Basic functionality of a prototype wearable assistive soft exoskeleton for people with gait impairments: a case study

XoSoft is a soft modular wearable assistive exoskeleton for people with mild to moderate gait impairments. It is currently being developed by a European Consortium (www.xosoft.eu) and aims to provide tailored and active lower limb support during ambulation. During development, user-centered design principles were followed in parallel with the aim of providing functional support during gait. A prototype was developed and was tested for practicability, usability, comfort and assistive function (summarized as basic functionality) with a potential end user. The prototype consisted of a garment, electromagnetic clutch-controlled elastic bands supporting knee- and hip flexion and a backpack containing the sensor and actuator control of the system. The participant had experienced a stroke and presented with unilateral impairment of the lower and upper extremities. In testing, he donned and doffed the prototype independently as far as possible, and performed walking trials with the system in both active (powered on) and passive (powered off) modes. Afterwards, the participant rated the perceived pressure and various elements of usability. Results highlighted aspects of the system for improvement during future phases of XoSoft development, and also identified useful aspects of prototype design to be maintained. The basic functionality of XoSoft could be assumed as satisfactory given that it was the first version of a working prototype. The study highlights the benefits of this participatory evaluation design approach in assistive soft robotics development.