The ICVSIE: A General Purpose Integral Equation Method for Bio-Electromagnetic Analysis

• Published in: IEEE transactions on biomedical engineering Vol. 65; no. 3; pp. 565 - 574
• Main Authors: Gomez, Luis J., Yucel, Abdulkadir C., Michielssen, Eric
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.03.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bio-electromagnetism; Biological tissues; Brain - diagnostic imaging; computational electromagnetics; Computer Simulation; Diagnostic software; Diagnostic systems; Electric breakdown; Electric fields; Electrical stimuli; electromagnetic (EM) analysis; Electromagnetic Fields; Equivalence; fast methods; Head - diagnostic imaging; high-contrast (HC) media; Humans; Image Processing, Computer-Assisted; Integral equations; internally combined volume surface integral equation (ICVSIE); Magnetic fields; Magnetic resonance imaging; magnetic resonance imaging (MRI); Magnetic Resonance Imaging - methods; Mathematical analysis; neuromuscular electrical stimulation (NMES); Permeability; Permittivity; Reproducibility of Results; Robustness (mathematics); Streamlining; Transcranial magnetic stimulation; transcranial magnetic stimulation (TMS); Transcranial Magnetic Stimulation - methods
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2017.2704540

Objective: An internally combined volume surface integral equation (ICVSIE) for analyzing electromagnetic (EM) interactions with biological tissue and wide ranging diagnostic, therapeutic, and research applications, is proposed. Method: The ICVSIE is a system of integral equations in terms of volume and surface equivalent currents in biological tissue subject to fields produced by externally or internally positioned devices. The system is created by using equivalence principles and solved numerically; the resulting current values are used to evaluate scattered and total electric fields, specific absorption rates, and related quantities. Results: The validity, applicability, and efficiency of the ICVSIE are demonstrated by EM analysis of transcranial magnetic stimulation, magnetic resonance imaging, and neuromuscular electrical stimulation. Conclusion: Unlike previous integral equations, the ICVSIE is stable regardless of the electric permittivities of the tissue or frequency of operation, providing an application-agnostic computational framework for EM-biomedical analysis. Significance: Use of the general purpose and robust ICVSIE permits streamlining the development, deployment, and safety analysis of EM-biomedical technologies.