Contribution of artificial proprioception on a dynamic finger flexion task

Abstract

There has been a considerable effort to provide sensory feedback for myoelectric prostheses. Among thesolutions provided in the literature, sensory substitution is an easy and cost-effective way to provide feedback throughdifferent sensory modalities at different locations on the body. In this study, we evaluate the effect of sensory substitutionof force and position feedback on a two-degree-of-freedom dynamic finger flexion task. For this purpose, a newmethodology and an experimental setup are developed. The experimental methodology is based on the “strengthdexterity test”, working on the principle of buckling of compression springs. The experimental setup comprises a hapticinterface, an input device, a force sensor, two vibration feedback tactors, and a virtual environment. A psychophysicaltest is conducted where subjects interact with a virtual spring with the index finger of their dominant hand through thehaptic interface, the input device, or the force sensor in either isotonic or isometric mode. Three feedback conditions aretested: no sensory substitution, modality-matched sensory substitution, and modality-mismatched sensory substitution(through vibration). Sensory substitution feedback is provided on the subject’s contralateral arm. Results show thatsensory substitution of force and position does not have a significant contribution to subjects’ performance in the proposeddynamic task.