FLASH VAPORIZATION SURGICAL SYSTEMS

• US 20130035676A1
• Filed: 04/22/2011
• Published: 02/07/2013
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Precise Light Surgical, Inc.
• Original Assignee: Precise Light Surgical, Inc.
• Inventors: Mitchell, Gerald, Arnold, Kenneth J.
• Granted Patent: US 9,622,819 B2
• Time in Patent Office: Days
• US Class Current: 606/10
• CPC Class Codes: A61B 18/22 the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
• CPC Class Codes: A61B 2017/00172 Pulse trains, bursts, intermittent continuous operation
• CPC Class Codes: A61B 2017/00199 with a console, e.g. a control panel with a display
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00601 Cutting
• CPC Class Codes: A61B 2018/00607 Coagulation and cutting with the same instrument
• CPC Class Codes: A61B 2018/00696 Controlled or regulated parameters
• CPC Class Codes: A61B 2018/00714 Temperature
• 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 2018/2222 Fibre material or composition
• CPC Class Codes: A61B 2018/2244 Features of optical fibre cables, e.g. claddings
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems

Abstract

A laser can produce pulses of light energy to eject a volume of the tissue, and the energy can be delivered to a treatment site through a waveguide, such as a fiber optic waveguide. The incident laser energy can be absorbed within a volume of the target tissue with a tissue penetration depth and pulse direction such that the propagation of the energy from the tissue volume is inhibited and such that the target tissue within the volume reaches the spinodal threshold of decomposition and ejects the volume, for example without substantial damage to tissue adjacent the ejected volume.

Claims

1. A method for tissue removal, comprising

producing laser pulses having a wavelength between 1400 and 1520 nm or between 1860 and 2500 nm, having between 1 and 40 milliJoules per pulse, and having a pulse duration less than 200 nsec;

and

delivering the pulses to a spot on the tissue, whereby an interaction volume defined by the area of the spot and the penetration depth (1/e) for the pulse in water, the interaction volume having a ratio of depth to width from 2;

1 to 1;

6.

2. The method of claim 1, including delivering the laser pulses to the target tissue using a silica waveguide.

3. The method of claim 1, wherein a pulse repetition rate, is from single shot to 2 kHz.

4. The method of claim 1, wherein the laser pulses deliver a volumetric power density to the interaction volume that induces spinodal decomposition of water in the tissue and kinetic energy confined within the interaction volume to eject tissue.

5. The method of claim 1, wherein the volumetric power density delivered to each spot is greater than 10¹⁰ W/cm³.

6. The method of claim 1, wherein the laser pulses have a pulse duration less than 100 nsec.

7. The method of claim 1, wherein the wavelength is between 1860 and 2500 nm and pulse energy from 1 to 30 milliJoules per pulse.

8. A method for tissue removal, comprising producing laser pulses having a wavelength between 1880 and 2080 nm or between 2340 and 2500 nm, having between 1 and 10 milliJoules per pulse, and having a pulse duration less than 200 nsec;

and

delivering the pulses to a spot on the tissue having a spot width or diameter in a range of 10 to 300 microns.

9. The method of claim 8, including delivering the pulses using a silica fiber optic.

10. The method of claim 8, wherein a pulse repetition rate, is from single shot to 2 KHz.

11. The method of claim 8, wherein the laser pulses deliver a volumetric power density to the interaction volume that induces spinodal decomposition of water in the tissue and kinetic energy confined within the interaction volume to eject tissue.

12. The method of claim 8, wherein the volumetric power density delivered to each spot is greater than 10¹⁰ W/cm³.

13. The method of claim 8, wherein the pulse duration is less than 100 nsec.

14. A method for tissue removal, comprising

producing laser pulses having a wavelength (λ

) and pulse duration (t_p); and

delivering the laser pulses to spots on the tissue, the laser pulses having an energy per pulse (E_p) to heat an interaction volume of the tissue above a spinodal decomposition threshold for water within the pulse duration, and cause sufficient pressure for ejection of remaining tissue, and wherein the spots have a dimension equal to a smallest distance across the spot, and the pulse duration (t_p) is within a factor of 3 of a time for propagation of an acoustic wave a lesser of one-half said dimension and the penetration depth.

15. The method of claim 14, including delivering the sequence laser pulse using a silica optical fiber, with energy and pulse duration combinations that are below the damage threshold for the silica optical fiber.

16. The method of claim 14, wherein the volumetric power density delivered to each spot is greater than 10¹⁰ W/cm³.

17. The method of claim 14, wherein the tissue is heated with substantial stress and thermal confinement above a threshold of spinodal decomposition to a temperature of at least about 300 degrees C., such that a temporally and spatially uniform phase transition occurs within the volume, generating sufficient pressure to eject the volume without substantial energy deposition to tissue adjacent a cavity left by the ejected tissue.

18. The method of claim 14, wherein the temporally and spatially uniform phase transition within the interaction volume creates a confined recoil stress to efficiently remove tissue within the interaction volume without depositing substantial energy in the tissue adjacent a cavity left by the removed tissue.

