Fig. 3.

Discretization of the cardiac model: (a) The idealized LV was modeled as a thick-walled ellipsoid truncated at $\frac{3}{4}$ of the total height. Typical cardiac dimensions were used (semi-major axis=$8\mathit{cm}$, semi-minor axis=$5.5\text{cm}$, wall thickness= $0.5\text{cm}$ at the apex, $1\text{cm}$ at the base). The red and blue curves denote the epicardium ($f_{\mathit{epi}}$) and endocardium ($f_{\mathit{endo}}$) fiber directions [63,7], respectively. Zero traction condition was applied on the epicardial surface, and the base was held fixed. (b) Number of elements and degrees of freedom (DOFS) in each discretization and error of the three methods when used in the cardiac cycle test ($k={10}^7$ for the penalty (PEN) and weakly penalized (WP) methods). (For interpretation of the references to colour in this figure caption, the reader is referred to the web version of this article.)