Photo: David Clugston
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THE DOCTOR IS IN: Developed at the University of Washington’s
BioRobotics Lab, a remote-controlled two-armed
surgical robot “operates” on a plastic and
rubber anatomical model of a human torso.
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On a hot morning this past June, our research group at
the University of Washington, in Seattle, crammed into
two cargo vans and drove 2000 kilometers south to the
rangeland north of Simi Valley, in southwestern
California. In the back of one of the vans was our
latest creation: a prototype surgical robot we’d been
developing for the past four years. Our mission was to
field-test the robot—by operating not on a person but
rather on latex objects mimicking human organs, with a
surgeon commanding the robot from a control console 100
meters away.
At the test site, we met the rest of our
team—surgeons, aerospace engineers, networking
experts—and set up a base camp on a flat expanse
circled by undulating hills. Under a blistering sun,
some of us assembled the robot, a portable surgery
table, and a video camera under a canopy tent, while
another group installed the surgical control console and
a video monitor in a second tent. With all systems
ready, we waited for the communications channel to be
set up to link the two locations.
Remote surgery technologies like the ones we were
testing have long interested military groups all over
the world. On the battlefield, medical response time
often determines who lives and who dies. A recent study
of combat casualties found that in nearly two-thirds of
fatal battlefield injuries, death comes within 30
minutes. There’s precious little time to perform even
simple life-saving procedures, such as controlling bleeding.
Surgical robots offer a tantalizing possibility [see
" "]. They would allow military
doctors, stationed safely distant from the front line,
to perform operations without once putting their hands
on patients. Medical vehicles equipped with such
remote-controlled robots could get surgical care to
soldiers in a lot less time than it would take to
evacuate them to the nearest base or hospital.
For that vision to become reality, however, surgical
robots need plenty of improvement. One challenge is
designing systems that can work under conditions very
different from those of pristine operating rooms.
Indeed, what was new about our trial in California was
the fact that the whole setup was compact, rugged, and
easy to transport. Local conditions for the experiment,
organized by Gerald Moses and Timothy Broderick of the
U.S. Army’s Telemedicine and Advanced Technology
Research Center, in Frederick, Md., included sandy gusts
of wind, high humidity, and an ambient temperature
crawling toward 40 °C. Gasoline-fueled generators were
all we had to power our electronics.
Our system is one of a new generation of surgical
robots that may one day bring advanced medical care not
only to soldiers but also to people in remote locations
lacking specialized physicians. Disaster relief, too,
could be revolutionized. Last year’s Hurricane Katrina
in the United States, the October 2005 earthquake in
northern Pakistan, and the December 2004 Indian Ocean
tsunami overwhelmed the medical resources available in
those places. The hope is that in the not-so-distant
future, fleets of ambulances or helicopters equipped
with surgical robots would rush to such areas, allowing
faraway doctors to save lives and limbs.
Indeed, some of the military projects seem to be quite
easily convertible to civilian use. Our group is
participating in another U.S. military–funded
initiative, the US $12 million Trauma Pod program,
launched last year by the Defense Advanced Research
Projects Agency (DARPA). Managed by SRI International,
in Menlo Park, Calif., the program aims to develop an
unmanned, mobile operating room that is equipped with a
host of automated surgical systems and could be quickly
dispatched anywhere in a war zone.
But giving surgical robots the necessary mobility
requires meeting another challenge: the reliable
transmission of the surgeon’s commands to a system often
roaming in far-flung places. Surgeons have remotely
commanded surgical robots before, even with real
patients under the robots’ scalpels. But those setups
took place in well-equipped hospitals and relied on
dedicated, wired communications channels. How, then, to
break free from wires?
Geosynchronous satellites have good data bandwidth,
but they don’t cover all regions of the world and their
delayed transmissions make surgery difficult. With our
experiment in California [see illustration, “Far-Flung
Fingers”], we wanted to test an alternative
that could be heaved into the air—literally—in a
matter of seconds: a wireless link enabled by an
unmanned aircraft. Launched from the ground, a small
drone was sent to fly in lazy circles above us. Video
from the camera near the robot was compressed by special
hardware into MPEG format and beamed to the plane, which
relayed the feed to the monitor below. At the same time,
motion commands from the surgeon’s console were bounced
through the plane to the robot, which responded only a
fraction of a second later, performing such tasks as
tying suture knots.
Photo: David Clugston
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Sewing IT up: The University of Washington’s surgical robot
ties suture knots, one of the most complex tasks
in minimally invasive surgery.
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Surgery has come a long
way from the prehistoric days when operations
were done with sharpened flints and bones or when the
barber-surgeons of the Middle Ages in Europe did
haircuts as well as surgery. Modern surgery has
benefited from many technological advances, notably the
relatively recent invention of minimally invasive
instrumentation. These tools include laparoscopic
devices, which are the size of chopsticks, with tiny
surgical tools at their tips. They enter the body
through small incisions—0.25 to 1 centimeter, compared
with several centimeters in conventional open
surgery—and surgeons maneuver them guided by images
from tiny camera probes.
Nevertheless, surgery today remains fundamentally the
same as it was centuries ago in its basic aspects: it
relies heavily on the experience of the surgeons and the
dexterity of their hands.
The idea of robot surgeons may conjure visions of
C-3PO–like androids clad in scrubs excising appendixes,
but existing systems and those being developed by our
group and others are actually more like robotized
laparoscopic instruments. They function as a surgeon’s
miniaturized and electromechanically enhanced hands,
maneuvering tools with greater dexterity, accuracy, and
stability than humans could ever achieve. The tools,
positioned by high-precision motors, can reach spaces,
such as those around the prostate gland or in the tiny
bodies of infants, that surgeons often can’t reach using
their hands.
Indeed, robotically assisted surgery is already a bona
fide, if small, category of robotics. In its “World
Robotics 2005” report, the International Federation of
Robotics estimated the number of robots used in surgery
and therapy—including electromechanical arms to
position instruments, robotic bone drills, and
computer-controlled radiotherapy equipment—at 2800
units worldwide. These units include the da Vinci
surgical system, by Intuitive Surgical, of Sunnyvale,
Calif., currently the only commercially available
surgical robot approved by the U.S. Food and Drug
Administration. It has two or three arms equipped with
surgical tools and an extra arm with a stereoscopic
video camera probe. A surgeon controls the machine from
a console located in the same room as the patient.
Currently, some 400 da Vinci units are installed
worldwide, a new unit costing about $1.5 million.
For at least one procedure, the da Vinci system is
beginning to show advantages over conventional surgical
techniques: the laparoscopic radical prostatectomy, in
which the prostate gland is removed through tiny
incisions in the lower abdomen. Surgeons have reported
that patients undergoing the robotic procedure had less
blood loss, fewer complications, and shorter hospital
stays. Some experts say that cardiac and gynecological
procedures could be next, but further studies have yet
to show the benefits of robotic surgery—considering its
higher costs—over conventional techniques.
And despite its achievements, the da Vinci system
wasn’t engineered to stand up to the extremes of work in
the field. It weighs nearly half a ton, and controlling
it remotely requires substantial electronic
modifications. Moreover, the system is designed
specifically for minimally invasive surgery, precluding
significant use for trauma procedures.