DYNAMIC STRESS SCORING WITH WEIGHTED CONTRIBUTIONS OF CARDIAC PARAMETERS
A stress score from a physiological monitor provides a local, objective, quantitative measurement of stress in a numerical form that can be used as the basis for real time coaching, decision-making, and so forth.
1 . A computer program product comprising computer executable code embodied in a non-transitory computer readable medium that, when executing on one or more computing devices, causes the one or more computing devices to perform the steps of:
providing a heart rate variability metric for a user based on heart rate data received from a physiological monitoring device over an interval;
providing a heart rate metric for the user by aggregating the heart rate from the physiological monitoring device over the interval;
determining a resting state of the user based on a difference between the heart rate metric for the user and a resting heart rate for the user; and
calculating a stress score for the user wherein:
the stress score is calculated based on a weighted combination of the heart rate variability metric and the heart rate metric,
the weighted combination uses a first weight for the heart rate metric based on the resting state of the user, and
the weighted combination uses a second weight for the heart rate variability metric based on the resting state of the user.
2 . A method comprising:
providing a heart rate variability metric for a user;
providing a heart rate metric for the user;
determining a resting state of the user; and
calculating a stress score for the user wherein:
the stress score is calculated based on a weighted combination of the heart rate variability metric and the heart rate metric,
the weighted combination uses a first weight for a first component of the stress score based on the heart rate metric, wherein the first weight is based on the resting state of the user, and
the weighted combination uses a second weight for a second component of the stress score based on the heart rate variability metric, wherein the second weight is based on the resting state of the user.
3 . The method of claim 2 , wherein the second weight is equal to one minus the first weight.
4 . The method of claim 3 , wherein the first weight approaches one as the heart rate metric approaches a resting heart rate for the user.
5 . The method of claim 4 , wherein the first weight monotonically approaches one as the heart rate metric approaches the resting heart rate.
6 . The method of claim 4 , wherein the first weight sigmoidally approaches one as the heart rate metric approaches the resting heart rate.
7 . The method of claim 2 , wherein the first weight increases according to a proximity of the resting state to a sleep state for the user.
8 . The method of claim 2 , further comprising periodically calculating the stress score over an interval, thereby providing a timeline of stress scores for the user over the interval.
9 . The method of claim 8 , further comprising displaying the timeline of stress scores on a user device as a stress score graph.
10 . The method of claim 2 , wherein providing the heart rate variability metric and the heart rate metric includes acquiring the heart rate variability metric and the heart rate metric from a physiological monitor worn by the user.
11 . The method of claim 2 , further comprising displaying the stress score on one or more of a wearable physiological monitor and a user device.
12 . The method of claim 2 , further comprising generating an intervention recommendation for the user based on the stress score, wherein the intervention recommendation includes a real time recommendation based on at least one of a current stress score and a current activity.
13 . The method of claim 2 , wherein the resting state is based on a circadian state of the user.
14 . The method of claim 13 , wherein the circadian state is based on at least one of: (i) a probability of a sleep state for the user; a circadian rhythm model for a population; and a circadian rhythm model for the user.
15 . The method of claim 2 , wherein the resting state is based on a difference between the heart rate metric of the user and a resting heart rate of the user.
16 . The method of claim 2 , wherein providing the heart rate metric includes acquiring at least one of an aggregate heart rate measurement and an aggregate heart rate variability measurement over an interval with a wearable physiological monitor.
17 . The method of claim 16 , wherein providing the heart rate variability metric includes acquiring an aggregate heart rate variability measurement over the interval with the wearable physiological monitor.
18 . The method of claim 2 , further comprising adjusting the stress score based on motion data obtained from a wearable monitor worn by the user.
19 . The method of claim 2 , wherein providing the heart rate variability metric includes scaling a heart rate variability measurement based on at least one of: a distribution of historical heart rate variability measurements, and a distribution of historical heart rate measurements.
20 . A system comprising:
a wearable physiological monitor including one or more sensors and a first processor configured to continuously acquire heart rate data for a user based on a signal from the one or more sensors;
one or more processors coupled in a communicating relationship with the wearable physiological monitor, the one or more processors configured by computer executable code to receive data from the wearable physiological monitor and to:
calculate a heart rate variability metric for the user based on the heart rate data,
calculate a heart rate metric for the user based on the heart rate data,
determine a resting state of the user based on the heart rate data, and
calculate a stress score for the user wherein:
the stress score is calculated based on a weighted combination of the heart rate variability metric and the heart rate metric,
the weighted combination uses a first weight for the heart rate metric based on the resting state of the user, and
the weighted combination uses a second weight for the heart rate variability metric based on the resting state of the user, and
a display device in communication with the one or more processors, the display device including a user interface configured to present a value to the user indicative of the stress score.