Research On Bio-impedance Spectroscopy Measurement And Analysis Methods

Bioelectrical impedance measurement technique is a technique that can measure impedance data of tissues or blood using the impedance measurement system.Abundant physiological and pathological condition information can be acquired by analyzing the corresponding impedance data.The technique plays an increasingly important role in biomedical research because it's several advantages,such as low-cost,no damage to the measured object,and online monitoring,etc.During the process of bioelectrical impedance measurement,an important problem cannot be ignored called electrode polarization,which is caused by the re-arrangement of electric charge between the measured object and the electrode surface.General depolarization methods are optimization of measuring equipments and appropriate correction on original impedance data.This paper focus on the study of bio-impedance spectroscopy measurement and analysis methods,and the main work includes three aspects:(1)Analyzed and discussed the degree of influence on biological tissue impedance measurements caused by the electrode polarization.Build an impedance measurement system with type ZM2371 LCR meter for the core,measuring impedance spectroscopy data of rat's liver tissue in the frequency range of 1?100 KHz,and using experimentally measured data to verify a depolarization correction algorithm.(2)Designed and completed the measurement and analysis experiment to measure and analyze the blood impedance of rats with lung cancer in different stages.That comparing the measurement data from different periods is studied to discover the changes in blood impedance spectra characteristic during the growth process of lung cancer.With the cancer cells are spreading into surrounding tissues and organs,the blood impedance spectroscopy data of lung cancer rats show a significant change.That is to say,with the growth of the tumor,the complex permittivity of cancer rats' blood gradually increased,and the imaginary part of complex permittivity variation is more obvious than the real part of complex permittivity variation.(3)In the embedded Linux development environment,developed a cross-platform application based on QT to analysis and display the bioelectrical impedance data.Combined the depolarization correction algorithm with the GUI,which made the process of depolarization correction becomes simple and easy.