Nurses get bionic "power suit"
By Peter Hadfield and Paul Marks A robotic exoskeleton has been created by Japanese researchers to allow nurses to 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. 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,