Recording of the temperature distribution on a bed and its application to the assessment of body movement

: In order to assess body movements during sleep, a system which records the temperature on a bed was developed. The system consists of 16 temperature sensors and a data logger with a memory card (RAM card). The 15 temperature sensors were arranged in line with a separation of 6 cm on a flat cable which was placed between the bed sheet and the mattress in such a manner that it crossed the bed at the level of the breast. 15 temperatures on the bed and the room temperature were stored in a RAM card at interval from 30 seconds to 30 minutes. The memory card can store 504 successive data. The stored data were transferred into a micro computer. It was shown that posture changes and the body movements during sleep, could be recognised from the changes in the temperature profile, and these changes were well visualized by a three-dimensional display of the successive temperature profile on the bed.