Cadence Biomedical’s Kinetic Orthosis
October 2011 Issue
First Steps: Inspired by nature, Cadence Biomedical's Kinetic Orthosis helps users walk.
After Heather Montag took her first solo steps in more than six years, she had one word to say: "Wow."
Montag was wearing a prototype kinetic orthosis designed by Cadence Biomedical, Fremont, Washington, a privately held, early-stage medical device company, whose mission is to improve mobility for people with disabilities.
Montag, 45, has a rare form of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, which has a prognosis of chronic remission. She calls her form of ALS "a blessing," given that 99 percent of people with the disease die within three to five years of its onset. She was 18 and starting her first year of college when she first noticed she had difficulty dancing, playing the piano, and speaking.
"It was so seemingly insignificant that no one noticed," recalls Montag, who lives in Kirkland, an eastside suburb of Seattle. "I thought I was just tired."
Several years would pass before a physician told her she had ALS.
Montag can walk for short periods of time as long as someone holds her hand and provides her with support.
"I can't walk confidently unassisted with my current leg braces," she says. "It's too dangerous for me to walk on my own because my arms aren't quick enough to break my fall if I become unsteady."
Montag has walked with the Cadence orthosis a number of times, but the first two stand out. The first time she tried the device, she was able to walk for more than an hour with support. The second time, Montag decided to try walking without support. She was successful. It was the first time she had walked unassisted since 2005.
"I physically experienced a tiny glimpse of freedom," she says.
Montag's initial success is encouraging for Cadence President and CEO Brian Glaister.
"We're excited about the success Heather had with our device," he says. "While these results are preliminary, they speak to the potential our technology holds to improve mobility and independence for millions of people with severe disabilities."
The best thing about Montag's second time walking with the device-she was able to break a sweat.
"Walking long enough and hard enough to work up a cardio sweat is not an option for me because I tire out before I sweat," she says. "That's why walking [with the kinetic orthosis] long enough was totally exhilarating."
Montag also noticed a difference in her muscles and her breathing.
"It was as if the [device] was teaching my muscles and nerves to function the way they were...designed to function but haven't been able to for years,"she says. "My memory was saying 'this feels so good.' Then I walked without the [device and] there were feelings in my muscles and nerves of walking correctly."
While some inventors look to science fiction for inspiration, Glaister says it was better to look to nature for inspiration when building the kinetic orthosis. More specifically, horses, which are among the most efficient ambulators in the animal kingdom.
"Horses can run all day and not get tired," he says.
Unlike the human anatomy, which is characterized by long muscles and short tendons that span single joints, a horse's anatomy is characterized by short muscles and long tendons that span multiple joints.
"Tendons are nature's rubber bands and can stretch to store energy only to snap back and return that energy at a later point," says Glaister, who began work on the orthosis from his basement office back in 2003.
Cadence's kinetic orthosis doesn't use motors or batteries to enable walking. Rather, it relies on a proprietary, tuned system of cams and springs to capture energy during the beginning of a step and then return that energy at the end of a step to amplify muscular strength, thereby enabling users not only to walk faster, but also for a longer duration.
Cadence is currently recruiting patients for a study to further investigate the performance of its kinetic orthosis. One such test subject is Richard Harrington, who fell while skiing in 1999 on Blackcomb Mountain, British Columbia, Canada, and ruptured the disc between his C3 and C4 vertebrae. He was transported by helicopter to Vancouver General Hospital, British Columbia, and then transferred to Harborview Medical Center, Seattle, Washington, for rehabilitation. Harrington was temporarily paralyzed from the shoulders down before the disc was removed and the vertebrae were fused together with a bone graft and plate. He now walks with a cane, as his central spinal cord injury affects nerve conduction and reduces his balance and muscle strength.
Harrington's participation in Cadence's user study involved making a trip to the company's office for an initial fitting. From there, he and the Cadence team went to the PotentRXTM, Seattle, lab for gait testing with and without the device. He had several electromyography (EMG) electrodes attached to his legs to record muscle activity as he walked. His walking speed was assessed during a 50-foot walk test and an eight-minute walk test.
"Picture a pogo stick storing energy on the down stroke and returning it on the up," Harrington says when describing walking while wearing the orthosis. "The only moving parts are two springs for energy storage and some pulleys to create torque at the hip, knee, and ankle during gait. The side bars provide some lateral stability, which felt good for me in helping my balance."
George Saul, who is on Cadence's board of directors, and is also an investor in the company, says that because the product is mechanical rather than electro-mechanical or hydraulic-based, it is relatively inexpensive to operate.
"It's very orthotist friendly, very easy for the patient to adjust," Saul says. "There are no charging requirements, no electric circuits to fail or debug. There's no noise."
Montag also appreciates how quiet the device is. "People who are injured or disabled and have a difficult time walking stand out," she says. "Other people often look at them uncomfortably or turn away. As a person with a disability, walking quietly to go about my day in relative obscurity sounds very inviting."
Thanks to investors like Saul, Cadence's kinetic orthosis will be available for people such as Montag, Harrington, and others with conditions, including strokes, muscular dystrophy (MD), and multiple sclerosis (MS), that result in physical disabilities. In fact, Saul referred Montag into the user study. Montag worked for Saul at Cypress Semiconductor, where she was a technical writer and he was the CEO.
"He is tough as nails, but with a golden heart," Montag says.
When Saul retired, he says he wanted to do something meaningful with his time and money. He met Glaister in the summer of 2010 at the Northwest Entrepreneur Network's First Look Forum, a venue that brings together start-up companies and angel investors. Since Saul had benefited from angel investments for some of his own start-up companies during his career, he wanted to return the favor.
"I wanted to become involved in investing in companies or ventures that have socially redeemable aspects," he says.
A medical device start-up company like Cadence Biomedical was exactly what he had in mind.
"I was drawn to Cadence's vision of helping people," adds Saul, who has also volunteered at the Seattle Veterans Administration (VA) Hospital Spinal Cord Injury Unit for the past few years. It was there that Saul says he came to see how improving one's mobility also improves one's quality of life.
Saul says he sees Cadence Biomedical's orthosis doing just that "for thousands of people around the world."
Cadence is planning to release its kinetic orthosis to the marketplace early next year.
Betta Ferrendelli can be reached at