Catheters adapted to exchange heat with a body fluid flowing through a body conduit employ helical elongate lumens for heat transfer with the body fluid. The helical elongate lumen of a catheter forms multiple turns extending longitudinally of a portion of the catheter with the turns each being bonded...http://www.google.co.uk/patents/US6589271?utm_source=gb-gplus-sharePatent US6589271 - Indwelling heat exchange catheter
