Design A System For Heart Rate Monitoring By Photoplethysmography And Fall Detection With Multi-sensor Section

Nowadays,with the improvement of people’s quality of life and the progress of social medical treatment,people’s life has been greatly improved,the problem of aging population is becoming more and more serious.At the same time,people focus on personal privacy and the gap between of the young and the old is being aggravated.Small family is generally accepted,empty nest elderly is increasing,them are prone to accidents.Falls and heart disease are important factors in casualty of accidents.Abnormality in heart rate is often predated prior to the heart disease onset.Timely detection of falls and abnormal heart rate and provide timely relief will greatly reduce the proportion of casualties.This paper designed a system for heart rate monitoring by Photoplethysmography and fall detection with multi-sensor,timely detection of fall events and abnormal heart rate,automatically notify the remote monitor.In fall detection,not only using a three axis acceleration sensor to detect the body acceleration,but also a pressure-altitude sensor measuring the vertical height difference before and after the fall,extract some eigenvalues in acceleration and pressure,design a fall detection algorithm based on threshold method with a sensitivity of 97.78% and a specificity of 94.29%.We also detect heart rate by Photo Plethysmo Graphy,using a reflective photoelectric sensor SON1303 which include two green led with the wavelength of 570 nm.The heart rate was extracted by voltage difference method,removed the baseline drift of the pulse signal.In 5 minutes,the error of the average and standard deviation measurement by this paper with ECG is 0.21% and 2.39%.The algorithm of fall detection and heart rate extraction run in the embedded processor CC2541F256.The paper also designed an APP of android,communication with CC2541F256 by BLE,with the functions of abnormal heart rate analysis,GPS positioning and remote alarm.The APP simplifying the hardware of the wearable device,reduce the cost and space,make the system easy to practical application.