The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 30, 1981
Filed:
Aug. 12, 1977
Robert K Mitchiner, Longmont, CO (US);
Valleylab, Inc., Boulder, CO (US);
Abstract
Cryosurgical apparatus for necrosing human tissue or the like, the apparatus comprising a coolant supply where coolant comprising nitrous oxide, carbon dioxide, Freon 13 or Freon 23 is disposed within a container as a liquid under its own vapor pressure; pressure elevating means for increasing the vapor pressure so that it is greater than what it would be at room temperature and for maintaining the elevated vapor pressure substantially constant; a cryosurgical instrument having a hollow tissue contacting portion and a coolant expansion means disposed at the distal end of a feed passageway and a discharge path disposed outside of the passageway; and means for supplying the coolant to the feed passageway of the cryosurgical instrument so that the temperature of the coolant discharged through the expansion means is lowered. Means are also disclosed including switchable valve means connected to the discharge path of the cryosurgical instrument, the switchable valve means being switchable to a first position freeze mode to exhaust the coolant from the apparatus and to a second position defrost mode for closing the switchable valve means; defrost discharge means also connected to the discharge path of the cryosurgical instrument, the flow impedance of the defrost discharge means being substantially greater than that of the switchable valve means when it is in its first position freeze mode and substantially less than that of the switchable valve means when it is in its second position defrost mode.