Coil positioning system

• US 10,254,739 B2
• Filed: 03/24/2017
• Issued: 04/09/2019
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Mevion Medical Systems Incorporated
• Original Assignee: Mevion Medical Systems Incorporated
• Inventors: Jones, Mark R., Robinson, Mark, Franzen, Ken Yoshiki
• Primary Examiner(s): Stoffa, Wyatt A
• Application Number:
  US15/468,656
• Publication Number:
  US 20170199506A1
• Time in Patent Office: 746 Days
• Field of Search: 250290-294, 250298, 250436, 250396 R, 25049221, 2504923, 376112, 376121, 376141, 376142, 315502, 315503, 315507, 313 62, 600 1
• CPC Class Codes: A61N 2005/1095 Elements inserted into the radiation path within the system, e.g. filters or wedges
• CPC Class Codes: A61N 5/1077 Beam delivery systems
• CPC Class Codes: G05B 19/19 characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
• CPC Class Codes: G05B 2219/39221 Control angular position of joint by length of linear actuator
• CPC Class Codes: G05B 2219/40555 Orientation and distance
• CPC Class Codes: H02K 11/215 Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
• CPC Class Codes: H02K 11/30 Structural association with control circuits or drive circuits
• CPC Class Codes: H02K 7/08 Structural association with bearings
• CPC Class Codes: H02K 7/116 with gears
• CPC Class Codes: H05H 13/02 Synchrocyclotrons, i.e. frequency modulated cyclotrons
• CPC Class Codes: H05H 2007/004 for modifying beam energy, e.g. spread out Bragg peak devices
• CPC Class Codes: H05H 7/04 Magnet systems , e.g. undulators, wigglers free-electron laser H01S3/0903; Energisation thereof

Abstract

An example system includes: a magnet including one or more coils to conduct current to generate a magnetic field, with the magnetic field to affect output of radiation to a target; and one or more actuators, with an actuator among the one or more actuators being at least part of a physical coupling to the one or more coils, and with the actuator being controllable to move the one or more coils via the physical coupling based on movement of the magnet.

Claims

1. A system comprising:

a magnet comprising one or more coils to conduct current to generate a magnetic field, the magnetic field to affect output of radiation to a target; and

one or more actuators, an actuator among the one or more actuators being at least part of a physical coupling to the one or more coils, the actuator being controllable to move the one or more coils via the physical coupling based on movement of the magnet.

2. The system of claim 1, further comprising:

a housing that at least partly encloses the magnet;

wherein movement of the magnet causes the one or more coils to move relative to the housing in a first direction; and

wherein the one or more actuators are controllable to move the one or more coils relative to the housing in a second direction that is substantially opposite to the first direction in response to movement of the one or more coils in the first direction.

3. The system of claim 1, further comprising:

a housing that borders the magnet;

wherein movement of the magnet causes the one or more coils to move relative to the housing; and

wherein the one or more actuators are controllable to move the one or more coils relative to the housing to compensate, at least partly, for movement of the one or more coils relative to the housing caused by movement of the magnet.

4. The system of claim 1, further comprising:

a housing that holds the magnet;

wherein the magnet is movable from a first orientation to a second orientation, the movement of the magnet causing the one or more coils to move from a first position relative to the housing at the first orientation to a second position relative to the housing at the second orientation; and

wherein the one or more actuators are controllable to move the one or more coils so that the one or more coils are at the first position relative to the housing when the housing is at the second orientation.

5. The system of claim 1, wherein the magnet comprises a support structure to hold the one or more coils;

and

wherein the physical coupling comprises the support structure, the actuator being configured to move the one or more coils by moving the support structure.

6. The system of claim 5, further comprising:

a vacuum enclosure around the magnet;

wherein the physical coupling comprises a strap connected between the actuator and the support structure; and

wherein the actuator is connected to the vacuum enclosure and to the strap, the actuator being configured to increase tension on the strap to move the one or more coils.

7. The system of claim 6, wherein the actuator comprises a differential screw that connects to the strap, and the actuator comprises a motor connected to drive the differential screw to increase tension on the strap.

8. The system of claim 1, wherein the actuator is controllable to move the one or more coils via the physical coupling based on movement of the magnet in order to achieve a target magnetic field distribution.

9. The system of claim 6, wherein the magnet is a superconducting magnet;

wherein the system further comprises a cryostat to maintain the one or more coils at temperatures that enable superconductivity in the one or more coils, the cryostat including the support structure.

