New ‘soft robotic arm’ could help stroke recovery

People recovering from strokes could soon have their recovery boosted by a new ‘soft robotic arm‘ being developed at the University of Aberdeen. 

James Greig, a final year PhD researcher, has designed and built the device which could allow patients to carry out invaluable physiotherapy at home in addition to existing assisted physio sessions. 

The lightweight, affordable equipment uses flexible, inflatable material to support the arm as it makes basic repetitive movements – essential for rehabilitation following a stroke.

Like many public services, access to physiotherapy is limited and so James identified a need for technologies that patients can use safely at home to compliment their regular physio.

“What we’re trying to address is a product to address the lack of availability to physiotherapy for stroke patients who have maybe suffered some loss of mobility in the arm,” James said. “I wanted to make a lightweight device that can be made readily available in the community. So it’s cheap, easy to wear, and doesn’t need specialist assistance. It means people can have more physiotherapy so they can do some work at home as well as the work that they’ve been doing with the physiotherapist.”

All strokes are different depending on what part of the brain has been affected, but many people will be left with high muscle tone where the muscles develop spasticity, and the contracted muscles can leave the arm in an almost fixed pose. Typically, throughout rehabilitation, physiotherapists will try to mobilize the limb. If done from an early stage, high spasticity can be reduced.

“We’re basically trying to mimic the same movement that physios will encourage in their sessions but using robotics in a way that allows people to do this at home without the physiotherapist actually being there. If we can augment the physio-led rehabilitation with some work they can do at home using the robotic device, then we can improve their recovery,” James said.

The wearable robotic device, secured with straps on the arm, operates by pumping air into inflatable material strips, facilitating arm movement similar to a bicep curl. Originally designed for stroke patients, this innovation has the potential to assist anyone undergoing arm physiotherapy.

Soft robotics, a recent development, employs flexible materials to mobilize and maneuver limbs, in contrast to traditional rigid robots made from metals and hard plastics.

“The key challenge is how we scale up these devices to generate enough force to allow them to work on larger joints without making them too heavy and too cumbersome.”

Although clinical trials have not yet commenced, the device received positive feedback from a group of physiotherapists during information and feedback sessions, indicating promising potential.

“This is an exciting development in the field of robotic technology, offering the potential to provide an adjunct to rehabilitation therapies such as occupational therapy and physiotherapy and the opportunity to increase intensity through repetition,” said Thérèse Lebedis, Consultant AHP (Occupational Therapist) in Stroke, who has worked with James on the project.