Ultrasonic transmission apparatus

• US 5,269,297 A
• Filed: 02/27/1992
• Issued: 12/14/1993
• Est. Priority Date: 02/27/1992
• Status: Expired due to Fees

• Current Assignee: Angiosonics, Inc. (Acolysis Intravascular Ultrasound Business) (Teleflex Incorporated)
• Original Assignee: Angiosonics, Inc. (Acolysis Intravascular Ultrasound Business) (Teleflex Incorporated)
• Inventors: Scribner, Robert M., Weng, Li
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): GILBERT, SAMUEL G
• Application Number:
  US07/842,529
• Time in Patent Office: 656 Days
• Field of Search: 128/24 AA, 604/22, 606/128, 433/119, 310/15, 310/328
• US Class Current: 606/128
• 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 2017/00336 with a protective sleeve, e.g. retractable or slidable
• CPC Class Codes: A61B 2017/22018 segmented along its length
• CPC Class Codes: A61B 2017/22092 Lubricant
• CPC Class Codes: A61B 2017/320073 probe
• CPC Class Codes: B06B 3/00 Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency

Abstract

A horn connectable to an energy source to amplify ultrasound displacement is connected to a transmitter formed of material having relatively high mechanical Q for transmitting ultrasonic energy therethrough at a frequency f, the transmitter having a horn-shaped configuration of length that is a multiple of a half-wavelength λ/2, and preferably this horn-shaped configuration is comprised of multiple horn segments, each of a length substantially equal to a multiple of λ/2, where λ=c/f (c is the speed of sound in the high Q material). The transmitter has a proximal end of cross-sectional diameter D₁ connected to the horn and a distal end of cross-sectional diameter D₂, where D₁ >D₂. Ultrasonic energy transmitted through the transmitter drives a tip which is coupled to the transmitter by means of a flexible connector.

Claims

1. Ultrasonic transmission apparatus comprising:

a horn connectable to an energy source for amplifying ultrasound displacement;

transmission means formed of material having relatively high mechanical Q for transmitting ultrasonic energy therethrough at a frequency f and comprised of multiple ultrasonic horn-shaped segments distributed longitudinally along said transmission means, each horn-shaped segment having a length substantially equal to a multiple of λ

/2, where λ

=c/f (c is the speed of sound in said material), the transmission means having a proximal end of cross-sectional diameter D₁ connected to said horn and a distal end of cross-sectional diameter D₂, where D₁ >

D₂ ;

a tip driven by said ultrasonic energy; and

flexible means having a first end connected to the distal end of said transmission means and a second end connected to said tip for transferring to said tip the ultrasonic energy which is received from said transmission means.

2. The apparatus of claim 1 wherein said flexible means is comprised of plural wires, each of a diameter less than D₂.

3. The apparatus of claim 2 wherein said flexible means further includes means for isolating each of said plural wires.

4. The apparatus of claim 3 further including a base member coupling ends of said plural wires to said distal end of said transmission means.

5. The apparatus of claim 4 wherein said base member has a length L_b, said flexible means has a length L and said tip has a length L_t and L+L_b +L_t =k λ

/2, where k is an integer, λ

'"'"'=c'"'"'/f, c'"'"' is the effective speed of sound through said base member, said flexible means and said tip, and f is the frequency of said ultrasonic energy.

6. The apparatus of claim 4 wherein said base member comprises a generally cylindrical housing having a central recess of diameter substantially equal to D₂ open at one end of said housing receiving said distal end of said transmission means, and plural recesses open at an opposite end of said housing receiving the first ends of said plural wires.

7. The apparatus of claim 3 wherein said means for isolating each of said plural wires comprises tubular channel means for disposal about said wires.

8. The apparatus of claim 7 wherein said tubular channel means is comprised of plural flexible tubes, each disposed about a respective wire.

9. The apparatus of claim 7 wherein said transmission means is further comprised of straight segments interspersed with said horn-shaped segments, each straight segment having a length substantially equal to a multiple of λ

/2.

10. The apparatus of claim 9 wherein said transmission means further comprises a sleeve disposed about at least those of said horn-shaped and straight segments expected to be inserted in a lumen with which said apparatus is used, said sleeve having a proximal end portion and a distal end portion secured to said tubular channel means.

11. The apparatus of claim 10 wherein said sleeve is of flexible material and has an inner diameter which, at any longitudinal location thereof, is greater than the diameter of said transmission means at the same longitudinal location.