10. The system of claim 1, wherein the one or more actuators comprise a group of actuators, each actuator in the group being at least part of a separate physical coupling to the one or more coils, each actuator in the group being controllable to move the one or more coils via a respective physical coupling based on movement of the magnet.

11. The system of claim 10, further comprising:

an enclosure that houses the magnet;

wherein the group of actuators are mounted inside an external perimeter of the enclosure, each actuator being configured to pull the one or more coils at least partly inwards towards an interior of the external perimeter.

12. The system of claim 10, further comprising:

an enclosure that houses the magnet;

wherein each actuator in the group of actuators is configured to pull the one or more coils at least partly outwards relative to an external perimeter of the enclosure.

13. The system of claim 10, further comprising:

an enclosure that houses the magnet;

wherein the group of actuators are mounted in a symmetric arrangement on the enclosure and are controllable to act in concert.

14. The system of claim 1, further comprising:

an enclosure that at least partly surrounds the magnet;

wherein the system comprises;

one or more sensors to detect movement of the one or more coils relative to the enclosure, the actuator being controllable based on detection of the movement of the one or more coils relative to the enclosure.

15. The system of claim 14, wherein the one or more sensors comprises one or more magnetic field sensors mounted to the enclosure, the one or more magnetic field sensors being configured to detect a change in the magnetic field generated by the one or more coils relative to the one or more magnetic field sensors, the detected change in the magnetic field being indicative of the movement of the one or more coils relative to the enclosure.

16. The system of claim 14, wherein the one or more sensors comprises one or more displacement sensors mounted to the enclosure to obtain measurements based on positions of the one or more coils;

and

wherein the system comprises one or more processing devices to determine the movement of the one or more coils based on the measurements.

17. The system of claim 1, further comprising:

a particle accelerator, the magnet being part of the particle accelerator, the particle accelerator being configured for movement, wherein the magnet is configured for movement as a result of the magnet being part of the particle accelerator.

18. The system of claim 17, wherein the particle accelerator is a synchrocyclotron, the magnet is a superconducting magnet, and the system further comprises:

a gantry on which the particle accelerator is mounted to produce the movement of the particle accelerator and of the magnet.

19. The system of claim 1, wherein the radiation comprises a particle beam, and wherein current in the one or more coils is controllable to affect the particle beam prior to application to an irradiation target.

20. The system of claim 19, wherein the current is controllable to direct the particle beam to one or more points in the irradiation target.

21. The system of claim 19, wherein the current is controllable to focus the particle beam prior to output to the irradiation target.

22. A particle therapy system comprising:

a magnet comprising one or more coils to conduct current to generate a magnetic field, the magnetic field to affect output of a particle beam;

a housing to hold the magnet;

a mount to which the housing is connected to enable movement of the housing, the movement causing a displacement of the one or more coils relative to the housing; and

one or more actuators that are part of a physical coupling to the one or more coils, the one or more actuators being controllable to move, via the physical coupling, the one or more coils relative to the housing to at least partly correct the displacement.

23. The particle therapy system of claim 22, wherein two or more of the actuators are controllable to act in concert to move the one or more coils.

24. The particle therapy system of claim 22, wherein the displacement occurs along a first direction, and the one or more actuators are controllable to move the one or more coils in a second direction that is substantially opposite to the first direction.

25. The particle therapy system of claim 22, wherein the one or more actuators are controllable to move the one or more coils in real-time during movement of the housing.

26. The particle therapy system of claim 22, wherein the one or more actuators are controllable to move the one or more coils following the movement of the housing that caused the displacement.

27. The particle therapy system of claim 22, wherein the magnet comprises a support structure to hold the one or more coils;

and

wherein the physical coupling comprises the support structure, the one or more actuators being configured to move the coil by moving the support structure physically.

28. The system of claim 27, wherein, for an actuator among the one or more actuators, a physical coupling comprises a strap connected between the actuator and the support structure;

and

wherein the actuator is connected to the housing and to the strap, the actuator being configured to increase tension on the strap to move the one or more coils.

29. The system of claim 28, wherein the actuator comprises a differential screw that connects to the strap, and the actuator comprises a motor connected to drive the differential screw to increase tension on the strap.

30. The system of claim 22, wherein the one or more actuators are controllable to move the one or more coils via the physical coupling based on movement of the magnet in order to achieve a target magnetic field distribution.

