Article
Electrical Stimulation of the optic nerve for neuroprosthetic applications
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Published: | December 10, 2019 |
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Objective: To evaluate the ability of a 12-channels intra-neural electrode (OpticSELINE) to selectively stimulate different portions of the optic nerve, and to develop a computational model that would allow predicting in silico the selectivity of the stimulation.
Materials and methods: The OpticSELINE was implanted in the optic nerve of anesthetized rabbits, while the electrical activity of the contra-lateral visual cortex was recorded. We tested stimulating current pulses with varying amplitudes and number of repetitions. We used independent component analysis (ICA), and support machine vector (SVM)-based classification to evaluate the selectivity of the stimulation. The model of the optic nerve was built using the finite element method / Neuron software hybrid approach.
Results: It was possible to modulate the magnitude of the cortical response by changing the amplitude or the number of the stimulating current pulses. Based on the model, we estimate what portion of the optic nerve was activated by these different stimulation configurations. We showed that components of the original cortical signal could be associated with one or a small-subset of neighboring stimulating channels, suggesting that our device can selectively stimulate different portion of the optic nerve, which is further supported by the accuracy of our classifier (60-70%).
Discussion: We established two different methods to modulate the magnitude of the cortical response. These results, coupled with the results of the ICA, SVM classification, and simulations, make electrical stimulation of the optic nerve a relevant approach for vision restoration in blind patients.
Acknowledgment: This work has been supported by École polytechnique fédérale de Lausanne, Medtronic, Bertarelli Foundation, and Wyss Center for Bio and Neuroengineering. Dr. Artoni is supported by the European Union's Horizon 2020 research and innovation programme under Marie Skłodowska Curie Action agreement No. 750947 (BIREHAB).