Evaluating Acceptability and Minimal Sensor Configuration for Home-Based Monitoring of Upper Extremity Use After Stroke

Background : Home rehabilitation for stroke survivors is crucial to promote upper extremity (UE) use and improvement of functional abilities, enhancing independence and quality of life. Wearable sensors enable monitoring of movement trends and progress during home rehabilitation. The feasibility of using sensors in the home of stroke survivors depends both on survivors’ acceptability and on sensors’ accuracy in capturing the movement. The aim of this study was to identify a feasible sensor setup for monitoring stroke survivors’ UE movements during daily activities at home by evaluating 1) survivors’ subjective acceptability of wearing sensors, and 2) the number of sensors necessary to accurately capture the complexity of behavioral data. Methods : Eleven chronic stroke survivors were observed in a natural or simulated home environment, while attempting to attach/detach sensors and wearing them doing self-chosen Activities of Daily Living. Nine inertial measurement unit sensors were placed on participants’ UE and sternum. Acceptability was assessed with a custom-made questionnaire consisting of 14 items scored on a 1–5 Likert scale, and five open-ended questions. Further, information entropy was calculated to determine the minimal number of sensors needed to capture movement complexity. Results : Total acceptability of wearing sensors was high, with a median score of 57 out of 70 (81%; IQR = 11), while usability was moderate, with a median score of 11 out of 20 (55%; IQR = 5.5). Lower usability was also reported in the open-ended responses and observed when participants attempted attaching and detaching sensors. The minimal sensor setup to capture behavior complexity consisted of three-to-four sensors, placed on the sternum, non-affected and affected forearms, with or without affected upper arm. Conclusions : The sensors were found to have high acceptability, although usability challenges remained. The proposed three-to-four sensor setup was sufficient to maintain accuracy of the sensors, while potentially increasing stroke survivors’ acceptability and usability. In turn, this may enhance feasibility and improve stroke survivors’ adherence to wearing sensors at home.