Electrical impedance myography method of measuring anisotropic tongue tissue

Abstract

Objective: To date, measurement of conductivity and relative permittivity properties of anisotropic biological tissues using electrical impedance myography (EIM) is only possible through an invasive ex vivo biopsy procedure. Here, we present a novel forward and inverse theoretical modeling framework to estimate these properties combining surface and needle EIM measurements. Methods: The framework presented models the electrical potential distribution within a monodomain, homogeneous, and three-dimensional anisotropic tissue. Finite element method simulations and tongue experimental results verify the validity of our method to reverse-engineer three-dimensional conductivity and relative permittivity properties from EIM measurements. Results: FEM-based simulations confirm the validity of our analytical framework, with relative errors between analytical predictions and simulations smaller than 0.12% and 2.6% in a cuboid and tongue model, respectively. Experimental results confirm qualitative differences in the conductivity and the relative permittivity properties in x, y, and z directions. Conclusion: Our methodology enables EIM technology to reverse- engineer the anisotropic tongue tissue conductivity and relative permittivity properties thus unfolding full forward and inverse EIM predictability capabilities. Significance: This new method of evaluating anisotropic tongue tissue will lead to a deeper understanding of the role of biology necessary for the development of new EIM tools and approaches for tongue health measurement and monitoring.

Tongue electrical impedance myography correlates with functional, neurophysiologic, and clinical outcome measures in long‐term oropharyngeal cancer survivors with and without hypoglossal neuropathy: An exploratory study

“…[15][16][17] EIM measures muscle volume electrical conductivity properties to detect alterations in tissue composition (e.g., deposition of fatty infiltration and connective tissue) and structure (e.g., changes of muscle fiber type and myofiber atrophy). [18][19][20] Specifically, tongue EIM has shown promise in evaluating neuromuscular disorders affecting the tongue, 21 including amyotrophic lateral sclerosis. [22][23][24] Compared to EMG, performing tongue EIM measurements is noninvasive and quick, thus has the potential to serve as an adjunctive quantitative tool to follow progression and monitoring response to therapy in OPC survivors.…”