| abstract |
Methods and devices monitor health by detection of a sleep stage. For example, the sleep stage monitor 100 may access sensor data signals related to body movement and / or breathing movement. At least some of the detected signals may be analyzed to calculate respiratory variability. The rate of respiratory variability may include one or more of a rate of variation of respiratory rate and a rate of variation of respiratory amplitude. The processor may then determine the sleep stage based on one or more of respiratory rate and body movement, such as a combination thereof. The determination of the sleep stage may distinguish between sleep and other stages of sleep, or it may distinguish between sleep, shallow sleep and REM sleep. The body's athletic and respiratory movement signals may be derived from one or more sensors, such as non-invasive sensors (eg, non-contact radio-frequency motion sensors or pressure sensitive mattresses). |