Patent ID: 8439906

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; during a first phase of a cryotherapy procedure, using a pressure source to inflate a first distal balloon portion of the cryotherapy balloon catheter, independently of a release of cryogenic fluid into the first distal balloon portion, to expand the first distal balloon portion and to cause an initial pressure to be maintained inside the first distal balloon portion that is sufficiently high to cause an outer wall of the first distal balloon portion to be pressed against body tissue at the treatment site; starting a flow of cryogenic fluid to the first distal balloon portion and a corresponding flow of exhaust from the first distal balloon portion; and regulating, during a second phase of the cryotherapy procedure, flow of cryogenic fluid to and exhaust from the first distal balloon portion to cause a) a temperature inside the first 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.