FEATURES:                                                            26 Aug
00
 #36  Access all areas: High kerbs, steep slopes and stairs are well-nigh
          impossible for your average wheelchair to cope with, but now
there's
          a chair that will even catch you when you fall, says Bennett
Daviss.

I'm on Easy Street. However, from where I'm sitting, it looks anything but.
Easy Street is a lab in a renovated mill in Manchester, New Hampshire. Only
you won't find lasers and test tubes in this open-plan, single-storey room,
only a very unusual assault course. There are stairs everywhere, lots of
ramps, kerbs and even a long thin sandpit.
This strange lab houses Project Fred-a secret endeavour started six years
ago by Deka, an engineering and development company. More than 60 of Deka's
staff now work full-time on Fred. The project has attracted a commercial
partner in Johnson & Johnson and consumed more than Dollars 100 million in
capital. And I'm sitting in the result-the world's most sophisticated
wheelchair.
Deka refers to its invention-the Independence 3000 IBOT-not as a chair, but
as an all-terrain transporter. At first glance the IBOT looks similar to a
typical electric wheelchair. The main difference is that instead of two very
large rear wheels, it has four small powered wheels, two on each side, plus
two small castor wheels, one below each of the passenger's feet. But this
isn't simply a piece of rolling furniture: it's a sophisticated vehicle with
on-board intelligence and powerful four-wheel drive that would be the envy
of Detroit. It even has an innate sense of balance. Most importantly for
disabled people, the IBOT is going to equal the stakes. They'll be able to
travel faster, negotiate irregular surfaces with ease, and if they want to
reach the top shelf, they can. The IBOT allows its passenger to feel six
feet tall, literally.
It's time for project manager Lucas Merrow to demonstrate the IBOT's powers.
He hops into the seat and enters a few quick keystrokes on the control pad
built into the armrest. This is to program the IBOT to respond for his body
weight and height. Motors and gears hum into action, driving the transporter
gently over a kerb.
But Merrow doesn't tilt dangerously backward as he would in a standard
wheelchair. The passenger seat tilts, keeping him perfectly level. Next, the
IBOT breezes up an 18-degree ramp from street level to an elevated platform.
'Way steeper than allowed by US law,' he says.
Using a joystick alongside the keypad, Merrow turns the transporter in a
circle over the rough cobblestones on the platform. It spins around on the
spot. In a normal wheelchair 'a disabled person would need a lot of upper
body strength to do that', says Merrow. Then he pushes the joystick forward
and plunges into the sand trough. Amazingly, he and the IBOT sail through
the 20-centimetre deep sand like a sailboat on water. 'We had a disabled man
in his regular chair try to do that,' says Merrow. 'He had tremendous
muscular development in his upper body and he couldn't get much farther than
a metre.' Next, Merrow backs up to the bottom of a staircase and taps a few
keys. This is where the IBOT really starts to show its skills. As Merrow
grabs the stair's handrail beside him, the front-drive wheels rise up and
revolve over the ones behind. As these wheels meet and settle on the tread
of the first step, the rear pair repeat the action, pulling the chair
upwards and backwards. With Merrow gripping the handrail for control, the
wheels revolve backwards over each other in a kind of mechanical hand-over
hand-lifting chair and passenger up the stairs. To come back down, Merrow
simply reverses the action and the IBOT rolls back down: the rear-drive
wheels rise up, over and down past the front-drive wheels to settle on the
step below and so on.
But Merrow has saved the most dramatic feat for last. Back on level ground,
he suddenly rears up and throws himself backwards in the chair with as much
force as he can muster. The chair begins to tip backwards and I lunge to
grab him.
Before I can reach him, the IBOT rises to the occasion. A motor under the
seat lifts the transporter's two front-drive wheels off the ground-just as
they did when Merrow started to climb the stairs. But the motor stops when
the wheels are directly above the other pair. So now, instead of the drive
wheels being side by side, one pair is atop the other (see Diagram, p 30).
Within seconds, I'm looking Merrow in the eye. Now that the transporter is
raised up on two wheels, he is sitting at standing height. The IBOT is
balancing on two wheels the way that most people balance on two feet.
'It doesn't take that much force to raise the IBOT to two wheels,' says
Merrow. 'You can do it with a shrug, a push off a solid object, or by
tapping the keypad. If you're on a smooth, level surface, you can ride
around on two wheels as easily as if you were down on all four.'
