Portable Hand Rehabilitation Device for Patients with Neurological Disorders

Abstract

Individuals who have experienced a stroke or suffer from central nervous system disorders often endure persistent upper limb deficits, including limited range of motion and increased muscle contraction, even months after the onset of the condition. Complementing traditional occupational and physical therapies, robotic-assisted therapy has shown enhancements in the recovery of hand impairments. This paper presents a portable, handheld sensory-motor training device, offering patients the opportunity to engage in daily hand-opening and closing exercises within the comfort of their homes. The device employs a cable-driven capstan mechanism, allowing a single motor to actuate two output drums in different rotational directions, ensuring compactness. This mechanism facilitates a comprehensive opening and closing procedure involving the four fingers on one side and the thumb on the other. Furthermore, sensors for torque estimation along with a computer interface are incorporated for assessments and recovery monitoring. As the stiffness of the hand is related to the spasticity, the device measures the applied torque to assess the level of the spasticity. Using data from preliminary tests with six healthy participants, showed that a torque measurement using motor current monitoring suffices. This allows for a compact, and lightweight device design compared to using additional force sensors. This self-administered therapy not only increases the frequency and duration of rehabilitation but also contributes to cost savings within the healthcare system by minimizing the need for continuous therapist involvement.