The effect of the scalp and the skull bone in the total impedivity of the neonatal head and its implications in the detection of brain cellular edema

Paper in proceeding, 2005

Hypoxic-ischemic encephalopathy (HIE) affects severely and frequently on newborns and yet not an efficient detection method has been implemented to assist the early initiation of a saving therapy. Invasive measurements of electrical bioimpedance can be used to detect the changes in the electrical properties of brain tissue as a consequence of the hypoxic cellular edema. In the case of non-invasive measurement the skull and the scalp will modified the measurements in a certain way. In this work, using numerical calculations on a four-concentric spheres model, we study the contribution of the scalp and the skull bone to the total equivalent impedivity, complex resistivity, of the neonatal head and its effect on the non-invasive detection of brain cellular edema. The results confirm the importance of the reactive part of the impedivity on the electrical bioimpedance monitoring of hypoxic brain damage.