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

Abstract

Neural interfaces that can both stimulate and record from the peripheral nervous system are an important component of future bioelectronic devices. However, despite a long history of neurostimulation, there has been relatively little success in the design of a chronically implantable device for recording from peripheral nerves. This fundamental road block must be overcome if the design of advanced implantable devices is to continue. In this paper, we demonstrate the effectiveness of one method: velocity selective recording, a method that has been proposed as a tool for online neural recording that does not require training. We present results and analysis from invivo recordings made on the right vagus nerve of pig using a multiple-electrode cuff as a chronically implantable recording array.

The Use of the Velocity Selective Recording Technique to Reveal the Excitation Properties of the Ulnar Nerve in Pigs

“…It also increases the SNR by , where n is the number of channels in the multi-electrode cuff (MEC) [ 17 , 18 ]. To date, the VSR has been investigated in animal models, including the rat dorsal root [ 19 ], frog sciatic nerve [ 20 , 21 ], earthworms [ 22 ], pig vagus nerve [ 23 ], and pig median nerve [ 24 ]. In these experiments, the effect of stimulation amplitude was considered; however, no investigation was performed to analyse the effect of the pulse duration on the recruitment of nerve fibres.…”

An in-vitro system for closed loop neuromodulation of peripheral nerves

“…As this eCAP propagates along the nerve, the amplitude decreases and time duration increases. This has been discussed previously and arises because an eCAP is comprised of individual action potentials travelling at different speeds, hence dispersing in time as they propagate along the recording array [10]. When examining the eCAPs in the time domain at temperatures reaching up to 37 • C, it can be seen that the amplitude of the eCAP first increases at 32 • C, but decreases as the temperature increases beyond Compared to the in vitro data, the peak in the IVS is now at a velocity of 58 m s −1 and a considerably larger amplitude of 6.4 mV that point.…”

Array processing of neural signals recorded from the peripheral nervous system for the classification of action potentials

“…The eCAP is produced when a large number of axons generate APs simultaneously at the point of stimulation, their individual APs superimposing to produce a handful of large amplitude eCAPs. For large nerves there are often 2 or more eCAPs with different velocities, likely caused by multi-modal fibre-diameter distributions (see [17] and Fig. 1a for an exemplar recording).…”

“…Typically L will be on the order of centimetres and u n+1 − u n on the order of millimetres. The number of electrodes N varies depending on the available space for the implant, but typically will be about 10 [17]. The length of the cuff, the number of electrodes, and the electrode positions will all affect the ability of the array to discriminate different velocities.…”