Electrical discharge devices and techniques for medical procedures

• US 20030125727A1
• Filed: 10/28/2002
• Published: 07/03/2003
• Est. Priority Date: 05/24/1999
• Status: Active Grant

• Current Assignee: Relign Corporation (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Csaba Truckai, John H. Shadduck
• Inventors: Shadduck, John H., Truckai, Csaba
• Granted Patent: US 6,890,332 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 17/22004 using mechanical vibrations, e.g. ultrasonic shock waves A61B17/225 takes precedence
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: A61B 2017/22008 used or promoted
• CPC Class Codes: A61B 2018/1213 creating an arc

Abstract

A medical instrument coupled to first and second energy means and a computer controller for the controlled volumetric removal of thin tissue layers. The system provides a source for introducing a gas to controllably form and capture transient gas volumes in a microchannel structure at the working surface of the instrument that interfaces with a targeted tissue site. Each of the microchannel features of the working surface carries an electrode element coupled to the electrical source. The energy may be applied to the targeted site in either of two modes of operation, depending in part on voltage and repetition rate of energy delivery. In one mode of energy application, electrical potential is selected to cause an intense electrical arc across the transient ionized gas volumes to cause an energy-tissue interaction characterized by tissue vaporization. In another preferred mode of energy delivery, the system applies selected levels of energy to the targeted site by means of an energetic plasma at the instrument working surface to cause molecular volatilization of surface macromolecules thus resulting in material removal. Both modes of operation limit collateral thermal damage to tissue volumes adjacent to the targeted site. Another preferred embodiment provides and an ultrasound source or other vibrational source coupled to the working end to cause cavitation in fluid about the working end.

Claims

1. A method for application of energy to a targeted site on a body structure, comprising the steps of:

(a) positioning an instrument working surface in proximity to the targeted site, wherein the working surface carries at least one media entrance channel and at least one electrode;

(b) providing at least one bubble of a selected gas between a termination of the channel and the targeted site, wherein each bubble defines a selected dimension between the electrode in end and the targeted site; and

(c) applying vibrational energy to said working surface; and

(d) applying electrical energy from said electrode to said targeted site across said at least one bubble wherein said vibrational energy alters said selected dimension of said at least one bubble to thereby reduce the voltage required for said application of energy thereacross.

2. The method of claim 1 wherein said vibrational energy comprises ultrasonic vibration.

3. The method of claim 1 wherein said vibrational energy reduces said selected dimension of said at least one bubble.

4. The method of claim 1 wherein step (b) provides said at least one bubble in a fluid environment

5. The method of claim 1 wherein said selected gas is a neutral gas and wherein step (d) further comprises the step of ionizing the said gas volume from a source independent of said electrode surfaces.

6. The method of claim 5 wherein the ionizing step is caused by ionization means selected from the class of photoionization means and field ionization means.

7. The method of claim 1 wherein in step (b) provides the selected gas through said at least one channel.

8. The method of claim 1 wherein in step (d) the energy application is of sufficient intensity to cause volumetric material removal.

9. A medical device for delivering energy to targeted tissue, comprising:

a member defining a distal working surface;

at least one electrode element carried in said working surface; and

a vibration source coupled to said working surface.

10. The medical device of claim 9 wherein the vibrational source in an ultrasonic source

11. The medical device of claim 9 wherein the member comprises a tuned acoustic transmission assembly.

12. The medical device of claim 9 further comprising at least one channel with open distal termination in the said working surface for carrying a gas to said working surface.

13. The medical device of claim 9 further comprising at light energy delivery one channel with a distal termination in the said working surface.

14. The device of claim 12 wherein said at least one channel has an open distal terminations with a cross-sectional dimension less than 1_m.

15. The device of claim 12 wherein said at least one channel has an open distal terminations with a cross-sectional dimension less than 0.5_m.

16. The device of claim 12 wherein said at least one channel defines a selected cross-sectional dimension that prevents fluid flows therethrough.

17. The device of claim 12 further comprising an electrical source coupled to said at least one electrode element, said electrical source capable of delivering from about 100 to 2000 volts to said at least one electrode element.