Robot-aided Rehabilitation with SREx: A Smart Robotic Exoskeleton for reducing therapists' physical stress

Research Objectives: Upper limb dysfunctions (ULD) are common following a neurological insult. Passive range of motion (PROM) exercise of the affected extremity is one of the critical components of current rehabilitation plans of care when treating these patients. Robot-aided rehabilitation is a promising technology for this and comes with the added advantage of reducing therapists’ physical burden. This study describes the development of a robot-aided upper limb rehabilitation device, 7 degrees of freedom exoskeleton type robot named SREx. It also shows the preliminary testing results on healthy participants with emulated ULD patients.

Design: Experimental study

Setting: In the BioRobotics Lab

Participants: Five healthy male human subjects (age: 26-30 years) participated in this study.

Interventions: Healthy human subjects (n=5) wore the SREx on the lateral side of their right hands while being seated on chair. Isolated, composite joint PROM sessions containing slower, medium, and faster speed cycles.

Main Outcome Measures: Tests were carried out in three settings: (a) subject exerts no effort, (b) resistance to motion equivalent to patient with generalized spasticity resulting from ULD, and (c) sudden jerking/ perturbation during motion emulating real patients’ muscle spasm. During all exercises human-robot interaction was measured with force-torque sensor. Collected ROM data was statistically analyzed.

Results: The robot was able to provide therapeutic PROM to all subjects’ UL with a maximum ROM error of ~3.6 degrees even under external perturbation of force at 6.8 lbs. The preliminary testing showed that the robot was able to provide PROM exercise without the need for physical intervention from anyone else, in an effective manner for emulated patient conditions.

Conclusions: The SREx can provide safe and measurable PROM exercises to healthy patients. The next step is to receive feedback from individuals suffering from ULD.

Author(s) Disclosures: The authors declare no conflict of interest.