Modified Kohonen's self-organizing feature map and its application to automatic sleep cycle recognition

In order to increase the adaptive ability of the Kohonen's self-organizing feature map algorithm, we modify the updating rule of its partition boundary. The modified algorithm, together with the genetic algorithm, is applied to the detection of the REM (rapid eye movement) cycle of the sleep, which is said to be related to comfortableness of the sleep. We used the heart-rate alone (not EEG) and succeeded to achieve a high detection accuracy.