Ultrasonic medical device operating in a transverse mode

• US 6,551,337 B1
• Filed: 07/19/2000
• Issued: 04/22/2003
• Est. Priority Date: 10/05/1999
• Status: Expired due to Term

• Current Assignee: Cybersonics, Inc
• Original Assignee: OmniSonics Medical Technologies, Inc.
• Inventors: Fischer, David M., Levine, Andy, Hare, Brad A., Rabiner, Robert A.
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): BAXTER, JESSICA R
• Application Number:
  US09/618,352
• Time in Patent Office: 1,007 Days
• Field of Search: 606/169, 606/170, 606/171, 606/177, 606/178, 606/180, 604/22
• US Class Current: 606/169
• CPC Class Codes: A61B 17/22012 in direct contact with, or very close to, the obstruction or concrement for removing obstructions in blood vessels by laser A61B18/245
• CPC Class Codes: A61B 2017/00137 Details of operation mode
• CPC Class Codes: A61B 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• CPC Class Codes: A61B 2017/22002 preventing restenosis
• CPC Class Codes: A61B 2017/22007 Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing
• CPC Class Codes: A61B 2017/22008 used or promoted
• CPC Class Codes: A61B 2017/22015 with details of the transmission member
• CPC Class Codes: A61B 2017/22018 segmented along its length
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/293 with means preventing relative rotation between the shaft and the actuating rod
• CPC Class Codes: A61B 2017/32007 with suction or vacuum means
• CPC Class Codes: A61B 2017/320084 Irrigation sleeves
• CPC Class Codes: A61B 2017/320089 node location
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61B 2018/00982 combined with or comprising means for visual or photographic inspections inside the body, e.g. endoscopes
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61B 2217/007 with irrigation system
• CPC Class Codes: A61N 2007/0008 Destruction of fat cells
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

An ultrasonic medical device comprises an ultrasonic vibration generator that generates vibration along its longitudinal axis. The ultrasonic vibration is transmitted through an ultrasonic coupler and a series of transformer sections that amplify the ultrasonic vibration. A flexible member is coupled to the distal end of the transformer sections, and is thus supplied with a longitudinal vibration at its base by the transformer sections. The flexible member is designed so that it converts the longitudinal vibration into a standing wave that runs along the length of the flexible member. The standing wave produces a series of nodes and anti-nodes along the length of the flexible member. Each of the anti-nodes produces cavitation in fluids in contact with the probe. The cavitation of the fluids causes destruction of adjacent tissue. In this manner, the entire length of the flexible member becomes a working surface that may be utilized for destroying tissue.

Claims

1. An ultrasonic medical device comprising:

an ultrasonic generator for producing an ultrasonic vibration in a direction along a longitudinal axis of the ultrasonic generator;

an ultrasonic coupling horn;

at least one transformer section ultrasonically coupled to the ultrasonic source by the ultrasonic coupling horn, the transformer section modifying the amplitude of the ultrasonic vibration; and

a flexible member driven by the transformer section wherein the flexible member has a degree of stiffness which allows the flexible member to support a transverse ultrasonic vibration,

wherein the transverse ultrasonic vibration along a length of the flexible member produces a plurality of transverse nodes and anti-nodes along the length of the flexible member wherein at least a portion of the length of the flexible member is used in a medical procedure, wherein more than one of the plurality of transverse anti-nodes are in communication with a biological material.

2. A device according to claim 1, wherein the ultrasonic generator produces an ultrasonic vibration in the range of about 20 khz to about 80 khz.

3. A device according to claim 1, wherein the ultrasonic generator produces an ultrasonic vibration of approximately 20 khz.

4. A device according to claim 3, wherein a length of the flexible member is chosen so that eight nodes are produced along the length of the flexible member.

5. A device according to one of claims 1-4, wherein the flexible member is a thin, flexible member capable of being deflected and articulated when the device is in operation.

6. A device according to claim 5, wherein at least one transformer section is formed of one of the following materials:

titanium, aluminum, or steel.

