FLASH VAPORIZATION SURGICAL SYSTEMS

• US 20110196355A1
• Filed: 04/22/2011
• Published: 08/11/2011
• Est. Priority Date: 11/18/2008
• Status: Active Grant

• Current Assignee: Precise Light Surgical, Inc.
• Original Assignee: Precise Light Surgical, Inc.
• Inventors: Arnold, Kenneth J., Mitchell, Gerald
• Granted Patent: US 8,881,735 B2
• Time in Patent Office: Days
• US Class Current: 606/11
• 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 system for treating tissue, the system comprising:

a laser to generate a laser beam;

a controller which controls the laser in response to parameters including pulse length and pulse energy; and

a user interface connected to controller, said interface comprising a user selectable adjustment to select first and second modes;

wherein the controller adjusts the laser to operate successively in the first mode with a first set of adjustable parameters and the second mode with a second set of adjustable parameters, and wherein the controller causes dynamic transition between the first and second modes during an exposure; and

a beam delivery device coupled to the laser to deliver the laser beam to target tissue during the exposure.

2. The system of claim 1, wherein the controller controls both a q-switch and a pump source, and the first set of parameters includes a first set of q-switch parameters and a first set of pump pulse parameters which cause generation of one or more pulses each having both a pulse width between 1 ns and 500 ns and a fluence at the treatment site between 5 J/cm2 and 500 J/cm2 and the second set of parameters includes a second set of q-switch parameters and a second set of pump pulse parameters, wherein the q-switch is in the off mode, which cause generation of an average irradiance at a treatment site between 500 W/cm2 and 1 MW/cm2.

3. The system of claim 1, wherein the controller controls both a q-switch and a pump source, and the first set of parameters includes a first set of q-switch parameters and a first set of pump pulse parameters generating one or more pulses each having both a pulse width between 1 ns and 500 ns and a fluence at a treatment site between 5 J/cm2 and 500 J/cm2, and the second set of parameters includes a second set of q-switch parameters and a second set of pump pulse parameters with one or more pulses each having both a pulse width of at least 1.2×

greater than the pulse width of the first mode and a fluence at a treatment site of at least 0.8×

less than the fluence at the treatment site of the first mode.

4. The system of claim 1, wherein a pulse period between each pulse of said first mode is between 200 us and 200 ms.

5. The system of claim 1, wherein the laser beam has a treatment spot size between 10 μ

m and 300 μ

m.

6. The system of claim 1, wherein the laser beam has a wavelength between 1.8 μ

m and 2.2 μ

m.

7. The system of claim 1, wherein the laser beam has a wavelength of substantially 1.94 μ

m.

8. The system of claim 1, wherein the laser has a gain medium comprising Tm doped host.

9. The system of claim 1, wherein the laser has a gain medium comprising Ho doped host.

10. The system of claim 1, wherein the laser gain medium is end pumped.

11. The system of claim 1, wherein the laser beam has an M2 is less than 10.

12. The system of claim 1, wherein the system further comprises a silica core waveguide to deliver the laser energy to the treatment site.

13. The system of claim 12, wherein the waveguide core diameter is between 25 μ

m and 150 μ

m.

14. The system of claim 1, wherein the user selectable adjustment is presented on the user interface in terms of to a depth of thermal damage.

15. The system of claim 14 wherein the depth of thermal damage represented on the user interface is between 0 μ

m and substantially 2 mm.

16. The system of claim 1, wherein the depth of thermal damage in one of the first and second modes is less than 50 μ

m.

17. The system of claim 1, wherein one of the first and second sets of parameters causes flash vaporization.

18. A method of treating tissue comprising:

storing laser system parameters for first and second modes;

generating a laser beam in response to the parameters and delivering the laser beam to a treatment site during an exposure;

under control of a controller, running the laser during the exposure successively in the first mode with a first set of adjustable parameters and the second mode with a second set of adjustable parameters, and transitioning dynamically between the first and second modes during the exposure.

19. The method of claim 18, wherein the first set of parameters includes a first set of q-switch parameters and a first set of pump pulse parameters with one or more pulses each having both a pulse width between 1 ns and 500 ns and a fluence at the treatment site between 5 J/cm2 and 500 J/cm2, and the second set of parameters includes a second set of q-switch parameters and a second set of pump pulse parameters wherein the laser beam is substantial continuous wave with an average irradiance at the treatment site between 500 W/cm2 and 1 MW/cm2.

20. The method of claim 18, wherein the first set of parameters includes a first set of q-switch parameters and a first set of pump pulse parameters generating one or more pulses each having both a pulse width between 1 ns and 500 ns and a fluence at a treatment site between 5 J/cm2 and 500 J/cm2, and the second set of parameters includes a second set of q-switch parameters and a second set of pump pulse parameters with one or more pulses each having both a pulse width of at least 1.2×

greater than the pulse width of the first mode and a fluence at a treatment site of at least 0.8×

less than the fluence at the treatment site of the first mode.

21. The method of claim 18, wherein a pulse period between each pulse of said first mode is between 200 us and 200 ms.

22. The method of claim 18, wherein the laser beam has a treatment spot size between 10 μ

m and 300 μ

m.

23. The method of claim 18, wherein the laser beam has a wavelength between 1.8 μ

m and 2.2 μ

m.

24. The method of claim 18, wherein the laser beam has a wavelength of substantially 1.94 μ

m.

25. The method of claim 18, wherein the laser has a gain medium comprising a Tm doped host.

26. The method of claim 18, wherein the laser has a gain medium comprising Ho doped host.

27. The method of claim 18, wherein the laser gain medium is end pumped.

28. The method of claim 18, wherein the laser beam has an M2 is less than 10.

29. The method of claim 18, wherein the method further comprises using a silica core waveguide to deliver the laser energy to the treatment site.

30. The method of claim 29, wherein the waveguide core diameter is between 25 μ

m and 150 μ

m.

31. The method of claim 18, including presenting a user interface to a user representing user selectable adjustment to specify the first and second sets of parameters in terms of a depth of thermal damage.

32. The method of claim 31, wherein the depth of thermal damage represented on the user interface is between 0 μ

m and substantially 2 mm.

33. The method of claim 18, wherein the depth of thermal damage in one of the first and second modes is from less than 50 μ

m.

34. The method of claim 18, including presenting a user interface to a user representing user selectable adjustments for specifying the parameters, wherein the user selectable adjustment corresponds to at least one of;

said first set of q-switch parameters, first set of pump pulse parameters, second set of q-switch parameters, second set of pump pulse parameters, duration of first mode and duration of second mode.

35. The method of claim 18, wherein one of the first and second modes causes flash vaporization.