Patent ID: 7967815
Filing Date: 2011-06-28
Classification: A61B

Abstract:
1. A cryosurgical instrument comprising: a tubular housing having a longitudinal axis, a proximal end, and a tip at a distal end; a cryogen supply passage extending from the proximal end to the distal end along the longitudinal axis, the supply passage having an upstream portion proximate to the proximal end and a downstream portion proximate to the distal end; a heat exchange enhancing member in the housing, disposed along the longitudinal axis, and surrounding at least some of the downstream portion of the supply passage, the enhancing member having a plurality of return channels circumferentially disposed about the longitudinal axis and extending longitudinally through the enhancing member; and a flow deflector between the tip and the supply passage, the flow director adapted and configured to deflect a cryogen flow exiting from the supply passage to the return channels and to absorb heat, thereby cooling the tip, the flow director fixedly and spacedly disposed from the supply passage, wherein a flow of cryogen in the cryogen supply passage urges cryogen that has exited the cryogen supply passage to flow into the return channels, and wherein a sum of cross-sectional areas of the plurality of return channels is about equal to a cross-sectional area of the supply passage.