19. The method of claim 14, wherein the laser pulses have a tissue penetration depth of at least about 50 microns.

20. The method of claim 14, wherein the laser pulses have a tissue penetration depth of within a range from at least about 50 microns to no more than about 700 um.

21. The method of claim 14, wherein the volume is ejected without substantial stress propagation of mechanical energy into the tissue adjacent to the target volume and without substantial thermal diffusion of thermal energy into the tissue adjacent to the target volume.

22. The method of claim 14, wherein the laser pulses are transmitted through an optical fiber and have a wavelength from about 1.4 microns to 1.52 microns or from about 1.86 to about 2.5 microns to define the interaction volume based substantially on water absorption.

23. The method of claim 14, wherein the duration of each pulse is within a range from about 100 pico seconds to about 1 micro second.

24. The method of claim 14, wherein the duration of each pulse is within a range from about 500 pico seconds to about 200 nano seconds.

25. The method of claim 14, wherein the pulse duration is within a range from about 1 nanoseconds to about 100 nanoseconds.

26. The method of claim 14, wherein the interaction volume corresponds to a depth and a width ejected with each pulse and wherein a ratio of the depth to the width is within a range from about 2:

1 to 1;

6.

27. The method of claim 14, wherein the amount of energy of each pulse is within a range from about 1 milli Joule to about 40 milli Joules.

28. The method of claim 14, wherein the tissue comprises collagen and wherein the collagen is liquefied with each pulse of the light energy.

29. The method of claim 14, wherein the tissue comprises one or more of vascular soft tissue, cartilage or bone.

30. The method of claim 14, wherein an elongated incision having a length and a depth is formed in the tissue with the laser pulses, and wherein the length and the width correspond to an area of the incision into the tissue and wherein tissue removal rate is at least about 10⁻

8 cm³/pulse.

31. The method of claim 14, wherein the removal rate comprises at least about 10⁻

7 cm³/pulse.

32. The method of claim 14, wherein the light energy is transmitted through at least one optical fiber with an energy transmission efficiency of at least about 80%.

33. An apparatus to treat tissue, the apparatus comprising:

a laser system to generate a laser pulses having a wavelength between 1400 and 1520 nm or between 1860 and 2500 nm, having between 1 and 40 milliJoules per pulse, and having a pulse duration less than 200 nsec; and

a beam delivery device coupled to the laser, to deliver pulses from the laser to spots on the tissue;

whereby an interaction volume defined by the area of the spot and the penetration depth (1/e) for the pulse in water, the interaction volume having a ratio of depth to width from 2;

1 to 1;

6.

34. The apparatus of claim 33, wherein the beam delivery device includes a silica waveguide.

35. The apparatus of claim 33, wherein the silica waveguide has a core diameter in a range of 10 to 300 microns.

36. The apparatus of claim 33, wherein a pulse repetition rate is from single shot to 2 kHz.

37. The apparatus of claim 33, wherein the wavelength is between 1880 and 2080 nm or between 2340 and 2500 nm, and the pulses have between 1 and 30 milliJoules per pulse, and a pulse duration less than 200 nsec.

38. The apparatus of claim 33, wherein the pulse duration is less than 100 nsec.

39. The apparatus of claim 33, wherein the laser system includes a gain medium comprising a thulium doped host.

40. The apparatus of claim 33, wherein the beam delivery device comprises a plurality of waveguides, arranged to deliver a plurality of pulses in a pattern of spots on the tissue.

41. The apparatus of claim 33, wherein the beam delivery device comprises a plurality of waveguides, arranged to deliver a plurality of pulses in parallel to a single spot.

42. The apparatus of claim 33, wherein the beam delivery device comprises an endoscope including one or more waveguides.

43. The apparatus of claim 33, wherein the beam delivery device comprises a flexible endoscope including a silica optical fiber having a core diameter between 50 microns and 200 microns.

44. The apparatus of claim 33, wherein the laser pulses deliver a volumetric power density to the interaction volume that induces spinodal decomposition of water in the tissue and kinetic energy confined within the interaction volume to eject tissue.

45. The apparatus of claim 33, wherein the volumetric power density delivered to each spot is greater than 10¹⁰ W/cm³.

46. An apparatus to treat tissue, the apparatus comprising:

a laser system to generate a laser pulses having wavelength between 1880 and 2080 nm or between 2340 and 2500 nm, having between 1 and 10 milliJoules per pulse, and having a pulse duration less than 200 nsec; and

a beam delivery device including a fiber optic and delivers the laser pulses to the tissue with a spot size in a range of 10 to 300 microns coupled to the laser.

47. The apparatus of claim 46, wherein the laser pulses deliver a volumetric power density to the interaction volume that induces spinodal decomposition of water in the tissue and kinetic energy confined within the interaction volume to eject tissue.

48. The apparatus of claim 46, wherein the volumetric power density delivered to each spot is greater than 10¹⁰ W/cm³.

49. The apparatus of claim 46, wherein the fiber optic is a silica fiber with a core from 50 to 200 um.

50-159. -159. (canceled)