Researchers have developed a soft, robotic suit to help people living with Parkinson’s disease walk without freezing.
The robotic suit, worn around the hips and thighs, gives a gentle push to the hips as the leg swings, helping the patient achieve a longer stride.
The device completely eliminated the participant’s freezing while walking indoors, allowing them to walk faster and further than they could without the garment’s help.
“We found that just a small amount of mechanical assistance from our soft robotic apparel delivered instantaneous effects and consistently improved walking across a range of conditions for the individual in our study,” said Conor Walsh, the Paul A Maeder Professor of Engineering and Applied Sciences at SEAS and co-corresponding author of the study.
The research, ‘Soft robotic apparel to avert freezing of gait in Parkinson’s disease,’ is published in Nature Medicine.
Over a decade of research has resulted in the final product
For over a decade, Walsh’s Biodesign Lab at SEAS has been developing assistive and rehabilitative robotic technologies to improve mobility for individuals post-stroke and those living with ALS or other diseases that impact mobility.
Walsh explained: “Leveraging a soft, wearable robotic suit to prevent freezing of gait in patients with Parkinson’s disease required a collaboration between engineers, rehabilitation scientists, physical therapists, biomechanists, and apparel designers.”
The team spent six months working with a 73-year-old man with Parkinson’s disease, who endured substantial and incapacitating freezing episodes more than ten times a day, causing him to fall frequently.
These episodes prevented him from walking around his community and forced him to rely on a scooter to get around outside.
In previous research, Walsh and his team leveraged human-in-the-loop optimisation to demonstrate that a soft, wearable device could be used to augment hip flexion and assist in swinging the leg forward to provide an efficient approach to reduce energy expenditure during walking in healthy individuals.
Here, the researchers used the same approach but to address freezing. The robotic suit uses cable-driven actuators and sensors worn around the waist and thighs. Using motion data collected by the sensors, algorithms estimate the phase of the gait and generate assistive forces in tandem with muscle movement.
How did the device improve mobility for people with Parkinson’s disease?
The effect was instantaneous. Without special training, the patient could walk without freezing indoors and with occasional episodes outdoors.
He could also walk and talk without freezing, a rarity without the robotic suit.
“Our team was really excited to see the impact of the robotic suit on the participants’ walking,” said Jinsoo Kim, a former PhD student at SEAS and co-lead author of the study.
During the study visits, the participant told researchers: “The suit helps me take longer steps, and when it is not active, I notice I drag my feet much more. It has really helped me, and I feel it is a positive step forward. It could help me to walk longer and maintain the quality of my life.”
“Our study participants who volunteer their time are real partners,” said Walsh.
“Because mobility is difficult, it was a real challenge for this individual to even come into the lab, but we benefited so much from his perspective and feedback.”
Future uses of the device
The robotic suit could also be used to better understand the mechanisms of gait freezing, which is poorly understood.
Ellis concluded: “Because we don’t really understand freezing, we don’t really know why this approach works so well.
“But this work suggests the potential benefits of a ’bottom-up’ rather than ’top-down’ solution to treating gait freezing. We see that restoring almost-normal biomechanics alters the peripheral dynamics of gait and may influence the central processing of gait control.”