7. A device according to one of claims 1-4, wherein the flexible member is formed of one of the following materials:

titanium, aluminum, or steel.

8. A device according to one of claims 1-4, wherein the transformer section is sized so that it produces a gain of about 4-5 over a transducer.

9. A device according to claim 1, wherein the flexible member has a circular cross-section.

10. A device according to claim 9, wherein the flexible member has a diameter of less than about 1 mm.

11. A device according to claim 9, wherein the flexible member has a diameter of about 0.020 inches.

12. A device according to claim 9, wherein the flexible member has a diameter of about 0.030 inches.

13. A device according to claim 1, wherein the flexible member has a square cross-section.

14. A device according to claim 1, wherein the flexible member has a rectangular cross-section.

15. A device according to claim 1, wherein the flexible member has an elliptical cross-section.

16. A device according to claim 1, wherein the flexural stiffness of the flexible member is in the range of about 2.5×

10⁷ N/m to about 8.5×

10⁷ N/m.

17. A method of removing a biological material from a cavity in a human body, comprising the steps of:

(a) providing a flexible member with a proximal end, a distal end and a longitudinal axis wherein the flexible member has a degree of stiffness which allows the flexible member to support a transverse ultrasonic vibration;

(b) providing an ultrasonic vibration to the proximal end of the flexible member, the ultrasonic vibration being along the longitudinal axis of the flexible member;

(c) sweeping a length of the flexible member through the biological material so that it emulsifies the biological material;

wherein the ultrasonic vibration creates the transverse ultrasonic vibration along the length of the flexible member so that a plurality of transverse nodes and anti-nodes are formed along the length of the flexible member.

18. A method according to claim 17, wherein the ultrasonic generator produces an ultrasonic vibration in the range of about 20 khz to about 80 khz.

19. A method according to claim 17, wherein the ultrasonic generator produces an ultrasonic vibration of approximately 20 khz.

20. A method according to claim 19, wherein a length of the flexible member is chosen so that eight nodes are produced along the length of the flexible member.

21. A method according to one of claims 17-20, wherein the flexible member is a thin, flexible member capable of being deflected and articulated.

22. A method according to claim 17, wherein the flexible member is formed of one of the following materials:

titanium, aluminum, or steel.

23. A method according to claim 17, wherein the flexible member has a circular cross-section.

24. A method according to claim 23, wherein the flexible member has a diameter of less than about 1 mm.

25. A method according to claim 23, wherein the flexible member has a diameter of about 0.020 inches.

26. A method according to claim 23, wherein the flexible member has a diameter of about 0.030 inches.

27. A method according to claim 17, wherein the flexible member has a square cross-section.

28. A method according to claim 17, wherein the flexible member has a rectangular cross-section.

29. A method according to claim 17, wherein the flexible member has an elliptical cross-section.

30. A method according to claim 17, wherein the flexural stiffness of the flexible member is in the range of about 2.5×

10⁷ N/m to about 8.5×

10⁷ N/m.

31. A method according to claim 17, wherein the biological material is emulsified by the mechanism of cavitation.

32. A method according to claim 17, wherein the biological material is emulsified by mechanical action.

33. A method according to claim 17, wherein the flexible member has an area of the biological material destroying effect greater than a cross-sectional area of the flexible member.

34. The method of claim 17 wherein the biological material is a tissue.

35. A method of destroying a biological material comprising the steps of:

(a) providing a flexible member with a proximal end, a distal tip, and a longitudinal axis wherein the flexible member has a degree of stiffness which allows the flexible member to support a transverse ultrasonic vibration;

(b) applying an ultrasonic vibration to the proximal end of the flexible member, the ultrasonic vibration being in the direction of the longitudinal axis of the flexible member;

(c) generating a series of transverse nodes and anti-nodes along a length of the flexible member so that there is substantially no longitudinal motion of the distal tip; and

(d) placing the length of the flexible member in communication with the biological material so that the length of the flexible member destroys the biological material.

36. A method according to claim 35, wherein the flexible member communicates with the biological material through a fluid, and the flexible member causes cavitation which destroys the biological material.

