title: Computation of induced electric field for the sacral nerve activation.
abstract: The induced electric field/current in the sacral nerve by stimulation devices for the treatment of bladder overactivity is investigated. Implanted and transcutaneous electrode configurations are considered. The electric field induced in the sacral nerve by the implanted electrode is largely affected by its surrounding tissues, which is attributable to the variation in the input impedance of the electrode. In contrast, the electric field induced by the transcutaneous electrode is affected by the tissue conductivity and anatomical composition of the body. In addition, the electric field induced in the subcutaneous fat in close proximity of the electrode is comparable with the estimated threshold electric field for pain. These computational findings explain the clinically observed weakness and side effect of each configuration. For the transcutaneous stimulator, we suggest that the electrode contact area be increased to reduce the induced electric field in the subcutaneous fat.
authors.affiliation: Department of Computer Science and Engineering, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.
authors.forename: Akimasa
authors.initials: A
authors.lastname: Hirata
authors.forename: Junya
authors.initials: J
authors.lastname: Hattori
authors.forename: Ilkka
authors.initials: I
authors.lastname: Laakso
authors.forename: Airi
authors.initials: A
authors.lastname: Takagi
authors.forename: Takuo
authors.initials: T
authors.lastname: Shimada
mesh_terms: D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D006801:Humans; D008953:Models, Anatomic; D012445:Sacrococcygeal Region / Q000294:innervation; D013127:Spinal Nerves / Q000502:physiology*