Assessment of vibration perception with the robotic sensory trainer

Despite the fact that sensory perception is crucial for motor learning and fine manipulation of small objects, therapy after stroke still focuses strongly on motor skills. Sensory assessments are often left out or provide only very subjective data from poorly controlled stimuli. This paper presents a robotic device that focuses purely on the assessment and training of sensory function of the hand, with the aim of gaining insights into the prevalence and severity of sensory deficits after stroke, and to provide semi-objective data on absolute and difference perception thresholds in patients. The device is capable of presenting three kinds of physical stimuli, and collects feedback from the user through an intuitive touch panel with augmented reality feedback. An initial study investigating localization performance and reaction time during the discrimination of vibration stimuli was performed, showing the feasibility of using the device for such investigations and revealing no significant difference between the four different locations as well as between the dominant and non-dominant hand. These data will serve as baseline, and suggest that data from the non-impaired hand can be used to identify sensory deficits in stroke patients.