Cable-Driven Exosuit to Assist Affected Upper-Limb Users with Hemiparesis

Abstract

Neurological impairments such as stroke cause muscular weakness in several joints in the human body. As a result, the development of activities of daily living (ADL) is affected. Particularly, upper limb movements executed with external loads are restricted for post-stroke patients who present extreme sensitivity to mechanical loading. In rehabilitation, upper limb gravity support and assistive torques improve post-stroke users' skills and support the elbow joint's flexors muscle during the therapy. In this sense, this work presents the design and a preliminary assessment for a portable upper limb exosuit to assist flexor muscles in the elbow joint. The robotic device comprises a wearable structure employing a cable-driven system that does not generate limitations in the elbow joint. An impedance controller was implemented based on the right elbow joint movements to generate estimated torques applied in the left elbow joint. The experimental findings with three healthy participants showcase the short-term effects of a notable reduction in muscle activity, ranging from 60% to 72%, when the exosuit was tested in lifting a 2.5 Kg load.