On the measurement of skeletal muscle anisotropic permittivity property with a single cross-shaped needle insertion

Abstract

Application of minimally invasive methods to enable the measurement of tissue permittivity in the neuromuscular clinic remain elusive. This paper provides a theoretical and modeling study on the measurement of the permittivity of two-dimensional anisotropic tissues such as skeletal muscle with a multi-electrode cross-shaped needle. For this, we design a novel cross-shaped needle with multiple-electrodes and analyse apparent impedance corresponding to the measured impedance. In addition, we propose three methods of estimate anisotropic muscle permittivity. Compared to existing electrical impedance-based needle methods that we have developed, the new needle design and numerical methods associated enable estimating in vivo muscle permittivity values with only a single needle insertion. Being able to measure muscle permittivity directly with a single needle insertion could open up an entirely new area of research with direct clinical application, including using these values to assist in neuromuscular diagnosis and to assess subtle effects of therapeutic intervention on muscle health.

Electrical impedance myography method of measuring anisotropic tongue tissue

“…An alternative approach consists of developing computationally efficient analytical inverse measurement methods, such as in Rush (1962), Rush et al (1963), and Kwon et al (2017Kwon et al ( , 2022. To date, however, the existing analytical methods we have developed only allow one to reconstruct the admittivity property of twodimensional anisotropic tissue .…”

A scoping review of current and emerging techniques for evaluation of peripheral nerve health, degeneration, and regeneration: part 1, neurophysiology

“…It has proven sensitive to changes in structure and composition of denervated muscle, with current research efforts focused on understanding histopathological features affecting EIM data over a range of conditions and electrode types [128][129][130][131][132], as well as correlation with complementary metrics such as quantitative utlrasound [133] and EMG [126]. Most recently, coupling of EIM with EMG (needle impedance EMG, iEMG) and EIM with ultrasound represent further examples of potential composite metrics of nerve health [134][135][136][137][138] that promise to increase both clinical and research efficiency and accuracy.…”