First demonstration of velocity selective recording from the pig vagus using a nerve cuff shows respiration afferents

Abstract

Neural interfaces have great potential to treat disease and disability by modulating the electrical signals within the nervous system. However, whilst neural stimulation is a well-established technique, current neural interfaces are limited by poor recording ability. Low signal amplitudes necessitate the use of highly invasive techniques that divide or penetrate the nerve, and as such are unsuitable for chronic implantation. In this paper, we present the first application of the velocity selective recording technique to the detection of respiration activity in the vagus nerve, which is involved with treatments for epilepsy, depression, and rheumatoid arthritis. Further, we show this using a chronically implantable interface that does not divide the nerve. We also validate our recording setup using electrical stimulation and we present an analysis of the recorded signal amplitudes. The recording interface was formed from a cuff containing ten electrodes implanted around the intact right vagus nerve of a Danish Landrace pig. Nine differential amplifiers were connected to adjacent electrodes, and the resulting signals were processed to discriminate neural activity based on conduction velocity. Despite the average single channel signal-to-noise ratio of-5.8 dB, it was possible to observe distinct action potentials travelling in both directions along the nerve. Further, contrary to expectation given the low signal-to-noise ratio, we have shown that it was possible to identify afferent neural activity that encoded respiration. The significance of this is the demonstration of a chronically implantable method for neural recording, a result that will transform the capabilities of future neuroprostheses.

A wrappable microwire electrode for awake, chronic interfacing with small diameter autonomic peripheral nerves

“…) of the vagus nerve. Preclinical studies for chronic vagus nerve electrodes have been successfully conducted in large animal models (Zhang et al 2009;Ardell et al 2017;Hamann et al 2013;Metcalfe et al 2018;Valdés-Cruz et al 2002) and in rats (Somann et al 2017;McCallum et al 2017;Grimonprez et al 2015;Li et al 2004;Khodaparast et al 2016). Thus far, no studies for chronic mouse vagus nerve interfacing have been reported.…”

Velocity Selective Recording: A Demonstration of Effectiveness on the Vagus Nerve in Pig

“…As the separation between the stimulation and recording sites increases, the individual action potentials that form the eCAP will spread out in space and time; although this would enable a finer level of discrimination it would also reduce the overall SNR. The limit of this case might be considered the physiological neural activity, which we have discussed previously [7].…”

“…using hook electrodes in rat [6]. This work was further developed by recording respiration afferents from a much larger nerve (the right vagus) in pig, using a chronically implantable cuff electrode [7]. In this paper, we present an analysis of the electrically evoked potentials within pig vagus, including a discussion on the validation of previous approaches, and evaluate the effectiveness of velocity discrimination as a tool for online neural recording and analysis.…”

Deep Learning-Based Template Matching Spike Classification for Extracellular Recordings

“…Recently, deep learning-based algorithms have shown their efficiency in numerous fields and tasks, especially in classification. Starting with the year 2012 award winning AlexNet [22] from ILSVRC's ImageNet, deep learning-based methods have shown high performance in cases of large 1-dimensional and 2-dimensional data analysis and classification [23]. Its application in the field of neural signal analysis can also be seen.…”