Development and validation of a REHAB glove device for post-stroke hand rehabilitation

INTRODUCTION Approximately 800,000 people in the United States have a stroke each year, of which 30% to 66% of all survivors have impaired hand functions. Certain therapeutic interventions such as Continuous Passive Motion (CPM) capitalize on the brain’s inherent neuroplasticity to increase adaptation to stroke. Currently, no dedicated system exists which effectively applies post-stroke hand therapy. To address this need, a soft robotic rehabilitation system capable of monitoring and assisting hand motion for post-stroke patients has recently been developed. This abstract compares simulation and experimental data on a human finger with a corresponding robotic digit to evaluate the viability of the current design for rehabilitation purposes and to ensure patient safety and performance. METHODS/RESULTS Glove and Soft Robotic Digits: This system consists of five sensorized robotic digits and a wearable fixture along with a programmable control unit that monitors and modulates the trajectory of the fingers. Finger motion is accomplished by pneumatically actuated soft robotic digits based on hybrid soft-and-rigid actuator technology. Computer simulations have shown the resulting relative angles between rigid sections at the metacarpal phalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints can reach full anatomical range of motion (ROM) at a single actuation pressure of 24.3kPa. Kinematic study: A kinematic study was conducted to compare one subject’s index finger with a robotic digit using a motion capture system to analyze spatial and angular position. This study determined the functional anatomical ROM requirements at each joint for both the robotic digit and index finger. The achieved ROM for MCP, PIP, and DIP joints of the robotic digit are 85˚, 96˚, and 53˚, respectively, which are in good agreement with full anatomical ROM. It should be noted that the human finger (MCP: 45˚, PIP: 75˚, and DIP: 45˚) did not quite reach full ROM during testing due to obstacles in tracking. Still, these achieved ROM are consistent with the functional ROM of human fingers. DISCUSSION A hand therapy glove has been designed to provide flexion and extension of the fingers as an adjunct to hand rehab. A prototype has been fabricated based on initial design parameters and is able to provide joint ROM based on the literature. Functional grasp parameters have been experimentally measured in a human finger and will be used for future design improvements.