Research And Design Of Head-mounted And Chest-worn Signs Parameters Acquisition Device

In recent years,wearable devices used in the field of medical monitoring have become more and more popular in people's daily life due to their unique portability and real-time performance,but there are few physical parameter monitoring devices which can be used by workers on the market.Workers in High-intensity working condition generally don't have enough cognition about their physical condition,which causes workers suddenly become seriously ill or even die.Therefore,it is particularly important to monitor the physical parameter of workers.Based on the above facts,a set of physical parameters acquisition device which can real-time monitor the workers' blood oxygen saturation,heart rate and respiratory rate is designed,and parameters can be received by mobile phone through Bluetooth and display on the corresponding APP in real time.The device can realize the monitoring of workers' vital signs and reduce the losses caused by sudden diseases.Considering the wearability,accuracy of testing parameters and low power consumption,a set of signs parameters acquisition device which is suitable for workers is designed.The device consists of a head-mounted device and a chest-mounted device.The head-mounted device uses a helmet as the carrier,and uses biosensor based on reflective principle to collect pulse wave signal from forehead and detect blood oxygen saturation.The chest-mounted device uses conductive silica gel to collect ECG breathing signals from the chest and detect heart rate and breathing rate.For hardware design,by using the low power consumption microcontroller and optimizing the component layout,the board size is narrowed and the power consumption of the device is reduced.In the study of sign parameters algorithms,high-frequency interference and baseline drift are removed by using smoothing and morphological filtering.On this basis,the extreme point of the pulse wave signal is located by Differential differential sign method,and the blood oxygen saturation is calculated;the R wave of ECG signal is located by differential threshold method to calculate the heart rate;the maximum point of the respiratory signal is found by point-by-point discrimination method,and the respiratory rate is calculated.A series of tests are carried out on the designed device for collecting physical parameters,and it was found that the device can complete acquisition and processing of the physiological signals,the charging function is normal,and the device can work more than 9 hours.In the state of rest,the average error rate of blood oxygen saturation,heart rate and respiration rate are within 3%,2% and 3% respectively;Under normal exercise conditions,the average error rate of blood oxygen saturation,heart rate and respiratory rate are within 5%,5% and 6% respectively.The test results show that the wearable device meets the design requirements and can complete the detection of workers' vital signs.