Mimics research 20

The left atrium and the left ventricle of an LVAD patient were segmented from computed tomography (CT) images using Mimics Research 20.0 and 3-matic Research 13.0 (Materialise, Belgium NV). The end systolic volume of the atrium and ventricle of this patient were 169 and 295 cm³, respectively (Figure 1). The left atrial appendage geometry was occluded virtually (Ansys, SpaceClaim 19.3, Pennsylvania, United States) (Figure 1).
A mitral valve model (Domenichini and Pedrizzetti, 2015 (link)) was defined using the following parametric equations: ${\mathit{x}}_{\mathit{v}}\left(\mathit{\theta },\mathit{s}\right)=\mathit{R}\mathbf{cos}\mathit{\theta }\left(1-\mathit{s}\mathbf{cos}\mathbf{\phi }\right)-\mathit{\epsilon }\mathit{R}\mathit{s}\mathbf{cos}\mathbf{\phi }$
${\mathit{y}}_{\mathit{v}}\left(\mathit{\theta },\mathit{s}\right)=\mathit{R}\mathbf{sin}\mathit{\theta }\left(1-\mathit{s}\mathit{k}\mathbf{cos}\mathbf{\phi }\right)$
${\mathit{z}}_{\mathit{v}}\left(\mathit{\theta },\mathit{s}\right)=-{\mathit{s}}^{\mathbf{2}}\left(\frac{1+\mathit{k}}{2}+\mathit{\epsilon }\mathbf{cos}\mathit{\theta }+\frac{1-\mathit{k}}{2}\mathbf{cos}2\mathit{\theta }\right)\mathit{R}\mathbf{sin}\mathit{\phi }$
In which $\theta$ is 100 points from $\mathit{0}$ to $\mathit{2}\pi$ and $\mathit{s}$ is 40 points from 0 to 1. $\epsilon =\mathit{0.35}$ shows the symmetry ratio between anterior and posterior leaflet. $k=\mathit{0.6}$ , shows the ellipticity of the valvular edge. $\phi =\mathit{60}$ , shows the opening angle of the mitral valve.
The created valve geometry was placed at the position and matching the orientation of the mitral valve as defined via the CT images.
The mitral valve was considered in the open status with a rigid wall and the flow rate over the mitral valve was controlled using the volume change of the left atrium and left ventricle, leading to zero flow rate over the mitral valve during systole.

Each specimen was thawed at room temperature over a period of 24 h before being imaged using a 64-slice Discovery HD 750 CT scanner (GE Healthcare, Little Chalfont, UK; display field of view (DFOV): 173 mm; slice thickness: 0.625 mm; pixel spacing: 0.338/0.338 mm, voxel size: 0.071 mm³; 100 kV; 180 mA; image size: 512  × 512 pixels). A radio-translucent rig with a small (50 mm) and large diameter peg (125 m) was used to standardize each hand in the five functional grip positions (i.e., powerL, powerLA, powerLE, powerS, and pinch). This resulted in a total of 24 scan positions, as we were unable to position specimen Pp5 in a powerL grasp. Each trapezium and the first metacarpal was segmented separately using Mimics Research 20.0 (Materialise, Leuven, Belgium) and exported as triangular meshes.