Study And Design Of A Portable And High-precision Asthma Monitor System

With the continuous spread of haze in China during recent years,environmental problems has been becoming increasingly serious,resulting in high prevalence of asthma,which has brought a heavy burden to the community and family.This situation has aroused widespread concern in the whole society.Since asthma has a sudden onset of particularity,patients need long-term routine care.However,so far,domestic asthma monitoring equipment has been mainly applied for medical with bulky and complex operation,which is not conducive to the daily use for patients,while the portable home monitoring equipment is heavily dependent on Europe and the North America and other countries import at high prices,which is not conducive to popularization in China.Therefore,it's of important significance and great social value to research and develop a set of portable high-precision asthma monitoring system with independent intellectual property rights.This paper thoroughly study the asthma monitoring mechanism.Basis on the concept of "Internet + health" and combining the emerging Internet technology with traditional hardware technology,a high-precision asthma monitoring system which includes portable asthma monitor,handheld terminal APP and cloud management platform is developed.The system has built a bridges between asthmatic patients and doctors,servicing as a key monitoring node technology for future telemedicine.In order to achieve the high precision of the system,for one thing,this paper proposes a dual sensor combination monitoring scheme based on Big-Little structure,which uses large and small range sensors to monitor the large and small airflow signals separately in the front-end signal acquisition,and combine the 16 Bit quantitative sampling method to improve the monitoring quality of small air flow signals.For another,owing to the massive noise to calibration sample signal,Mallat algorithm is used to perform wavelet multi-resolution analysis to achieve denoising in this paper for obtaining pure calibration samples.At the same time,in order to construct the accurate calibration curve,this paper also adopts the neural network by comparative studies on other multi-polynomial fitting methods.Finally,the Mallat algorithm combining with calibration curve mathematical mode is applied to the signal processing.The results show that the method can effectively improve the monitoring precision.The system developed in this paper is portable,intelligent,low cost,low power consumption and high precision etc.The instrument size is 50 mm * 120 mm * 20 mm.Asthma pathological indicators of the system are PEF(expiratory peak velocity value),FEV1(forced vital capacity first seconds),FEV1 %(forced expiratory volume in one second to forced vital capacity ratio),and the total power consumption of 137 mW which can last for more than 30 days standby time by recharging once.Lots of experimental results show that the asthma monitoring has repeatability.PEF maximum relative differential is below 5%.PEF maximum value error is less than 10%,satisfying with industry standards.At the same time,in contrast to the United States Piko detector for lung function Bland-Altman consistency analysis,monitoring results indicate that the same level is reached.In this paper,the development of portable high-precision asthma monitoring system is practical and reliable,which can be widely used in asthma patients daily household monitoring.