User-centered design and spatially-distributed sequential electrical stimulation in cycling for individuals with paraplegia

Abstract

Background In this work, we share the enhancements made in our system to take part in the CYBATHLON 2020 Global Edition Functional Electrical Stimulation (FES) Bike Race. Among the main improvements, firstly an overhaul, an overhaul of the system and user interface developed with User-centered design principles with remote access to enable telerehabilitation. Secondly, the implementation and experimental comparison between the traditional single electrode stimulation (SES) and spatially distributed sequential stimulation (SDSS) applied for FES Cycling. Methods We report on the main aspects of the developed system. To evaluate the user perception of the system, we applied a System Usability Scale (SUS) questionnaire. In comparing SDSS and SES, we collected data from one subject in four sessions, each simulating one race in the CYBATHLON format. Results User perception measured with SUS indicates a positive outcome in the developed system. The SDSS trials were superior in absolute and average values to SES regarding total distance covered and velocity. We successfully competed in the CYBATHLON 2020 Global Edition, finishing in 6th position in the FES Bike Race category. Conclusions The CYBATHLON format induced us to put the end-user in the center of our system design principle, which was well perceived. However, further improvements are required if the intention is to progress to a commercial product. FES Cycling performance in SDSS trials was superior when compared to SES trials, indicating that this technique may enable faster and possibly longer FES cycling sessions for individuals with paraplegia. More extensive studies are required to assess these aspects.

How the CYBATHLON Competition Has Advanced Assistive Technologies

“…SDSS has shown performance improvement in a 6-min knee extension task (39). A comparison between SES and SDSS that simulated a race in the same setup used for CYBATHLON 2020 showed slight improvement with SDSS (40). However, a study that applied SDSS with the same indoor trainer used in CYBATHLON 2020 showed significantly lower performance by SDSS (41).…”

ICEP: An Instrumented Cycling Ergometer Platform for the Assessment of Advanced FES Strategies

“…Cadence-controlled cycling ergometers that provide motor and crank position data can be adapted for FES cycling, and the torque produced by the cyclist can be derived from the motor current [ 18 ]. Another approach is utilizing the recumbent tricycle by replacing the crank set with a crank power meter [ 17 , 19 ]. Hunt et al [ 20 ] have expanded on this by motorizing the recumbent tricycle and integrating the power meter into the crank, allowing the system to be cadence- and output-power-controlled.…”