Patent ID: 8080005

Claim:
A system for delivering a phase changing cryogen to a surgical device, comprising: a first reservoir of the cryogen in a liquid phase; a liquid feed conduit through which cryogen travels from the first reservoir to the surgical device; a second reservoir of the cryogen in a gaseous phase; a gaseous feed conduit through which cryogen travels from the second reservoir to the surgical device; a return conduit through which cryogen that is exhausted from the surgical device returns to at least one of the first and second reservoir, the exhausted cryogen being in the gaseous phase; a cryogen return control section that controls the return of cryogen via the return conduit and that includes a pump disposed therein, the pump selectively pumping the returning cryogen to at least one of the first and second reservoir; a pressure control section including a first pressure sensor that senses a pressure in the first reservoir, a second pressure sensor that senses a pressure in the second reservoir, and a pressure regulator that regulates the pressure of the first reservoir based on information from the pressure sensors, wherein said pressure regulator is placed between said first and second reservoirs; and a logic section that selectively energizes the pump to control an overall pressure in the system, based on information from the pressure sensors and flow meters.