April 17, 2023 – When Ozzy Osbourne canceled a tour this year due to health issues, his Instagram post cryptically mentioned the kind of treatment he’d received since a 2019 back injury and Parkinson’s disease diagnosis.
Osbourne, 74, said he’d had “groundbreaking Cybernics (HAL) Treatment,” medical technology developed in Japan that became available in the United States about 5 years ago.
The former Black Sabbath frontman was referring to a type of exoskeleton (its makers at Cyberdyne prefer “wearable cyborg”) called a hybrid assistive limb, or HAL. It helps patients with stroke, spinal injury, or neurodegenerative disease regain function in their limbs.
Robotic exoskeletons from several companies have been used in physical therapy since the mid-2010s. Other major players – like Ekso Bionics, ReWalk, and SuitX – make devices with programmed movement patterns, allowing wheelchair users to stand, walk, or climb stairs.
Cyberdyne’s HAL is able to detect faint or disorganized signals in the nerves and help perform the intended movement, whether it’s as simple as flexing an elbow or as complex as walking.
Plainly put: HAL senses what move your brain is trying to tell your muscles to do, and then helps you do it. It’s the only FDA-cleared exoskeleton with this feature, though researchers have built devices with similar control systems in labs.
“These devices realize the fusion of humans, AI robotic technology, and IT together,” said Yoshiyuki Sankai, PhD, the founder and CEO of Cyberdyne. “That is one of the great challenges for human beings.”
Yes, “Cyberdyne” is also the fictional company in the Terminator movies that builds killer robots. And yes, “HAL” is the malevolent AI from 2001: A Space Odyssey.
But the real-life Cyberdyne’s products are only for helping people, not for military use, Sankai insists. (The sci-fi similarities are a coincidence, he says.)
Sankai started working on HAL in 1991 at the University of Tsukuba in Japan, where he is a professor of engineering, information, and systems. He defined the interdisciplinary field of “cybernics,” which combines “robotics, brain science and neuroscience, IT, ergonomics, Kansei engineering, physiology, social sciences, and ethics,” as Sankai described it in his 2014 academic book Cybernics.
Simpler exoskeletons are used in industrial workplaces (for repetitive tasks like lifting, or static tasks like holding heavy tools). But these more sophisticated medical devices are showing promise, says Jason Wheeler, PhD, a robotics engineer at Sandia National Laboratories in Albuquerque, NM. Wheeler is not involved with Cyberdyne. “The technology is advancing in exciting ways, and that will be followed by regulatory approval in medical environments,” he says.
Encouraging Progress for Patients
Over a recent video chat, Sankai proudly showed off videos of patients who made startling progress after using HAL.
- A teenage boy who had no feeling from the waist down after a car accident at the age of 2 was able to move his hips and lift his leg without the help of HAL after more than a year of treatment with the device. He also regained bowel and bladder control.
- A middle-aged woman who couldn’t move her right leg after a car accident 5 years prior spent 3 months in HAL treatment and regained the ability to jog, and ultimately returned to normal life.
Research has shown that the HAL device can help victims of spinal cord injury, cerebral palsy, neurological damage from a stroke, chronic lower back pain, plus degenerative neuromuscular diseases such as amyotrophic lateral sclerosis, muscular dystrophy, and Parkinson’s disease. HAL has even helped heart patients too frail to walk move like healthy subjects. Sankai co-authored a 2021 study on 28 people with chronic heart failure. Eight patients regained the ability to walk independently after an average of 7 days of treatment, compared to three patients who could walk again after receiving conventional therapy.
In the United States, HAL is available in three variations. A lower-body version fits like a girdle around the midsection, with bracers that run down the sides of the legs to the patient’s feet, and motorized joints at the hips and knees to help with walking. The HAL “lumbar” attaches to the lower back and upper thighs, allowing patients to bend and sit; and the “single joint” can be used on the knees, arms, or shoulders.
A new design that covers the hand to improve fine motor control has completed testing and is nearly ready to move into production, Sankai said.
Connecting Body and Machine
Tony Stark wields Iron Man suits with ease in the comics and movies, but real-life exoskeletons can be challenging to use. They are “complex systems” that “can be difficult to implement in a field setting,” Wheeler said. “Learning how to control them is complicated because everyone moves differently.”
When a patient steps into HAL, a therapist places electrode sensors (like pads used in an electrocardiogram) on several places on the patient’s skin. The sensors can detect nerve transmissions below the skin’s surface, activating the joint motors to produce the intended movement. Currently, U.S. patients must be strapped into an overhead harness to aid balance during sessions with HAL.
Our bodies have sensory receptors called “proprioceptors” that detect motion and our body’s position. HAL treatment taps into this.
“The movement is felt by proprioceptors that are naturally present in the muscles of the patient’s body, and this information synchronizes with the patient’s intention to move as it returns to the brain,” said Tetsu Sugie, senior manager for corporate development at Cyberdyne.
