Please use this identifier to cite or link to this item:
Main Title: User-centered practicability analysis of two identification strategies in electrode arrays for FES induced hand motion in early stroke rehabilitation
Author(s): Salchow-Hömmen, Christina
Jankowski, Natalie
Valtin, Markus
Schönijahn, Laura
Böttcher, Sebastian
Dähne, Frank
Schauer, Thomas
Type: Article
Language Code: en
Abstract: Background Surface electrode arrays have become popular in the application of functional electrical stimulation (FES) on the forearm. Arrays consist of multiple, small elements, which can be activated separately or in groups, forming virtual electrodes (VEs). As technology progress yields rising numbers of possible elements, an effective search strategy for suitable VEs in electrode arrays is of increasing importance. Current methods can be time-consuming, lack user integration, and miss an evaluation regarding clinical acceptance and practicability. Methods Two array identification procedures with different levels of user integration—a semi-automatic and a fully automatic approach—are evaluated. The semi-automatic method allows health professionals to continuously modify VEs via a touchscreen while the stimulation intensities are automatically controlled to maintain sufficient wrist extension. The automatic approach evaluates stimulation responses of various VEs for different intensities using a cost function and joint-angles recordings. Both procedures are compared in a clinical setup with five sub-acute stroke patients with moderate hand disabilities. The task was to find suitable VEs in two arrays with 59 elements in total to generate hand opening and closing for a grasp-and-release task. Practicability and acceptance by patients and health professionals were investigated using questionnaires and interviews. Results Both identification methods yield suitable VEs for hand opening and closing in patients who could tolerate the stimulation. However, the resulting VEs differed for both approaches. The average time for a complete search was 25% faster for the semi-automatic approach (semi-automatic: 7.3min, automatic: 10.5min). User acceptance was high for both methods, while no clear preference could be identified. Conclusions The semi-automatic approach should be preferred as the search strategy in arrays on the forearm. The observed faster search duration will further reduce when applying the system repeatedly on a patient as only small position adjustments for VEs are required. However, the setup time will significantly increase for generation of various grasp types and adaptation to different arm postures. We recommend different levels of user integration in FES systems such that the search strategy can be chosen based on the users’ preferences and application scenario.
Issue Date: 29-Dec-2018
Date Available: 4-Mar-2019
DDC Class: 610 Medizin und Gesundheit
Subject(s): functional electrical stimulation
electrode array
virtual electrodes
hand rehabilitation
user-centered design
Sponsor/Funder: TU Berlin, Open-Access-Mittel - 2018
BMBF, 16SV7069K, Bewegungsfähigkeit und Mobilität wiedererlangen
Journal Title: Journal of NeuroEngineering and Rehabilitation
Publisher: BioMed Central
Publisher Place: London
Volume: 15
Article Number: 123
Publisher DOI: 10.1186/s12984-018-0460-1
EISSN: 1743-0003
Appears in Collections:FG Regelungssysteme » Publications

Files in This Item:
File Description SizeFormat 
s12984-018-0460-1.pdf2.44 MBAdobe PDFThumbnail

This item is licensed under a Creative Commons License Creative Commons