Patent ID: 9072500
Filing Date: 2015-07-07
Classification: A61B

Abstract:
1. A cryoablation system, comprising: a gas source which provides a working nitrogen gas at room temperature and at a constant set pressure; a liquid generator which is coupled to the gas source to receive the working gas, and which then generates a working cryogen fluid; and a steerable catheter coupled to the liquid generator for receiving the working cryogen, the catheter having a distal section having a freezing element which delivers the working cryogen to a treatment location, the catheter also having a balloon having an interior space and enclosing the freezing element, a pull wire for steering, and an angiogram fluid delivery system, with a balloon fluid occupying the space inside the balloon; wherein the working gas travels inside the freezing element and is separated from the balloon by the balloon fluid; wherein the freezing element is a tubular looped element and the working gas travels inside the tubular looped element; and wherein the cross-sectional flow area defined by the inner diameter of the freeze element is maintained at a constant value to eliminate the effect of pressure changes do to fluid expansion/contraction along non-uniform flow passages to preserve the quality of the sub-cooled liquid.