Master-Slave Control for a Pneumatically Actuated Low Pressure Soft Robotic Glove to Facilitate Bilateral Training for Stroke Patients

Abstract

Strokes are one of the leading causes of disability worldwide. Most stroke survivors will have some degree of paralysis immediately after a stroke, which in many could be lost hand motor functions. In order to encourage a faster motor function recovery, many researchers have been working on improving existing rehabilitation techniques and assistive hand exoskeleton designs. However, many of the current assistive hand technologies, especially rigid hand exoskeletons, seem to be ineffective due to limitations in their mechanical designs. This paper focuses on designing a low pressure soft robotic glove to facilitate bilateral hand training. In this kind of therapy, a movement in the healthy hand generates a similar movement in the paretic hand. Researchers found that the activation of both cerebral hemispheres in rehabilitation exercises, improves outcomes significantly. To allow for this to happen, a design of soft actuators that can be quickly fabricated, and be operated on low pressures while achieving high flexion forces is proposed. The mechanical performance of the actuator was analyzed based on its blocked tip force capabilities and its capability in supporting full range of motion of the fingers. Then, a master-slave controller is proposed such that a glove (master) with flex sensors is worn on the healthy hand to generate a similar movement on the soft robotic glove that is worn on the paretic hand. The glove was successful in meeting the design requirements and assisting a person without hand motor dysfunction in performing a pinch, tripod pinch, and full grasp movements.