Isotherm-based tissue ablation control system

A system for use with at least one cryoprobe for the treatment of biological tissue with thermal ablation, the system comprising:

• at least one cryoprobe comprising a distal treatment portion, an exchange chamber in said distal treatment portion, an inflow conduit transporting a cryogen towards said exchange chamber of the distal tissue treatment portion, and an outflow conduit for transporting said cryogen from said exchange chamber of the distal tissue treatment portion;
• an inflow temperature sensor at a first location along the inflow conduit and configured to detect an inflow temperature of the cryogen flowing through said inflow conduit at the first location;
• an outflow temperature sensor at a second location along the outflow conduit and configured to detect an outflow temperature of the cryogen flowing through said outflow conduit at the second location;
• and
• a processor programmed to
• receive procedure data comprising a cryogen flowrate, the inflow temperature and the outflow temperature over time;
• calculate a procedure signature based on the cryogen flowrate and a temperature difference between said inflow temperature and said outflow temperature over time;
• compare the procedure signature to a planning signature, said planning signature based on previously acquired image data of said tissue;
• and
• adjust power to the at least one cryoprobe based on comparing said procedure signature to said planning signature.