Thermal system with overshoot reduction

Patent metadata

Field	Value
Publication number	US-12226340-B2
Application number	US-202218080341-A
Country	US
Kind code	B2
Filing date	Dec 13, 2022
Priority date	Dec 26, 2017
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

A thermal control unit for controlling a patient's temperature includes a fluid outlet for delivering temperature-controlled fluid to a patient, a pump, a heat exchanger, and a controller that automatically pauses thermal treatment of the patient prior the patient reaching a target temperature. During the pause, the controller assesses a reaction of the patient and changes a temperature of the fluid only inside the thermal control unit if the patient is likely to reach the target temperature without further thermal treatment. However, if the patient is unlikely to reach the target temperature without further thermal treatment, the controller restarts the thermal treatment. The controller may pause thermal treatment again prior to reaching the target temperature and assess the patient's reaction. In some embodiments, the controller may selectively include and exclude a fluid reservoir in a circulation channel within the thermal control unit.

First claim

What is claimed is:

1. A thermal control unit for controlling a patient's temperature, the thermal control unit comprising:
a fluid outlet adapted to fluidly couple to a fluid supply line;
a fluid inlet adapted to fluidly couple to a fluid return line;
a circulation channel coupled to the fluid outlet and the fluid inlet;
a pump for circulating fluid through the circulation channel from the fluid inlet to the fluid outlet;
a heat exchanger adapted to add or remove heat from the fluid circulating in the circulation channel when activated;
a fluid temperature sensor adapted to sense a temperature of the fluid;
a patient temperature probe port adapted to receive patient temperature readings from a patient temperature probe;
a user interface adapted to receive a patient target temperature; and
a controller in communication with the patient temperature probe port, the pump, the fluid temperature sensor, and the user interface, the controller adapted to stop a flow of fluid out of the fluid outlet prior to the patient temperature reaching the patient target temperature, wherein the controller is adapted to monitor a slope of the patient temperature readings after the flow of fluid out of the fluid outlet is stopped for a predefined time period, and to restart the flow of fluid out of the fluid outlet after the predefined time period if the slope of the patient temperature readings changes by more than a threshold.

2. The thermal control unit of claim 1 wherein the controller, after restarting the flow of fluid out of the fluid outlet, is adapted to re-stop the flow of fluid out of the fluid outlet after the patient temperature has moved toward the patient target temperature but prior to the patient temperature reaching the patient target temperature.

3. The thermal control unit of claim 1 wherein, if the slope of the patient temperature readings does not change by more than the threshold during the predefined time period, the controller is adapted to activate the pump and close a valve such that the fluid circulates within the circulation channel of the thermal control unit but does not flow out of the fluid outlet, wherein the controller is further adapted to activate the heat exchanger while the valve is closed until the temperature of the fluid reaches a specific temperature.

4. The thermal control unit of claim 3 wherein the controller is adapted to open the valve after the temperature of the fluid reaches the specific temperature.

5. A thermal control unit for controlling a patient's temperature, the thermal control unit comprising:
a fluid outlet adapted to fluidly couple to a fluid supply line;
a fluid inlet adapted to fluidly couple to a fluid return line;
a circulation channel coupled to the fluid outlet and the fluid inlet;
a pump for circulating fluid through the circulation channel from the fluid inlet to the fluid outlet;
a heat exchanger adapted to add or remove heat from the fluid circulating in the circulation channel when activated;
a fluid temperature sensor adapted to sense a temperature of the fluid;
a patient temperature probe port adapted to receive patient temperature readings from a patient temperature probe;
a user interface adapted to receive a patient target temperature; and
a controller in communication with the patient temperature probe port, the pump, the fluid temperature sensor, and the user interface, the controller adapted to stop a flow of fluid out of the fluid outlet prior to the patient temperature reaching the patient target temperature; wherein the controller is adapted to stop the flow of fluid out of the fluid outlet by closing a valve to the fluid outlet, and the controller is further adapted to continue to activate the pump such that fluid is pumped internally within the circulation channel while the flow of fluid out of the fluid outlet is stopped.

6. A thermal control unit for controlling a patient's temperature, the thermal control unit comprising:
a fluid outlet adapted to fluidly couple to a fluid supply line;
a fluid inlet adapted to fluidly couple to a fluid return line;
a circulation channel coupled to the fluid outlet and the fluid inlet;
a pump for circulating fluid through the circulation channel from the fluid inlet to the fluid outlet;
a heat exchanger adapted to add or remove heat from the fluid circulating in the circulation channel when activated;
a fluid temperature sensor adapted to sense a temperature of the fluid;
a patient temperature probe port adapted to receive patient temperature readings from a patient temperature probe;
a user interface adapted to receive a patient target temperature; and
a controller in communication with the patient temperature probe port, the pump, the fluid temperature sensor, and the user interface, the controller adapted to stop a flow of fluid out of the fluid outlet prior to the patient temperature reaching the patient target temperature; wherein the controller is adapted to control the heat exchanger using first and second control loop feedback mechanisms, the first control loop feedback mechanism using a first set of coefficients and an error value, the second control loop feedback mechanism using a second set of coefficients and the error value, and the error value being defined as a difference between a current patient temperature reading and the patient target temperature.

7. A thermal control unit for controlling a patient's temperature, the thermal control unit comprising:
a fluid outlet adapted to fluidly couple to a fluid supply line;
a fluid inlet adapted to fluidly couple to a fluid return line;
a circulation channel coupled to the fluid outlet and the fluid inlet;
a pump for circulating fluid through the circulation channel from the fluid inlet to the fluid outlet;
a heat exchanger adapted to add or remove heat from the fluid circulating in the circulation channel when activated;
a fluid temperature sensor adapted to sense a temperature of the fluid;
a patient temperature probe port adapted to receive patient temperature readings from a patient temperature probe;
a user interface adapted to receive a patient target temperature; and
a controller in communication with the patient temperature probe port, the pump, the fluid temperature sensor, and the user interface, the controller adapted to deactivate the heat exchanger prior to the patient temperature reaching the patient target temperature such that the heat exchanger does not actively add heat to, or remove heat from, the fluid, wherein the controller is adapted to monitor a slope of the patient temperature readings for a predefined time period after deactivating the heat exchanger and to reactivate the heat exchanger after the predefined time period if the slope of the patient temperature readings changes by more than a threshold.

8. The thermal control unit of claim 7 wherein the controller, after reactivating the heat exchanger, is adapted to deactivate the heat exchanger again after the patient temperature has moved toward the patient target temperature but prior to the patient temperature reaching the patient target temperature.

9. The thermal control unit of claim 7 wherein, if the slope of the patient temperature readings does not change by more than the threshold during the predefined time period, the controller is adapted to activate the pump and close a valve such that the fluid circulates within the circulation channel of the thermal control unit but does not flow out of the fluid outlet.

10. The thermal control unit of claim 9 wherein the controller is further adapted to reactivate the heat exchanger while the valve is closed until the temperature of the fluid reaches a specific temperature and to open the v

Assignees

• Stryker Corp

Inventors

• Taylor Gregory S
• Kostic Marko N
• Hopper Christopher John

Classifications

• A61B5/015

  By temperature mapping of body part · CPC title

• A61B5/7425

  Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image · CPC title

• A61F2007/0093

  programmed · CPC title

• A61B5/486

  Biofeedback (using electroencephalography [EEG] A61B5/375) · CPC title

• A61B2505/09

  Rehabilitation or training · CPC title