A summary of the theory of velocity selective neural recording

Abstract

This paper describes improvements to the technique of velocity selective recording (VSR) in which multiple neural signals are matched and summed to identify excited axon populations in terms of velocity. This form of recording has been termed intrinsic velocity selective recording (IVSR). The signals are acquired using a multi-electrode cuff (MEC) which is now available as a component for use in implantable neuroprostheses. The improvements outlined in the paper involve the use of bandpass filters at the output of the system which allows a higher level of selectivity to be obtained than is possible using IVSR.

Fibre-selective recording from peripheral nerves using a multiple-contact cuff: Report on pilot pig experiments

“…In order to address this problem, the method requires a tool for increasing the velocity selectivity. We show elsewhere that band-pass filtering in the frequency domain is a simple and effective tool for improving the selectivity of the method of multiple-contact cuff recordings [10].…”

Fibre-selective discrimination of physiological ENG using velocity selective recording: Report on pilot rat experiments

“…3) the quality factor was 1.48. Various methods exist to improve the velocity selectivity; such as the use of band pass filters [3] and neural networks [10].…”

“…A simple process called delay-and-add was used to extract the basic velocity information from the raw data, the recordings lasting 250 ms [3], [9]. The channels are delayed relative to the first channel V B1 by an interval that depends on both the electrode spacing and the propagation velocity of the signal.…”

“…While it is possible to calculate CV using only a single pair of electrodes (a dipole) it has been shown that the velocity selectivity of a system can be increased by using multiple electrodes [2]. The use of velocity selective recording (VSR) enables discrimination of action potentials based both on direction of propagation (afferent or efferent) and CV, without the need to submit the nerve to invasive and potentially damaging procedures [3], [4]. This method provides a viable interface for neural recording systems that have potential use in a range of prosthetic devices.…”

A Microchannel Neuroprosthesis for Bladder Control After Spinal Cord Injury in Rat

“…For example, recording of bladder sensory information has been attempted using cuffs in anesthetized humans (21), but the signal size (5 mV, SNR = 0.2) is insufficient for use while awake and moving. Techniques under development include velocity-selective recordings from multielectrode cuffs to generate a more detailed action potential profile (25,26), but these currently require a very high sampling rate and detailed offline analysis (27).…”