Researches On Key Technologies Of Wearable Physiological Monitoring Nodes

Since the 21 th Century, with the approach of aging society in china, health and safety of aged people has already become a hotspot of social attention. It has great practical value to monitor sport and physiological information to guarantee the healthy and safety of the old. In this paper, combining the current situation of wearable telemonitoring device at home and abroad, the wearable telemonitoring device with multi-physiological parameters has been designed with step node and heart rate node and sink node.It is the design of step node. The step node includes step decision and GPS function. Aiming at the step fuction, it analysises the signal of acceleration, comparing the results of median filter and sliding mean filter and mathematic morphology algorithm, discovering that the smoothness of the signal after filtered have bad efforts. At the same time, the signal processed by median filter and sliding mean filter have baseline drifting. So, the fusion algorithm consisted of the three algorithm is designed. The fusion algorithm can remove the baseline drifting and has good smoothness for step detection. It analysises the feature of the acceleration, comparing the results of threshold judgment and peak judgment algorithm, discovering that the algorithm mentioned above would make false positives or false negatives. On the basis of the above mentioned, it proposes the similarity selection algorithm to recognize the step through similarity of acceleration and standart signal, using the improved algorithm of peak value to reduce the effort of noise through the threshold condition of difference of peaks and troughs. The missing rate can be reduced to less than 5%.It is the design of heart rate node. The heart rate node includes heart rate detection, bluetooth and display. Aiming at heart rate detection, it analysises the characteristic that the pluse sampling circuit is easily disturbed by the light outside, comparing the waveform of pulse and differential of first older, discovering that the differential of first older can reflect the feature of pluse and has the stable signal which is easy to detect, in order to reduce the time consumption, the hardware design is adopted. It analysises the feature about the differential signal of first older, comparing the peak recognition and threshold recognition, discovering that the algorithm mentioned above would make false positives or false negatives. On the basis of the above mentioned, it proposes the slope detection algorithm based on differential signal of first older to calculate the heart rate quickly.It is about the design of sink node. The sink node includes data processing, short message and GPRS. It analysises the characteristic of MCU, discovering that real-time is not good when multiple tasks are working. Therefore, it designs the real-time system to process multiple tasks concurrently.In the paper, the wearable telemonitoring device with multi-physiological parameters is designed; proposing the step algorithm with temporal filtering-similarity selection, having well real-time, and the accuracy can reach 90% when it chooses the similarity of 72%. It proposes a heart rate calculation method with hardware diffenential-slope detection which can get the similar results with sphygmus. The system can work stability. In addition, it has the advantages of low cost, esay detection, good extention, and can be used in the domains, such as, health care of disabled old people, and postoperative rehabilitation of patients.