Smartphone and 3D Printing Based Home Rehabilitation System for Chronic Stroke

A Functional Upper Limb Training and Assessment Tool to Enhance Efficacy and Scalability of Rehabilitation in Ecological Environments

Interventions promoting optimum motor performance across the lifespan are a priority after a neurological insult such as stroke. The proposed research incorporates smart devices and 3D printing to create a patient-centered rehabilitation device, mRehab. This innovative blend of technology and principles of neuroplasticity can advance standards of practice in healthcare. In this feasibility study, it is hypothesized that individuals with chronic stroke can successfully use the portable rehabilitation unit, mRehab, at home with minimal oversight from the research team. Use of mRehab in a home based setting and functional changes in upper limb movement will be assessed.

Impairments following stroke make it one of the leading causes of disability. Many individuals with stroke do not recover complete function of the upper limb at time of discharge from clinical services. Moreover, early stage improvements may wane following the cessation of formal therapies. Regaining as much upper limb function as possible is important, as even mild impairments are associated with limitations in daily function and lower health-related quality of life. The overarching purpose of this project is to use portable technology, affordable for home use, to provide objective feedback on performance of upper limb motor tasks to individuals with residual deficits following chronic conditions such as stroke. Objective feedback serves to better inform the participant of their progress and actively engage them in their rehabilitation, thus encouraging self-management of rehabilitation. Results from a recent survey shows therapists predominantly provide patients with stroke written home exercise programs at time of discharge from therapies. With this static approach, patients have a limited capacity to evaluate their motor performance and no encouragement to refine their movement. Smartphones were coupled with three-dimensional (3D) printed objects to create a home rehabilitation system, mRehab. The built-in sensors in smartphones and a custom app can quantify characteristics of movement and provide actionable feedback to users during in-home rehabilitation. It was hypothesized that 1) participants with stroke could use mRehab in a home program with minimal oversight and 2) use of mRehab would result in changes in functional movement. Methodology: A single-subject experimental design with multiple baselines was used. A strength of the single-subject study design is that participants serve as their own control. Each participant had a varying length of the baseline and follow-up periods to establish that the intervention, rather than time, was the primary reason for any observed change in performance. Participants completed baseline measurements, a six-week mRehab home program, and follow-up measurements. Baseline measurements consisted of both in-lab and in-home measurements. Participants attended two lab visits prior to starting the home program to establish baselines on clinical assessments and to learn how to use mRehab. MRehab collected limited preliminary performance data without providing feedback during baseline. Participants then used mRehab in a six week home program receiving feedback on their performance each time they completed practice of an activity. At the completion of the home program participants completed follow up assessments that were similar to the baseline measurements. In addition, usability of mRehab was assessed.

The purpose of the intervention was to provide proof of concept that it is feasible for individuals with stroke to use mRehab in a home program and to examine if changes in motor function were enhanced following the home program.

mRehab (mobile Rehab) was created to better support in-home upper limb rehabilitation programs. It incorporates a task-oriented approach and immediate performance-based feedback. mRehab consists of 3D-printed household items (a mug, bowl, key, and doorknob) integrated with a smartphone and an app. The app guides participants through practice of activities of daily living (ADL), for example, sipping from a mug. It can also consistently measure time to complete an activity and quality of movement (smoothness/accuracy) during the performance of ADLs. In each session of exercise participants receive feedback on the number of repetitions they complete for each activity, the average time to complete the activity and the average smoothness to perform the activity. Participants were trained in use of mRehab in lab visits and then took mRehab home to use the system. mRehab recorded longitudinal data.

average smoothness for each activity: Using the sensors in the smartphone, the custom mRehab app will record smoothness of movement represented as a normalized cumulative jerk (rate of change of acceleration) score.

Clinical assessment that assesses upper limb motor ability through timed functional tasks. Lower times represent better performance.

A timed clinical assessment used to measure finger dexterity. Lower times represent better performance.

A scale used to elicit user opinions on ease of use of the 3D printed objects (mug, bowl, key, and doorknob). It was a 7 point likert scale ranging from Very Difficult to Very Easy.

A reliable tool for measuring usability. Participants respond to questions on a 5 point likert scale ranging from Strongly agree to Strongly disagree. The SUS was used to assess the participant's satisfaction with the mRehab system.

Based on the Technology Acceptance model it uses a seven-point Likert scale - highly disagree to highly agree. Questions probed user's perceived usefulness, perceived ease of use, and behavioral intention to use the mRehab system in the future.

Individuals in the intervention all had a history of stroke. Inclusion Criteria for feasibility study: at least 18 years of age and living in the community had a history of one stroke six or more months previous had a minimum score of 124 on the Mattis Dementia Rating Scale (MDRS). Exclusion Criteria for feasibility study: acute or chronic pain that would interfere with participation severely limited range of motion or contractures of shoulder, elbow, wrist or hand, absent or severely impaired proprioception of the upper limb musculoskeletal or circulatory conditions affecting the upper limb such as vascular disease, tendonitis, cellulitis, Raynaud's syndrome, or severe osteoarthritis or rheumatoid arthritis spasticity graded as 3 or greater for upper extremity movement on the Modified Ashworth Scale (MAS) botulinum toxin injections for spasticity management within three months of starting the study

The final dataset will include self-reported demographic information (such as age and gender) cognitive assessments, motor performance on clinical assessments and data collected during rehabilitation from mRehab.

Bhattacharjya S, Cavuoto LA, Reilly B, Xu W, Subryan H, Langan J. Usability, Usefulness, and Acceptance of a Novel, Portable Rehabilitation System (mRehab) Using Smartphone and 3D Printing Technology: Mixed Methods Study. JMIR Hum Factors. 2021 Mar 22;8(1):e21312. doi: 10.2196/21312.

Langan J, Bhattacharjya S, Subryan H, Xu W, Chen B, Li Z, Cavuoto L. In-Home Rehabilitation Using a Smartphone App Coupled With 3D Printed Functional Objects: Single-Subject Design Study. JMIR Mhealth Uhealth. 2020 Jul 22;8(7):e19582. doi: 10.2196/19582.