Method and system for control of a patient's body temperature by way of transluminally insertable heat exchange catheter

• US 7,175,649 B2
• Filed: 08/20/2003
• Issued: 02/13/2007
• Est. Priority Date: 02/28/2000
• Status: Expired due to Fees

• Current Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Original Assignee: Radiant Medical, Inc. (Asahi Kasei Corporation)
• Inventors: Machold, Timothy R., Roth, Alex T., Keller, Wade A., Bloom, Nicole Denise
• Primary Examiner(s): Nasser; Robert L.
• Application Number:
  US10/645,891
• Publication Number:
  US 20040039431A1
• Time in Patent Office: 1,273 Days
• Field of Search: None
• US Class Current: 607/104
• CPC Class Codes: A61B 2017/00092 using thermocouples
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 2017/00123 and automatic shutdown
• CPC Class Codes: A61B 2017/00199 with a console, e.g. a control panel with a display
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61F 2007/0054 with a closed fluid circuit, e.g. hot water
• CPC Class Codes: A61F 2007/0096 with a thermometer
• CPC Class Codes: A61F 2007/126 for invasive application, e.g. for introducing into blood vessels
• CPC Class Codes: A61F 7/0085 Devices for generating hot or cold treatment fluids
• CPC Class Codes: A61F 7/0097 Blankets with active heating or cooling sources warming mats A61F7/08
• CPC Class Codes: A61F 7/10 Cooling bags, e.g. ice-bags
• CPC Class Codes: A61F 7/123 using a flexible balloon containing the thermal element
• CPC Class Codes: A61M 2025/1072 having balloons with two or more compartments
• CPC Class Codes: A61M 2025/1086 having a special balloon surface topography, e.g. pores, protuberances, spikes or grooves
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/127 with provisions for heating or cooling
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: A61M 25/1011 Multiple balloon catheters

Abstract

Methods and apparatuses for temperature modification of a patient, or selected regions thereof, including an induced state of hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette of any one of several disclosed variations is attached to the circulatory flow lines of the catheter, the heat exchange cassette being sized to engage a cavity within one of various described re-usable control units. The control units include a heater/cooler device, a user input device, and a processor connected to receive input from various sensors around the body and the system. The heater/cooler device may be thermoelectric to enable both heating and cooling based on polarity. A temperature control scheme for ramping the body temperature up or down without overshoot is provided. The disposable heat exchange cassettes may include an integral pump head that engages with a pump drive mechanism within the re-usable control unit. More than one control unit may be provided to receive the same heat exchange cassette so that a large capacity control unit can be used initially, and a smaller, battery-powered unit can be substituted once the patient reaches the desired target temperature.

Claims

1. A heat transfer catheter flow system, comprising:

a heat transfer medium circulation loop including a heat transfer catheter insertable within a patient, a heat transfer unit, and conduits coupled to the heat transfer catheter and heat transfer unit that enable circulation of a heat transfer medium therebetween;

a pump head in contact with heat transfer medium within the circulation loop for circulating heat transfer medium through the circulation loop;

a cassette including the heat transfer unit and containing the pump head;

a controller with which the cassette mates, the controller including a pump motor, wherein the pump head engages the pump motor when the cassette is mated with the controller;

a microprocessor connected to control the speed of the pump motor; and

an electronic feedback loop including the microprocessor that detects a back torque experienced by the pump motor and responsively controls the speed of the pump motor.

2. The system of claim 1, wherein the controller includes a cavity for receiving the cassette, and wherein the heat transfer unit includes an external heat exchanger including an outer flexible layer at least partly defining a flow channel therein, the flexible layer expanding outward upon flow of heat exchange medium through the flow channel, wherein the controller includes a heat and/or cold generating element facing the cavity that exchanges heat with the heat exchange medium in the flow channel through the flexible layer, the cavity being sized such that outward expansion of the flexible layer causes the external heat exchanger to be compressively retained within the cavity.

3. The system of claim 1, wherein the controller includes a cavity for receiving the cassette, the pump motor being positioned adjacent the opening of the cavity.