A decision support system for electrode shaping in multi-pad FES foot drop correction

• Published in: Journal of neuroengineering and rehabilitation Vol. 14; no. 1; p. 66
• Main Authors: Malešević, Jovana, Dedijer Dujović, Suzana, Savić, Andrej M, Konstantinović, Ljubica, Vidaković, Aleksandra, Bijelić, Goran, Malešević, Nebojša, Keller, Thierry
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 03.07.2017; BioMed Central; BMC
• Subjects: Aged; Algorithms; Analysis; Ankle; Annan elektroteknik och elektronik; Annan medicinteknik; Automation; Control algorithms; Decision support system; Decision support systems; Decision Support Systems, Clinical; Electric Stimulation Therapy - instrumentation; Electrical Engineering, Electronic Engineering, Information Engineering; Electrical stimuli; Electrodes; Elektroteknik och elektronik; Engineering and Technology; Equipment Design; Feasibility studies; Feet; Female; Foot - physiopathology; Foot drop; Foot movements; Functional electrical stimulation; Gait Disorders, Neurologic - therapy; Health aspects; Humans; Male; Measurement methods; Medical Engineering; Medicinteknik; Methodology; Middle Aged; Movement; Multi-pad electrode; Nerves; Other Electrical Engineering, Electronic Engineering, Information Engineering; Other Medical Engineering; Paresis - etiology; Paresis - rehabilitation; Peroneal Nerve; Plantar flexion; Range of Motion, Articular; Rehabilitation; Selectivity; Stimulation; Stroke; Stroke Rehabilitation - instrumentation; Stroke Rehabilitation - methods; Teknik; Tibial Nerve; Training; Walking; Foot drop; Functional electrical stimulation; Stroke; Decision support system; Multi-pad electrode
• ISSN: 1743-0003; 1743-0003
• DOI: 10.1186/s12984-017-0275-5

Functional electrical stimulation (FES) can be applied as an assistive and therapeutic aid in the rehabilitation of foot drop. Transcutaneous multi-pad electrodes can increase the selectivity of stimulation; however, shaping the stimulation electrode becomes increasingly complex with an increasing number of possible stimulation sites. We described and tested a novel decision support system (DSS) to facilitate the process of multi-pad stimulation electrode shaping. The DSS is part of a system for drop foot treatment that comprises a custom-designed multi-pad electrode, an electrical stimulator, and an inertial measurement unit. The system was tested in ten stroke survivors (3-96 months post stroke) with foot drop over 20 daily sessions. The DSS output suggested stimulation pads and parameters based on muscle twitch responses to short stimulus trains. The DSS ranked combinations of pads and current amplitudes based on a novel measurement of the quality of the induced movement and classified them based on the movement direction (dorsiflexion, plantar flexion, eversion and inversion) of the paretic foot. The efficacy of the DSS in providing satisfactory pad-current amplitude choices for shaping the stimulation electrode was evaluated by trained clinicians. The range of paretic foot motion was used as a quality indicator for the chosen patterns. The results suggest that the DSS output was highly effective in creating optimized FES patterns. The position and number of pads included showed pronounced inter-patient and inter-session variability; however, zones for inducing dorsiflexion and plantar flexion within the multi-pad electrode were clearly separated. The range of motion achieved with FES was significantly greater than the corresponding active range of motion (p < 0.05) during the first three weeks of therapy. The proposed DSS in combination with a custom multi-pad electrode design covering the branches of peroneal and tibial nerves proved to be an effective tool for producing both the dorsiflexion and plantar flexion of a paretic foot. The results support the use of multi-pad electrode technology in combination with automatic electrode shaping algorithms for the rehabilitation of foot drop. This study was registered at the Current Controlled Trials website with ClinicalTrials.gov ID NCT02729636 on March 29, 2016.