Experimental Validation of a Rapid, Adaptive Robotic Assessment of the MCP Joint Angle Difference Threshold

  • Mike D. RinderknechtEmail author
  • Werner L. Popp
  • Olivier Lambercy
  • Roger Gassert
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8619)


This paper presents an experimental evaluation of a rapid, adaptive assessment of the difference threshold (DL) of passive metacarpophalangeal index finger joint flexion using a robotic device. Parameter Estimation by Sequential Testing (PEST) is compared to the method of constant stimuli (MOCS) using a two-alternative forced-choice paradigm. The pilot study with \(13\) healthy subjects provided DLs within similar ranges for MOCS and PEST, averaging at \(2.15^{\circ }\pm 0.77^{\circ }\) and \(1.73^{\circ }\pm 0.78^{\circ }\), respectively, in accordance with the literature. However, no significant correlation was found between the two methods (\(r(11) = 0.09\), \(p = 0.762\)). The average number of trials required for PEST to converge was \(58.7\pm 17.6\), and significantly lower compared to \(120\) trials for MOCS (\(p < 0.001\)), leading to an assessment time of under \(15\) min. These results suggest that rapid, adaptive methods, such as PEST, could be successfully implemented in novel robotic tools for clinical assessment of sensory deficits.


Robot-assisted assessment Sensory function Proprioception Difference threshold Psychophysics Hand function 



The authors would like to thank J.-C. Metzger for inspiring and profitable discussions, as well as J. Liepert, M. Kaiser and V. Raible for their help in defining the clinical requirements for stroke patients. This research was supported by the National Center of Competence in Research on Neural Plasticity and Repair of the Swiss National Science Foundation, the Janggen-Pöhn Foundation and ETH Zurich.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Mike D. Rinderknecht
    • 1
    Email author
  • Werner L. Popp
    • 1
  • Olivier Lambercy
    • 1
  • Roger Gassert
    • 1
  1. 1.Rehabilitation Engineering LabETH ZurichZurichSwitzerland

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