A SYSTEM-BASED STUDY OF THE VARIATION IN THE AMPLITUDE OF THE COMPOUND SENSORY NERVE ACTION-POTENTIAL RECORDED USING SURFACE ELECTRODES

This study arose from the impression that there is a wide variation in the amplitude of the compound sensory nerve action potential (SNAP) w hen recorded using surface electrodes. Both the physiological factors influencing the SNAP and the method of measurement itself can be viewe d as inputs to a system that produces the recorded value as its output . Taking a systems approach to the analysis of the variation in the re corded value of the SNAP on repeat testing, the techniques of statisti cal process control and experimental design were used to study three e lectrodes. AII showed wide variation of the results in a single contro l subject. Many different factors were studied but no single factor wa s found to be the cause for a significant amount of the variation. Thi s finding, coupled to the wide variation demonstrated, has implication s for the use of surface recording of the SNAP. Copyright (C) 1996 Els evier Science Ireland Ltd.