Triphasic theory has been proposed to couple mechanical, chemical and electrical phenomena in the analysis of hydrated charged soft tissues. As a cardiac myocyte, which consists of a solid phase and a charged fluid phase filling its interstices, is this type of tissue, the applicability of the triphasic theory to the modeling of cardiac myocyte was discussed in this research. An efficient finite element formulation for large deformation analyses was newly developed. The concentration of each ion is set as a primary variable to treat major ions, such as sodium, calcium, and potassium, separately. Physiological features of cardiac myocyte, such as activities of ion channels and sarcoplasmic reliculum, were reasonably included into. the new formulation. Even under a simple 2D modeling with limited number of parameters, the simulation qualitatively reproduced various cardiac behaviors such as excitations of cardiac cells induced by current stimuli and field stimuli.
