Patent ID: 7300453
Filing Date: 2007-11-27
Classification: A61B,A61F

Abstract:
1. A catheter system to determine pressure in a catheter for use in the system to change the temperature of blood by heat transfer to or from a circulating working fluid, comprising: a supply lumen to introduce a circulating working fluid to a heat transfer element wherein said supply lumen is substantially straight through the heat transfer element; a helical return lumen, helically encircling the substantially straight supply lumen, to extract a circulating working fluid from the heat transfer element, the return lumen having a cross-sectional area greater than the cross-sectional area of the supply lumen to enhance flexibility of the heat transfer element, a pump for circulating fluid through the supply lumen and helical return lumen to change the temperature of the heat transfer element to a temperature different from a patient temperature, to heat or cool the patient, wherein the pump speed and current drawn by the pump are used in a calculation of pressure.