Encephalic hemodynamic monitoring using electrical impedance tomography

Abstract

Continuous cerebral hemodynamics monitoring is important to quickly detect cerebral blood flow alterations, speeding up the doctor's decision-making on the pacient's treatment. Since some techniques for monitoring cannot be done bedside and continuously, Electrical Impedance Tomography (EIT) appears as a promising candidate for this task. This work will investigate cerebral hemodynamics detection capacity by EIT, quantitatively evaluating changes in circulation caused by ischemia in regions of the brain and the dilation of blood vessels by blood pressure waves in the neck and brain arteries.Differential and absolute images of EIT will be evaluated for monitoring.For the generation of absolute images, Newton-Raphson's method or its variants will be used and, for differential images, a sensitivity method. Prior statistical information will be introduced for the solution of the ill-posed inverse problem associated with imagegeneration.Initially, numerical phantoms of normal and pathological conditions will be made to evaluate the ability of EIT to detect changes in circulation.Then, an experimental phantom already developed by the research group will be employed.The resulting images will be evaluated and compared with the literature using figures of merit already established by the EIT area community. (AU)