ABSTRACT
ABSTRACT: Extensive research is performed with the bioimpedance method internationally for developing medical applications. Before novel diagnostic methods can be developed in hardware and tested in vivo, research must be made with computer-models of the anatomy and physiology for running computer-simulations of measurement configurations. The modeling performed in this paper is for simulation of bioimpedance signals in organs and the whole body, where lung impedance plays a role. The objective of this work is building a model for estimating the bioimpedance signal from the dynamics occurring in the lung anatomy-the cardiac pulse that is featured in the pulmonary vascular network. 3D model of a 3 cm cube sized lung tissue is created with dynamic arterial network. The arterial system in the lung tissue is modeled with automatic generation of hierarchical vascular network using Constrained Constructive Optimization method. The pulmonary artery pressure pulse is used as the input for the arterial system and the wave propagation speed is modeled as 1.5 m/s in the arterial network. The resulting change in the volume of blood in the pulmonary arterial system is modeled taken into account the distensibility of pulmonary arteries. The propagating wave of blood content in the lungs therefore introduces a specific dynamic pattern in the bioimpedance signal, when measured across the lung.
