Application And Research Of Fabric Sensor In Human Respiratory Monitoring

Respiration is one of the most important physiological signals of human body.Monitoring human respiration is also an important part of modern medical technology.In recent decades,respiratory monitoring was an important physiological index in all aspects of medical research.At present,the development of respiratory monitoring technology laged behind that of ECG monitoring technology,and there was a widespread phenomenon that clinicians attached more importance to "heart" than to "lung".Through the measure and analysis of respiratory rate,we can get many inherent physiological information hidden behind it,and it is easy to monitor it daily,so the main parameter of the existing human respiratory monitoring equipment is respiratory frequency.The common respiratory monitoring equipment in hospitals is large and expensive,so it can only be measured in the ward,which is not conducive to carrying on and monitoring daily.Therefore,it is necessary to design a portable breathing monitoring device with small size,lower power consumption and suitable price.Considering these aspects and the development trend of intelligent terminal equipment,the structure of common respiratory monitoring system can be divided into two parts,one is signal acquisition and conditioning unit and signal processing unit,the other is signal display unit.Signal acquisition and conditioning unit and signal processing unit achieve more stable performance and more accurate testing on the original basis;signal display unit uses portable intelligent terminals(smart phones or tablets)to achieve.As a result,a small,low-power,affordable breathing monitoring device emerged.In this design,the fabric sensor was used as the front-end acquisition module,and the respiratory frequency was measured by the output voltage change of Wheatstone Bridge.The signal amplification filter conditioning circuit was designed at the same time.IAP15W4 K was taked as the core of the microprocessor and had AD conversion module.Fourier transforming program was writed to process the signal obtained by digital-to-analog conversion so as to realize the measurement of respiratory frequency,then low power Bluetooth sent the data to display on the mobile phone APP.Based on the fabric sensor,a prototype of respiratory monitoring equipment was designed to monitor accurate human breathing in real time.The waveform of human breathing can be observed and the frequency of human breathing can be calculated.Compared with other methods such as mouth-nose airflow method,impedance volume tracing technology and piezoresistive sensor method,the prototype of respiratory monitoring equipment had the advantages of large strain,comfort and portabitity.It can achieve long-term and stable measurement and is suitable for the elderly.