title: A New Semi-Automatic Approach to Find Suitable Virtual Electrodes in Arrays Using an Interpolation Strategy.
abstract: Functional Electrical Stimulation via electrode arrays enables the user to form virtual electrodes (VEs) of dynamic shape, size, and position. We developed a feedback-control-assisted manual search strategy which allows the therapist to conveniently and continuously modify VEs to find a good stimulation area. This works for applications in which the desired movement consists of at least two degrees of freedom. The virtual electrode can be moved to arbitrary locations within the array, and each involved element is stimulated with an individual intensity. Meanwhile, the applied global stimulation intensity is controlled automatically to meet a predefined angle for one degree of freedom. This enables the therapist to concentrate on the remaining degree(s) of freedom while changing the VE position. This feedback-control-assisted approach aims to integrate the user's opinion and the patient's sensation. Therefore, our method bridges the gap between manual search and fully automatic identification procedures for array electrodes. Measurements in four healthy volunteers were performed to demonstrate the usefulness of our concept, using a 24-element array to generate wrist and hand extension.
authors.affiliation: Control Systems Group, Technische Universität Berlin , Berlin, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Salchow
authors.affiliation: Control Systems Group, Technische Universität Berlin , Berlin, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Valtin
authors.affiliation: Control Systems Group, Technische Universität Berlin , Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Seel
authors.affiliation: Control Systems Group, Technische Universität Berlin , Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schauer
keywords: electrode arrays; feedback control; functional electrical stimulation; hand extension; identification strategy; virtual electrode