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鈥檚 designed to help
nurses lift patients effortlessly鈥攁nd without damaging their backs.
鈥淏ack injuries are a huge problem for us,鈥� says a spokeswoman for the Royal
College of Nursing in London. Every year, 3600 nurses from Britain鈥檚 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 鈥減ower
suit鈥� with a jointed metal framework that straps on to the wearer鈥檚 limbs. While
the prototype is distinctly unlovely鈥攊t trails an unwieldy thicket of
cables and compressed-air lines鈥擸amamoto says he鈥檚 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鈥攇iving 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鈥檚 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. 鈥淎nd
since the mechanics of the suit are hidden behind the wearer, the nurse can be
in direct contact with the patient,鈥� says Yamamoto. 鈥淭hat鈥檚 very reassuring for
the patient.鈥�
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 拢15,000, Yamamoto says health authorities will be
able to buy a commercial version of the suit for around 拢1200 within two
years.