Investigation On The Origin Of Thoracic Impedance Cardiogram And The New Detecting System Of Multi-Lead Impedance Cardiogram

In recent decades, the use of electrical bioimpedance technique to assess the state and the activitiesof human organs becomes an important research aspect in the clinical noninvasive measurement, impedance cardiography (ICG), as to detect heart pump function of human, has been put into widely use, because of its safety, repeatability, easy to be operate and inexpensiveness. Whereas there have to be many problems in this method, as the conventional model is not well fit into human thoracic structure. Theoretically, the views about the origin and mechanism of ICG are quite controversial. Practically, the reliability of method, for instance in stroke volume calculation, is rather poor. Therefor, up to now, there still is no clear answer to the question -- how does and in what extent the ICG reflect heart pump function and relate to the relevant physiological events.In this experiment, we, based on electric field theory, use a self-made dual channel impedance meter to detect and analyze thoracic impedance changes in several animal models under different conditions, including the results from normal subjects and patients with cardiac ischaemia.The purposes of the experiment are as to investigate the origin of ICG, and the spatial characteristics of it; to establish a new detecting system for measuring multi-lead cardiac impedance loop; to test and explain the effects of myocardial ischaemia on the ICG and cardiac impedance loops;...