Hand rehabilitation research has significantly advanced with the introduction of soft actuators in gloves. However, current designs of soft rehabilitation gloves face limitations in finger movements. Recently, researchers have successfully incorporated finger straightening or extension into soft rehabilitation gloves using a unique foldable pouch actuator. This innovation enhances hand rehabilitation capabilities without compromising finger bending or flexion functionality.
Soft rehabilitation gloves are valuable tools for aiding patients with hand function-related disabilities in regaining finger movement. These gloves commonly utilize soft pneumatic actuators that use air pressure to enable movements. Despite advancements in design, many soft actuators struggle to achieve bidirectional motion similar to natural finger joints. While these actuators enable finger bending, they often lack the ability to support finger straightening.
A team of biomedical researchers at Chiba University has successfully addressed this limitation by creating a foldable pouch actuator (FPA) that seamlessly integrates with existing soft actuators in rehabilitation gloves. Led by Professor Wenwei Yu from the Center for Frontier Medical Engineering at Chiba University, Japan, the research group, including Dr. Shota Kokubu and Mr. Pablo E. Tortós Vinocour from the Graduate School of Science and Engineering at Chiba University, published their findings in IEEE Access on April 30, 2024.
Prof. Yu shared his motivation behind the study, stating, “Many older individuals with hand function-related disabilities, despite having partial hand function, require substantial care. I envisioned an efficient and safe assistive device that could enhance their hand function for daily tasks, improving their quality of life. The ability to use their hands for eating utensils like spoons or chopsticks could bring them joy.” The FPA represents a significant step towards realizing this vision.
The FPA, a joint-modular bi-directional soft actuator, is the first of its kind, developed by Prof. Yu and his team. It features a flat, foldable structure that expands under pressure to provide the necessary force for finger extension. Importantly, the FPA enables finger extension in soft rehabilitation gloves without compromising the functions of other actuators supporting finger flexion. Testing on a synthetic finger model confirmed the actuator’s ability to generate ample torque for finger movements, including a bending torque of 0.17 Newton meters (Nm) and an estimated straightening torque of 0.12 Nm.
The enhanced design of soft rehabilitation gloves has broad clinical implications. Prof. Yu highlighted potential applications of the upgraded gloves, stating, “High-performance modular soft actuators could aid hand function restoration in tele-rehabilitation and care facilities.” He also noted, “These soft actuators could serve as assistive devices for daily activities, offering both rehabilitation support and enhancing daily living. Their safety, functionality, and ease of wear could significantly benefit our aging population.”
Looking ahead, Prof. Yu suggested that future soft rehabilitation glove designs could benefit from improved manufacturing precision and control systems to support joint-specific rehabilitation.
