Analysis of sensitivity distribution in human chest during multichannel bioimpedance measurements

Gaining information on mechanical contraction of a particular heart chamber is essential in many clinical situations. There are a few techniques which may provide such information, e.g. Magnetic Resonance Imaging (MRI), Multislice Computed Tomography (MSCT) or Ultrasonography (USG). However, each of the mentioned technique has limitations. The main aim of the study is to develop an impedance-based method enabling a continuous monitoring of mechanical activity of the left and the right ventricles separately. Simulation study is an essential part of the project and is presented in the paper. A Finite Element Method (FEM) model of the thorax consisting of 212 000 tetrahedral elements has been developed. It is used for calculation spatial sensitivity distributions involved by different configurations of electrode matrices. The selected electrodes configurations, including transversal and longitudinal position in relation to the direction of the descending aorta, have been tested for several conductivity distributions inside the thorax. It has been found that appropriate configuration of the electrode matrix may enhance contribution from the Region Of Interest (ROI).