Analysis of pulse rate, respiration rhythm, and body movement during sleep detected by pressure sensor

We have proposed a network based system for long-term recording pulse rate (PR), respiration rhythm (RR), and body movement (BM) detected by a sensor unit placed beneath a pillow during sleep from pressure variations corresponding to changes in the heartbeat and respiratory motion. In this research, we studied the analysis of the long-term monitored PR, RR, and BM during sleep recorded by this system. Using data collected over a 13-month period from a female subject, the average frequency of BM in a day varied from 4.4 to 22.4 h^-1, and the mean frequency of BM over 332 nights was 8.3 h^-1 with a standard deviation of 2.2 h^-1. Periodic biorhythms were also assessed using the profiles of the average PR and certain frequency domain parameters of PR variability. The rhythmic property of these profiles was confirmed to coincide with the subject´s menstrual cycle. The results of this 13-month trial operation show that it is possible to long-term monitor PR, RR, and BM during sleep by using our system, and analyze various physiological rhythms in humans over prolonged periods.