Parkinson’s disease affects more than 9.4 million people worldwide and is expected to increase significantly by 2040. As the disease progresses, up to 80 percent of patients experience freezing of gait, characterized by unintended stops while walking, often causing the patient to fall.
A new advancement in robotics has led to the creation of a soft, wearable robot that provides new levels of support for patients with Parkinson’s, helping to overcome the FoG challenge. The breakthrough technology demonstrated its potential in a study where it improved the mobility of a 73-year-old patient who experienced more than 10 FoG episodes a day (along with frequent falls).
The research, “Soft robotic apparel to avert freezing of gait (FoG) in Parkinson’s disease,” was published in the Nature Medicine journal.
Gait freezing causes people with Parkinson’s to suddenly lose the ability to move their feet, often in mid-stride, as their stride gets shorter in range until the person stops walking. Freezing is currently treated with a range of medicines and surgical or behavioral therapies, all of which have limited effectiveness.
Wearable robots have so far shown promise for neurological disorders like stroke, cerebral palsy, and spinal cord injury. The researchers from the Boston University Sargent College of Health & Rehabilitation Sciences and the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), responsible for the FoG study, previously demonstrated that a soft, wearable device could augment hip flexion and assist in swinging a leg forward to reduce energy use during walking. Now, in a global first, a similar approach using a robotic device is helping avert FoG for Parkinson’s disease.
Suiting Up
This breakthrough in Parkinson’s treatment brought together an impressive range of specialists in their respective fields. “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,” said Conor Walsh, Paul A. Maeder Professor of Engineering and Applied Sciences, whose team collaborated with Terry Ellis, Professor and Physical Therapy Department Chair and Director of the Center for Neurorehabilitation at Boston University.
The research team designed soft robotic apparel that assists hip flexion by modifying a previous, portable hip exosuit. The resulting wearable garment uses cable-driven actuators and sensors. It is worn around the hips and thighs (Figure 1), providing a gentle push to the patient’s hips as the leg swings so that the patient achieves and maintains a longer stride. The garment features a waist belt, two thigh wraps, and suspension shoulder straps made of layers of abrasion-resistant plain-weave textile and lightweight custom sailcloth material. Actuators are mounted onto the front of the waist belt using 3D-printed plastic parts and fastened to the back using Velcro. Suspension shoulder straps prevent the waist belt from sliding down. The design has only one on/off switch and takes 5–10 minutes to put on or remove.
The garment has a small rope winch design that generates hip flexion. Each of the two winches mounted on the front of the waist contains a motor, encoder, and a Dyneema rope that spans the length of the thigh. One end of the rope is attached to the motor, and the other to the thigh wrap via a metal buckle. The wearable device uses cable-driven actuators and sensors worn around the thighs and waist. An actuator transmits torque to a cylindrical drum, spooling in the rope and generating an external flexion movement around the hip joint. Algorithms are used to estimate gait and trigger actuators to apply assistive forces in tandem with muscle movement.
The electronics powering this robotic apparel include a custom-made board with a microprocessor, motor driver, and two lithium-ion batteries. Two load cells to measure tensile force on the rope are integrated into the thigh wrap, and two are attached to the anterior of the thigh wrap. Control of the apparel relies on the independent motion of each leg. Algorithm calculations cover the distance, step time, walking speed, all angles, hip flexion, and range of motion. One of the most critical features of the apparel is that it is lightweight, with most of its weight concentrated on the waist and each thigh.
“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 Walsh.
In the study, the device eliminated the participant’s freezing while walking indoors. This research could allow people with the disease to regain mobility and independence, enabling patients to walk more fluidly and further, and most importantly, avoid falls caused by FoG.
The Patient Weighs In
The team repeated measurements during timed walking trials across five study sessions over six months. Because gait freezing is still not fully understood, it is impossible to know exactly why wearable robotics work. But work, it did—instantaneously. Without any special training, the participant walked without freezing indoors and with only occasional FoG events outdoors. They could also walk and talk simultaneously without freezing, a rarity without the device.
The participant expressed that the robotic apparel would help expand their walking activities to different places outside their home. In their own words, “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 walk longer and maintain the quality of my life.”
As the researchers put it, “This study demonstrated that FoG was averted using soft robotic apparel in an individual with Parkinson’s disease, serving as an impetus for technological advancements in response to this serious yet unmet need.”
Conclusion
This development in medical robotics showcases a significant leap in the treatment of Parkinson’s disease. The approach improves mobility for patients with the disease and highlights the potential of combining soft robotics with therapeutic applications. Perhaps most importantly, it paves the way for broader applications of wearable robotics across many medical conditions.
Sources
N. Maserejian, L. Vinikoor-Imler, and A. Dilley. “Estimation of the 2020 global population of Parkinson’s disease (PD),” International Parkinson and Movement Disorder Society, https://www.mdsabstracts.org/abstract/estimation-of-the-2020-global-population-of-parkinsons-disease-pd/.
Jinsoo Kim, Franchino Porciuncula, Hee Doo Yang, Nicholas Wendel, Teresa Baker, Andrew Chin, Terry D. Ellis, and Conor J. Walsh. “Soft robotic apparel to avert freezing of gait in Parkinson’s disease,” January 5, 2024, https://www.nature.com/articles/s41591-023-02731-8.
Leah Burrows. “Soft robotic, wearable device improves walking for individual with Parkinson’s disease,” Harvard School of Engineering and Applied Sciences, https://seas.harvard.edu/news/2024/01/soft-robotic-wearable-device-improves-walking-individual-parkinsons-disease.
About the author
Carolyn Mathas is a freelance writer/site editor for United Business Media’s EDN and EE Times, IHS 360, and AspenCore, as well as individual companies. Mathas was Director of Marketing for Securealink and Micrium, Inc., and provided public relations, marketing and writing services to Philips, Altera, Boulder Creek Engineering and Lucent Technologies. She holds an MBA from New York Institute of Technology and a BS in Marketing from University of Phoenix.
