Stryker Corporation
Thermal system with step response

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 implements a step change in the temperature of the fluid delivered to the patient. The step change is implemented prior to the patient reaching a target patient temperature. In the moments after (and in some cases the moments before) the step change, the controller monitors the rate of change of patient's temperature to evaluate whether the patient will reach the target patient temperature without reversing the step change, and/or how long it will likely take for the patient to reach the target patient temperature without reversing the step change. The controller then determines whether to reverse the step change or to switch to another algorithm for controlling the fluid temperature.