3D Upper-extremity ExoNET: Improved Passive Exoskeleton for Gravity Compensation and Motor Rehabilitation

Although passive designs may appear simple, their lightweight, low cost, and user-friendly configuration make them highly practical for use beyond controlled laboratory settings. Min imal setup, easy donning and doffing, and low maintenance allow both patients and clinicians to operate on them with little supervision, promoting wider adoption in home and community environments. Furthermore, by lowering logistical and technical barriers, passive systems en courage consistent engagement in therapeutic and functional activities. The Shoulder ExoNET (Exoskeletal Network for Elastic Torque) is conceived to provide effective gravity compensation for the upper limb through a fully passive, elastic based mechanism. The theoretical model re lies on a network of diagonal elastic elements acting as basis functions to generate torque–angle f ields that counteract the effects of gravity. Unlike active robotic systems, which although ca pable of offering effective assistance, costly, and difficult to use outside controlled environments, Shoulder ExoNET offers a lightweight, modular, and ergonomic solution designed for real world rehabilitation and daily assistance. Building on an optimization framework that refines key de sign parameters, the system allows seamless translation from simulation to hardware, ensuring that parameters such as spring stiffness, anchor geometry, and routing are faithfully imple mented in the physical prototype. The modular hardware architecture enables patient specific customization, targeting specific joint movements or workspace regions. Compared to previous versions limited to sagittal plane operation, the 3D Shoulder ExoNET extends functionality to multi planar movements and enabled us to directly measure medial deltoid activity; even with preliminary data from a single participant, this allowed us to establish a protocol and specifically test the effect of the exoskeleton on this muscle. Moreover, the rapid transition between different hardware configurations makes this exoskeleton highly adaptable and easy to personalize for different users and tasks, without extensive reassembly. These developments make this device a practical, wearable platform bridging the gap between laboratory prototypes and clinically applicable assistive technologies.

Author dc:creator

• Pietro Bonato (24399386)

• Biomechanics
• Rehabilitation Robotics
• Exoskeletons
• Human–Robot Interaction
• Assistive Devices

Statement dc:rights

• In Copyright

DOI dc:identifier

https://doi.org/10.25417/uic.32993789.v1

OAI identifier oai:identifier

oai:figshare.com:article/32993789