This robotic exosuit from Harvard helps eliminate gait freezing in Parkinson’s patients
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Boston University Sargent College of Health & Rehabilitation Sciences in the US have used a soft, wearable robot to help find a solution to the issue of gait freezing among people with Parkinson’s disease.
The assistive exosuit, worn around the hips and thighs, gives a gentle push to the hips as the leg swings, helping the patient achieve a longer stride.
Gait freezing is a common symptom of Parkinson’s disease, which makes it feel like the person is suddenly unable to move their feet. According to Parkinson’s UK, the sensation feels as though the individual’s feet are glued to the ground. Freezing can occur when the person starts to walk, when they are walking, or when they are trying to turn around.
However, Harvard’s new assistive technology helps completely eliminate the wearer’s gait freezing while walking indoors, allowing them to walk faster and further than they could without the exosuit’s help.
The device could also be used to better understand the mechanisms of gait freezing.
“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 demonstrates the potential of soft robotics to treat gait freezing. Importantly, it could allow people with Parkinson’s disease to regain their mobility and independence.
To develop this exosuit, the researchers worked with engineers, rehabilitation scientists, physical therapists, biomechanists, and apparel designers.
The Harvard team spent six months working with a 73-year-old man with Parkinson’s disease, who experienced substantial and incapacitating freezing episodes more than 10 times a day, causing him to fall frequently. These episodes prevented him from walking around his community, and he had to use a mobility scooter to get around outside.
In previous research, Conor 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 wearable device 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.
The effect was instantaneous. Without any special training, the patient was able to walk without any freezing indoors and with only occasional episodes outdoors. He was also able to walk and talk without freezing.
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.”
See the exosuit in action here.
The research is published in the journal Nature Medicine.
Previous research has suggested that smartwatches could identify Parkinson’s disease up to seven years before hallmark symptoms appear and a clinical diagnosis can be made.