Vanderbilt Exoskeleton promises more independence for paraplegics

This is a guest post by Joseph Hill.

Until recently the thought of a wearable robot only came to mind when thinking of films such as Avatar or Matrix, but thanks to major advances in robotics, batteries, electric motors and microelectronics they are now a reality. A team of engineers at Vanderbilt University have recently developed an exoskeleton which allows people paralyzed below the waist, who thought they would never take another step, to walk again.

The exoskeleton provides its users with an unprecedented degree of independence which may have been absent due to their paraplegia or spinal injury. According to the National Spinal Cord Injury Statistical Centre, somewhere between 236,000 and 327000 people in the US are living with serious spinal cord injuries and around 155,000 have paraplegia. The exoskeleton’s lightweight and compact size enables this minority to stand, walk, sit and climb stairs, things that most of us take for granted.

The device straps securely around the torso for stability and then rigid supports are strapped to the legs, above and below the knee. The hip and knee joints are computer-controlled by electric motors which are powered by advanced batteries. The user is advised to use forearm crutches with the device to maintain balance.

“You can think of our exoskeleton as a Segway with legs,” said Michael Goldfarb, designer and professor of physical medicine and rehabilitation at Vanderbilt University. “If the person wearing it leans forward, he moves forward. If he leans back and holds that position for a few seconds, he sits down. When he is sitting down, if he leans forward and holds that position for a few seconds, then he stands up.”

Although exoskeletons have already been developed to help people walk, Goldfarb’s skeleton is completely unique and he has several patents pending for his designs. So why is this exoskeleton unique? Not only does it give independence to the paralyzed to walk, but Goldfarb has integrated functional electrical stimulation (FES) technology into the design. FES applies small electrical pulses to paralyzed muscles, causing them to contract and relax. This not only helps the device when walking but for complete paraplegics, it can improve circulation, reduce muscle atrophy and change bone density. The amount of robotic assistance also adjusts automatically for users who have some muscle control in their legs which is another unique addition. This allows them to use their own muscles while walking to strengthen their legs and get vital exercise which is extremely useful from a rehabilitation perspective.

Brain Shaffer, who was involved in a car accident around Christmas 2010, leaving him paralysed from the waist down, has been testing the apparatus at the Sheppard centre in Atlanta. “My kids have started calling me ‘Ironman’” said Shaffer.

“It’s unbelievable to stand up again. It takes concentration to use it at first but, once you catch on, it’s not that hard: The device does all the work. I don’t expect that it will completely replace the wheelchair, but there are some situations, like walking your daughter down the aisle at her wedding or sitting in the bleachers watching your son play football, where it will be priceless.”

The exoskeleton weighs about 27 pounds, which is about half of the weight of other models which weigh approximately 45-50 pounds. The price is also rumoured to be lower than competitors although the product is not fully commercial yet and the pricing has not been finalised. The price tags of other models have been as high as $140,000. Goldfarb is hopeful that its minimalist design combined with Parker Hannifin’s manufacturing capability will effectively keep the cost down and make it more of an affordable product.

Joseph Hill writes on behalf of Pannone Personal Injury documenting research into disability and assistive technology.