Soft wearable robot tested for Parkinson's support

Freezing is a common and debilitating symptom of Parkinson’s disease which reportedly affects more than 9 million people worldwide. When freezing occurs, people with the disease lose the ability to move their feet, mid-stride, resulting in stuttering steps that get shorter until they stop altogether. 

The robotic garment which was developed by the researchers, is worn around the hips and thighs and works by giving a push to the hips as the leg swings to help the person achieve a longer stride.

Having tested the wearable, the team found it eliminated the participant’s freezing while walking indoors.

“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, Paul A. Maeder Professor of Engineering and Applied Sciences at SEAS and co-corresponding author of the study. 

The study

The researchers spent six months working with a 73-year old man with Parkinson’s disease who in spite of the usual treatments - surgical and pharmacologic - suffered substantial and incapacitating freezing episodes more than 10 times a day.

From previous research, Walsh and his team used human-in-the-loop optimisation to demonstrate a soft, wearable device could be used to augment hip flexion and assist in swinging the leg forward.

The researchers used the same approach but this time to address freezing. The device uses cable-driven actuators and sensors and using motion data collected, algorithms estimate the phase of the gait and generate assistive forces in tandem with muscle movement.

The result was the participant could walk without freezing indoors and with occasional episodes outdoors.

“Our team was really excited to see the impact of the technology on the participant’s walking,” said Jinsoo Kim, former PhD student at SEAS and co-lead author on the study.

“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.” 

Demonstrating the viability of soft robotics

The device could also be used to better understand the mechanisms of gait freezing, which is currently poorly understood. 

“Because we don’t really understand freezing, we don’t really know why this approach works so well,” said Ellis. “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.”

Thanks to the research, it has demonstrated the viability of soft robotics in treating this symptom of Parkinson’s disease and its potential to help people living with the disease regain their mobility and independence.

“Leveraging soft wearable robots to prevent freezing of gait in patients with Parkinson’s required a collaboration between engineers, rehabilitation scientists, physical therapists, biomechanists and apparel designers,” explained Walsh, whose team worked closely with Terry Ellis, Professor and Physical Therapy Department Chair and Director of the Center for Neurorehabilitation at Boston University.

Walsh’s Biodesign Lab based at SEAS has been developing assistive and rehabilitative robotic technologies to improve mobility for individuals after experiencing a stroke, living with ALS or other diseases that affect mobility.

Some of the technologies have received support from the Wyss Institute for Biologically Inspired  Engineering and Harvard’s Office of Technology Development coordinated a licence agreement with ReWalk Robotics to commercialise the technology.

Additionally, in 2022 SEAS and Sargent College were given a grant from the Massachusetts Technology Collaborative to support the development and translation of next-gen robotics and wearable technologies. This research came from that partnership.