Development of a Geometric Model of the Heart and Chest for Multichannel Electrical Impedance Computer Cardiography Technology

Impedance cardiography methods are inexpensive and convenient, they allow to get hemodynamic characteristics in real time. Electrical impedance methods for the heart reseach are met with distrust. This is due to the fact heart stroke volume is determined by empirical ratios, which do not always reflect the formation mechanisms of the electrical impedance signal in seriously ill patients [1]. The mathematical models use, both numerical and analytical, gave the development of new impedance cardiography (i.e. ICG) methods [2]. In this study, the influence of the heart and chest geometric model parameters on the results of calculations in precardial electroimpedance heart mapping was evaluated. In the work, a semi-infinite chest model was compared with real geometry obtained from MRI data. A comparison was also made of a real heart 3D model according to MRI and a sphere model approximating the heart blood. Studies have shown that the error in electrical impedance signal modeling brought in by using a semi-infinite chest model and simplification to the sphere is significant.