Validating the Safe and Effective Use of a Neurorehabilitation System (InTandem) to Improve Walking in the Chronic Stroke Population: Usability Study

BACKGROUND: Persistent walking impairment following a stroke is common. Although rehabilitative interventions exist, few exist for use at home in the chronic phase of stroke recovery. InTandem (MedRhythms, Inc) is a neurorehabilitation system intended to improve walking and community ambulation in adults with chronic stroke walking impairment. OBJECTIVE: Using design best practices and human factors engineering principles, the research presented here was conducted to validate the safe and effective use of InTandem. METHODS: In total, 15 participants in the chronic phase of stroke recovery (≥6 months after stroke) participated in this validation study. Participants were scored on 8 simulated use tasks, 4 knowledge assessments, and 7 comprehension assessments in a simulated home environment. The number and types of use errors, close calls, and operational difficulties were evaluated. Analyses of task performances, participant behaviors, and follow-up interviews were conducted to determine the root cause of use errors and difficulties. RESULTS: During this validation study, 93% (14/15) of participants were able to successfully complete the critical tasks associated with the simulated use of the InTandem system. Following simulated use task assessments, participants’ knowledge and comprehension of the instructions for use and key safety information were evaluated. Overall, participants were able to find and correctly interpret information in the materials in order to answer the knowledge assessment questions. During the comprehension assessment, participants understood warning statements associated with critical tasks presented in the instructions for use. Across the entire study, 3 “use errors” and 1 “success with difficulty” were recorded. No adverse events, including slips, trips, or falls, occurred in this study. CONCLUSIONS: In this validation study, people in the chronic phase of stroke recovery were able to safely and effectively use InTandem in the intended use environment. This validation study contributes to the overall understanding of residual use–related risks of InTandem in consideration of the established benefits.