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

• US 6,695,874 B2
• Filed: 02/01/2002
• Issued: 02/24/2004
• Est. Priority Date: 08/24/1998
• Status: Expired due to Term

• Current Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Original Assignee: Radiant Medical, Inc. (Asahi Kasei Corporation)
• Inventors: Keller, Wade A., Machold, Timothy R., Roth, Alex T.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/061,692
• Publication Number:
  US 20030135252A1
• Time in Patent Office: 753 Days
• Field of Search: 607/104-107, 607/117
• US Class Current: 607/106
• 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 inducing 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. 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 allowing substitution of a smaller, battery-powered unit for a large capacity control once the patient reaches the desired target temperature.

Claims

1. A heat transfer catheter system, comprising:

a heat transfer catheter insertable into a patient;

a disposable heat exchange plate having two layers, a stiff back plate and a thinner heat exchange layer bonded thereto, the pattern of bonding between the two layers defining a serpentine pathway;

conduits coupled to the heat transfer catheter and heat exchange plate that enable circulation of a heat exchange medium therebetween; and

a master control unit housing a heater/cooler unit within and having a slot, the slot being sized so that the disposable heat exchange plate can be installed therethrough into the master control unit and into thermal communication with the heater/cooler unit, wherein the heater/cooler unit can influence the temperature of the patient via the disposable heat exchange plate, conduits, and heat transfer catheter.

2. The system of claim 1, wherein the slot in master control unit defines a cavity into which the heat exchange plate installs, wherein fluid flow through the serpentine pathway causes inflation of the thinner heat exchange layer relative to the stiff back plate and subsequent compressive retention of the heat exchange plate within the cavity.

3. The system of claim 1, wherein the disposable heat exchange plate incorporates an integral pump head adapted to move the heat exchange medium through the serpentine pathway.

4. The system of claim 3, wherein the master control unit houses a pump driver adapted to engage and power the integral pump head when the disposable heat exchange plate is installed in the slot.

5. The system of claim 3, wherein the disposable heat exchange plate further incorporates a reservoir for storing a quantity of the heat exchange medium.

6. The system of claim 1, wherein the heater/cooler unit comprises a thermoelectric heater/cooler.

7. The system of claim 1 wherein the master control unit includes a microprocessor configured to receive a target temperature input and a sensor signal that represents a sensed patient temperature, the microprocessor being configured to add heat to the heat exchange medium if the target temperature is above the patient temperature and remove heat from the heat exchange medium if the target temperature is below the patient temperature, and wherein the microprocessor responds to the signal from the sensor with a proportional integrated differential (PID) response such that the rate at which patient temperature approaches the target temperature is controlled.

25. The system of claim 1, wherein the heat exchange plate comprises two layers, at stiff back plate and a thinner heat exchange layer bonded thereto, the pattern of bonding between the two layers defining a serpentine pathway.

26. The system of claim 25, wherein the slot in master control unit defines a cavity into which the heat exchange plate installs, wherein fluid flow through the serpentine pathway causes inflation of the thinner heat exchange layer relative to the stiff back plate and subsequent compressive retention of the heat exchange plate within the cavity.

8. A heat transfer catheter system, comprising:

a heat transfer catheter insertable into a patient;

a disposable heat exchange unit having a stiff back plate and a thinner heat exchange layer bonded thereto, the pattern of bonding between the stiff back plate and the thinner heat exchange layer defining a serpentine fluid pathway therewithin and incorporating an integral pump head adapted to move fluid through the fluid pathway;

conduits coupled to the heat transfer catheter and heat exchange unit that enable circulation of a heat exchange medium therebetween upon operation of the pump head; and

a reusable master control unit having a heater/cooler and a pump driver, the disposable heat exchange unit being adapted to couple to the master control unit such that the pump driver engages the integral pump head and so that the fluid pathway is in thermal communication with the heater/cooler.

