MOM 2006 journal for pdf.pmd - University of Michigan-Flint
MOM 2006 journal for pdf.pmd - University of Michigan-Flint
MOM 2006 journal for pdf.pmd - University of Michigan-Flint
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idomain conductivities (σ iL<br />
, σ iT<br />
, σ eL<br />
, σ eT<br />
) as well as other tissue parameters are given in Table 1.<br />
The conductivities in the x-y coordinate system are related to the conductivities in the fiber<br />
coordinate system by (Roth and Langrill Beaudoin, 2003)<br />
The active sodium channel membrane kinetics are described by the Ebihara Johnson model<br />
(Ebihara and Johnson, 1980)<br />
where m and h are dimensionless first order variables that vary between 0 and 1.<br />
At the sealed surface the y-component <strong>of</strong> the current density is zero. Because the fibers<br />
approach the surface at an angle, this boundary condition is not equivalent to the normal gradient<br />
<strong>of</strong> the potential being zero.<br />
Consider a rectangular strip <strong>of</strong> tissue, 5 mm x 1 mm with 800 x 161 nodes, having its upper<br />
and lower edges sealed (Fig. 1). Initially, the tissue is at rest, -85 mV. The transmembrane<br />
potential along the left edge is raised to +35 mV, and an action potential wave front propagates to<br />
the right. The bidomain equations are solved using a finite difference approximation, with time<br />
step <strong>of</strong> 0.1 μs and space step <strong>of</strong> 6.25 μm.<br />
Meeting <strong>of</strong> Minds <strong>2006</strong> 65