| Health monitoring systems have drawn more and more attention from the research community and the industry,as people who suffer from age related diseases are increasing and aging process is speeding up in many countries.People need health service more than hospital medical treatment,they demand daily monitoring and health management for everyday lives.The technology of wearable multiple physiological parameters monitoring(WMPPM)mainly focuses on electrocardiogram(ECG),respiration rate(RESP),body temperature(BT),pulse rates(PR),blood pressure(BP),blood oxygen saturation(SaO2),blood glucose and other basic physiological parameters of human body,which are closely related to many diseases prevention and control.WMPPM technology,which appears as the characteristics of easy to operate,working for a long time,intelligent interaction,abnormal physiology alarm,wireless data transmission,has the ability of daily health care monitoring with no interference.The research of WMPPM with the characteristics of miniaturization,low power consumption,strong anti-interference ability is challenging,while it is meaningful to health care services and chronic disease management.This thesis focused on the research of WMPPM devices.This thesis designed a multiple physiological parameters monitoring system(MPMS)which can monitor six vital physiological parameters at the same time based on wearable Body Sensor Network.The main research contents and results are as follows:1).Design of smart shirt:Both conventional Ag/AgCl electrodes and fabric electrodes are acceptable to monitor ECG parameter.As all the sensors and electrodes are demountable,this smart shirt is washable and more reliable than some other smart clothes for long time monitoring.The sensors connect to the MPMS by means of wires,which are stitched in the middle layer in the trace.The shirt is made of knitted lycra material and cotton.2).Design of physiological parameters monitoring function module:The MPMS Device is mainly composed of ECG/RESP parameters monitoring subsystem1 with embedded algorithms,SaO2/PR/BT/BP parameters monitoring subsystem2 with embedded algorithms,main control subsystem3 which is in charge of system level power administration,communication and interaction design.Distributed and flat design methods are applied to miniaturize the monitoring system.A power reduction technique at physical/hardware level is designed.Low power consumption processor and peripheral devices are applied when design hardware.Optimization design of power consumption in operation process and application are designed.3).Algorithm implementation of dynamic monitoring technology:Study of algorithm for ECG signal processing,QRS complex detection,dynamic respiration signal processing and real time monitoring for respiration rate.Analyze the QRS complex detection algorithm based on peak detection and wavelet analysis.Peak detection based algorithm has low computational complexity and is suitable for WMPPM with low capacity.Design proper digital filter which is suitable for real time monitoring and occupies less MCU resource.4).Prototype test and scientific&technical novelty checking:The WMPPM designed here was tested by ZheJiang Institute for the Control of medical device,the results showed that the functions meets the standards accordingly.To the best of our knowledge,we cannot find a low power system which monitors these six physiology parameters at the same time and is smaller in size and lighter in weight than our prototype of MPMS Device until now.The implementation of clinical experiment for teaching and research purpose was carried out in community hospitals,the results showed basically identical compared with other instrument.For the specific requirements from family daily monitoring and movement monitoring,this thesis studied low-power wrist-worn miniature device used for real-time wireless heart rate(HR)monitoring.The main research contents and results are as follows:1).Wrist-worn watch like device based on piezoelectric sensor:a novel pulse signal detection method based on double channels of pulse sensing of the radial artery and ulnar artery as well as their differential signal are proposed,while low power and power management design are optimized at the same time.The main disadvantage of this design is that pulse signal obtained is easily saturated.So,this thesis presents a miniaturized,battery powered wrist worn artifact-resistive pulse rates monitoring system(PRMS)based on photoplethysmography(PPG).2).The tissue optical model and motion interference elimination prototype are analyzed here,while high gain and phase consistency circuits are also applied.As human tissue is a strongly scattering media,in which the movement of light is random,different radial distance and different forms of sensor array are studied.Research of the mechanism for reflex heart rate detection and one possible optical model:According to the tissue optical model designed,it can be explained that body motion causes the changes in optical path lengths between tissue and LEDs.Using ZEMAX optical simulation software to simulate the geometric optical path and to choose the optimal scheme,which provides design basis for hardware design.3).Circuit design of double light-path heart rate detection and research of anti-interference technology:According to the tissue optical model designed and the result of ZEMAX simulation,The thesis proposed an scheme with low algorithm complexity,high dynamic range and high anti-motion interference ability.In this study,red and green double color LEDs in which the wavelength of red light is 620?630nm and the wavelength of green light is 518?530nm are used.The temporal resolution of the system is 2ms,and spatial resolution is 0.85mm.Four kinds of motions were performed and the results showed that the differential channel improved the morphology of the PPG signal and appeared to be artifacts resistive during motions. |
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