Stand alone wearable power assisting suit - sensing and control systems

A stand alone wearable power assisting suit was developed, which gives nurses the extra muscle they need to lift their patients and avoid back injuries. The suit consists of shoulders, arms, back, waist and legs units to be fitted on the nurse´s body. The arms, waist and legs have pneumatic rotary actuators driven directly by micro air pumps supplied by portable Ni-Cd batteries. The muscle forces are sensed by a new muscle hardness sensor utilizing a sensing tip mounted on a force sensing film device. The embedded microcomputer calculates the necessary joint torque for maintaining a position according to the equations derived from static body mechanics using the joint angles, and the necessary joint torque is combined with the output signals of the muscle sensors to make control signals. The suit was applied practically to a human body and movement experiments that weights in the arms were held and take up and down was performed. Each unit of the suit could transmit assisting torque directly to each joint verifying its practicability.