摘要 |
<p>A miniature refrigeration system and method of operation. A primary refrigerant is pressurized by a compressor (130) to a relatively low pressure, for safety reasons. The compressed primary refrigerant is passed through a primary-to-secondary heat exchanger (240), to precool the gas mixture. The secondary side of the primary-to-secondary heat exchanger (240) is cooled by a secondary refrigeration system. The primary refrigerant exiting the primary outlet of the primary-to-secondary heat exchanger passes to a primary Joule-Thomson expansion element (150) where the high pressure gas is expanded to a lower temperature. This low temperature gas cools a heat transfer element mounted in the outer wall of the catheter of cryoprobe, to cool surrounding tissue. Return gas can flow back through a distal primary-to-primary heat exchanger (160) to further cool the incoming high pressure gas mixture. A proximal primary-to-primary heat exchanger (140) can be added between the primary-to-secondary heat exchanger (240) and the primary compressor (130).</p> |