“That feedback loop helps the nervous system repair damaged cells or find new connections, ultimately helping patients to recover movement.”
The biofeedback principle is not new. It’s standard practice for physical therapists to assist patients with their movements to help recover lost motor function.
“In the past, I would need to get down on the ground and move the patient’s legs with my hands to give tactile cues that provide input to the central nervous system that travels up through the spinal cord,” said Bob McIver, a doctor of physical therapy, who runs the Cyberdyne HAL treatment program at Brooks Rehabilitation in Jacksonville, FL.
With HAL, therapists can monitor the information that the sensors gather, including the strength of the nerve signals, pressure on the footpads through the step cycle, the torque of the motors, gait form, and posture. All the data is displayed in real time on a touchscreen tablet.
This feedback allows therapists to fine-tune how the device interacts with the body. If a patient tires during an exercise session with HAL (typically about 45 minutes), McIver can crank up the torque so the device provides greater assistance.
As they progress, he can dial back the assistance or even add resistance to spur muscle growth and increase strength. “The end goal is to dial all those back to zero so the patient gets back to normal walking function,” McIver says.
In healthy patients, HAL can move your limbs even if you simply say the words in your head. “If you think, ‘Lift right leg,’ the device will do that for you,” said Navid Hannanvash, doctor of physical therapy, the CEO and owner of RISE Physical Therapy. “You feel weightless.”
Barriers to Wider Availability
Individual success stories can be encouraging, but wider results remain hard to predict. Medical exoskeletons “can have measurable benefits,” Wheeler said, “but until we deploy them at scale, we won’t really know how people are truly responding.”
Only two clinics in the United States use HAL: RISE Physical Therapy, which has HAL devices in four locations in Southern California, and Brooks Rehabilitation in Florida.
“We’ve only really started over the first few months putting the word out,” said Hannanvash. “We want to make sure that we’re prepared for that influx.”
For patients, treatment with HAL generally costs the same as or a little more than regular physical therapy. “It’s no different than going to another center and doing a leg press – we charge the same codes,” McIver says. “There’s no special Medicare code for ‘Cyberdyne HAL.’”
While that keeps fees manageable for many patients, the flat reimbursement scale puts more of the cost burden on clinics that carry the HAL. The devices are leased from Cyberdyne, which handles maintenance and support, for around $35,000 per year for each lower-limb model.
“Right now, major insurance providers don't have the education and knowledge of the device necessary to adequately assess the device and its benefits,” Hannanvash said. More and larger clinical trials are needed to establish the scientific backing that would allow the Centers for Medicare and Medicaid Services to create a unique billing code.
Meanwhile, Cyberdyne is exploring ways to make the device cheaper. “HAL is a hybrid system that integrates computers, and communication systems, and high-level, very thin motors and self-developed actuators,” Sankai said. “So, every part is very expensive.”
Universal components for use across the HAL product line are being developed. Sankai envisions affordable HALs that a patient could take home for a few months.
Future HAL devices could look sleeker and feel more like clothes.
Cyberdyne has even done basic research on implantable semiconductors to improve nerve signal detection, but Cyberdyne USA chief clinical affairs officer Hiroki Kimura emphasized that “we do not have any devices that are invasive in our commercial lineup.”
Uses in the Workplace, Sports, and Disaster Response
HAL technology is in use in more than 20 countries, led by Japan, Germany, and Malaysia. In Japan, non-medical HAL wearable cyborgs are also used by workers to help carry heavy loads, and to analyze their movements to help prevent injuries. Japanese patients can also take home the lumbar version of HAL for up to 3 months at a time for $1,200.
Cyberdyne adapted the movement-sensing technology to control remotely operated robots. Researchers developed the system after the 2011 Fukushima Daiichi nuclear power plant disaster to investigate areas too hazardous for humans. A non-medical version of the HAL was also developed to support the weight of radiation-shielding suits for early responders working in irradiated areas.
A few professional athletes in Japan have worked with HAL to improve strength and movement form, including 2022 French Open mixed doubles winner Ena Shibahara and the Shizuoka Blue Revs professional rugby team.
“It is currently used to train athletes to have greater command of the timing in which their muscles transition from relaxed to fully engaged and vice versa,” Sugie says. Pro athletes have seen quick improvement in such abilities as vertical leap, he says.
Americans have expressed mixed feelings about the technology. In a 2022 survey by the Pew Research Center, 33% of Americans said widespread use of exoskeletons would be a “good idea,” with 24% saying it was a bad idea, and 42% not sure. But when asked about using exoskeletons to improve quality of life for the physically disabled, approval jumped to 79% in favor and just 6% opposed.
So far in the United States, HAL devices are reserved for medical use. “I’ve said, ‘Let me serve the people who couldn’t walk and couldn’t move first, and then we’ll serve those other people,’” Hannanvash said.