A Usability Study in Patients With Stroke Using MERLIN, a Robotic System Based on Serious Games for Upper Limb Rehabilitation in Home Setting

Abstract Background: Neuroscience and neurotechnology are changing stroke rehabilitation. Robotic devices as well as telerehabilitation have become of great interest and are increasingly being used to train the upper extremities after stroke. Its use in home settings allows to extend institutional rehabilitation by increasing and prolonging therapy. The aim of this study is to assess the usability of MERLIN robotic system based on serious games for the upper limb rehabilitation in stroke patients in a home environment.Methods: 12 participants with a stroke in three different stages of evolution (subacute, chronic of short evolution and long-term chronic) with impaired arm/hand function were recruited to use the MERLIN system for 3 weeks: one week of training at the Maimonides Biomedical Research Institute of Cordoba (IMIBIC), and 2 weeks at patients’ home. Evaluation of usability involved System Usability Scale (SUS), Adapted Intrinsic Motivation Inventory (IMI), Quebec User Evaluation of Satisfaction with assistive Technology (QUEST), and ArmAssist Usability Assessment Questionnaire which were evaluated post-intervention. Clinical outcomes on upper extremity motor function were assessed pre- and post-intervention.Results: Finally, 9 patients participated in the study, 3 drop-off due to the COVID-19. The usability assessment reported a high level of satisfaction: mean SUS score was 71.94 % (SD=16.38), mean QUEST scale was 3.81 (SD=0.38), and mean IMI score was 6.12 (SD=1.36). The results of the ArmAssist Questionnaire was an average of 6 out of 7, which indicates that MERLIN is easy to learn, easy to use and intuitive. Regarding clinical assessment, Fugl-Meyer scores showed moderated improvements from pre- to post-intervention in the total score of motor function (p = 0.002). There were no significative changes in Modified Ashworth scale outcomes (p = 0.169) Conclusions: This usability study indicates that home-based rehabilitation for upper limb with MERLIN system is safe, useful, feasible and motivating. The telerehabilitation suppose an important step towards an intensive rehabilitation to be bring to home.Trial registration: ClinicalTrials.gov, NCT04405609. Registered 06 January 2020 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04405609