We have developed HandMATE (Hand Movement Assisting Therapy Exoskeleton); a wearable motorized hand exoskeleton for home-based movement therapy following stroke. Each finger and the thumb is powered by a linear actuator which provides flexion and extension assistance. Force sensitive resistors integrated into the design measure grasp and extension initiation force. An assistive therapy mode is based on an admittance control strategy. We evaluated our control system via subject and bench testing. Errors during a grip force tracking task while using the HandMATE were minimal (<1%) and comparable to unassisted healthy hand performance. We also outline a dedicated app we have developed for optimal use of HandMATE at home. The exoskeleton communicates wirelessly with an Android tablet which features guided exercises, therapeutic games and performance feedback. We surveyed 5 chronic stroke patients who used the HandMATE device to further evaluate our system, receiving positive feedback on the exoskeleton and integrated app.

In previous work, we developed an exoskeleton, Hand Spring Operated Movement Enhancer (HandSOME II), that allows movement at 15 hand degrees of freedom (DOF). Eleven separate elastic elements can be added to customize the extension assistance for individuals with impaired hand function. In this pilot study of twelve individuals with stroke, we measured the immediate improvements in range of motion (ROM) and upper extremity function when wearing the device. Index finger ROM was significantly improved at the PIP (p=.01) and DIP joints (p=.026), and the max extension was significantly increased at the MCP (p<.001), PIP (p=.013) and DIP joints (p=.016). The thumb CMC abduction max (p=.017) and CMC flexion/extension ROM also increased (p=.04). In a grip and release task involving various objects, six subjects were unable to complete the tasks without assistance. Across these 6 subjects, 13 of 42 tasks were completed without assistance, while 36 of 42 tasks were completed when wearing HandSOME II. Despite the extension assistance provided by the device, flexion grip force was not statistically decreased. HandSOME II can potentially increase the effectiveness of repetitive task practice in patients with moderate-severe hand impairment by allowing completion of grasp and release tasks that are impossible to complete unassisted.

BACKGROUND: Dynamic exoskeleton orthoses provide assistance needed to complete movements that would otherwise be impossible after stroke. Beyond the demonstration of their effectiveness, the subjective experience of dynamic orthoses also needs to be considered. OBJECTIVE: To support functional recovery after stroke through the development of Hand-TaPS (Task Practice after Stroke), an instrument to evaluate dynamic hand orthoses in home therapy. METHODS: Dynamic hand orthosis subject matter experts (N= 14), professionals and consumers, considered the items of PYTHEIA, a valid and reliable instrument merging well-tested, assistive technology (AT) assessment items with those tuned to the greater complexity of emerging technologies. Experts reflected on how each item aligned with their personal experience of dynamic orthosis use. Interpretative Phenomenological Analysis guided identification of themes. RESULTS: Four themes (5/20 items) appraised highly relevant for Hand-TaPS. The remaining eight themes (15/20 items) were deemed in need of modification. CONCLUSIONS: Dynamic hand orthoses constitute a special case of AT; the assistance they provide targets therapy, not ADLs. Our work to develop Hand-TaPS provides a clear example of the theoretical difference between rehabilitative and assistive technology and underscores the importance of consideration of how a device is used in its assessment.