A Semi-passive Planar Manipulandum for Upper-Extremity Rehabilitation

Abstract

Robotic rehabilitation is a promising approach to treat individuals with neurological or orthopedic disorders. However, despite significant advancements in the field of rehabilitation robotics, this technology has found limited traction in clinical practice. A key reason for this issue is that most robots are expensive, bulky, and not scalable for in-home rehabilitation. Here, we introduce a semi-passive rehabilitation robot (SepaRRo) that uses controllable passive actuators (i.e., brakes) to provide controllable resistances at the end-effector over a large workspace in a manner that is cost-effective and safe for in-home use. We also validated the device through theoretical analyses, hardware experiments, and human subject experiments. We found that by including kinematic redundancies in the robot's linkages, the device was able to provide controllable resistances to purely resist the movement of the end-effector, or to gently steer (i.e., perturb) its motion away from the intended path. When testing these capabilities on human subjects, we found that many of the upper-extremity muscles could be selectively targeted based on the forcefield prescribed to the user. These results indicate that SepaRRo could serve as a low-cost therapeutic tool for upper-extremity rehabilitation; however, further testing is required to evaluate its therapeutic benefits in patient population.

Vector Field Control Methods for Discretely Variable Passive Robotic Devices

“…Depending on the dimension n of the device taskspace and the dimension of C q,k ⊥ , motion with a certain valve setting may be allowed in all directions (p = n, as when all cylinders are connected to the reservoir), a single heading (p = 1), or a higher dimensional manifold 7 (e.g., when C q,k ⊥ ∈ 3×2 , a p = 2 plane through a 3D space is imposed).…”

“…To the operator, ideal motion guidance feels like a hard wall, curve, or surface. Motion-guiding robots have been developed to facilitate human/robot collaborative assembly operations [1], to perform haptic rendering [2], to train manual skill [3], [4], and to rehabilitate motor function after neurological injury [5], [6], [7]. Both in manual skill training and robotic rehabilitation, it has been suggested that the human should take an active role to maximize therapeutic or training effects [8], [9], [10].…”

“…Second, we present a control method that is in a sense dual to the existing SDOF velocity field methods: it uses constraint fields (see Fig. 1b) to select from 1 Many devices based on brakes ( [17], [18], [19], [7], among others) have been proposed to guide motion or render virtual environments by resisting user motion. An important distinction is that devices that modulate braking force are not discretely variable.…”

Development, Dynamic Modeling, and Multi-Modal Control of a Therapeutic Exoskeleton for Upper Limb Rehabilitation Training

“…Kang et al proposed a modular and reconfigurable wrist robot called CR2-Haptic for post-stroke subjects to train forearm and wrist movements [ 7 ]. Besides, many other end-effector-based therapeutic robot have been investigated and can be referred to [ 8 , 9 , 10 , 11 , 12 , 13 ]. Comparatively, the exoskeleton-based rehabilitation robots are developed with more complex structures imitating the anatomical human skeleton and guaranteeing the alignment between the joints axis of robot and impaired limb.…”

2019 Athanasiou ABME Student Awards

“…Chang et al developed a semi-passive rehabilitation robot for patients with neurologic or orthopedic disorders. 3 The device was validated through theoretical analyses, hardware experiments, and human subject testing, and showed potential for use as a low-cost therapeutic tool for upper-extremity rehabilitation.…”