Patent ID: 8092448
Filing Date: 2012-01-10
Classification: A61B

Abstract:
1. A cryosurgical system comprising a cryoprobe; a cryogen source comprising a reservoir of cryogenic liquid, said reservoir comprising a volume of cryogenic liquid and volume of gas; a supply tube connecting the cryoprobe with the reservoir; a pressurizing means for pumping pressurized gas into the reservoir; a fluid pathway communicating from the volume of gas to atmosphere, and a valve disposed in said fluid pathway; a control system operable to control the pressure pump to pump pressurized gas into the reservoir, and operate the control valve to vent the pressurized gas from the reservoir as necessary maintain pressure within the reservoir in a predetermined pressure range; wherein the pressurizing means comprises: an accumulator disposed in parallel between a compressor and the cryogen source; and a stop valve disposed between the accumulator and compressor combination and the reservoir; wherein the control system is operable, on command from an operator to initiate cryogen flow to the cryoprobe, to control the pressurizing means and stop valve to charge the accumulator without charging the reservoir for an initial period, and thereafter operate the stop valve to pressurize the dewar from the accumulator and also from the pressurizing means to pressurize the dewar.