Safety devices for cryoablation probe

A cryoablation system comprising:

• a working gas circuit;
• a vacuum chamber;
• a vacuum pump configured to pull a vacuum on one of the working gas circuit and the vacuum chamber;
• a console configured to toggle the vacuum pump between the working gas circuit and the vacuum chamber;
• and
• a pressure sensor configured to measure a vacuum pressure in the working gas circuit;
• wherein the console is further configured to:
• toggle the vacuum pump to the working gas circuit;
• control the vacuum pump to pull a vacuum on the working gas circuit;
• after the vacuum has been pulled for a predetermined amount of time, measure a vacuum pressure in the working gas circuit with the pressure sensor;
• and
• if the vacuum pressure is above a threshold pressure value, determining that a shaft is compromised.

A cryoablation system comprising:

• a pre-cooler fluid circuit;
• a working fluid circuit;
• a vacuum circuit;
• and
• a shaft, the shaft comprising
• an insulated portion, wherein the vacuum circuit is defined within the insulated portion;
• and
• an expansion chamber, the expansion chamber comprising:
• a supply tube having a distal outlet in the expansion chamber, wherein fluid from the working fluid circuit travels through the supply tube and expands in the expansion chamber;
• a first layer, wherein the first layer is configured to contain fluid from the working fluid circuit;
• and
• a second layer, wherein the second layer is configured to increase a radial strength of the expansion chamber;
• wherein the shaft has a lower burst strength in the insulated portion at a first location and a higher burst strength in the expansion chamber at a second location.