Researchers at the Medical University of Vienna, in collaboration with ETH Zurich, the Technical University of Munich and Medical Faculty Belgrade, announced on June 19 the development of a wearable neurorobotic system that combines electrical neurostimulation with hand exoskeletons. In a clinical trial involving 14 patients with hand impairments caused by neurological injury, the technology supported finger mobility, tactile perception and grip control. The results demonstrate potential for personalised assistive systems for people living with spinal cord or brain injuries. The study was published in Science Advances.
The system was tested on 14 patients who all exhibited sensory deficits and therefore received tactile feedback via transcutaneous electrical nerve stimulation. For seven individuals with particularly severe motor impairments, functional electrical muscle stimulation was also used to support hand opening and grip strength.
The study compared three conditions: no support, support from an exoskeleton alone, and combined use of an exoskeleton and neurostimulation. Eight participants also completed functional grasping and releasing tasks using bulky and fragile objects. This part of the investigation showed that combining exoskeletons with neurostimulation provided additional benefits over using an exoskeleton alone. In those with severe motor impairment, SensoExo improved finger mobility more than the exoskeleton alone. Artificially mediated tactile feedback increased areas where touch sensations could be perceived.
"The results show that motor assistance and sensory feedback must be considered together," said lead author Andrea Cimolato from the Center for Medical Physics and Biomedical Engineering at MedUni Vienna. "The system can be adapted depending on the individual's impairment profile. People with more severe motor impairments benefited particularly from additional motor support, while those with pronounced sensory loss used the sensory feedback to grasp fragile objects more precisely." In functional tests, participants using SensoExo achieved higher success rates when grasping and carrying objects; muscle stimulation supported grip strength for bulky items, while sensory feedback helped avoid excessive pressure on fragile ones.
"The technology is currently a prototype and not a fully developed medical device for everyday use," said Raspopovic. "However, the study provides early clinical evidence that non-invasive neurostimulation combined with wearable robotics can form a realistic basis for future personalised assistance systems." Research teams led by Lorenzo Masia at Technical University of Munich and Olivier Lambercy from ETH Zurich developed exoskeletons; Ljubica Kostadinovic's team at Medical Faculty Belgrade supported clinical assessments.
Future studies involving larger patient groups will help determine how robust these effects are across different types and severities of symptoms, as well as whether such systems can be integrated into rehabilitation or daily life over time.
