title: Reliability of closed double helix electrode for functional electrical stimulation.
abstract: The reliability of a closed double helix electrode in the lower limbs was studied. This electrode is an implanted intramuscular electrode and is used for a totally implantable functional electrical stimulation system. Eighty electrodes were evaluated retrospectively with a mean period of 15 months. The total implant time was 1222 electrode months. The cumulative proportion surviving was 0.934 at 6 months, 0.855 at 1 year, 0.765 at 2 years, and 0.730 after 30 months. Fifteen of 80 electrodes failed, seven showed increasing electrode impedance, and eight had undesirable changes in recruitment. Of the failed electrodes, 2/3 failed during the first 10 months. The reliability was 0.91 at 6 months and 0.80 at 1 year after implantation in all muscle groups. The closed double helix electrode displayed an increased reliability when compared with the open double helix electrode at 6 months, and an equivalent reliability as compared with the electrodes developed by Handa and colleagues at 6 months and 1 year, using the chi squared test for independence. This study suggests that the closed double helix electrode has an acceptable reliability and can be used as a part of a totally implantable functional electrical stimulation system.
authors.affiliation: Veterans Administration Medical Center, Cleveland, OH 44106-1702, USA.
authors.forename: H
authors.initials: H
authors.lastname: Kagaya
authors.forename: M
authors.initials: M
authors.lastname: Sharma
authors.forename: G
authors.initials: G
authors.lastname: Polando
authors.forename: E B
authors.initials: EB
authors.lastname: Marsolais
mesh_terms: D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004867:Equipment Design; D006801:Humans; D018482:Muscle, Skeletal / Q000503:physiopathology; D010243:Paralysis / Q000534:rehabilitation; D012189:Retrospective Studies; D016896:Treatment Outcome