Angel-suit: a Modularized Lower-limb Wearable Robot for Assistance of People with Partially Impaired Walking Ability

The design of an assistive robot for people with partially impaired walking ability demands unique requirements, such as minimal mechanical impedance and high back-drivability, as well as high power density. Mechanical parts must be ergonomically designed, such that users can use the devices for a long period of time without discomfort. The motor control function of the incomplete paraplegics is not as robust as that of the normal, and thus the overall human body system becomes vulnerable to disturbances (i.e., external forces, inclinations, etc.) or model variations (i.e., loads, etc.). It is, however, still active, unlike complete paraplegic patients, and thus the robot must not generate any unexpected resistance to the voluntary motions of the incomplete paraplegics for the sake of minimal discomfort. This paper introduces a new wearable robot, called Angel-suit, particularly developed for assisting such people with partially impaired walking ability. The transparent assistance is achieved by series-elastic actuation mechanism. A case study of Angel-suit for a 11-years-old female patient with spina bifida is also briefly introduced in this paper.