ZMIND - An interactive environment for electrical modeling of the thorax

Interest in the electrical modeling of the thorax is motivated by various desires ranging from determining cardiac function, optimizing defibrillation efficacy, monitoring pulmonary edema, etc. However, existing models represent the thorax with rather coarse anatomical details, limiting their utilizations for accurately simulating small electrodes which typically occurs in pacing and defibrillation clinical practices. In this paper, we describe an anatomically realistic finite difference modeling software environment, referred as ZMIND. Segmented image-based finite difference models of a male adult at the end of systole and the end of diastole were constructed based on ECG-gated MRI scans. Up to 36 types of tissues were identified and included in the model, providing fine anatomical details in the heart and lung regions. The environment enables placing electrodes interactively and also provides a library of clinically-based, user-configurable electrodes. The analysis module of this environment allows performing sensitivity analysis and visualizing the computed electric fields, current density, and sensitivity distribution.