Shape memory polymer actuator and catheter

• US 20020095169A1
• Filed: 01/16/2001
• Published: 07/18/2002
• Est. Priority Date: 11/06/2000
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Jungreis, Charles A., Lee, Abraham P., Maitland, Duncan J., Matthews, Dennis L., Schumann, Daniel L., Decker, Derek E.
• Granted Patent: US 6,740,094 B2
• Time in Patent Office: Days
• US Class Current: 606/194
• CPC Class Codes: A61B 17/22031 Gripping instruments, e.g. forceps, for removing or smashing calculi A61B17/221 takes precedence
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 17/32075 Pullback cutting; combined forward and pullback cutting, e.g. with cutters at both sides of the plaque
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2017/00871 polymeric
• CPC Class Codes: A61B 2017/22034 for gripping the obstruction or the tissue part from inside
• CPC Class Codes: A61B 2017/320064 with tissue or sample retaining means
• CPC Class Codes: A61M 2025/0064 which become stiffer or softer when heated
• CPC Class Codes: A61M 25/0158 with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials

Abstract

An actuator system is provided for acting upon a material in a vessel. The system includes an optical fiber and a shape memory polymer material operatively connected to the optical fiber. The shape memory polymer material is adapted to move from a first shape for moving through said vessel to a second shape where it can act upon said material.

Claims

1. An actuator for acting upon a material in a vessel, comprising:

a transport vehicle,

a shape memory material operatively connected to said transport vehicle, said shape memory material adapted to move from a first shape that can be moved through said vessel, to a second and different shape for acting upon said material, and

a heat transfer mechanism operatively connected to said shape memory material, adapted to transfer heat to said shape memory material to move said shape memory material from said first shape to said second shape.

2. The actuator of claim 1 wherein said heat transfer mechanism includes an optical fiber.

3. The actuator of claim 2 including a diffusing chamber operatively connected to said optical fiber and said shape memory material that distributes the light evenly to said shape memory material.

4. The actuator of claim 2 including one or more reflective coatings operatively connected to said optical fiber and to said shape memory material to maximize the amount of light transmitted to the portion of said shape memory material where actuation is desired.

5. The actuator of claim 2 including a reflective plug operatively connected to said optical fiber and to said shape memory material to maximize the amount of light transmitted to the portion of said shape memory material where actuation is desired.

6. The actuator of claim 1 wherein said heat transfer mechanism is induced heating.

7. The actuator of claim 1 wherein said heat transfer mechanism is electrical induction heating.

8. The actuator of claim 1 wherein said heat transfer mechanism is electrothermal heating.

9. The actuator of claim 1 wherein said heat transfer mechanism utilizes acoustic energy source.

10. The actuator of claim 1 wherein said heat transfer mechanism utilizes ultrasonic energy.

11. The actuator of claim 1 wherein said heat transfer mechanism utilizes radio frequency (RF) energy.

12. The actuator of claim 1 wherein said heat transfer mechanism utilizes magnetic energy.

13. The actuator of claim 1 wherein said shape memory material is in the general shape of an umbrella.

14. The actuator of claim 13 wherein said shape memory material in the general shape of an umbrella is slit to allow it to collapse.

15. The actuator of claim 2 including a catheter operatively connected to said optical fiber and said shape memory material.

16. The actuator of claim 15 including a centering device operatively connected to said optical fiber.

17. The actuator of claim 15 wherein said catheter has a flared distal end.

18. The actuator of claim 15 including a delivery catheter operatively connected to said catheter.

19. The actuator of claim 15 including radio markings operatively connected to said shape memory material.

20. The actuator of claim 15 including radio markings operatively connected to said shape memory material and catheter.

21. The actuator of claim 2 including a balloon operatively connected to said optical fiber.

22. The actuator of claim 1 including tethers operatively connected to said shape memory material.

23. The actuator of claim 1 including slits in said shape memory material.

24. The actuator of claim 1 including radio markings operatively connected to said shape memory material.

25. The actuator of claim 1 including a sensor operatively connected to said shape memory material.

26. The actuator of claim 1 including a reflector operatively connected to said shape memory material.

27. The actuator of claim 2 including a second shape memory material operatively connected to said optical fiber, adapted to move from a first shape to a second shape where it can act upon said material.

28. The actuator of claim 1 including a shape memory material clamp utilized to hold said shape memory material in a closed position.

29. The actuator of claim 2 including a second shape memory material operatively connected to said optical fiber, adapted to move from a first shape and position, to a second shape and position where it can act upon said material.

30. The actuator of claim 29 including teeth operatively connected to shape memory material for improved scraping.

31. The actuator of claim 30 including teeth operatively connected to second shape memory material for interlocking with said teeth operatively connected to shape memory material.

32. The actuator of claim 2 including hooks operatively connected to shape memory material for gripping said material.

33. A method of removing matter from a vessel, comprising the steps of:

passing a transport vehicle and a shape memory polymer material through or around said matter,

transmitting energy to said shape memory polymer material for moving said shape memory polymer material from a first shape to a second and different shape, and

withdrawing said transport vehicle and said shape memory polymer material through said vessel carrying said matter.

34. The method of removing matter from a vessel of claim 33 wherein said second shape is in the general shape of an umbrella.

35. The method of removing matter from a vessel of claim 33 wherein said step of transmitting energy to said shape memory polymer material includes transmitting light through an optical fiber.

