Method of coagulating muscle tissue

• US 4,597,379 A
• Filed: 03/30/1983
• Issued: 07/01/1986
• Est. Priority Date: 05/16/1979
• Status: Expired due to Fees

• Current Assignee: Cabot Corporation
• Original Assignee: Cabot Medical Corp. (Olympus Corporation)
• Inventors: Kihn, Harry, Ackman, C. F. Douglas
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US06/478,813
• Time in Patent Office: 1,189 Days
• Field of Search: 128/1 R, 128/303.1, 128/303.17, 128/303.13, 128/804, 128/306, 128/1.3, 128/24.1, 128/402, 128/400, 128/399
• US Class Current: 606/40
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2090/034 abutting on parts of the device itself
• CPC Class Codes: A61F 6/22 implantable in tubes occluding by internal devices A61B17/12022

Abstract

A method of coagulating a muscle tissue contained within fat tissue substantially without harming the fat tissue, comprising directing microwave radiation through the fat tissue towards the muscle tissue at a selective frequency effective to cause coagulation of the muscle tissue substantially exclusively of the fat tissue, for sufficient time to heat the muscle tissue to temperature at which the muscle tissue coagulates.

Claims

1. An in vivo, non-invasive method of permanently coagulating muscle tissue contained within fat tissue substantially without harming said fat tissue comprising directing radiation through said fat tissue towards said muscle tissue at a frequency of about 6 GHz to cause permanent coagulation of said muscle tissue substantially exclusively of said fat tissue, for about one minute to heat said muscle tissue within said fat tissue to a temperature of at least about 55°

C. at which said muscle tissue permanently coagulates.

2. An in vivo, non-invasive method for coagulating human muscle tissue bounded by fatty tissue substantially without harming said fatty tissue, comprising directing radiation, at a frequency of about 6 GHz providing a low ratio of absorption of radiation by said fatty tissue relative to said muscle tissue, from a waveguide in a predetermined path of length between about 5 and about 20 millimeters through said fatty tissue towards said muscle tissue with electric and magnetic vectors of said radiation parallel to an exterior surface of said fatty tissue at which said radiation is applied, for about one minute at said frequency to heat said muscle tissue substantially exclusively of said fatty tissue to a temperature between about 55°

C. and about 80°

C. at which said muscle tissue permanently coagulates without substantial damage to said fatty tissue due to excessive heating thereof while leaving said fatty tissue in the neighborhood about said waveguide exposed to ambient air for natural convection cooling of the exposed portion of said fatty tissue about said waveguide as heat generalted within said muscle tissue conductively flows from said muscle tissue through said fatty tissue to an interface of said fatty tissue and said ambient air.

3. An in vivo non-invasive method for coagulating living human muscle tissue using an instrument having a body with two members adapted for closing towards each other and holding therebetween said muscle tissue and any fat tissue contiguous therewith, and having a waveguide means constructed to emit electomatic radiation at a frequency of about 6 GHz for coagulation of said muscle tissue, said waveguide means disposed on at least one of said body members, comprising:

a. holding said muscle tissue and said contiguous fat tissue between said bodyymembers towards each other at a predetermined pressure sufficient to retain said muscle tissue and said contiguous fat tissue between said body members without damaging said retained muscle tissue and contiguous fat tissue due to application of excessive pressure thereto;

b. causing emission of elecromagnetic radiation from said waveguide means in one of said body members towards the remaining body member at said frequency to selectively permanently coagulate only said muscle portion of said tissue retained between said body members by heating said muscle portion to a temperature of at least about 55°

C. without significant thermal damage to said fat portion of said tissue held between said body members; and

c. subjecting the held tissue to said emitted waveguide radiation for only a period of time sufficient to permanently coagulate said heated muscle portion exclusively of any said contiguous fat portion of said tissue and in no event for a period greater than about one minute.

4. An in vivo non-invasive method for coagulating a living human muscle tissue contained within fat tissue using an instrument having two body members adapted for retaining said muscle-containing fat tissue therebetween, waveguide means carried on at least one of said body members so that electromagnetic radiation emitted therefrom impinges on said muscle-containing fat tissue retained between said body members, said emitted electromagnetic radiation being of frequency of about 6 GHz for coagulation of said retained muscle tissue by selective heating thereof to a temperature of at least about 55°

C. and electromagnetic radiation sensing means on the other end of said body members, the steps comprising;

a. temporarily retaining said muscle containing fat tissue between said body members;

b. emitting electromagnetic radiation from said waveguide means at said frequency through a thickness of retained tissue of from about 5 to about 20 millimeters to selectively permanently coagulate only muscle portions of said retained tissue without significant damage to fat portions of said retained tissue when said radiation is applied to said retained tissue for a period sufficient to permanently coagulate said muscle portions of said retained tissue by heating said muscle portions at least to about 55°

C. but to heat fat portions of said retained tissue only to a temperature at which said fat portions are hot to the touch without significant thermal damage from said heating to said fat portions;

c. causing said emitted electromagnetic radiation to impinge and penetrate the retained tissue but only for said period of time sufficient to permanently coagulate said muscle tissue portion of said retained tissue by raising said muscle tissue portion, exclusively of said fat portions, to a temperature of at least about 55°

C.,

d. directly detecting the electromagnetic radiation passing through said retained tissue, thereby sensing that said emitted radiation is impinging on said retained tissue; and

e. halting radiation application when detected level thereof drops substantially thereby indicating permanent coagulation of said muscle portion of said retained tissue.

5. An in vivo non-invasive method for permanently coagulating a muscle portion of living human tissue also containing a fat portion having a skin portion, by directing radiation at a frequency of about 6 GHz at said muscle portion from exterior said skin portion, a distance of from about 5 to about 20 millimeters through said skin and fat portions, in the absence of active cooling of said skin portion, for sufficient time of about one minute to only heat said muscle at least to about a 55°

C. permanent coagulation temperature without substantial damage to said fat portion of said skin portion due to excessive heating thereof, said frequency of about 6 GHz being selected as effective to permanently coagulate said muscle portion substantially exclusively of said fat and skin portions of said tissue without thermal damage to said fat and skin portions.