Task analysis and kinematic design of a novel robotic chair for the management of top-shelf vertigo

The present work addresses the task analysis and the kinematic design of a novel robotic chair to be used for diagnosing and treating Benign Paroxysmal Positional Vertigo (BPPV). The task analysis process is based on: 1) Direct specifications given by well-trained doctors; 2) Theoretical considerations built upon a mathematical model describing BPPV dynamics. BPPV is the most frequent cause of vertigo and it is characterized by intense symptoms of dizziness and nausea of short duration which are induced by a postural variation of the patient. A common name for BPPV is "top-shelf vertigo", since dizziness often occurs when tilting back the head, such as when looking at objects on the top shelf. In the elder patients, it represents a frequent cause of equilibrium loss and consequent possible traumatic injuries. Sometimes BPPV symptoms disappear spontaneously but more often they tend to last for months or even years if not adequately treated. It was estimated that 20% of the patients that complain about dizziness are affected by BPPV (approximately 64 in 100,000 people per year in Northern America (Baloh et al., 1989; Froehling et al., 1991; Honrubia et al., 1996)).