title: Monitoring brain damage using bioimpedance technique in a 3D numerical model of the head.
abstract: Disturbance in the blood supply to the brain causes a stroke or cerebrovascular accident. This can be due to ischemia caused by blockage (thrombosis, arterial embolism) or a hemorrhage. In this study, the feasibility of basic electrical impedance technique for monitoring such damage was analyzed using a computerized model. Simulations were conducted on a realistic 3D numerical model of the head. Tissues were assumed to act as linear isotropic volume conductors, and the quasi-static approximation was applied. Electrical potentials were calculated by solving Poisson's equation, using the finite volume method and the successive over relaxation method. Left-right asymmetry was calculated for several conductivities and volumes of the damaged region. The results were compared with the left-right asymmetry in a head model with normal brain. A negative asymmetry was revealed for blockage (i.e. the potential amplitude over the ischemic hemisphere was greater than that over the intact hemisphere). In case of hemorrhage, a positive asymmetry was found. Furthermore, correlation was found between the location of the damaged region and the electrodes with significant asymmetry. The 3D numerical simulations revealed that the electrical conductivity and the size of the damaged tissue have an effect on the left-right asymmetry of the surface potential.
authors.affiliation: Department of Biomedical Engineering, Tel-Aviv University, Israel.
authors.forename: Rotem
authors.initials: R
authors.lastname: Cohen
authors.affiliation: Department of Biomedical Engineering, Tel-Aviv University, Israel. Electronic address: abboud@post.tau.ac.il.
authors.forename: Shimon
authors.initials: S
authors.lastname: Abboud
authors.affiliation: Department of Geriatric Rehabilitation, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel.
authors.forename: Marina
authors.initials: M
authors.lastname: Arad
mesh_terms: D001921:Brain / Q000503:physiopathology*; D003198:Computer Simulation; D019719:Diagnostic Equipment; D003943:Diagnostic Techniques, Neurological / Q000295:instrumentation; D017097:Electric Impedance; D004566:Electrodes; D005240:Feasibility Studies; D007839:Functional Laterality; D006257:Head; D006801:Humans; D020767:Intracranial Thrombosis / Q000503:physiopathology; D008954:Models, Biological
keywords: Bio impedance; Brain damage; Numerical model of the head