Patent ID: 7775993

Claim:
A medical system comprising: a plurality of sensors, each of the sensors generating a signal as a function of at least one physiological parameter of a patient; and an implantable medical device including a processor configured to: monitor a plurality of physiological parameters of the patient based on the signals output by the sensors, for each of the plurality of physiological parameters, determine a respective one of a plurality of sleep metric values, each of the sleep metric values indicating a probability of the patient being asleep based on the respective physiological parameter, and mathematically combine the plurality of sleep metric values that each indicates the probability of the patient being asleep based on the respective one of the plurality physiological parameters to determine an overall sleep metric value that indicates an overall probability of the patient being asleep, wherein the physiological parameters comprise at least one of electrocardiogram morphology, core temperature, subcutaneous temperature, muscular tone, brain electrical activity, or eye motion.