V.N. Biktashev, R. Suckley
Submitted to PRL: 2003/12/03. Accepted: 2004/08/25. Reference: Phys. Rev. Lett. 93, 168103 (2004)
Models of electric excitability of cardiac cells can be studied by singular perturbation techniques. To do this one should take into account parameters appearing in equations in non-standard ways. Physical reason for this is near-perfect switch behavior of ionic current gates. This leads to a definition of excitability different from the currently accepted one. The asymptotic structure revealed by our analysis can be used to devise simplified ``caricature'' models, obtain approximate analytical solutions, and facilitate numerical simulations.
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