Study On Data Processing Method Of Bioeletrical Impedance Spectrum Based On Matlab

This thesis deals with the data processing method of bioelectrical impedance spectroscopy based on MATLAB.The data processing structure of bioelectrical impedance and the structure of GUI graphical user interface are comprehensively designed,which is accurate in grasping the data processing method of bioelectrical impedance spectroscopy.The results of Cole-Cole fitting are achieved by the least square and least one multiplication method to extract the Cole parameters successfully.The BIS data processing system of the visualized operation is finally realized through the MATLAB programming.The specific work of this article is as follows:First,the basic theory of bioelectrical impedance,the development of the bioelectrical impedance measurement technology are briefly described as well as the current application field.It is pointed out that the characteristic parameters of the bioelectrical impedance spectroscopy are the important basis to analyze of the change law of the organism.Meanwhile,the methods of extracting the characteristic parameters of the bioelectrical resistance spectrum at home and abroad are summarized.There are mainly two methods:least squares and least absolute deviation.Secondly,according to the solving pattern of four parameters in bioelectrical impedance equation,the specific algorithm is studied.On the basis of the classical least square curve fitting,an impedance model based on the least squares is designed on the basis of the classical least square curve fitting.The aim is to avoid the iterative solution of the target parameters.By constructing the matrix of impedance model,the target parameters and the Cole parameters are obtained indirectly.Due to the existence of absolute value,it is very difficult to solve the problem straightly in the minimum one multiplier curve.Therefore,the annealing algorithm is adopted to the least absolute deviation fitting.The algorithm flow chart and MATLAB program code are designed for the two parameter extraction methods.This thesis also designs the comparison test of the least square and the least one multiplicative Cole-Cole circle.It concludes that the least one multiplication shows better robustness than the least square for the small sample with abnormal value.Thirdly,the structure of the bioelectrical impedance data processing structure is constructed.The user interface structure of the graphical user interface(GUI)of the bioelectrical impedance data processing based on MATLAB is designed.The GUI interface design mainly includes the main interface,the drawing interface and the Cole-Cole fitting interface.The data processing functions include file management,spectrum drawing,least square/least one multiplier Cole-Cole fitting algorithm,and four characteristic parameters calculation.The method of using GUI interface and the core MATLAB program of function in each module are introduced in detail.Finally,the feasibility of GUI data processing interface is verified by processing the real-time measured data of fresh meat BIS.A total of two groups of experiments are designed.The first group is a single group of BIS data processing experiments,which is used to compare the fitting effect of the least squares and the smallest multiplier to the measured data.The same results also draw the conclusion that the smallest one shows better robustness for the small samples with abnormal values.The second group is groups of BIS data batch processing experiments,mainly drawing frequency spectrogram to compare the fresh meat and water-injected meat.The Cole parameters were calculated can be analyzed.The experimental results show that the characteristic parameters of impedance model can effectively distinguish the quality of water injected meat,which shows the GUI data processing system designed in this thesis is feasible.