9. The system of claim 8, wherein the master control unit defines a cavity into which the heat exchange unit couples, wherein fluid flow through the serpentine pathway causes inflation of the thinner heat exchange layer relative to the stiff back plate and subsequent compressive retention of the heat exchange unit within the cavity.

10. The system of claim 8, wherein heater/cooler comprises a thermoelectric heater/cooler.

11. The system of claim 8, further including a plurality of sensors supplying patient data to the master control unit, the master control unit being adapted to operate the heater/cooler based on the supplied patient data.

12. The controller of claim 11, wherein the master control unit comprises a microprocessor responsive to each of the sensors to control the heater/cooler, wherein the microprocessor is configured to compare the signals from at least two of the plurality of sensors and produce an alarm condition when the signals do not agree.

13. The controller of claim 8, wherein the microprocessor further receives a target temperature input and a sensor signal that represents a sensed patient temperature, the microprocessor being configured to add heat to the heat exchange medium if the target temperature is above the patient temperature and remove heat from the heat exchange medium if the target temperature is below the patient temperature, and wherein the microprocessor responds to the signal from the sensor with a proportional integrated differential (PID) response such that the rate at which patient temperature approaches the target temperature is controlled.

14. The system of claim 8, further including a slot provided in the master control unit, the disposable heat exchange unit being plate-shaped so as to fit within the slot and couple with the master control unit.

15. The system of claim 8, wherein the disposable heat exchange unit further incorporates a reservoir for storing a quantity of the heat exchange medium.

16. The system of claim 15, further including at least one optical sensor for sensing the level of heat exchange medium within the reservoir.

17. A method of regulating the temperature of at least a portion of a patient, comprising:

providing a disposable heat transfer catheter having a heat transfer region and a heat exchange unit having a pump head, the heat transfer catheter and heat exchange unit coupled via conduits that enable circulation of a heat exchange medium therebetween;

providing a master control unit housing a heater/cool unit within and having a slot;

installing the heat exchange unit through the slot into the master control unit and into thermal communication with the heater/cooler unit;

inserting the heat transfer catheter into the patient;

sensing the patient'"'"'s body temperature;

selecting a target temperature different than the body temperature;

circulating fluid between the heat transfer catheter and heat exchange unit in the master control unit, the heat exchange unit, heater/cooler unit, and pump head being adapted to flow heat exchange medium through the conduits to elevate or depress the temperature of the catheter heat transfer region relative to the body temperature; and

transferring heat between the heat exchange unit and a heater/cooler unit so as to regulate the temperature of the patient via the heat transfer catheter;

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 heat exchange medium within 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.

18. The method of claim 17, wherein the disposable heat exchange unit includes a serpentine pathway through which the heat exchange medium flows, and circulating includes circulating the heat exchange medium back and forth through the serpentine pathway.

19. The method of claim 17, wherein the disposable heat exchange unit incorporates a fluid pathway and an integral pump head, and circulating includes driving the pump head.

20. The method of claim 19, wherein the master control unit houses a pump driver, and installing comprises engaging the pump driver with the pump head.

21. The method of claim 17, wherein heater/cooler unit comprises a thermoelectric heater/cooler, and transferring comprises either heating or cooling the temperature of the patient based on the polarity that the thermoelectric heater/cooler is operated.

22. The method of claim 17, further including a plurality of sensors supplying patient data to the master control unit, the method further including operating the heater/cooler unit based on the supplied patient data.

23. A heat transfer catheter system, comprising:

a heat transfer catheter insertable into a patient;

a disposable heat exchange plate;

conduits coupled to the heat transfer catheter and heat exchange plate that enable circulation of a heat exchange medium therebetween;

a plurality of sensors for monitoring at least one selected parameter of a patient and for providing signals representative of the at least one selected parameter;

supplying patient data to the master control unit, the master control unit being adapted to operate the heater/cooler unit based on the supplied patient data;

a master control unit housing a heater/cooler unit within and having a slot, the slot being sized so that the disposable heat exchange plate can be installed therethrough into the master control unit and into thermal communication with the heater/cooler unit, the master control unit including a microprocessor responsive to each of the plurality of sensors to control the heater/cooler unit, the microprocessor being configured to compare the signals from at least two of the plurality of sensors and produce an alarm condition when the signals do not agree, and wherein the heater/cooler unit can influence the temperature of the patient via the disposable heat exchange plate, conduits, and heat transfer catheter.

