Torso Control System with A Sensory Safety Bar for a Standing Mobility Device

With a focus on lower-body mobility impairment, we have developed a device for standing mobility: Qolo, which allows a user with full lower-body paralysis to displace around in a standing posture. In this paper, we propose a torso control system for allowing a hands-free operation through what we hypothesize to be a natural motion of the upper body. We introduce a new interface of motion control of the intended users through an ergonomic bar at the user's waist level with an array of force sensitive resistor (FSR) on the surface. We present the interface and the user's intention detection algorithms and evaluate it with a set of five healthy participants to examine and compare the motion interface with a traditional bi-dimensional joystick. Results show that users are able to adapt and use the proposed interface at a cost of longer training and task completion time; pointing out a higher level of skill required in compensation for achieving hands-free control.