Wearable Health Parameter Monitoring Method And System Design

With the improvement of the quality of life,people's demand for early detection of disease is higher and higher.This has made the wearable health equipment receive rapid attention.The continuous measurement of the parameters of human health signs can reflect the physiological state of the human body in real time and play an important role in people's health.Heart rate,blood oxygen saturation and blood pressure are three important health parameters of the human body.Continuous and accurate measurement of these parameters can effectively judge the health of the human body and prevent the disease.In this thesis,the photoplethysmography pulse waves at the two radial and radial arteries are taken as objects,and a wearable multi-health parameter monitoring system is designed with the goal of detecting three health parameters of heart rate,blood oxygen saturation,and blood pressure.The main work of the thesis is:Firstly,the principle of photoplethysmography pulse and the detection methods of various health parameters based on volume pulse wave were described.The position of detection was determined and a multi-parameter monitoring system based on dual photoelectric pulse wave sensor was proposed.A health parameter monitoring hardware system based on STM32 was designed and built.Adopts Maxim's MAX30102 integrated chip to drive its internal LED dual light source to alternately emit light.The internal photodetector is used as a sensor to convert the light intensity signal into a voltage signal,integrating 18-bit A/D analog-to-digital conversion,digital filtering,and ambient light.Filtering greatly reduces the size of the acquisition side.The STM32F103C8T6 micro-controller accesses its internal FIFO through the I2C bus to obtain acquired pulse wave data.The waxveform data is processed in the micro-controller and extracted to obtain various health parameters.The health parameter results are displayed in real time through the OLED,and the wireless data communication between the system and the smart phone is achieved through the low power Bluetooth 4.0.STM32-based health parameter monitoring system software design was completed.The collected pulse wave raw data was denoised and the 38pt moving average algorithm was used to eliminate high-frequency burrs caused by muscle jitters.Then,a traditional differential threshold method was used to extract the pulse wave feature parameters.The pulse wave propagation time and R value were calculated from the pulse wave characteristic parameters.The calculation formula of blood oxygen saturation was calibrated,and the blood oxygen measurement was achieved by using the calibrated calculation formula;A mathematical model of systolic and diastolic blood pressure and pulse wave conduction time was established,and the blood pressure measurement was realized by using this model.Finally,the system test was completed and comparative experiments were performed on various health parameters.Through preliminary experiments,the following conclusions are drawn.The experimental results of heart rate measurement show that:the heart rate measurement error was within ±4 BPM,and the heart rate data error above 96%was within ±3 BPM;the experimental results of arterial oxygen saturation measurement showed that:the arterial oxygen saturation error was within ±2%;arterial blood pressure measurement results show that:the average absolute error of systolic blood pressure is 5.7mmHg,the standard deviation is 6.41mmHg,the average absolute error of diastolic pressure is 8.OmmHg,the standard deviation is 8.85mmHg,systolic blood pressure conforms to the AAMI standard,which means the standard deviation is not larger than 8mmHg,and the diastolic pressure slightly exceeds the standard.