Study Of Pervasive Sleep Monitoring System With Zigbee And Wearable Antenna

Pervasive sleep monitoring is the PSG (Polysomnography) based on the concept of pervasive computing. Different from the medical equipment for hospital, the pervasive sleep monitoring is a kind of medical devices for family. According to main problems of pervasive sleep monitoring, this article design a wearable pervasive sleep monitoring system based on the concept of BSN (body sensor network) and Zigbee wireless technology.The current common pervasive sleep monitoring systems could collect one or two kind of physiological data, and the system that this paper presents can get various physiological data of various people at the same time. Two node modules are placed on body in this system, and they are called wrist node and chest node depending on the placement. The wrist node can collect oxygen saturation、pulse rate、human motion and temperature data, and the chest node can collect ECG (electrocardiogram) and respiratory wave signal. Node modules and coordinator module form Zigbee wireless network, node modules send the signal to coordinator module by Zigbee network, then the coordinator module send signal to upper computer by the serial communication protocol. For this system the upper computer is PC, and the interface program is compiled by C++ programming language, it can achieve the function of display and data storage. This system has many advantages, such as portability、low cost、low power、easy operation and so on.In order to better implement the portability of the pervasive sleep monitoring system and increase the signal transmission distance. A 2.4GHz wearable antenna with new structure is presented in this paper. This wearable antenna is a kind of planar microstrip antenna, its radiation patch is made by the conductive fabric and the substrate of this antenna is pasted with 2mm thickness and dielectric constantεr=1.2. This wearable antenna has smaller volume and lighter weight, so it will not make the user feel unwell. The bending feature of antenna is analyzed in this paper, and the results show this antenna has good transfer characteristic in the bend condition.