36. The method of removing matter from a vessel of claim 33 wherein an induced heating mechanism is used in said step of transmitting energy to said shape memory polymer material.

37. The method of removing matter from a vessel of claim 33 wherein an electrical induction heating mechanism is used in said step of transmitting energy to said shape memory polymer material.

38. The method of removing matter from a vessel of claim 33 wherein an electrothermal heating mechanism is used in said step of transmitting energy to said shape memory polymer material.

39. The method of removing matter from a vessel of claim 33 wherein an acoustic energy transfer source is used in said step of transmitting energy to said shape memory polymer material.

40. The method of removing matter from a vessel of claim 33 wherein an ultrasonic energy transfer source is used in said step of transmitting energy to said shape memory polymer material.

41. The method of removing matter from a vessel of claim 33 wherein a radio frequency (RF) energy transfer source is used in said step of transmitting energy to said shape memory polymer material.

42. The method of removing matter from a vessel of claim 34 wherein a magnetic energy transfer source is used in said step of transmitting energy to said shape memory polymer material.

43. The method of removing matter from a vessel of claim 33 including the step of releasing agents carried by said shape memory polymer material.

44. The method of removing matter from a vessel of claim 43 wherein said agents are liquid held by said shape memory polymer material.

45. The method of removing matter from a vessel of claim 43 wherein said agents are coatings on said shape memory polymer material.

46. The method of removing matter from a vessel of claim 33 wherein a dye is operatively connected said shape memory polymer material.

47. The method of removing matter from a vessel of claim 46 including the step of adjusting concentration of said dye so that said light is optimally absorbed in the active region of said shape memory polymer material.

48. The method of removing matter from a vessel of claim 33 including the step of using radio markings operatively connected to said shape memory polymer material to determine the position of said shape memory polymer material.

49. The method of removing matter from a vessel of claim 33 including the step of using a catheter to direct said shape memory polymer material to said matter.

50. The method of removing matter from a vessel of claim 49 including the step of using a delivery catheter to carry said catheter and said shape memory polymer material to said matter.

51. The method of removing matter from a vessel of claim 33 including the steps of transmitting light energy through an optical fiber to said shape memory polymer material and using a catheter to direct said shape memory polymer material to said matter.

52. The method of removing matter from a vessel of claim 33 including the step of scraping the wall of said vessel to remove more of said matter.

53. The method of removing matter from a vessel of claim 33 including the step of using a diagnostic sensor operatively connected to said shape memory polymer material for the interrogation of the environment of said matter in said vessel.

54. The method of removing matter from a vessel of claim 53 wherein said diagnostic sensor measures the viability of the vessel relative to reinstated blood flow.

55. The method of removing matter from a vessel of claim 53 wherein said diagnostic sensor is light based.

56. The method of removing matter from a vessel of claim 53 wherein said diagnostic sensor is a heterodyne detection sensor.

57. The method of removing matter from a vessel of claim 53 wherein said diagnostic sensor is an interference sensor.

58. The method of removing matter from a vessel of claim 53 wherein said diagnostic sensor is a fluorescence sensor.

59. The method of removing matter from a vessel of claim 53 including the step of using a catheter to move said optical fiber and said shape memory material through said vessel.

60. The method of removing matter from a vessel of claim 59 including the step of using a guide catheter to move said catheter, said optical fiber, and said shape memory material through said vessel.

61. A method of manufacturing an actuator for acting upon a material in a vessel, comprising the steps of:

processing a shape memory polymer material so that it will expand into a somewhat umbrella shape upon being activated, and

operatively connecting said shape memory polymer material to an optical fiber.

62. The method of manufacturing an actuator for acting upon a material in a vessel of claim 61 wherein said step of processing a shape memory polymer material so that it will expand into a somewhat umbrella shape upon being activated, includes, heating said shape memory polymer material above its melting temperature during processing.

63. The method of manufacturing an actuator for acting upon a material in a vessel of claim 61 wherein said shape memory polymer material has a primary shape before being activated and said step of processing a shape memory polymer material so that it will expand into a somewhat umbrella shape upon being activated, includes, polymerizing said shape memory polymer material while in its primary shape.

64. The method of manufacturing an actuator for acting upon a material in a vessel of claim 62 wherein said shape memory polymer material possesses a glass transformation temperature (T_g) above which the material enters a reversible glassy phase where it becomes soft and flexible and easy to reshape the material and will return to its primary shape if not subjected to undue pressure and once cooled below T_g, the shape is frozen in place and the material becomes hardened and will hold its shape until it is intentionally relaxed by heating the SMP above T_g again.

65. An actuator for acting upon a material in a vessel, comprising:

a transport vehicle,

a shape memory material operatively connected to said transport vehicle, said shape memory material adapted to move from a first shape that can be moved through said vessel, to a second and different shape for acting upon said material,

a heat transfer mechanism operatively connected to said shape memory material, adapted to transfer heat to said shape memory material to allow said shape memory material to be moved from said first shape to said second shape, and

a mechanism for moving said shape memory material from said first shape to said second shape.

66. The actuator of claim 65 wherein said mechanism for moving said shape memory material from said first shape to said second shape is a mechanical mechanism.

67. The actuator of claim 65 wherein said mechanism for moving said shape memory material from said first shape to said second shape is a electrostatic mechanism.

68. The actuator of claim 65 wherein said mechanism for moving said shape memory material from said first shape to said second shape is a fluidic mechanism.