Bioimpedance Parameter Measurement And Characterization

Bioelectrical impedance measuring technology is a new research direction in recent years. Researchers have paid more attentions to it, which is based on the electrical properties of human tissues and organs. The impedance measurement system can get the real and imaginary parts information of the measured objects. Through analyzing, abundant information associated with the state of human’s physiology and pathology can be obtained, it is of great significance for the early detection and treatment of diseases. Bioelectrical impedance measurement technique is reasonably simple with low cost, and the whole measuring process will cause no harm to the patients. Compared with other techniques, this technique is more suitable for clinical testing, and has broad application prospects.The main research work is introduced in this paper respectively from three aspects.The first aspect is that a set of analysis software is developed to image reconstruction and impedance analysis based on MATLAB. We developed a graphical user interface (GUI) by combining the user control commands and adding the callback functions, which achieves the following functions:1.Drawing the impedance spectroscopy and calculating the impedance characteristic parameters.2. Reconstructing the image of the impedance distribution within an internal field.3. Communicating the computers and impedance measuring system.The second aspect is measuring the impedances of animals and persons by accordance measuring systems, the spectral characteristics of the measured tissues are analyzed. In this section, the research of impedance measurement and dielectric spectrum characteristics are illustrated as following:1. AD5933is utilized to measure and analysis the circuit models and pig tissues impedances. The results are displayed by Cole-Cole plots, and the characteristic parameters are calculated.2. A set of impedance measurement system6500B, as a standard device, is also used to measure the above tissues.3. The results from two different devices are compared. The results prove that home-made AD5933system is feasible to meet the accuracy requirement of impedance measurement.The third aspect is the recognition of human lung cancers from normal tissues based on pattern recognition algorithms. 1. Human lung tumor tissues are identified by the morphological slice images. The results are analyzed by statistical methods. A relationship between morphological indicators and the impedance characteristic parameters is built up, a hypothesis is put forward:three impedance parameters can effectively determine whether the tissue belongs to the either tumor tissue or normal tissue.2. Over one hundred human lungs tissues are gotten from the General Hospital are identified based on LMSE and Fisher algorithms. The research results show that both algorithms can classify the malignant tumors and the tumor tissue with high resolution, which lay a good foundation for further study of impedance detection for cancerous.