The mechanical bidomain model of cardiac tissue

The heart is a pump, so its mechanical behavior is critical to life. Mathematical models describing the biomechanics of cardiac muscle have been around for years, and are quite sophisticated and complex. However, these models treat the tissue as a single material, when in fact it consists of a mixture of two, the intracellular space and the extracellular space, that have very different mechanical properties. Of course, the two materials are coupled: if the intracellular space contracts, it will drag the extracellular space along with it. But when this happens, it stresses the cell membrane, which separates the inside and outside of the cells. These membrane forces could affect proteins in the membrane, leading to a cascade of physiological effects.

CBR member Brad Roth, of the Department of Physics, has recently published a review describing a new mathematical model that accounts for the intracellular and extracellular spaces individually, and the coupling between them. His article The Mechanical Bidomain Model: A Review appeared in the journal ISRN Tissue Engineering (Vol. 2013, Article Number 863689). This journal is open access, so you can download and read the article for free.

The mechanical bidomain model was first derived by Roth and Steffan Puwal, who obtained a PhD in the Biomedical Sciences: Medical Physics PhD program, worked as a post doc with Roth, and is now a lecturer in the Department of Physics. The model was analyzed further by OU undergraduate Vanessa Punal, who obtained a BS degree in physics last May and is now a graduate student studying Neuroscience at Duke University. The mechanical bidomain model has many potential applications in the fields of biomechanics, mechanobiology, and tissue engineering.

This research was supported by a grant (R01EB008421) from the National Institute of Biomedical Imaging and Bioengineering, one of the National Institutes of Health.