Detecting sleep onset and wake

A medical device comprising:

• at least one sensor to sense physiologic information;
• and
• a control portion configured to:
• receive a plurality of inputs each corresponding to a different sleep-wake determination parameter, the plurality of inputs comprising the sensed physiologic information;
• detect initial sleep onset based on at least a first subset of the plurality of inputs and first threshold values for the at least first subset of the plurality of inputs;
• detect wake after sleep onset (WASO) based on at least a second subset of the plurality of inputs and second threshold values for the at least second subset of the plurality of inputs;
• and
• detect sleep onset after WASO based on at least a third subset of the plurality of inputs and third threshold values for the at least third subset of the plurality of inputs,
• wherein the third threshold values are different from the first threshold values and the second threshold values.

A medical device comprising:

• at least one sensor to generate a sensor signal indicative of motion of a patient;
• and
• a control portion configured to detect initial sleep onset by:
• calculating magnitudes of the sensor signal to generate a motion magnitude signal;
• in response to each respective peak of the motion magnitude signal, starting a respective countdown timer having an initial value corresponding to a magnitude of the respective peak, the respective countdown timer representing a respective shadow cast by the respective peak;
• determining a fraction of a moving window covered by the shadows;
• starting a delay period in response to the fraction dropping below a first threshold value;
• and
• in response to the fraction remaining below the first threshold value for the delay period, detecting initial sleep onset.

A medical device comprising:

• at least one sensor to generate a sensor signal indicative of motion of a patient;
• and
• a control portion configured to detect wake after sleep onset (WASO) by:
• calculating magnitudes of the sensor signal to generate a motion magnitude signal;
• starting a window of time in response to a respective peak of the motion magnitude signal exceeding a second threshold value;
• and
• in response to a selected number of respective peaks of the motion magnitude signal exceeding the second threshold value prior to the window of time expiring, detecting WASO.