Research On Wearable Physiological Information Monitoring And Its Self-powered Syste

With the aging of society and the increasing trend of younger cardiovascular and cerebrovascular diseases,the incidence of chronic diseases is increasing year by year,and people’s awareness of disease prevention and health protection has also been upgraded.More and more people are beginning to pay attention to the daily monitoring of physiological information,which has promoted the development of wearable physiological information monitoring technology.At the same time,people have paid attention to the problem of battery power supply.In order to solve the problem of limited product life and pollution caused by batteries,researchers have explored alternatives to harvesting human motion energy and weak energy in the environment and converting them into electrical energy through transducers to power wearable systems.Based on this,this paper studies wearable physiological information monitoring and its self-powered system.The main contents of the paper are as follows:First of all,this paper theoretically analyzes the working mechanism of piezoelectric conversion and photoelectric conversion,and compares the power output characteristics of various piezoelectric materials and photovoltaic cells.PZT-5H bicrystalline piezoelectric ceramic sheets are selected as the piezoelectric material and flexible amorphous silicon solar cell films are selected as optoelectronic materials.Combined with the characteristics of the physiological structure of the foot and the distribution of the force on the sole of the foot during movement,a variety of piezoelectric energy harvesting devices were designed,including arch,hexagonal and double-layer piezoelectric disk array structures.Then,taking sneakers as the carrier,the piezoelectric energy collector is placed on the sole of the foot,and the photoelectric energy collector is bonded to the upper to form a composite energy collection shoe.At the same time,an energy storage management control circuit with timers and Schmitt triggers as the core components is designed,and the super capacitor is used to store the electric energy output by the above collectors and serve as the power supply of the whole system.The energy management control circuit powers up the physiological information monitoring system every 20 minutes,and the power will be cut off immediately after one round of work.Secondly,the low-power hardware and software design of the physiological information monitoring system based on STM32L1 is completed.This part of the design is divided into two parts: data acquisition module and data communication module.The data acquisition module includes DW1000 ranging and positioning unit,ADS1292 R ECG and respiratory signal acquisition unit and LIS3 DH motion parameter acquisition unit.The data communication module selects ultra-low power Bluetooth JDY-19 to wirelessly transmit data to the upper computer.In terms of software design,combined with the hardware design of the power-on switch of each unit,the time-sharing work of each unit is realized.In order to realize the judgment of human physiological movement,160 groups of heart rate,respiratory rate and SMV values are collected as training and test samples,the PSO-BP neural network model is constructed,and the Android Studio development platform is applied to design an upper computer APP to feed back the monitoring and judgment results to users.Finally,the output of the composite energy acquisition device and the operation of the system are tested.The results show that the average output power of the photoelectric energy collection device indoors from 7 a.m.to 7 p.m.is 590 μW,the average output power of the piezoelectric energy collection device driven by walking is 540 μW,the composite energy output power is stable above 1.124 m W,and the power generation is 1.349 J.Through the data acquisition test and power consumption test of each unit of the system,it is concluded that the energy consumption of the system in one round of operation is 1.04 J,which verifies the feasibility of intermittent self power supply from the perspective of energy balance.