WHAT do you get when you cross the robotic exoskeleton from the movie Aliens
with a bunch of concertinas? A bionic nurse, of course. It’s designed to help
nurses lift patients effortlessly—and without damaging their backs.
“Back injuries are a huge problem for us,” says a spokeswoman for the Royal
College of Nursing in London. Every year, 3600 nurses from Britain’s National
Health Service have to take time off work because of back problems.
To address this global problem, Keijiro Yamamoto and his team at the Kanagawa
Institute of Technology in Japan have designed and built a prototype “power
suit” with a jointed metal framework that straps on to the wearer’s limbs. While
the prototype is distinctly unlovely—it trails an unwieldy thicket of
cables and compressed-air lines—Yamamoto says he’s begun refining his
design.
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So how does it work? Sensor pads taped to the major muscle groups calculate
how much force you need to pick up a patient. As you lift, the sensors send data
to a microcomputer that triggers the business end of the system: a bunch of
concertina-like limb and body actuators powered by compressed air. These move
slowly and create low mechanical stress—giving someone as much or as
little help as they need, says Yamamoto.
The suit has five actuators: one for each elbow, one for the waist (not shown
in Graphic for clarity) and one for each knee. The elbow actuators push on the
frame that lets your forearms lift the patient, while the waist actuator helps
straighten your back and the knee actuators help you straighten your legs. The
computer simply works out when the nurse’s limbs and joints have enough
artificial support, allowing them to continue working, but effortlessly.
The main role of the Power Assist Suit will be helping nurses and
physiotherapists lift patients on and off beds. In tests, a nurse weighing 64
kilograms was able to pick up and carry a patient weighing 70 kilograms. “And
since the mechanics of the suit are hidden behind the wearer, the nurse can be
in direct contact with the patient,” says Yamamoto. “That’s very reassuring for
the patient.”
The prototype suit weighs 18 kilograms, but Yamamoto believes he will be able
to cut the weight in half for a commercial version. Although developing the
prototype cost around £15,000, Yamamoto says health authorities will be
able to buy a commercial version of the suit for around £1200 within two
years.