Modelling Fibrillation Potentials—Analysis of Time Parameters in the Muscle Intracellular Action Potential

Abstract

A single fiber action potential (SFAP) can be modelled as the convolution of a biolectrical source and a filter impulse response. In the Dimitrov-Dimitrova (D-D) convolutional model, the first temporal derivative of the intracellular action potential (IAP) is used as the source, and Tspl is a time parameter related to the duration of the IAP waveform. This paper is centred on the relation between Tspl and the main spike duration (MSD), defined as the time interval between the first and third phases of the SFAP. We show that Tspl essentially determines the MSD parameter. As experimental data, we used fibrillation potentials (FPs) of two different muscles to study the D-D model. We found that Tspl should have a certain statistical variability in order to explain the variability in the MSD of our FPs. In addition, we present a method to estimate the Tspl values corresponding to a given SFAP from its measured MSD.

Analysis of the relationship between the rise-time and the amplitude of single-fibre potentials in human muscles

“…The results of the present work suggest that we should admit some variability in the duration of the IAP depolarization portion in order to be able to generate the range of risetimes observed experimentally. This proposal is in agreement with several other studies that have demonstrated that to explain the changes of certain SFAP parameters it is necessary to consider the excitation source as a variable function (Rodriguez et al, 2006(Rodriguez et al, , 2007(Rodriguez et al, , 2009(Rodriguez et al, , 2010.…”

“…However, by making the same assumptions as we made for the rise-time, analysis of the (3). The ranges of variation of excitation and IR parameters have been chosen to be the same as or similar to those used in previous works (Nandedkar and Stålberg, 1983;Rodriguez et al, 2007;Arabadzhiev et al, 2008). …”

“…Influence of IR parameters on SFAP rise-time RT (µs) of variation of excitation and IR parameters have been chosen to be the same as or similar to those used in previous works (Nandedkar and Stålberg, 1983;Rodriguez et al, 2007;Arabadzhiev et al, 2008). effects of the excitation and impulse response functions on V pp could be simplified as to consider only the influence of parameters T dep , v and r.…”

Identification procedure in a model of single fibre action potential – Part II: Global approach and experimental results

“…Parameter A 2b has a variation of ± 0.5 around the value of A 2 . Parameter T spl ranges from 1.0 to 3.5 ms, in accordance with our previous studies (Rodríguez-Falces et al, 2006;Rodríguez-Falces et al, 2007).…”

“…A method for estimating the T spl value of an IAP from the MSD (time interval from the two SFAP positive peaks) of its SFAP (see Fig. 1c) is proposed in Rodríguez-Falces et al (2007).…”