Modelling and Analysis of Magnetic Fields from Skeletal Muscle for Valuable Physiological Measurements

TL;DR

This paper presents a detailed protocol for modeling and analyzing magnetic fields generated by skeletal muscles during electrical activity, aiming to improve physiological measurements through MagnetoMyoGraphy.

Contribution

It introduces a comprehensive finite-element analysis protocol to characterize magnetic fields from skeletal muscles, linking electrical activity to magnetic measurements.

Findings

Protocol enables identification of muscle fiber subpopulations.

Characterizes magnetic field behavior in temporal, spectral, and spatial domains.

Provides a method to calculate magnetic fields from muscle currents.

Abstract

MagnetoMyoGraphy (MMG) is a method of studying muscle function via weak magnetic fields generated from human active organs and tissues. The correspondence between MMG and electromyography means directly derived from the Maxwell-Amp\`ere law. Here, upon briefly describing the principles of voltage distribution inside skeletal muscles due to the electrical stimulation, we provide a protocol to determine the effects of the magnetic field generated from a time-changing action potential propagating in a group of skeletal muscle cells. The position-dependent and the magnetic field behaviour on account of the different currents in muscle fibres are performed in temporal, spectral and spatial domains. The procedure covers identification of the fibre subpopulations inside the fascicles of a given nerve section, characterization of soleus skeletal muscle currents, check of axial intracellular currents, calculation of the generated magnetic field ultimately. We expect this protocol to take approximately 2-3 hours to complete for the whole finite-element analysis.