Evaluation of the Hephaestus Smart Wheelchair System

Hephaestus, the Greek god of fire, craftsmen and smiths was the only Olympian with a disability. Hephaestus was injured when his father, Zeus, flung him off Mount Olympus for siding against Zeus in a dispute with Hephaestus' mother, Hera. To compensate for his disability Hephaestus built two robots, one silver and one gold, to transport him. The Hephaestus Smart Wheelchair System is envisioned as a series of components that clinicians and wheelchair manufacturers will be able to attach to standard power wheelchairs to convert them into “Smart Wheelchairs.” This paper describes a prototype of the system and presents the results from preliminary user trials involving both able-bodied and disabled subjects. BACKGROUND Independent mobility is critical to individuals of any age. While the needs of many individuals with disabilities can be satisfied with power wheelchairs, there exists a significant segment of the disabled community who find it difficult or impossible to operate a standard power wheelchair. This population includes, but is not limited to, individuals with low vision, visual field neglect, spasticity, tremors, or cognitive deficits. To accommodate this population, several researchers have used technologies originally developed for mobile robots to create “Smart Wheelchairs.” Smart wheelchairs typically consist of a standard power wheelchair base to which a computer and a collection of sensors have been added. Smart wheelchairs have been designed which provide navigation assistance to the user in a number of different ways, such as assuring collision-free travel, aiding the performance of specific tasks (e.g., Figure 1. Overview of Hephaestus Smart Wheelchair System