The 22-year-old paraplegic, who captured headlines recently when he walked across the stage at his commencement wearing bionic legs, now spends long days with the engineers who developed the customized robotic suit. He passionately believes in the device and its potential to alter the lives of those with spinal cord injuries, and he wants to do whatever he can to help perfect the prototype--for himself and others like him.
"We want to make the Model T version of an exoskeleton," Whitney said. "There are health benefits to mobility. It's good for the circulatory and muscular systems, and there's a social and mental benefit. Four years ago, I thought I was going to die on a hospital bed."
That was 2007, when Whitney was 18 years old and got into a car accident that left him paralyzed from the waist down.
"The spinal cord injury meant I would likely never walk again," he said. But he did, taking his first public steps in four years at a graduation ceremony at Edwards Track Stadium on May 7.
During the nine months prior, however, he had experimented with walking in a custom-fit robotic device developed on campus in the lab of mechanical engineering professor Professor Homayoon Kazerooni, who is also founder of Berkeley Bionics. That company makes the eLegs robotic exoskeleton, which is currently undergoing trials and is expected to become available to rehabilitation centers by the end of the year, with a personal version for sale for an as-yet-undisclosed price in 2013.
A friend who plays wheelchair basketball with Whitney told him about Kazerooni, one of a number of innovators around the world devoted to developing robotic exoskeletons for wheelchair users. After speaking with him on the phone, Whitney decided to visit the Berkeley Robotics and Human Engineering Laboratory. "It is like something out of a movie set--exoskeletons hanging from the walls everywhere," he said.
It's inside that lab where Whitney does most of his walking these days, though he does on occasion roam the campus in his bionic suit. He has degrees in history and political science, and plans to attend law school in the fall of 2012. But for now, he spends about six hours a day, from noon to 6 p.m., working (for pay) in the lab.
A typical day involves two tests of Whitney in the suit, followed by discussions aimed at helping the engineers improve everything from the comfort of the straps to the machine's ease of control. "We're usually testing different components on the robot that we changed or added to see how they perform; or testing a new walking gait, crutch, or walker strategy; or just training Austin in general," said Jason Reid, one of the UC Berkeley mechanical engineering graduate students who's working with Kazerooni to develop exoskeletons. "It's good for him to use the machine regularly to load his bones and stand upright."
A carefully curated playlist of rock tunes accompanies the daily work. Whitney is attached to a tether cable--that way, if he trips or falls, he doesn't land on his face. If Whitney feels any discomfort at all, the mission is aborted. Safety comes first.
The 40-pound exoskeleton Whitney walked in at graduation is called "Austin" in honor of its first test pilot. Like other robotic exoskeletons aimed at getting paraplegics standing and walking--including Rex Bionics' Robotic Exoskeleton (Rex) out of New Zealand and the ReWalk by Israel's Argo Medical Technologies--it has motorized joints controlled by actuators; electronic sensors; and a portable power source. And it requires that the wearer have enough upper body strength to strap in.
Whitney can lift himself from his wheelchair into the exoskeleton and lock in his knees and hips. The two motors on the back of the machine are similar to those that drive a Tesla electric car. The motors literally propel him forward, by driving the hip joint, so the energy naturally transfers from machine to Whitney.
When he started in the lab nine months ago, the exoskeleton was just bits of hardware, and sometimes those bits would break loose. "It's frustrating when we break a piece," Whitney said. "It takes a few weeks to machine a new part."
It's not likely Whitney or others will be using an exoskeleton to ski or climb mountains anytime soon. But exoskeletons can help users improve their respiratory and circulatory systems and avert some of the health problems related to immobility, not to mention give them the gift of step again.
So far, the exoskeleton has taken Whitney the equivalent of a city block, as longer distances tire him out. But over time, he hopes to be able to build up his stamina and keep up with the exoskeleton's lithium ion battery, which can run for up to eight hours before it needs to be recharged. (The small backpack that contains the battery also contains a computer that sends movement instructions to the motors and gears.)
Strapped in the exoskeleton, Whitney can't feel his legs. But he can feel the pull of his bionic legs, which are becoming a natural extension of his body. There's a sensation that hits his hip, as the exoskeleton rocks his legs forward and the sensors from a computer control each stride in real time. When he's strapped in the device, it kicks his legs forward, then it clears the ground, pushes down, and moves them back.
The last time Whitney could walk was July 21, 2007, the day he crashed his car into a tree in his hometown of San Juan Capistrano in Southern California. He broke his spinal cord, pelvis, and ribs--and suffered major internal bleeding. He spent 41 days in the hospital, followed by a long rehabilitation.
Since then, Whitney has been recertified to Scuba dive and is working on his Scuba diving instructor certification, but despite being athletic, his first steps in Austin didn't occur overnight. The first three months of training involved standing for hours each day in a frame at home. Standing helped increase Whitney's bone density so he could set foot in his custom-made exoskeleton.
Whitney sees others like him using such a device regularly only if the price of the machines drop (New Zealand Paralympian Dave MacCalman recently spent $150,000 to become the first person to buy a commercially available pair of Rex legs).
If Whitney had a wish list for the next-generation exoskeleton he'd make it a master stair climber and would want to know the system is stable enough that he wouldn't have to worry about falling flat on his face if there were a computer glitch.
"I cannot begin to tell you how much it means to me to be able to walk at my graduation or be able to hug my mom, after years of not being able to," he said, echoing similar sentiments of others who have tried such devices.
Photos: Sarah Peet