Method and device for electro microsurgery in a physiological liquid environment

• US 6,620,160 B2
• Filed: 01/10/2002
• Issued: 09/16/2003
• Est. Priority Date: 09/26/1996
• Status: Expired due to Fees

• Current Assignee: Nanoptics, Incorporated
• Original Assignee: Nanoptics, Incorporated
• Inventors: Palanker, Daniel V., Turovets, Igor, Lewis, Aaron
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US10/041,746
• Publication Number:
  US 20020062126A1
• Time in Patent Office: 614 Days
• Field of Search: 606/41, 606/42, 606/45-50, 606/169, 606/2.5, 604/114, 607/100-105
• US Class Current: 606/45
• CPC Class Codes: A61B 17/22022 using electric discharge
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 18/26 for producing a shock wave, e.g. laser lithotripsy
• CPC Class Codes: A61B 2017/00154 pulsed
• CPC Class Codes: A61B 2017/22008 used or promoted
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00601 Cutting
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/1425 Needle
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: Y10S 977/856 including etching/cutting

Abstract

A method and device for electrical emulation of pulsed laser is disclosed. The device utilizes high voltage electrical discharges of sub-microsecond duration in a liquid medium to produce cavitation bubbles of sub-millimeter size for use in high speed precision cutting. Such bubbles are produced by a micro-electrode (1.6) having a central wire having a diameter of 1 microns to 100 microns embedded in an insulator. A coaxial electrode (1.9) surrounds the insulator, and may be spaced from the outer surface of insulator to provide a path for removing tissue.

Claims

1. A method of cutting and removing tissue in a physiological liquid environment comprising:

generating a high-voltage, submicrosecond duration electrical discharge in a conducting liquid-containing medium with pulse energies in the range of 1-1000 μ

J to produce a cavitation bubble in said medium;

causing said discharge to have a duration sufficiently short to produce a bubble having a diameter no greater than about 0.5 mm in said medium with characteristics that emulate the action of pulsed lasers in said medium;

and directing said cavitation bubbles toward said tissue.

2. The method of claim 1, further including generating a discharge having a duration in the range of 0.030 to 3.0 microseconds.

3. The method of claim 2, further including generating said cavitation bubbles so as to cause the bubbles to collapse after reaching a maximum diameter of 0.5 mm.

4. The method of claim 1, including generating a parallel array of said cavitation bubbles in said medium.

5. The method of claim 1, further including generating said cavitation bubbles so as to cause said bubbles to collapse after reaching a maximum diameter of between about 0.4 and 0.5 mm.

6. The method of claim 1, further including causing said discharge to have a duration in the range of 0.030 to 3.0 microsecond.

7. The method of claim 1, wherein generating a high-voltage discharge includes:

forming a microelectrode having a single wire inside an insulator and a second electrode surrounding the insulator; and

applying a voltage pulse having an amplitude in the range of 100 V to 10 kV and having a duration in the range of 0.030 to 3.0 microseconds between said wire and said second electrode to generate said discharge.

8. The method of claim 7, where said discharge causes said cavitation bubble to collapse after reaching a maximum diameter of between about 0.4 and 0.5 mm.

9. A method cutting tissue in a physiological environment, comprising:

forming a microelectrode having first and second spaced electrodes in a conducting liquid-containing medium;

applying a voltage pulse having an amplitude in the range of 100 V to 10 kV and having a duration in the range of 0.030 to 3.0 microseconds between said electrodes to generate a high-voltage submicrosecond duration electrical discharge between said electrodes in said medium, said discharge producing in said medium a cavitation bubble having a diameter no greater than about 0.5 mm and having characteristics which emulate the action of pulsed lasers in said medium; and

directing said cavitation bubble to cut tissue in contact with said medium.

10. The method of claim 9, further including generating said discharge so as to cause said cavitation bubble to collapse after reaching a maximum diameter of between about 0.4 and 0.5 mm.

11. A method of cutting and removing tissue in a physiological liquid environment, comprising:

providing a microelectrode having a single metal wire inside an insulator, wherein the wire has an exit diameter of less than 100 microns, and having an electrical conductor surrounding the insulator; and

generating a high-voltage electrical pulse having a duration in the range of 0.03 to 3.0 μ

sec to produce between said wire and said conductor in a conducting liquid-containing medium an electron avalanche having a pulse energy sufficient to cut tissue in said liquid-containing medium.

12. The method of claim 11, wherein generating said electrical pulse includes producing a voltage between said wire and said conductor having a pulse energy that fill produce a cavitation bubble in said medium.

13. The method of claim 11, wherein generating said electrical pulse includes producing a voltage between said wire and said conductor having a duration and amplitude sufficient to produce an electron avalanche that emulates the action of pulsed lasers in said medium.

14. The method of claim 13, further including producing an electron avalanche in said medium having a pulse energy appropriate for bubble formation.

15. The method of claim 11, wherein generating said electrical pulse includes generating an electron avalanche having a pulse energy in the range of 1-1000 μ

J.