Effect of contact pressure on porcine postmortem brain tissue impedance

In this experimental study we demonstrate the influence of contact pressure on porcine postmortem brain tissue impedance using a movable electrode array and a load cell. We show that the variation of the contact pressure between the tissue and the measurement probe leads to a coefficient of variation in the measured impedance of under 3%. Its influence can therefore be neglected. Further, we fit the measured impedances to an equivalent circuit model and compare the resistance as well as the cell density of grey and white matter brain tissue based on the model parameters.