As Merrow stirs and shifts in the seat, the two wheels on the floor move
constantly, inching back and forth to keep him upright-the mechanical
equivalent of a person unconsciously shifting body weight from foot to foot
while standing still. Suddenly Merrow throws himself backward again, but the
transporter races back to stay under him. He starts to fall forward out of
the chair and it scoots forwards to catch him.
He taps a few keys to settle the IBOT back down on four wheels. 'You try
it,' he says. It takes me a few tries-abandoning your physical safety to the
intelligence of an inanimate object takes some doing. Once I'm balanced
aloft in the IBOT, Merrow holds up his hands, palms toward me. 'Push,' he
commands.
We lock fingers. I push. The machine beneath me doesn't roll back-it stands
its ground. 'Harder,' Merrow urges. I push harder, as hard as I can, and
after a few moments Merrow staggers backward under the force. 'Under any but
the most extreme force, the IBOT won't let you fall,' he says. The secret
lies not only in the durability of its motors and gears, but also in the
host of sensors, solid-state gyroscopes and three Pentium-class processors
mounted beneath the seat. The sensors 'feel' things, for example when the
wheels have run up against the riser of the next stair. The gyroscopes
determine balance and the pro-cessors make the million tiny decisions that
allow the IBOT to get around.
If you look at the chair and its rider from the side, you can imagine a
pyramid: the apex is the driver's head and the front and rear of the chair's
base form two of the bottom edges of the pyramid. The job of the processors
and the gyroscopes is to make sure that the pyramid's centre line remains
parallel to the force of gravity-even when the chair's chassis tips.
It was back in 1991 that Dean Kamen, Deka's founder, first thought of this
remarkable wheelchair. While at a shopping mall, he watched a strapping
young man in a wheelchair try repeatedly to heft himself up and over a kerb.
If we can put a man on the Moon, thought Kamen, why can't we get a man in a
wheelchair over a kerb? Kamen wasn't one to let the problem go. At college,
he'd patented the first automatic portable infusion pump for dispensing
drugs. At 25, he founded a medical device firm, AutoSyringe.
Kamen began prototyping a vast array of ideas to solve the wheelchair
problem. 'Walking machines, robotic legs, things you'd strap onto yourself,
things that were unstable and unreliable,' Merrow says. 'That went on for
three or four years.'
The turning point came when Kamen had a near-accident of his own. Getting
out of the shower, he slipped on the wet floor and windmilled his arms to
catch his balance. 'It dawned on him that in order to have a machine that
could do what he'd just done, which was to lose his balance and then
recover,' says Merrow, 'you had to have a machine with a sense of balance in
the first place.'
So Kamen went back to his lab and built a platform with two legs, with the
whole thing mounted on wheels. It had a bunch of circuit boards with wires
hanging off, some bicycle chains and a pair of motors from an old sewing
machine, Merrow says. 'It was rickety. It shook and shuddered. But it
worked.' At that point, Kamen assigned a few of his engineers to take things
farther. Someone on the development team realised that they couldn't climb
kerbs and stairs using one drive wheel on each side of the chair. So they
put two on each side, added a pair of smaller wheels and slid a desktop PC
under the seat. 'That's the machine we took to Johnson & Johnson in 1995,'
Merrow says.
Kamen knew that Deka needed a manufacturing and marketing partner. But they
didn't know who. 'We thought, 'this is a vehicle', so we talked to the car
companies,' Merrow recalls. 'But the IBOT has orders of magnitude more
software, processing power and back-up systems than a car has. To a car
company, the IBOT looks more like a computer. But to a computer company, it
looks more like a vehicle.' They also talked to defence contractors, who
were accustomed to making complex combinations of hardware and software.
'But they were never comfortable about how their expertise (would) fit the
project,' he says. As part of the search, Kamen contacted Robert Gussin,
then Johnson & Johnson's chief technology officer. Gussin saw the
transporter's prototype and became a convert. However, his bosses were a
tougher nut to crack. 'Johnson & Johnson had once owned what is now the
world's largest wheelchair company,' Merrow says. 'They decided that they
didn't like that business and they sold it. But Gussin kept pressing them,
telling them that this is nothing like a regular wheelchair, it's the kind
of thing that can turn an industry on its head, and the kind of thing that
the company should be doing.'
