A body-hugging robotic suit lets the wearer turn as they walk – a first for this technology. It’s an important step toward finally letting people take home supportive exosuits after injuries, rather than having to stay in hospital.
By Sandrine Ceurstemont, New Scientist 12 October 2017
Robotic exoskeletons are often used for rehabilitation: they do your walking for you. Typically, they do this using motors placed at the joints, which transmit forces to rigid components that move the wearer’s legs.
There’s just one problem: they can’t turn. All they can do is walk you in a straight line. “Helping people to turn is really important, yet has rarely been addressed,” says Steve Collins at Stanford University in California.
Now, Stephen John at Panasonic Research in Japan and his colleagues have tackled the problem. Their design, made from snug-fitting soft robotics, looks a bit like Spanx with an outboard motor – a pack on the back contains eight motors, batteries and a control system. Instead of joint motors driving leg movement, it has four actuators at the hips to control criss-crossing soft plastic wires that mimic the action of human muscles, which contract to generate movement. “One of the unique aspects of this exosuit is the way the fabric is wrapped around the legs to allow different combinations of motors to turn a leg,” says Collins.
In preliminary tests, five able-bodied people tried out the exosuit with their eyes closed and in each case the suit could change direction without them losing their balance. John plans to do larger tests with people with disabilities.
The ability to change direction while walking will be key for take-home exoskeletons. “Being able to turn is important for home use,” says John.
Once people who have had a stroke, for example, have recovered enough function in the clinic, they could wear the suit to move more naturally at home. It could also be a boon for older people, allowing them to live independently. “They could put it on the morning and wear it all day,” says John.
The next step is to make the suit easier for the user to control. John is working on a sensor system that will detect when a wearer makes a slight turning motion, and complete the motion for them. He is also working on a way for the suit to sit down and stand up. “Our goal is to assist with all the important movements that people encounter in their daily lives,” says John.
The system was presented last month at the IROS conference in Vancouver, Canada.
Cross-wire assist suit concept, for mobile and lightweight multiple degree of freedom hip assistance, John SW, Murakami K, Komatsu M, Adachi S. IEEE Int Conf Rehabil Robot. 2017 Jul;2017:387-393. doi: 10.1109/ICORR.2017.8009278.
Source New Scientist
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