Session: ASME Undergraduate Student Design Expo

Paper Number: 176170

A Bioinspired Exoskeleton Reproducing Arm Motion in Stroke Patients 

Partial paralysis and degenerative muscle weakness can severely limit an individual’s ability to perform essential daily tasks such as eating, dressing, and maintaining personal hygiene. These conditions reduce motor control and strength, making it difficult to carry out movements that require coordination and stability. Among the various causes, stroke is one of the most common causes of upper limb paralysis and weakness, with over 795,000 cases reported annually in the United States and a mortality rate of approximately 39.5%. It remains the leading cause of serious long-term disability, often resulting in permanent neuromuscular impairments. Among stroke survivors, approximately 77.4% suffer from upper limb motor deficits that hinder independent function. Exoskeletons are a promising technology for restoring motor function, with most designs targeting either the lower or upper limbs. Lower-limb devices require high torque output to move the mass of the legs but benefit from ground-supported weight transfer, which reduces the burden on the user. Their control is further aided by the repetitive and predictable nature of the gait cycle, which facilitates intent detection and coordination. In contrast, upper-limb exoskeletons pose greater challenges: their weight must be fully supported by the user, and their control systems must adapt to irregular, task-specific arm motions rather than a uniform cyclical pattern.Upper-limb exoskeletons can be broadly divided into two categories based on intended use: rehabilitation and assistive devices. Rehabilitation exoskeletons are primarily designed to support recovery by guiding patients through prescribed physical therapy exercises, typically under the supervision of a clinician. These devices are usually stationary or grounded to a stable reference point, and while they may offer a high number of degrees of freedom (DOFs), they lack mobility. Assistive exoskeletons, in contrast, are body-worn devices intended for use during daily activities. As such, they must be lightweight and unobtrusive while still capable of detecting and responding to user intent in real time. This fundamental difference in mounting and control requirements strongly shapes their respective designs.

This study presents the design and development of a daily assistive stroke patient exoskeleton (DASPE), a cable-driven, semi-compliant exoskeleton intended to support stroke patients by mirroring the motion of their healthy arm. Motion data from inertial sensors placed on the healthy arm is used to compute joint angles, allowing the exoskeleton to mirror elbow and shoulder movements. The design incorporates compliant elements at the spine and shoulders to allow flexible motion and avoid bulky, rigid components. Initial testing demonstrates the system's ability to perform elbow flexion-extension, shoulder abduction-adduction, and shoulder flexion-extension, with good alignment between user and exoskeleton motion for angles up to 35°.

Presenting Author: William Thomspon Kennesaw State University

Presenting Author Biography: William Thompson is an undergraduate student in mechanical engineering department at Kennesaw State University.

Authors:

William Thomspon Kennesaw State University
Aaron Grann Kennesaw State University
Connor Talley Kennesaw State University
Vanessa Young kennesaw state university
Ayse Tekes Kennesaw State University