the collimator exit 6, and stepless changes in the taper of the cavity between the collimator entrance 5 and the collimator exit 6. Therefore, it is not only possible to provide the most suitable radiation field size according to treatment needs and improve the flexibility of use, but also to minimize the shielding of the edge rays of the radiation field, so that the intensity of the rays at the edge can be equivalent to that at the center, thereby ensuring the effect of radiation therapy.

[0039] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0040] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A stepless variable collimator suitable for radiotherapy equipment, characterized in that: It comprises a shell (1), a beam-shaped structure (2) is provided on the shell (1), and a driving structure (3) is provided on the beam-shaped structure (2); The beam-shaped structure (2) comprises a connecting plate (201) and a sliding block (202); one end of the housing (1) is detachably mounted with one of the connecting plates (201); the other end of the housing (1) is slidably connected with a sliding cylinder (207); the end of the sliding cylinder (207) is fixedly connected with another connecting plate (201); a plurality of sliding grooves (203) are provided on the connecting plate (201); the interior of the sliding grooves (203) is slidably matched with the sliding block (202); the housing (1) A plurality of blades (206) are provided inside the collimator, two pin holes (205) are provided at both ends of the blades (206), a blade pin (204) is provided inside the pin hole (205), and the blade pin (204) passes through an adjacent slider (202), one end of the plurality of blades (206) is closed to form a collimator inlet (5), and the other end of the plurality of blades (206) is closed to form a collimator outlet (6), and a driving structure (3) is provided on the connecting plate (201).

2. A stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: The exterior of the slide cylinder (207) is fixedly connected to a plurality of guide posts (208); the inner wall of the housing (1) is provided with guide grooves (209) equal in number to the guide posts (208); the guide posts (208) are slidably fitted with adjacent guide grooves (209).

3. A stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: At least three blades (206) are provided, and a cavity formed when the plurality of blades (206) are closed presents a conical structure, and the diameter of the collimator inlet (5) is less than or equal to the diameter of the collimator outlet (6).

4. A stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: The centers of the collimator inlet (5) and the collimator outlet (6) are on the same straight line, and the center of the collimator inlet (5) and the axis of the housing (1) are on the same straight line.

5. The stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: The shell (1) is of cylindrical structure, the plurality of slide grooves (203) are distributed in a circular array about the axis of the shell (1), and the plurality of sliders (202) are distributed in a circular array about the axis of the shell (1).

6. The stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: The cross section of the middle portion of the blade (206) is a conical structure.

7. The stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: The driving structure (3) comprises a motor (301) and a first transmission member (302); the motor (301) is mounted on the connecting plate (201); the output shaft of the motor (301) passes through the connecting plate (201); the first transmission member (302) is fixedly connected to the output shaft of the motor (301); the second transmission member (303) is rotatably connected to the connecting plate (201); the first transmission member (302) is meshed with the second transmission member (303); a plurality of cam grooves (304) are provided on the second transmission member (303); one end of the slider (202) is fixedly connected to a cam (305); the cam (305) extends to the inside of an adjacent cam groove (304) and is slidably connected to the second transmission member (303).

8. The stepless variable collimator suitable for radiotherapy equipment according to claim 7, characterized in that: The rotation axis of the second transmission member (303) and the axis of the housing (1) are on the same straight line.

9. The stepless variable collimator suitable for radiotherapy equipment according to claim 7, characterized in that: The plurality of cams (305) are distributed in a circular array about the rotation axis of the second transmission member (303), and the plurality of cam grooves (304) are distributed in a circular array about the rotation axis of the second transmission member (303).

10. The stepless variable collimator suitable for radiotherapy equipment according to claim 1, characterized in that: The driving structure (3) can also be driven by a motor, with different gear ratios to ensure that the taper of the collimator is always the same as the angle of the ray.

Images