12. The apparatus of claim 10 wherein said tubular channel means has a distal end spaced from said tip and open to permit fluid to flow through said tubular channel means.

13. The apparatus of claim 12 wherein said sleeve has an inner diameter spaced from said transmission means to define a fluid channel;

and further comprising fluid supply means for supplying fluid through said fluid channel to said tubular channel means to provide a lubricant for and to reduce the transverse vibration of said transmission means.

14. The apparatus of claim 13 wherein said fluid supply means comprises an input conduit coupled to said sleeve in the vicinity of said proximal end portion thereof for coupling fluid thereto, and valve means in fluid communication with said proximal end portion of said sleeve to prevent backflow of fluid through said sleeve.

15. The apparatus of claim 14 wherein said fluid supply means further includes a coupling channel for coupling said proximal end portion of said sleeve to said horn, and wherein said valve means comprises a manually tightened cap disposed over said coupling channel and said horn and operable to seal an O-ring at a node of longitudinal, ultrasonic vibration.

16. The apparatus of claim 15 wherein said horn is provided with a pair of annular shoulders at said node of longitudinal ultrasonic vibration to define the location of said O-ring.

17. The apparatus of claim 13 further including a protective sheath coupled in fluid tight relation to said sleeve and disposed over at least one segment at the proximal end of said transmission means to enable a user to grasp said proximal end when guiding said transmission means into the lumen without substantially damping ultrasonic vibrations of said transmission means.

18. The apparatus of claim 17 wherein said at least one segment over which said protective sheath is disposed is provided with plural annular shoulders located at nodes of ultrasonic vibration to contact said sheath in the event said sheath is deformed;

said sheath having an inner diameter spaced from said transmission means to define a fluid conduit in fluid communication with the fluid channel of said sleeve.

19. The apparatus of claim 18 wherein said means for supplying fluid to said channel is coupled to said protective sheath;

and wherein said fluid additionally prevents backflow through said tubular channel means and said fluid channel to said fluid conduit.

20. The apparatus of claim 2 wherein each of the wires of said flexible means is formed of material having a tensile strength different than that of the material of said transmission means.

21. The apparatus of claim 2 wherein said transmission means is formed of aluminum and the wires of said flexible means are formed of titanium.

22. The apparatus of claim 21 wherein said horn and transmission means are of unitary construction.

23. The apparatus of claim 1 wherein said transmission means includes straight segments each of a length that is a multiple of λ

/2 and interspersed with said horn-shaped segments, the transmission means further including a protective sheath disposed over at least one segment at the proximal end of said transmission means and formed of relatively rigid material which, when grasped by a user, does not deform into contact with said transmission means and thereby damp ultrasonic vibrations thereof.

24. The apparatus of claim 23 wherein the protective sheath has a distal end located substantially at a node of ultrasonic vibration in said transmission means.

25. The apparatus of claim 1 wherein said tip is configured to enhance cavitation in a fluid.

26. The apparatus of claim 25 wherein said tip is comprised of proximal and distal portions having respective diameters and interconnected by an intermediate portion having a thickness less than the diameter of each of said proximal and distal portions, said proximal, intermediate and distal portions having a common longitudinal axis.

27. The apparatus of claim 26 wherein said proximal, distal and intermediate portions are of unitary construction and said flexible means is secured to said proximal portion.

28. The apparatus of claim 26 wherein said distal portion is of substantially truncated semi-spheroid shape and said proximal portion is of cylindrical shape.

29. The apparatus of claim 26 wherein said distal and proximal portions both are of cylindrical shape.

30. The apparatus of claim 29 wherein said distal portion has a concave-shaped face.

31. The apparatus of claim 26 wherein said proximal, intermediate and distal portions have a common longitudinal channel to receive a guide wire for guiding said tip, and thereby said flexible means and said transmission means, through a lumen.

32. The apparatus of claim 31 wherein said flexible means includes a center channel in communication with said common longitudinal channel for receiving said guide wire.

33. The apparatus of claim 32 further comprising a central guide wire conduit disposed in said common longitudinal channel and said center channel for guiding said guide wire through said tip and through said flexible means.

34. The apparatus of claim 26 wherein the diameter of the proximal portion is substantially equal to the diameter of the distal portion.