24. The system of claim 23, wherein the disposable heat exchange plate includes a serpentine pathway through which the heat exchange medium flows.

27. The system of claim 23, wherein the disposable heat exchange plate incorporates a fluid pathway and an integral pump head adapted to move the heat exchange medium through the fluid pathway.

28. The system of claim 27, wherein the master control unit houses a pump driver adapted to engage and power the integral pump head when the disposable heat exchange plate is installed in the slot.

29. The system of claim 27, wherein the disposable heat exchange plate further incorporates a reservoir for storing a quantity of the heat exchange medium.

30. The system of claim 23, wherein the heater/cooler unit comprises a thermoelectric heater/cooler.

31. The controller of claim 23, wherein the microprocessor further receives a target temperature input and a sensor signal that represents a sensed patient temperature, the microprocessor being configured to add heat to the heat exchange medium if the target temperature is above the patient temperature and remove heat from the heat exchange medium if the target temperature is below the patient temperature, and wherein the microprocessor responds to the signal from the sensor with a proportional integrated differential (PID) response such that the rate at which patient temperature approaches the target temperature is controlled.

32. A heat transfer catheter system, comprising:

a heat transfer catheter insertable into a patient;

a disposable heat exchange unit having a fluid pathway therewithin and incorporating an integral pump head adapted to move fluid through the fluid pathway;

conduits coupled to the heat transfer catheter and heat exchange unit that enable circulation of a heat exchange medium therebetween upon operation of the pump head;

a plurality of sensors for measuring at least one patient parameter and for generating signals representative of a value of the at least one patient parameter; and

a reusable master control unit having a heater/cooler and a pump driver, the disposable heat exchange unit being adapted to couple to the master control unit such that the pump driver engages the integral pump head and so that the fluid pathway is in thermal communication with the heater/cooler, the master control unit also having a microprocessor responsive to each of the plurality of sensors to control the heater/cooler, the microprocessor also configured to compare the signals from at least two of the plurality of sensors and produce an alarm condition when the signals to not agree.

33. The system of claim 32, wherein the fluid pathway in the disposable heat exchange unit is serpentine.

34. The system of claim 33, wherein the heat exchange unit comprises two layers, a stiff back plate and a thinner heat exchange layer bonded thereto, the pattern of bonding between the two layers defining the serpentine pathway.

35. The system of claim 34, wherein the master control unit defines a cavity into which the heat exchange unit couples, wherein fluid flow through the serpentine pathway causes inflation of the thinner heat exchange layer relative to the stiff back plate and subsequent compressive retention of the heat exchange unit within the cavity.

36. The system of claim 32, wherein heater/cooler comprises a thermoelectric heater/cooler.

37. The controller of claim 32, wherein the microprocessor further receives a target temperature input and a sensor signal that represents a sensed patient temperature, the microprocessor being configured to add heat to the heat exchange medium if the target temperature is above the patient temperature and remove heat from the heat exchange medium if the target temperature is below the patient temperature, and wherein the microprocessor responds to the signal from the sensor with a proportional integrated differential (PID) response such that the rate at which patient temperature approaches the target temperature is controlled.

38. The system of claim 32, further including a slot provided in the master control unit, the disposable heat exchange unit being plate-shaped so as to fit within the slot and couple with the master control unit.

39. The system of claim 32, wherein the disposable heat exchange unit further incorporates a reservoir for storing a quantity of the heat exchange medium.

40. The system of claim 39, further including at least one optical sensor for sensing the level of heat exchange medium within the reservoir.