Method of using an electrically heated surgical cutting instrument

• US 4,198,957 A
• Filed: 03/22/1977
• Issued: 04/22/1980
• Est. Priority Date: 11/09/1967
• Status: Expired due to Term

• Current Assignee: Robert F. Shaw
• Original Assignee: Robert F. Shaw
• Inventors: Stoft, Paul E., Shaw, Robert F., Cage, John M.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Thaler, Michael H.
• Application Number:
  US05/780,031
• Time in Patent Office: 1,127 Days
• Field of Search: 128/303 R, 128/1 R, 128/303.1, 128/303.13, 128/303.14, 128/404-406, 30/140, 219/233, 219/251, 219/210, 219/239, 219/227-231, 219/512, 219/505, 219/520, 219/240, 219/241, 219/235-238, 219/499, 219/504
• US Class Current: 606/37
• CPC Class Codes: A61B 18/08 by means of electrically-heated probes
• CPC Class Codes: A61B 18/082 Probes or electrodes therefor
• CPC Class Codes: A61B 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2090/0813 Accessories designed for easy sterilising, i.e. re-usable
• CPC Class Codes: G05D 23/2401 using a heating element as a sensing element

Abstract

A surgical cutting instrument includes an electrically heated cutting edge and an automatic control system for maintaining the cutting edge at a constant high temperature for sterilizing the blade, cutting tissue, and cauterizing the incised tissue to reduce hemorrhage from the cut surfaces of the tissues (hemostasis).

Claims

1. A method of hemostatic cutting using a blade means having a cutting edge operating at an elevated temperature, the method comprising:

heating the cutting edge by conducting an electrical current in a conduction path along the cutting edge including a conductive means having a negative temperature coefficient of resistance; and

self regulating the heating of the cutting edge by increasing the electrical resistance of those portions of the electrical conduction path that are cooled.