Co-designed robotic glove gives a man with severe ALS his grip back
Scientists in Germany created the soft fabric device in partnership with the patient
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- A co-designed robotic glove restored grip and independent feeding for a man with severe ALS.
- The soft, wearable device uses inflatable cushions, controlled by residual muscle signals.
- This low-cost glove offers personalized hand function support for severe paralysis.
A new wearable soft-glove device has successfully restored hand function in a man with amyotrophic lateral sclerosis (ALS), allowing him to grip objects and feed himself independently.
The device was developed by a team of scientists in Germany who worked in direct collaboration with the patient himself. The man had lost virtually all ability to move his hand, except for small movements in one thumb joint. Yet, by using the new glove, he was able to reliably grasp a variety of everyday items.
“This patient has shown us that our soft-hand exoskeleton can support him despite one of the most severe neurological disorders,” Gordon Cheng, PhD, co-author of the study at the Technical University of Munich, said in a university news story.
Cheng and colleagues described the development of their new device in a study, “A dexterous soft hand exoskeleton restores intentional grasping in individuals with severe hand impairment,” published in Nature Machine Intelligence.
Understanding ALS and mobility loss
ALS is a disorder in which the nerve cells that control movement become progressively damaged and die, leading to gradually worsening muscle weakness. Over time, people with ALS lose the ability to move under their own power and become increasingly dependent on assistance to do their day-to-day activities.
A variety of strategies are being explored to restore independence to people with ALS who have lost the ability to move and communicate. For example, some brain implants have enabled patients to speak and control a computer using their own thoughts.
In the study, researchers set out to develop a soft-hand exoskeleton to restore hand function to a man with ALS. The device is basically a glove built from ordinary clothing fabrics that contains several inflatable air cushions. By inflating or deflating, the cushions can push the wearer’s fingers into different positions, allowing the hand to move even when the muscles that normally control hand movements are paralyzed.
When scientists develop this type of device, they often conduct most of the testing in a lab to create a final product that can then be tested in patients. These researchers took a different approach, actively involving the patient in the device’s design. Over several months, they conducted test sessions in which the patient tried out device prototypes and provided feedback on what was and wasn’t working.
“Our co-creation process exemplifies the value of moving beyond the user-centred design approach in assistive robotics where largely passive users are observed and interviewed, towards a participatory development process where users are actively testing multiple prototypes, enabling them to give tangible and concrete feedback on their experiences and priorities,” the researchers wrote.
The final device works by detecting small electrical signals from the patient’s flexor pollicis longus, a forearm muscle that is normally involved in grasping objects. Advanced computer analytics then translate those signals into the patient’s intended movements.
Based on the patient’s feedback, the glove was designed to provide preshaping support, essentially helping keep the hand in certain positions during movements.
“Our solution is intelligent in two ways,” said John Nassour, PhD, study co-author at the Technical University of Munich. “On the one hand, we’ve developed a highly reliable method of predicting grasping movements by inferring intentions from signals with 97% reliability. On the other hand, with our glove, we’ve developed hardware that optimally supports the intended movements.”
The patient was ultimately able to use the device to reliably grasp a variety of everyday objects, such as a bottle, a plate, an apple, and a pastry. Of particular note, the device allowed him to hold a fork to feed himself independently, which the researchers said was the most important benefit from his perspective.
Testing the device on stroke patients
After developing the device alongside the ALS patient, the researchers then tested the finished product in six people with hand paralysis from stroke. Three of the stroke patients had severe hand paralysis, similar to the ALS patient, and in those patients, the device generally improved grip abilities.
The other three stroke patients had more moderate paralysis, with greater ability to move their fingers using their own muscles. In these less-impaired individuals, the device showed markedly less benefit — and in some cases, it even worsened their performance.
The researchers said this divergence likely reflects the differing needs of patients with varying levels of hand functionality, highlighting the need for personalized strategies rather than a one-size-fits-all approach.
“A key finding of this study is that the utility of assistive hand exoskeletons is strongly dependent on the level of residual hand function,” the scientists wrote. “While patients with severe impairments benefitted substantially from the additional dexterity and preshaping support, some moderately impaired patients experienced no benefit or even reduced performance. This highlights that exoskeletons optimized for severe paralysis may interfere with voluntary motor strategies in patients with higher residual function, underscoring the need for impairment-specific assistive designs.”
The researchers stressed that more work is needed to develop and optimize this device for people with diverse support needs. However, they noted that the glove is compact, lightweight, and made of low-cost materials, which should support accessibility.
“We’ve found a solution that anyone can afford but still works very well,” Cheng said.
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