Patent ID: 7156840

Claim:
A cryoablation device having a pressure monitoring system, said device comprising: a refrigerant supply unit; an elongated catheter tube having a central lumen and formed with a closed distal end; a supply line having a proximal end connected to said refrigerant supply unit and a distal end disposed in said central lumen of said catheter tube and distanced from the distal end thereof to establish an expansion chamber therebetween, said supply line for delivering a refrigerant from said refrigerant supply unit to said expansion chamber for expansion therein; a return line in fluid communication with said expansion chamber for exhausting refrigerant from said expansion chamber; a first pressure sensor for measuring a supply pressure, P s , in said supply line at a pre-selected distance upstream from said expansion chamber; a second pressure sensor for measuring a return pressure, P r , in said return line at a pre-selected distance downstream from said expansion chamber; and a control unit connected to said first pressure sensor and to said second pressure sensor for using said measured pressures P s and P r for determining a pressure in said expansion chamber to monitor the expansion of said refrigerant therein.