System and method for inducing hypothermia with control and determination of catheter pressure
First Claim
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,wherein the helical return lumen encircles the supply lumen such that blood flows between the helical return lumen and the supply lumen, and wherein turbulence is induced in a substantial portion of a free stream of blood by contact with both the helical return lumen and the supply lumen, anda 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.
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Accused Products
Abstract
Embodiments of the invention provide a system for temperature control of the human body. The system includes an indwelling catheter with a tip-mounted heat transfer element. The catheter is fluidically coupled to a console that provides a heated or cooled heat transfer working fluid to exchange heat with the heat transfer element, thereby heating or cooling blood. The heated or cooled blood then heats or cools the patient'"'"'s body or a selected portion thereof. In particular, methods and devices are provided for control and determination of the pressure within the heat transfer element.
215 Citations
29 Claims
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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:
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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, wherein the helical return lumen encircles the supply lumen such that blood flows between the helical return lumen and the supply lumen, and wherein turbulence is induced in a substantial portion of a free stream of blood by contact with both the helical return lumen and the supply lumen, and 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of determining pressure in a catheter for use in a system to change the temperature of blood by heat transfer to or from a circulating working fluid, comprising:
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providing a catheter including; 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; and 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; circulating fluid via a pump through the supply lumen and 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 helical return lumen encircles the supply lumen such that blood flows between the helical return lumen and the supply lumen, and wherein turbulence is induced in a substantial portion of a free stream of blood by contact with both the helical return lumen and the supply lumen; and monitoring the pump speed and current drawn by the pump and using the same in a calculation of pressure. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of determining pressure in a catheter for use in a system to change the temperature of blood by heat transfer to or from a circulating working fluid, comprising:
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providing a catheter including; a supply lumen to introduce a circulating working fluid to a heat transfer element; and a return lumen to extract a circulating working fluid from the heat transfer element; circulating fluid via a pump through the supply lumen and 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; and monitoring the pump speed and current drawn by the pump and using the same in a calculation of pressure. - View Dependent Claims (29)
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Specification