Design And Implementation Of Portable Bioelectrical Impedance Monitoring System

Bioelectrical impedance technology is one of the important technologies in the field of biomedical industry.As a very important application technology in clinical medicine and even in the field of industrial production process control,it is of great significance to analyze and study this technology.In view of the current situation of this field,this thesis designs and implements a feasible portable bioelectrical impedance monitoring system from hardware and software system.The device supports long-term monitoring and analyzes the collected data as a reference for judging the state of the human nervous system.The specific work of this topic is as follows:Firstly,the research background of bioelectrical impedance technology is described,and the research status and development trend of this technology at home and abroad are evaluated from various application fields,and the possible application fields of this technology are discussed,and the significance of the research is pointed out.Then,the basic concept and theory of bioelectrical impedance technology are introduced,and the electrophysiological properties of cells and biological tissues under different excitation frequencies,RC three-element equivalent circuit model of biological tissues,Cole-Cole theory and frequency scattering principle are described.Secondly,the hardware system of the equipment is designed.Impedance is measured by AD5933 chip.At the same time,other parts of the system module circuit,PCB board and equipment shell are designed,and the software system of the lower computer and upper computer of the equipment is designed.The upper and lower computers of the subject equipment can communicate with each other,and use the upper computer to control the lower computer to select the parameters before the measurement,realize the measurement of impedance,store the measurement results,read the stored measurement results for processing and export the stored results.Thirdly,the test results show that the equipment is effective and portable,and can meet the needs of the research project.The repeatability experiment and interference factor experiment are carried out to verify the scientific nature and credibility of the experimental scheme.Finally,the impedance spectra of the left arm and right arm of 37 adults were measured by using this device.Two adult subjects were then subjected to long-term impedance monitoring,which was measured during periods of high mental stress,insomnia,stress,or other specific conditions.The experimental results are as follows:(1)The equipment of this subject has high accuracy and precision.(2)The impedance of adults with different genders,occupations,ages and physical states has obvious differences,which can be used as distinguishing characteristics among individuals.(3)When the same individual is in different mental states,the bioelectrical impedance at the same location has certain differences.At the same time,the variation trend of amplitude and phase of different frequency points is the same.The experimental results show the effectiveness and feasibility of bioelectrical impedance monitoring,and prove that bioelectrical impedance can be used to reflect the changes of human function and nervous system,as a reference to judge the state of human nervous system.