Robot-assisted assessment of vibration perception and localization on the hand

Abstract

Sensory perception is crucial for motor learning and the control of fine manipulations. However, therapy after stroke still strongly focuses on the training of motor skills. Sensory assessments are often left out or provide only very subjective data from poorly controlled stimuli. This paper presents a vibration detection/localization test with the Robotic Sensory Trainer, a device that focuses entirely 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 semiobjective data on absolute and difference perception thresholds in patients. An initial feasibility study investigated localization performance and reaction time during the discrimination of vibration stimuli presented in four locations on the dominant and nondominant hands of 13 healthy volunteers. High correct detection rates were observed (mean ± SD of 99.6% ± 0.6%), touch screen PC Robotic Sensory Trainer which were found to be significantly different between stimulus locations on the dominant hand. Average correct detection rates were not statistically different between dominant and nondominant hand. These data will serve as baseline for future measurements on elderly and stroke subjects, and suggest that data from the nonimpaired hand could be used to identify and assess sensory deficits in the affected hand of stroke patients.

Implications for Rehabilitation

• Sensory deficits may limit functional recovery after stroke, are poorly documented and often neglected in current therapeutic programs.

• Clinical sensory assessments are not well standardized, lack sensitivity and suffer from high variability.

• We present a novel device for the semiobjective assessment of hand sensory function, capable of providing vibration, proprioception and pressure stimuli.

• Vibration perception and localization on the hand were tested on 13 healthy subjects to serve as baseline data for future measurements with stroke patients.

Keywords::

• Hand
• robot-assisted assessment
• sensory function
• vibration localization
• vibration perception

Acknowledgments

The authors thank Joachim Liepert and Marcus Kaiser for their valuable input for the definition of the clinical require ments of the Robotic Sensory Trainer, and Thomas Lindenerg for his help in data collection.

Declaration of Interest:This research was supported by the National Center of Competence in Research in Neural Plasticity and Repair of the Swiss National Science Foundation. The authors declare no conflicts of interest