37. The method of claim 35 wherein the biological material is a tissue.

38. A method of treating a biological material comprising steps of:

(a) providing a flexible member with a longitudinal axis, a distal end, and a proximal end wherein the flexible member has a degree of stiffness which allows the flexible member to support a transverse ultrasonic vibration;

(b) generating the transverse ultrasonic vibration in a length of the flexible member so that a plurality of transverse nodes and anti-nodes are formed along the length of the flexible member; and

(c) placing the length of the flexible member into communication with the biological material so that the biological material is destroyed.

39. A method according to claim 38, wherein the flexible member causes cavitation in a fluid in contact with the biological material so that the biological material is destroyed by cavitation.

40. A method according to claim 38 or 39, wherein the step of generating the transverse ultrasonic vibration in the length of the flexible member is accomplished by providing an ultrasonic vibration to the proximal end of the flexible member.

41. A method according to claim 40, wherein the ultrasonic vibration has a frequency in the range of about 20 kHz to about 80 kHz.

42. A method according to one of claims 38-39, wherein there is substantially no longitudinal motion at the distal end of the flexible member.

43. The method of claim 38 wherein the biological material is a tissue.

44. A method of operating an ultrasonic medical device, comprising the steps of:

(a) providing a flexible member with a proximal end, a distal end, and a longitudinal axis wherein the flexible member has a degree of stiffness which allows the flexible member to support a transverse ultrasonic vibration;

(b) providing an ultrasonic generator to apply an ultrasonic vibration to the proximal end of the flexible member, the ultrasonic vibration being along the longitudinal axis of the flexible member;

(c) controlling the amplitude and frequency of the ultrasonic vibration to produce the transverse ultrasonic vibration in the flexible member; and

(d) producing a plurality of nodes and anti-nodes along a length of the flexible member wherein more than one of the plurality of transverse anti-nodes are in communication with a biological material.

45. A method according to claim 44, wherein the frequency is in the range of about 20 kHz to about 80 kHz.

46. A method according to claim 45, wherein the amplitude is in the range of about 150 microns to about 350 microns.

47. A method according to claim 44, wherein the amplitude is in the range of about 150 microns to about 350 microns.

48. A method according to claim 44, wherein the length of the flexible member is placed into contact with fluid in contact with the biological material so that the biological material is destroyed by cavitation.

49. A method according to one of claim 44, 45, 46 or 47 wherein there is substantially no longitudinal motion at the distal end of the flexible member.

50. An ultrasonic device comprising:

a flexible member with a longitudinal axis, a proximal end, and a distal end wherein the flexible member has a degree of stiffness which allows the flexible member to support a transverse ultrasonic vibration; and

an ultrasonic generator coupled to the proximal end of the flexible member, the generator creating ultrasonic vibrations in the direction of the longitudinal axis of the flexible member,

wherein a length and a cross-section of the flexible member are sized so that the ultrasonic vibrations are converted into the transverse ultrasonic vibration with a plurality of transverse nodes and anti-nodes along at least a portion of the length of the flexible member, and there is substantially no motion along the longitudinal axis at the distal end of the flexible member, wherein more than one of the plurality of transverse anti-nodes are in communication with a biological material.

51. A device according to claim 50, further comprising:

a series of transformer sections located between the ultrasonic generator and the flexible member, the transformer sections modifying the amplitude of the ultrasonic vibrations.

52. A device according to one of claim 50 or 51, further comprising:

a control device connected to the ultrasonic generator to control the frequency and amplitude of the generated vibrations.

53. A device according to one of claim 50 or 51, further comprising a sheath surrounding the transformer sections and a portion of the flexible member.

54. A device according to claim 53, wherein the sheath includes irrigation channels.

55. A device according to claim 53, wherein the sheath includes aspiration channels.

56. A device according to claim 53, wherein the sheath includes irrigation and aspiration channels.

57. A device according to claim 53, wherein the sheath and the flexible member are axially displaceable with one another so that a varying number of nodes are exposed.