Method and system for control of a patient's body temperature by way of transluminally insertable heat exchange catheter
First Claim
1. A controller for controlling the temperature and flow of a heat exchange fluid within a circuit, the circuit comprising a heat exchange catheter insertable within a patient, an external heat exchanger, and a pump for flowing heat exchange fluid through the circuit, the controller comprising:
- a heat and/or cold generating element, the generating element being in thermal contact with the external heat exchanger containing the heat exchange fluid;
a patient sensor positioned and configured to generate a signal representing a biophysical condition of a patient;
a microprocessor connected to receive the signal from the patient sensor and being responsive to the signal to control the generating element;
a mechanical drive unit for activating the pump contained in the circuit; and
a safety sensor for detecting a fluid parameter in the circuit and generating a safety signal representative of the presence or absence of the fluid parameter, the safety signal being transmitted to the microprocessor that responds by controlling the operation of the pump.
5 Assignments
0 Petitions
Accused Products
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.
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Citations
36 Claims
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1. A controller for controlling the temperature and flow of a heat exchange fluid within a circuit, the circuit comprising a heat exchange catheter insertable within a patient, an external heat exchanger, and a pump for flowing heat exchange fluid through the circuit, the controller comprising:
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a heat and/or cold generating element, the generating element being in thermal contact with the external heat exchanger containing the heat exchange fluid;
a patient sensor positioned and configured to generate a signal representing a biophysical condition of a patient;
a microprocessor connected to receive the signal from the patient sensor and being responsive to the signal to control the generating element;
a mechanical drive unit for activating the pump contained in the circuit; and
a safety sensor for detecting a fluid parameter in the circuit and generating a safety signal representative of the presence or absence of the fluid parameter, the safety signal being transmitted to the microprocessor that responds by controlling the operation of the pump. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A heat transfer catheter flow system, comprising:
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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. - View Dependent Claims (9, 10)
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11. A controller for controlling the temperature and flow of a heat exchange fluid within a circuit, the circuit comprising a heat exchange catheter insertable within a patient, an external heat exchanger, and a pump for flowing heat exchange fluid through the circuit, the controller comprising:
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a heat and/or cold generating element, the generating element being in thermal contact with the external heat exchanger containing the heat exchange fluid;
a mechanical drive unit for activating the pump contained in the circuit for pumping the heat exchange fluid;
a microprocessor connected to control both the generating element and the mechanical drive unit; and
a safety system for detecting problems in the circuit, the safety system including a plurality of sensors that generate signals indicative of respective parameters of the system and/or patient, the signals being transmitted to the microprocessor that responds by controlling the operation of the generating element and the mechanical drive unit. - View Dependent Claims (12, 13, 14, 15, 16)
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18. A heat transfer catheter system comprising:
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a heat transfer catheter;
a heat transfer unit defining a flow channel between opposite sidewalls, one of the sidewalls being relatively thin and flexible and providing minimal thermal insulation, while the opposite sidewall being relatively non-flexible so as to provide structural support to the heat transfer unit; and
conduits coupled to the heat transfer catheter and heat transfer unit that enable circulation of a heat transfer medium therebetween. - View Dependent Claims (17, 19, 20, 21, 22)
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23. A method of regulating the temperature of a patient, comprising:
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providing a heat exchange catheter system including a heat exchange catheter having a fluid path therethrough, a pair of conduits fluidly connected to the heat exchange catheter, and an external heat exchanger connected via the conduits to circulate heat exchange medium through the exchange catheter;
providing a first controller adapted to couple to the external heat exchanger of the heat exchange catheter system, the first controller including a heat and/or cold generating element therein for exchanging heat at a first rate with the heat exchange medium within the external heat exchanger;
providing a second controller adapted to couple to the external heat exchanger of the heat exchange catheter system, the second controller including a heat and/or cold generating element therein for exchanging heat at a second rate with the heat exchange medium within the external heat exchanger;
coupling the heat exchange catheter system with the first controller;
inserting the heat exchange catheter into the patient;
regulating the temperature of the patient by exchanging heat at the first rate between the generating element of the first controller and the external heat exchanger;
de-coupling the heat exchange catheter system from the first controller;
coupling the heat exchange catheter system with the second controller; and
regulating the temperature of the patient by exchanging heat at the second rate between the generating element of the second controller and the external heat exchanger. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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30. A method of controlling the rate of change of a patient'"'"'s body temperature using a heat transfer catheter and associated controller, comprising:
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providing a heat transfer catheter for insertion into a body cavity, the heat transfer catheter having a heat transfer region thereon;
sensing the patient'"'"'s body temperature in the body cavity or in another location;
determining the temperature of the catheter heat transfer region;
providing a controller in communication with the heat transfer catheter via conduits, the controller being adapted to elevate or depress the temperature of the catheter heat transfer region relative to the body temperature;
selecting a target temperature different than the body temperature;
selecting a ramp rate equal to the time rate of change of temperature from the body temperature to the target temperature;
setting the temperature of the catheter heat transfer region based on the ramp rate;
monitoring the temperature differential between the target temperature and the body temperature; and
reducing the ramp rate when the temperature differential reduces below a predetermined threshold. - View Dependent Claims (31, 32, 33, 34, 35, 36)
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Specification