Design of a Haptic Palmar Device with Thumb Flexion and Circumduction Movements for Sensorimotor Stroke Rehabilitation.

To address the clinical need for high-intensity, repetitive sensorimotor hand training after stroke, we developed in a first step a novel haptic device for practicing finger movements. Because the thumb plays a fundamental role in the loss of autonomy and prehensile functions after stroke, we present here the development of a thumb module that complements our previous design. The novelties of our device are that it reduces the complexity to a minimum from a user perspective while still allowing anatomical thumb flexion/extension and circumduction movements with a highly functional range of motion. Moreover, it enables sensorimotor training thanks to its backlash-free and backdrivable actuation that allows for high-quality haptic rendering. Our device was co-created together with clinicians to incorporate clinical and anatomical requirements, and therefore, maximize its clinical relevance.