Coiled heat exchanger for cyrosurgical instrument

摘要

A cryosurgical instrument including: a shaft having a closed distal end defining an expansion chamber and an open proximal end adapted and configured to receive an inflow of cryogen and to exhaust a flow of expanded cryogen; and a heat exchanger. The heat exchanger includes: a plurality of cryogen delivery tubes that spiral around a longitudinal axis thereof; and a diffuser having a plurality of branches, each of the branches supplying received cryogen to a respective one of the delivery tubes. The cryogen delivery tubes, where they spiral, are spaced from each other and in fluid tight contact with the inner surface of the shaft so as to form spiraling cryogen exhaust pathways that extend along a portion of a length of the cryosurgical instrument from the distal end of the shaft.

主权项

1. A cryosurgical instrument comprising:
a shaft having a closed distal end defining an expansion chamber and an open proximal end adapted and configured to receive an inflow of cryogen and to exhaust a flow of expanded cryogen; and a heat exchanger comprising:
a plurality of cryogen delivery tubes that spiral around a longitudinal axis thereof; anda diffuser having a plurality of branches, each of the branches supplying received cryogen to a respective one of the delivery tubes, wherein the cryogen delivery tubes, where they spiral, are spaced from each other and in fluid tight contact with the inner surface of the shaft so as to form spiraling cryogen exhaust pathways that extend along a portion of a length of the cryosurgical instrument from the distal end of the shaft, wherein the heat exchanger further comprises a solid core element extending alone a longitudinal axis of the heat exchanger, wherein the plurality of cryogen delivery tubes spiral around and in contact with the solid core element, and wherein the cryogen delivery tubes, where they spiral around the core, are in fluid tight contact with the solid core.