Cryosurgical instrument with vent holes and method
CA 2117081 A1 · Owner: Baust, John G. · Inventors: Finkelstein, J.J.; Chang, Zhao Hua; Baust, John G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A closed end surgical cryoprobe instrument (10) may have a probe shaft (13) diameter of 3 millimeters or less and can achieve and maintain freezing zone temperature close to that of the liquid cryogenic refrigerant. Using sub-cooled liquid nitrogen at approximately -208 ·C freezing zone (15) temperatures as low as -206 ·C can be achieved in under 1 minute. The liquid nitrogen supply tube (22) is provided with a plurality of small vent holes (29) to vent gas formed or present in the refrigerant supply tube to the return refrigerant flow channel (24). The vent holes (29) also allow small amount of liquid nitrogen to vent into the return flow channel to further reduce the temperature …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed September 4, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 4, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 4, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.