A Comparison of the Bidomain and EMI Models in Refractory Cardiac Tissue
Date
2023-01-19
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-7648-465X
Type
Thesis
Degree Level
Masters
Abstract
Computational cardiac modelling has made incredible strides over the past 40 years toward becoming an
integral component of healthcare. The majority of cardiac modelling is accomplished using the bidomain
or monodomain models, equations describing electrical conduction in cardiac tissue. These models use a
volume averaging approach in which the structure of individual cells is disregarded; instead, cells are treated
homogeneously as a continuum. Although this approach often provides an adequate view of cardiac activity
at the macro level, there are situations where this approximation is insufficient, such as when discontinuities
at the cellular level are implicated in a given disease or phenomenon. To address this, a more detailed tissue
model has recently been developed: the extracellular-membrane-intracellular (EMI) model. The EMI model
explicitly defines the extracellular, membrane, and intracellular compartments to form a highly detailed
model of cardiac tissue. However, this additional level of detail also poses a high computational cost.
This thesis investigates the trade-off that exists between the conventional bidomain model and the EMI
model. To do this, we carry out a comparison study. This constitutes the first EMI comparison study
that has been conducted outside of the research group that developed the model. Using both models, we
find the currents required to trigger consecutive action potentials at varying time intervals. We then use
these data points to construct refractory profiles for each model and compare these profiles against available
experimental data. Our findings demonstrate that within the framework of this study, the behaviour of the
EMI model is noticeably closer to experimental data than the behaviour of the bidomain model. These results
have implications on the way we approach tissue model selection in the future, as well as for our general
understanding of the refractory properties of cardiac tissue.
Description
Keywords
cardiac modeling, electrophysiology, bidomain model, EMI model, relative refractory period
Citation
Degree
Master of Science (M.Sc.)
Department
Biomedical Engineering
Program
Biomedical Engineering