35. The apparatus of claim 1 wherein said transmission means includes straight segments separating said horn-shaped segments, each straight segment having a length substantially equal to a multiple of λ

/2.

36. The apparatus of claim 35 wherein the length of a straight segment disposed between successive horn-shaped segments differs from the length of either of said successive horn-shaped segments.

37. The apparatus of claim 35 wherein each horn-shaped segment has a distal end diameter less than its proximal end diameter.

38. Ultrasonic transmission apparatus comprising:

an input horn connectable to an energy source for amplifying ultrasound displacement;

a horn-shaped transmitter formed of material having relatively high mechanical Q for transmitting ultrasonic energy therethrough at a frequency f and having a length substantially equal to a multiple of λ

/2, where λ

=c/f (c is the speed of sound in said material), the horn-shaped transmitter having a proximal end of cross-sectional diameter D₁, connected to said input horn and a distal end of cross-sectional diameter D₂, wherein D₁ >

D₂ ;

a tip driven by said ultrasonic energy; and

flexible means having a first end connected to the distal end of said horn-shaped transmitter and a second end connected to said tip for transferring to said tip the ultrasonic energy which is received from said horn-shaped transmitter, said flexible means being comprised of plural wires, each of a diameter less than D₂.

39. The apparatus of claim 38 wherein said flexible means includes means for isolating each of said plural wires.

40. The apparatus of claim 39 wherein each of said wires is formed of material having a tensile strength different than that of the material of said horn-shaped transmitter.

41. The apparatus of claim 40 wherein said means for isolating each of said plural wires comprises tubular channel means for disposal about said wires.

42. The apparatus of claim 41 wherein said tubular channel means is comprised of plural flexible tubes, each disposed about a respective wire.

43. The apparatus of claim 41 wherein at least a portion of said horn-shaped transmitter is disposed in a sleeve, the sleeve being formed of flexible material and having a distal end portion secured to said tubular channel means and a proximal end portion.

44. The apparatus of claim 43 wherein said tubular channel means has a distal end spaced from said tip and open to permit fluid to flow through said tubular channel means.

45. The apparatus of claim 43 further comprising fluid supply means for supplying fluid through said sleeve to said tubular channel means to provide a lubricant for and to reduce transverse vibration of said horn-shaped transmitter.

46. The apparatus of claim 45 further including a protective sheath coupled in fluid tight relation to said sleeve and disposed over a proximal portion of said horn-shaped transmitter to enable a user to grasp said proximal portion when guiding the transmitter into a lumen without substantially damping ultrasonic vibrations of said transmitter.

47. The apparatus of claim 46 wherein said protective sheath, said sleeve and said tubular channel means comprise a fluid conduit from said fluid supply means to said tip;

and wherein said fluid additionally prevents backflow through said fluid conduit.

48. The apparatus of claim 38 wherein the horn-shaped transmitter is formed of aluminum and the wires of said flexible means are formed of titanium.

49. A tip for use in ultrasonic transmission apparatus driven for longitudinal, reciprocating displacement, comprising a proximal portion connectable to an ultrasonic transmitter, a distal portion and an intermediate portion connecting said proximal and distal portions, the proximal and distal portions having respective diameters and the intermediate portion having a thickness less than the diameter of each of said proximal and distal portions, said proximal, distal and intermediate portions having a common longitudinal axis, said distal portion being of substantially truncated semi-spheroid shape and having a first front face and said proximal portion being of cylindrical shape.

50. A tip for use in ultrasonic transmission apparatus driven for longitudinal, reciprocating displacement, comprising a proximal portion connectable to an ultrasonic transmitter, a distal portion and an intermediate portion connecting said proximal and distal portions, the proximal and distal portions having respective diameters and the intermediate portion having a thickness less than the diameter of each of said proximal and distal portions, said proximal, distal and intermediate portions having a common longitudinal axis, said distal portion being mushroom-shaped and said proximal portion being reverse mushroom-shaped.

51. A tip for use in ultrasonic transmission apparatus driven for longitudinal, reciprocating displacement, comprising a proximal portion connectable to an ultrasonic transmitter, a distal portion and an intermediate portion connecting said proximal and distal portions, the proximal and distal portions having respective diameters and the intermediate portion having a thickness less than the diameter of each of said proximal and distal portions, said proximal, distal and intermediate portions having a common longitudinal axis, and a disk-shaped intermediate section secured to said intermediate portion and disposed between said distal and proximal portions.