Design And Implementation Of Biological Signal Acquisition And Analysis System

With the development of biomedical research,the importance of biological experiment is increasing.Biological signal acquisition and analysis system has gradually become an indispensable equipment in biomedical experiments because of its high integration,convenient operation and accurate data analysis.Therefore,in order to meet the needs of intelligent and networked devices,this paper designs and completes a multi-functional biological signal acquisition and analysis system,the main research work is as follows:1.An algorithm based on adaptive immune least absolute deviation is proposed to extract the characteristic parameters of bio impedance.Firstly,the nonlinear optimization is carried out according to the extraction method of biological impedance characteristic parameters;secondly,based on the traditional immune algorithm,the adaptive strategy is designed and the memory unit structure is introduced to form the adaptive immune least absolute deviation algorithm combined with the least absolute deviation;finally,for experimental verification,singular point noise and random noise are added to the standard biological impedance data set to form three different data sets.Meanwhile,the proposed algorithm is compared with the other three algorithms.The results show that the algorithm has higher fitting accuracy,faster running speed and lower initial value dependence.2.The biological signal acquisition system is designed and implemented.Considering the characteristics of biological signal,such as low signal-to-noise ratio,weak and high gain,the instrument amplifier combined with fifth order Bayesian filter is utilized to realize signal acquisition and filtering processing.In addition,the digital control technology is utilized to realize gain amplification and filtering program control,so as to complete the analog frontend circuit design.Considering the requirements of intelligent,networked and portable equipment,the low-power management technology and Wi Fi wireless communication technology are adopted to realize the network acquisition of ECG,EMG,bio impedance and other biological signals.3.The biological signal analysis system is designed and implemented.With the help of Ethernet technology to achieve multi device networking,complete the reliability of signal transmission,and meet the design requirements of system networking.Through introducing the signal slot mechanism the communication between classes and the functional layering of system software are achieved.Furthermore,QWT library is used to solve the problem of low refresh rate in software drawing which can collect the dynamic display of data waveform.Then,My SQL database is used to achieve the protection of experimental data save and share.Finally,a variety of signal analysis and processing algorithm library with MATLAB are developed to realize intelligent analysis of bioelectrical signals.4.The system test platform is built and the system performance is verified.For the purpose of verifying the performance of the biological signal acquisition and analysis system,the multi biological signal test environment is built,and the acquisition experiments of ECG signal,EMG signal and biological impedance are designed.The results show that the system can accurately collect a variety of biological signals.At the same time,combined with the biological signal processing algorithm,the collected signals are analyzed and processed.The results show that the ECG waveform recognition function can mark accurately,EMG analysis module can complete multi feature parameter extraction and effective action recognition,and the recognition accuracy is 97.5%.Impedance analysis module can accurately extract bio impedance feature parameters,and the maximum error is only 0.69%.