Patent ID: 8187261

Claim:
A method of performing a cryotherapy procedure, the method comprising: introducing a cryotherapy balloon catheter at a treatment site inside a patient's body; starting a flow of cryogenic fluid to a distal balloon portion of the cryotherapy balloon catheter and a corresponding flow of exhaust from the distal balloon portion; regulating, during a first phase of a cryotherapy procedure, the flow of cryogenic fluid to and the flow of exhaust from a distal balloon portion of the cryotherapy balloon catheter to expand the distal balloon portion and to cause an initial pressure to be maintained inside the distal balloon portion that is sufficiently high to cause an outer wall of the distal balloon portion to be pressed against body tissue at the treatment site; and regulating, during a second phase of the cryotherapy procedure, flow of cryogenic fluid to and exhaust from the distal balloon portion to cause a) a temperature inside the distal balloon portion to reach a value sufficient to deliver therapeutic levels of cryotherapy to the body tissue, and b) a second-phase pressure to be maintained that is within a threshold value of the initial pressure.