Grant, Peadar F.Peadar F.GrantLowery, Madeleine M.Madeleine M.Lowery2012-10-022012-10-022009 IPEM2009-11Medical engineering & physicshttp://hdl.handle.net/10197/3834This study presents a whole-head finite element model of deep brain stimulation to examine the effect of electrical grounding, the finite conducting volume of the head, and scalp, skull and cerebrospinal fluid layers. The impedance between the stimulating and reference electrodes in the whole-head model was found to lie within clinically reported values when the reference electrode was incorporated on a localized surface in the model. Incorporation of the finite volume of the head and inclusion of surrounding outer tissue layers reduced the magnitude of the electric field and activating function by approximately 20% in the region surrounding the electrode. Localized distortions of the electric field were also observed when the electrode was placed close to the skull. Under bipolar conditions the effect of the finite conducting volume was shown to be negligible. The results indicate that, for monopolar stimulation, incorporation of the finite volume and outer tissue layers can alter the magnitude of the electric field and activating function when the electrode is deep within the brain, and may further affect the shape if the electrode is close to the skull.enThis is the author’s version of a work that was accepted for publication in Medical Engineering & Physics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Medical Engineering & Physics (Volume 31, Issue 9, November 2009, Pages 1095–1103) DOI:10.1016/j.medengphy.2009.07.006, Elsevier Ltd.Deep brain stimulationFinite element modelVolume conductionBrain stimulationFinite element methodElectric stimulationJournal Article3191095110310.1016/j.medengphy.2009.07.0062012-09-12https://creativecommons.org/licenses/by-nc-nd/3.0/ie/