Design and Realization of Blood Oxygen and Heart Rate Sensor Nodes in Wireless Body Area Network

The blood oxygen saturation (SpO2) and heart rate of the human body contain much important physiological and pathological information, so they are important physiological indexes in biomedical detection. The method of measurement is obtained by detecting numerical pulse wave of the human body. And now to make sensor nodes in wireless body area network (WBAN), real-time monitoring of human health and real-time display, have great significance to the entire human rehabilitation project. Therefore, it has become a very important research direction to detect the pulse wave accurately, quickly and conveniently. In this paper, the sensor nodes for measuring blood oxygen saturation and heart rate are designed based on the near-infrared dynamic spectrum method. The working principle is that the MCU controls light source probe to emit light through body and the transmission light is received by the photodetector, which finishes the completion of the physiological signal to electric signal conversion. Then after a series of signal processing, the signal is sent to the microcontroller for calculation and analysis. The results are transmitted via Wi-Fi module to computer or mobile APP and then display. Through the experimental comparison and data accuracy of quantitative analysis, ultimately it is proved that the feasibility of this scheme is available and the sensor nodes can accurately measure blood oxygen saturation and heart rate values, and transmit these data to the upper monitor which achieves the wireless communication.