Estimation of Human Core Temperature based on Heart Rate System and Method

1 . A method for determining the core body temperature of a person comprising:

setting an initial core body temperature with a processor;

receiving a heart rate of the person with the processor;

calculating a predicted core body temperature with the processor using an extended Kalman filter based on the heart rate and the initial core body temperature; and

providing the predicted core body temperature.

2 . The method according to claim 2 , further comprising:

receiving another heart rate of the person with the processor;

calculating a new predicted core body temperature using the extended Kalman filter based on the another heart rate and the last predicted core body temperature; and

repeating the receiving another heart rate and calculating a new predicted core body temperature at predetermined intervals.

3 . The method according to claim 2 , further comprising:

when the new predicted core body temperature exceeds a predetermined threshold, sending an alarm signal prior to proceeding to repeating, wherein the alarm signal triggers an alarm; and

when the new predicted core body temperature does not exceed a predetermined threshold, proceeding to repeating.

4 . The method according to claim 2 , further comprising obtaining the predetermined interval.

5 . The method according to claim 1 , wherein providing the predicted core body temperature includes displaying the predicted core body temperature.

6 . The method according to claim 1 , wherein providing the predicted core body temperature includes transmitting the predicted core body temperature with a transmitter to an external device.

7 . The method according to claim 1 , wherein calculating a predicted core body temperature includes calculating a preliminary core body temperature;

calculating a preliminary estimate of the variance of a core body temperature estimate;

calculating an extended Kalman filter mapping function variance coefficient;

calculating a Kalman gain weighting factor based on the preliminary estimate of variance and the extended Kalman filter variance coefficient; and

calculating the predicted core body temperature using a preliminary time-update estimate, an error between the new heart rate and an expected heart rate given the preliminary estimate of the core body temperature.

8 . The method according to claim 7 , wherein calculating a predicted core body temperature further includes determining a variance of the predicted core body temperature.

9 . The method according to claim 1 , further comprising adjusting the extended Kalman filter based on at least one of a fitness level, an age, a maximum heart rate and a resting heart rate of the person.

10 . A system comprising:

a heart rate data source; and

a processor in communication with said heart rate data source, said processor capable of calculating a core body temperature based on constants and having as the only inputs heart rate information and prior core body temperature data.

11 . The system according to claim 10 , further comprising a display in communication with said processor.

12 . The system according to claim 10 , further comprising a transmitter for communication with an external system, said transmitter in communication with said processor.

13 . The system according to claim 10 , further comprising a temperature sensor in communication with said processor.

14 . The system according to claim 10 , wherein said processor includes

an initial core body temperature module for setting an initial core body temperature,

a heart rate module for obtaining heart rate information, and

a core body temperature calculator in communication with said initial core body temperature module and said heart rate module.

15 . The system according to claim 14 , where said processor further includes a timer module in communication with said heart rate module and said core body temperature calculator.

16 . The system according to claim 15 , where said processor further includes an alarm module in communication with said core body temperature calculator.

17 . The system according to claim 16 , further comprising:

a display in communication with said core body temperature calculator;

a transmitter in communication with said core body temperature calculator; and

a temperature sensor in communication with at least one of said timer module and said alarm module.

18 . A system comprising:

a heart rate data source; and

a processor in communication with said heart rate data source, said processor having program code embodied therewith, the program code executable by the processor to

set an initial core body temperature;

receive a heart rate of the person;

calculate a predicted core body temperature using an extended Kalman filter having as inputs the heart rate and the initial core body temperature; and

provide the predicted core body temperature.

19 . The system according to claim 18 , further comprising:

a display in communication with said core body temperature calculator; and

a transmitter in communication with said core body temperature calculator.

20 . The system according to claim 18 , wherein the initial core body temperature is set based on the initial heart rate of the person.