In Vivo Swine Measurements for a Priori Information In EIT Regularizations

In this paper, in vivo measurement of tissues in beta dispersion region (0-200 kHz) was acquired. The measurements were carried out on suine tissue and constitute data for an anatomy and physiology based priors to be used as an Electrical Impedance Tomography regularization. Plunge electrodes in four-terminal configuration and a computer-automated measurement system were used to acquire admitivity data. Measurements were taken on myocardial muscle (three different positions on epicardial surface), pectoral and intercostal muscles, adipose tissue, cartilage and lung (cranial, medial and caudal lobe tissues). The admitivity measurements were carried in such way to allow anisotropy detection, at 125 kHz. Four animals were used for this experiment. Admitivity temporal variations synchronized with perfusion and ventilation rates were observed. Increased PEEP lead to increased time averaged admitivity in lung tissues.