31. The system of claim 27, wherein the magnet is a superconducting magnet;

wherein the system further comprises a cryostat to maintain the one or more coils at temperatures that enable superconductivity in the one or more coils, the cryostat including the support structure.

32. The system of claim 22, wherein the one or more actuators comprise a group of actuators, each actuator in the group being at least part of a separate physical coupling to the one or more coils, each actuator in the group being controllable to move the one or more coils via a respective physical coupling.

33. The system of claim 32, wherein the group of actuators are mounted inside of an exterior perimeter of the housing, each actuator being configured to pull the one or more coils at least partly inwards towards an interior of the exterior perimeter.

34. The system of claim 32, wherein each actuator in the group of actuators is configured to pull the one or more coils at least partly outwards relative to an exterior perimeter of the housing.

35. The system of claim 32, wherein the group of actuators are mounted in a symmetric arrangement on the housing and are controllable to act in concert.

36. The system of claim 22, further comprising:

one or more sensors to detect movement of the one or more coils relative to the housing, the one or more actuators being controllable based on detection of the movement of the one or more coils relative to the housing.

37. The system of claim 36, wherein the one or more sensors comprises one or more magnetic field sensors mounted to the housing, the one or more magnetic field sensors being configured to detect a change in the magnetic field generated by the one or more coils relative to the one or more magnetic field sensors, the detected change in the magnetic field being indicative of the movement of the one or more coils relative to the housing.

38. The system of claim 36, wherein the one or more sensors comprises one or more displacement sensors mounted to the housing to obtain measurements based on the positions of the one or more coils;

and

wherein the system comprises one or more processing devices to determine the movement of the one or more coils based on the measurements.

39. The system of claim 22, further comprising:

a particle accelerator, the magnet and the housing being part of the particle accelerator, the particle accelerator being configured for movement that is at least partly rotational, wherein the magnet and the housing are configured for movement as a result of the magnet and the housing being part of the particle accelerator.

40. The system of claim 39, wherein the particle accelerator is a synchrocyclotron, the magnet is a superconducting magnet, and the mount comprises a rotatable gantry on which the particle accelerator is mounted.

41. The system of claim 22, wherein the current in the one or more coils is controllable to affect the particle beam prior to application to an irradiation target.

42. The system of claim 22, wherein the current is controllable to direct the particle beam to one or more points in the irradiation target.

43. The system of claim 22, wherein the current is controllable to focus the particle beam prior to output to the irradiation target.

44. A system comprising:

means for rotating a magnet, the magnet comprising one or more coils to conduct current to generate a magnetic field, wherein movement of the magnet causes displacement of the one or more coils away from a predefined position; and

means for physically moving the one or more coils so that, following movement of the magnet, the one or more coils are in the predefined position.

45. A system comprising:

a magnet comprising one or more coils to conduct current to generate a magnetic field; and

one or more actuators, an actuator among the one or more actuators being at least part of a physical coupling to the one or more coils, the actuator being controllable to move the one or more coils via the physical coupling to arrive at a target distribution of the magnetic field.

46. The system of claim 45, further comprising:

one or more sensors to detect movement of the one or more coils relative to a reference, the actuator being controllable based on detection of the movement of the one or more coils relative to the reference.

47. The system of claim 46, wherein the one or more sensors comprises one or more magnetic field sensors, the one or more magnetic field sensors being configured to detect a change in the magnetic field generated by the one or more coils relative to the one or more magnetic field sensors, the detected change in the magnetic field being indicative of the movement of the one or more coils.

48. The system of claim 46, wherein the one or more sensors comprises one or more displacement sensors to obtain measurements based on positions of the one or more coils;

and

wherein the system comprises one or more processing devices to determine the movement of the one or more coils based on the measurements.

49. The system of claim 45, further comprising:

a particle accelerator, the magnet being part of the particle accelerator, the particle accelerator being configured for movement, wherein the magnet is configured for movement as a result of the magnet being part of the particle accelerator.

50. The system of claim 49, wherein the particle accelerator is a synchrocyclotron, the magnet is a superconducting magnet, and the system further comprises:

a gantry on which the particle accelerator is mounted to produce the movement of the particle accelerator and of the magnet.

51. The system of claim 49, wherein the magnet is configured to accelerate particles in a cavity of the particle accelerator to produce a particle beam.

52. The system of claim 49, wherein the magnet is configured to focus particles during extraction of a particle beam from the particle accelerator.

53. The system of claim 49, wherein the magnet is configured to control movement of a particle beam output from the particle accelerator relative to a target of the particle beam.