Correction to “Experimental Validation of a Hybrid Computational Model for Selective Stimulation Using Transverse Intrafascicular Multichannel Electrodes” [May 12 395-404]

Abstract

Abstract-Recently a hybrid model based on the finite element method and on a compartmental biophysical representation of peripheral nerve fibers and intraneural electrodes was developed founded on experimental physiological and histological data. The model appeared to be robust when dealing with uncertainties in parameter selection. However, an experimental validation of the findings provided by the model is required to fully characterize the potential of this approach. The recruitment properties of selective nerve stimulation using transverse intrafascicular multichannel electrodes (TIME) were investigated in this work in experiments with rats and were compared to model predictions. Animal experiments were performed using the same stimulation protocol as in the computer simulations in order to rigorously validate the model predictions and understand its limitations. Two different selectivity indexes were used, and new indexes for measuring electrode performance are proposed. The model predictions are in decent agreement with experimental results both in terms of recruitment curves and selectivity values. Results show that these models can be used for extensive studies targeting electrode shape design, active sites shape, and multipolar stimulation paradigms. From a neurophysiological point of view, the topographic organization of the rat sciatic nerve, on which the model was based, has been confirmed.Index Terms-Electrical neural stimulation, finite element method, intrafascicular time electrodes, model validation, rat axon model, rat sciatic nerve, selectivity.

A Computational Model for Epidural Electrical Stimulation of Spinal Sensorimotor Circuits

“…We thus translated microscopic events, i.e., firing along any axon of the model, into a macroscopic quantity that can be measured experimentally, i.e., amplitude of EMG activity. We previously exploited this reductionism to validate a hybrid computational model of sciatic nerve stimulation (Raspopovic et al, 2012). Here, we expanded this method to a realistic number of motoneurons, interneurons, and fibers in the spinal cord; and to multiple motor responses conveyed through distinct neural pathways.…”