CYBATHLON
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Muhn from Team Cleveland.
Muhn’s electrodes had been surgi-
cally inserted inside his body. Developed
by Ron Triolo, Ph.D., lead engineer for
Team Cleveland, the multichannel
implantable pulse generator (IPG)
could potentially improve performance
in the bike race by 25 percent, a greater
advantage than Daniel received from
the ankle actuators in his exoskeleton.
Muhn smoked his competitors in the
race, winning by a half-lap over the sil-
ver medalist. “That impressed me, but
what really fascinated me was his mus-
cle mass,” Daniel says. “His implants
had stimulated his muscle fibers to
grow. Increased muscle mass can
improve your metabolism, blood lipid
profile, bone density—practically every
physical function. Mark Muhn actually
had an ass to sit on. I hadn’t had an ass
for nine years.”
IN 2016, DANIEL lined up for the finals
next to Andre van Rüshen, a burly mid-
dle-aged German wearing a suit from
ReWalk, a manufacturer of commer-
cially available exoskeletons. The
spectators packing the stands at the
SWISS Arena stomped their feet and
clanged cowbells. The couch challenge
was first, and Daniel stood up and sat
down deliberately and carefully. Head-
ing for the straight ramp, he and van
Rüshen were dead even. Daniel swung
up the ramp and poked a door open with
his cane.
Daniel pivoted to close the door, turn-
ing the entire rig 90 degrees, and as he
did so he tipped back for an instant. Two
spotters leaped forward to catch him,
but Daniel righted himself, regaining
his balance. He poked the door closed,
swiveled again, and swung down the
ramp to engage with the next challenge:
walking a stepping-stone course with-
out missing any of the stones. That was
where the gamesmanship began.
The rules permit you to omit one
challenge, and the German chose to
bypass the stepping stones. It’s worth
fewer points than the next challenge,
the tilted ramp, which Daniel and IHMC
team had decided to skip. In the lab,
their exo had performed awkwardly on
the tilt. “I was able to complete it,” Dan-
iel says, “but as a team, they decided that
it wasn’t worth the risk.”
Daniel nailed the stepping stones
and walked around the tilted ramp. He
and van Rüshen were even again as they
headed to the final challenge, the stairs.
The crowd noise pumped up a notch.
Daniel poled up the stairs facing
for ward. Reaching the platform, he
suddenly realized his right cane wasn’t
tethered to the exoskeleton. “I felt that
cane starting to slip, and if that hap-
pened, we were toast. You can’t walk
an inch in the exo without your canes,”
Daniel says. Everything went clear. He
reached out and grabbed the cable that
linked it to the suit and snatched the
cane back into his hand.
For better control, Daniel descended
the stairs backwards. Then one more
turn, and he and van Rüshen crossed
the finish line in a dead heat. Because
of the skipped ramp, the German won
on points, 552 to 545.SHORTLY AFTER HE returned from
Cybathlon 2016, Mark Daniel embarked
on another adventure: a wheelchair trek
across the United States. Daniel jour-
neyed solo, on a standard, manually
powered wheelchair largely unmodi-
fied for long-haul travel. “Far as I could
tell, no one had ever done that before,”
he says. “Turned out, I couldn’t do it
either.” He made it 352 miles, but devel-
oped pressure sores on his lower back
that required bed rest to heal. He’s
planning a second shot in early 2021,
after the next Cybathlon and the Toyota
Mobility Unlimited Challenge finals,
which he and the team qualified for
in 2019, and which came with a half-
million-dollar prize and a trip to Tokyo.
Daniel’s trust in the wheelchair is
absolute. “After 12 years, there isn’t
anything I can’t make it do,” he says.
The exo simply isn’t as reliable yet.
“It better be foolproof,” he says. “And
that’s the case for the great majority of
people with lower-limb paralysis. Until
that turns around—and I’m convinced it
will—the exo’s going to be a tough sell for
disabled people. I love piloting it, but it’s
not my way out. I’m doing this for some
18-year-old disabled kid in the future.
Years from now, that kid’s going to standup and walk in an exoskeleton with all
its bugs ironed out. That exo’s going to
be affordable, and as easy and natural to
use as a wheelchair is today.”
He takes a similarly measured view
of IPG technology. With the Team Cleve-
land research group financing the
procedure in exchange for Daniel volun-
teering as a test subject, he underwent
the difficult surgery in December 2018
at the VA hospital in Cleveland.
“It took 12 hours,” Daniel says. “First
I got this—” He lifts his shirt to show
the outline of a cigarette pack–sized
box bulging the f lesh of his abdomen.
“—then they wired it up to electrodes in
16 places around my body.” Daniel lifts
his pant leg to show one of the two-inch
scars from the 16 incisions.
IPG surgery carries a high risk of
infection, and the electrodes often wear
out. Mark Muhn has endured three sep-
arate surgeries over the last seven years,
ranging in duration from 5 to 12 hours.
“Is it worth it? Absolutely,” Muhn
says. “Everything is working better—
increased muscle mass, circulation,
metabolism, strength and endurance,
bone density. With the functional elec-
trical stimulation hookup on my bike,
I can ride outside in a park instead of
being stuck inside a gym.”
Daniel reports similar results. “Last
week, when I got out of the shower, I
could see definition in my calf muscle,”
he says. “And I’m steadily building an
ass to sit on.”
He acknowledges IPG’s limitations.
Daniel can only grow muscle mass
when exercising on the recumbent bike
connected to the device activating the
implants. Otherwise “all those wires are
dead weight inside me,” he says. And,
although researchers in Cleveland are
working on one, there is not yet an inter-
face between Team Cleveland’s IPG and
IHMC’s exoskeleton.
That means, unlike Muhn, Dan-
iel won’t directly benefit from his
implants when he steps to the start-
ing line for his race at Cybathlon 2020.
But to stand, to walk, and to know that
future generations will likely regard
today’s exoskeleton the way we look at
the Wright Brothers’ airplane—all of
that will be reward enough.84 May/June 2020