Robotic Glove Reimagines Hand Recovery

A groundbreaking neurorobotic system, a collaborative innovation from the Medical University of Vienna, ETH Zurich, the Technical University of Munich, and Medical Faculty Belgrade, has emerged. This pioneering assistive technology seamlessly integrates electrical neurostimulation with sophisticated hand exoskeletons. Clinical evaluations involving fourteen individuals who had sustained hand impairments due to neurological damage revealed the system’s efficacy in bolstering finger mobility, refining tactile perception, and enhancing grip control. These findings underscore the significant promise of tailored assistive solutions for individuals navigating the challenges of spinal cord or brain injury sequelae. The comprehensive study detailing this advancement has been recently disseminated in the esteemed journal, Science Advances.

The ability to manipulate objects with our hands and perceive tactile sensations is fundamental to performing daily tasks, encompassing activities such as grasping, eating, dressing, and maintaining personal hygiene. However, following damage to the central nervous system, persistent motor and sensory deficits affecting the hand are frequently observed. While conventional therapeutic interventions can yield improvements, they do not always facilitate a complete restoration of hand functionality. Consequently, there is a compelling need for highly functional assistive technologies that can be readily incorporated into everyday life.
A dedicated research consortium, spearheaded by study director Stanisa Raspopovic from the Center for Medical Physics and Biomedical Engineering at MedUni Vienna, has engineered the “SensoExo” system. This innovative device is meticulously designed to assist individuals grappling with sensorimotor impairments of the hand. It comprises a wearable hand exoskeleton coupled with a bespoke neurostimulation sleeve. This sleeve delivers targeted electrical stimulation to specific nerves and muscles within the forearm through the skin. Integrated sensors on the fingertips meticulously detect touch and grip forces, translating this data into electrical impulses that convey tactile feedback to the user. Moreover, the system employs functional electrical stimulation to facilitate effortless finger opening and closing movements.
Our objective extended beyond merely providing mechanical support for movement; we aimed to re-establish the crucial sense of touch. The synergistic interplay of strength, dexterity, and tactile sensation is paramount, particularly when executing grasping actions. Without adequate feedback regarding the applied pressure when holding an object, functional hand use remains considerably compromised in routine daily activities.”

Stanisa Raspopovic, Center for Medical Physics and Biomedical Engineering, MedUni Vienna

Personalized Assistance Tailored to Specific Impairments

The SensoExo system underwent rigorous testing with fourteen patients presenting with neurological hand impairments. All participants exhibited diminished sensory capabilities, thereby receiving tactile feedback via transcutaneous electrical nerve stimulation. For seven individuals experiencing particularly profound motor deficits, functional electrical muscle stimulation was also implemented to augment hand opening and bolster grip strength.
The investigation meticulously compared three distinct conditions: the absence of any assistive intervention, reliance solely on the exoskeleton’s mechanical support, and the synergistic application of both the exoskeleton and neurostimulation. Furthermore, eight of the fourteen participants engaged in functional tasks involving the grasping and releasing of objects of varying textures and fragility. This nuanced evaluation revealed that the combined approach of exoskeleton and neurostimulation conferred superior advantages compared to the exoskeleton utilized in isolation. Notably, patients with severe motor impairments witnessed a more substantial enhancement in finger mobility with the SensoExo system than with the exoskeleton alone. The artificially mediated tactile feedback also expanded the perceived tactile areas of the hand.
“Our findings emphatically demonstrate the necessity of simultaneously addressing both motor assistance and sensory feedback mechanisms,” elaborated lead author Andrea Cimolato from the Center for Medical Physics and Biomedical Engineering at MedUni Vienna. “The ingenuity of the system lies in its adaptability, allowing for adjustments contingent upon the individual’s specific impairment profile. Those with more pronounced motor deficits derived particular benefit from the augmented motor support, while individuals with significant sensory loss leveraged the sensory feedback to achieve greater precision when handling delicate objects.”

Enhanced Grasping Capabilities for Everyday Objects

During the functional assessments, participants utilizing the SensoExo system achieved the highest efficacy rates when executing tasks involving grasping and transporting objects. For larger, bulkier items, the integrated muscle stimulation proved instrumental in enhancing grip strength. Conversely, when interacting with fragile objects, the sophisticated sensory feedback provided by the system helped users to modulate their grip force and avoid excessive pressure.
“While the technology currently exists as a prototype and has not yet been fully developed into a commercially available medical device for widespread daily use,” emphasized Raspopovic, “this study provides compelling preliminary clinical evidence that the non-invasive integration of neurostimulation with wearable robotics can serve as a robust foundation for the development of future personalized assistive systems.”
In addition to the contributions from MedUni Vienna, research teams led by Lorenzo Masia at the Technical University of Munich and Olivier Lambercy at ETH Zurich were instrumental in the development of the exoskeletons. The clinical assessments were adeptly supported by the team under the guidance of Ljubica Kostadinovic from Medical Faculty Belgrade. Future research endeavors, involving more extensive patient cohorts stratified according to the specific type and severity of their symptoms, will be crucial in validating the robustness of these observed effects and ascertaining the optimal integration of such systems into long-term rehabilitation protocols and everyday life.