Keith Jasmer Nelson

US Patent:

39930750, Nov 23, 1976

Filed:

Dec 24, 1975

Appl. No.:

5/644162

Inventors:

Wayne F. Lisenbee - Simi CA
Keith E. Nelson - Los Angeles CA

Assignee:

Dynatech Corporation - Burlington MA

International Classification:

A61B 1736

US Classification:

1283031

Abstract:

A small, disposable cryosurgical probe having a self-contained liquid refrigerant supply can be operated in either a freeze mode or a defrost mode. During the freeze mode the refrigerant is conducted from the supply to the probe tip as a two phase fluid so that the probe can freeze tissue for a relatively long period with a limited refrigerant supply. To facilitate detaching the probe tip from tissue, a button on the probe is depressed which switches the probe to its defrost mode of operation wherein room temperature liquid refrigerant is conducted directly from the supply to the probe tip thereby immediately warming the tip. The probe may be cycled several times between its freeze and defrost modes before the refrigerant supply is exhausted.