Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for visualizing, scoring, recording, and analyzing sleep data and hypnograms. In some implementations, a method includes generating and providing a representation of sleep stages that includes a sequence of elements indicating a progression of the sleep stages over time during a sleep session. In some implementations, a method includes generating and providing one or more scores based on analysis of the sleep session. In some implementations, a wearable body data recorder includes a plurality of sensors and is configured to measure and process sensor data obtained during a sleep session of a subject.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining sleep stages and sleep events using sensor data. In some implementations, sensor data is obtained over a time period while a person is sleeping. The time period is divided into a series of intervals. Heart rate and changes in the heart rate are analyzed over the intervals. Based on the analysis of the heart rate changes, sleep stage labels are assigned to different portions of the time period. An indication of the assigned sleep stage labels is provided.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining sleep stages and sleep events using sensor data. In some implementations, sensor data is obtained over a time period while a person is sleeping. The time period is divided into a series of intervals. Heart rate and changes in the heart rate are analyzed over the intervals. Based on the analysis of the heart rate changes, sleep stage labels are assigned to different portions of the time period. An indication of the assigned sleep stage labels is provided.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for visualizing, scoring, recording, and analyzing sleep data and hypnograms. In some implementations, a method includes generating and providing a representation of sleep stages that includes a sequence of elements indicating a progression of the sleep stages over time during a sleep session. In some implementations, a method includes generating and providing one or more scores based on analysis of the sleep session. In some implementations, a wearable body data recorder includes a plurality of sensors and is configured to measure and process sensor data obtained during a sleep session of a subject.