Asking difficult questions
Eventually, Gussin's persistence paid off. Johnson & Johnson licensed the
IBOT's design and technology from Deka and set up a small company called
Independence Technology to make and sell it. For the next year, an IBOT
project team travelled the US convening more than 30 focus groups of up to
20 wheelchair users each. 'We asked them what they like about the chair they
use now, what they wish was different,' Merrow says. 'If you could have
anything you wanted, what would it be? Which wish would come second? What
kind of trade-offs would you be willing to make?'
Through the discussions and more than a thousand questionnaires, the team
discovered an untapped market: more than two million wheelchair users in the
US alone. 'They aren't in nursing homes or hospitals, they have more and
more discretionary income to spend, and no one is treating them like
customers,' Merrow says. 'Chair makers deal primarily with insurance
carriers, not directly with users, so they're trying to keep insurance
companies happy by keeping prices down. No one has ever bothered to ask
disabled people what they want in a wheelchair.'
The hardest work came next: not just creating the hardware and software to
carry out the tasks the users were calling for, but integrating those parts
into a practical system. 'We didn't have to invent hardware, but we had to
work with vendors to get them to understand our requirements,' Merrow
explains. 'For example, the company that makes transmissions for the IBOT
also makes transmissions for high-performance cars. Our transmissions needed
some similar characteristics but also some very different ones, such as the
ability to spin gears backwards as well as forwards.'
Two of the three main limitations were power and space. The transporter had
to fit through the narrowest doorways and hold a human frame, yet carry
enough batteries, gears and motors to tote a person weighing as much as 115
kilograms-the IBOT's weight limit-over kerbs and up ramps and stairs. Months
went into reshaping and streamlining components, cajoling suppliers to shave
a centimetre here or a few grams there, fitting the entire thing into a
space roughly half a metre square and a third of a metre high.
The third, but most important requirement is safety. 'We have three
processors so they can vote,' Merrow says. If you're going over a kerb, what
command do you send to the motor? How much torque do you apply? 'If there's
one (processor) and it's wrong, you're in trouble. If there are two and they
disagree, the device comes to a stop.' It's the same problem when the chair
is balanced on two wheels. 'If one processor fails, you fall over. If you
have two and they disagree, the machine freezes-and you still fall over. You
need three to validate decisions.'
The IBOT has two nickel-cadmium batteries, each of which can supply enough
power to keep the device moving on its own. Together they will power the
transporter for about 25 kilometres non-stop on a smooth, level surface.
'They were designed to provide a typical user with enough power to get
through an average day,' Merrow says.
There are also three motors. One spins the single axle attached to the two
pairs of drive wheels, enabling the IBOT to climb stairs and balance
upright. The other two motors drive the wheels directly, one motor per pair.
If a motor overheats, the chair automatically slows to a crawl and a yellow
warning light appears on the armrest's control panel. If overheating
continues, the chair simply stops. 'It's virtually impossible to burn out a
motor on this device,' Merrow says.
This summer Deka opened a durability testing area the size of a gymnasium.
Two shifts of eight volunteers will each spend eight hours a day using the
chairs non-stop-up and down stairs and ramps, in and out of vans, through
puddles and sand pits, over rough surfaces, indoors and out. Meanwhile,
IBOTs are being put through a gamut of other tests to check they can
withstand the stresses of everyday life.
Deka and Johnson & Johnson have been feeding their test data to the US Food
and Drug Administration. 'They've been great,' Merrow says, 'they've put us
on a fast track for approval.' The IBOT is expected to be certified for
commercial sale as a medical device some time next year. The price tag:
Dollars 25 000.
But will it sell at that price, especially in enough volume to recoup the
Dollars 100 million that the two companies have sunk into the venture? 'We
can't know for sure,' Merrow admits. 'But this isn't entirely about
business. This is something we couldn't not do. No one listens to people
with disabilities, but they want to be treated like anyone else-like
customers. We're going to give it a shot.'
Bennett Daviss is a freelance writer basedin New Hampshire For more
information, see www.indetech.com
New Scientist
Page_28; Photograph (omitted); Illustration (omitted)
Copyright (C) Reed Business Information Limited


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