THINKING OUTSIDE OF THE BODY
Last WEEKLY’s focus on Duchenne muscular dystrophy got us to thinking, what products are available for those with limited mobility? A new type of medical device called a powered exoskeleton certainly caught our eye. Originally conceived as a tool to aid soldiers in lifting heavy objects, medical device companies are turning to exoskeletons as a way to dramatically improve quality of life for a range of individuals. So, let’s uncork the current pipeline and learn about some of the inspirations behind these inventive products.
TERM OF THE WEEK: POWERED EXOSKELETON
An exoskeleton is an external skeleton thats supports the body instead of (or in addition) to an internal skeleton. Exoskeletons occur in nature—think insects and crustaceans. Fact: turtles have both an internal and external skeleton—bones on the inside and a shell on the outside.
A man made version of an exoskeleton is a mobile machine consisting of an outer framework worn by a person. It is mechanized by a system of motors, hydraulics and/or pneumatics that delivers at least part of the energy for limb movement, giving rise to the term powered exoskeleton.
A SKELETON IS BORN
The idea of an exoskeleton to assist human activity is not a new one. In 1890, the U.S. Patent Office gave Russian scientist Nicholas Yagn a patent for an “apparatus for facilitating walking, running, and jumping”. The apparatus used compressed gas bags to augment user movements and required human power to operate. In the 1960s, General Electric and the U.S. military collaborated to produce the first true exoskeleton—powered by hydraulics and electricity, wearers could increase their strength by a factor of 25. At 1500 pounds, however, the suit had major practical limitations and was never used in military or commercial applications.
By the mid-2000s, leaps in electronics technology and materials science had advanced to the point that functional exoskeletons were a realistic possibility for both military and medical applications.
SOLID TAKES ON DMD
In 2012, investment banker Ilan Ganot’s son Eytani was diagnosed with Duchenne muscular dystrophy (DMD). After learning more about the disease—such as the majority of patients are confined to wheelchairs by age 11 or 12, and few live beyond their mid-20s—Ganot quit his job and relocated his family to Cambridge, MA to start Solid Biosciences.
Solid maintains a multi-pronged approach to discover treatments for DMD—including a preclinical research collaboration with Pfizer (New York, NY) as well as as separate focus on gene therapy. Solid is also thinking outside of the body with one of its key projects—the Solid Suit, a powered exoskeleton device in early development.
The Solid Suit is envisioned as a soft, wearable, assistive device for DMD patients. The aim is to not only assist DMD patients with daily activities, but to preserve muscle function by helping to maintain at least some muscle usage. Solid is partnering with SRI International (Menlo Park, CA) to utilize innovations derived from military technologies designed to offset muscle fatigue and to augment muscle strength. In addition, Solid is partnering with Parent Project Muscular Dystrophy for critical patient feedback as the prototype and clinical development moves forward.
BIOM’S BIONIC LIMBS
BiOM (Bedford, MA) is developing next-generation bionic limbs. Founder Hugh Herr lost his own legs to frost bite decades ago and has spent the intervening years perfecting the technology to replace them.
BiOM limbs are covered with synthetic skin containing built in sensors, causing it to stiffen or soften as appropriate with movement. They have been designed by incorporating studies of normal human physiologies to best mimic the natural movement of human limb muscle function, enabling propulsion very similar to what natural walking entails. The BiOM limb also interacts with the patient’s nervous system through electrodes implanted on the residual limb to which the prosthetic is attached.
BiOM is also developing exoskeletons for human augmentation—in other words, exoskeletons to be worn by fully functioning adults, powering movement and enabling the user to carry out tasks that normally would be out of reach.
EKSO & REWALK
Ekso Bionics (Richmond, CA) markets Ekso, a wearable bionic suit—also an exoskeleton—that enables wheelchair users to stand and walk. The suit is coupled with crutches that contain sensors which send signals to a computer contained in the suit’s backpack. The backpack also contains batteries powering tiny motors in the suit’s hip and knee joints, enabling movement. ReWalk’s (Marlborough, MA) Personal 6.0 System is a similar product currently on the market.
The next phase in exoskeleton development? Mind control. The 2014 World Cup launched with a symbolic first kick by a paraplegic wearing an exoskeleton. Developed by a team of neuroscientists at Duke University, the suit is controlled directly by brain signals picked up by a cap worn on the patient’s head and relayed to a computer in the exoskeleton’s backpack.
