Low-cost Devices for Stroke Rehabilitation: A Review of Approaches, Designs, and Evidence

Rehabilitation devices are technologies that can automate repetitive features of therapy using force generation elements like motors to render training forces or gamified environments to improve user engagement (<i>e.g.,</i> rehabilitation robots). These devices have received considerable attention from researchers and clinicians over the past several decades as a means to increase dosage of intensive rehabilitation following a stroke. However, the commercial results of these efforts often manifest as highly motorized, expensive, and bulky devices that are unsuitable for the majority of clinical or home environments. Indeed, as access to rehabilitation resources begins to reveal itself as a critical obstacle to recovery for many stroke survivors, it is important for researchers to examine alternative approaches to facilitate device adoption. A handful of researchers have attempted to bridge this gap with increasing success by designing affordable and portable devices for post-stroke rehabilitation. However, the methods employed to lower device cost are quite varied; therefore, a synthesis of these approaches could benefit other researchers. In this review, we discussed the field of rehabilitation robots and provided a review of 37 existing low-cost devices for stroke rehabilitation. These devices engage patients using a variety of actuation methods to produce training forces: Active (controllable actuator that adds or dissipates energy <i>e.g.,</i> motors, stimulators), Passive (uncontrollable actuator that only dissipates energy <i>e.g.,</i> springs, cables), Semi-Passive (controllable actuator that only dissipates energy <i>e.g.,</i> brakes) and Augmented Feedback (no actuator). Following this review, we outline certain unexplored areas of low-cost devices that may be fruitful areas of future exploration.