Patient Specific Segmentation

 TETRAHEDRAL BI-VENTRICULAR MESHES CREATED FOR 50 INDIVIDUAL PATIENTS WITH THE  s2S  sOFTWARE.

TETRAHEDRAL BI-VENTRICULAR MESHES CREATED FOR 50 INDIVIDUAL PATIENTS WITH THE s2S sOFTWARE.

Using the Segmentation to Simulations (S2S) software developed by our group,  we can create personalized geometrical models that serve as a basis for our physical simulations. S2S processes MRI derived 4 chamber heart segmentations (provided by Phillips segmentation software and MedInria) to produce high fidelity tetrahedral based meshes of the left and right ventricles for electromechanical simulations. Although each patient's heart is unique, S2S automatically processes each one using basic common structure principles, allowing for comparison of large cohorts of patients.

Estimating Tissue Properties from 3D tagged MRI 

Heart muscle is a complex structure and its function during both systole and diastole are crucial to its overall purpose as a pump. During these two phases, the tissue itself exhibits separate material properties that pertain to the diastolic and systolic performance. Using models incorporating active and passive myocardial mechanics, we create individualised mechanical representations of the heart over the full cycle by assimilating motion data from 3D Tagged MRI. 

 two different mri scans (3d tagged MR and 3d ssfp) are combined together to personalise patient simulations, displayed here with a segmented left ventricle mesh. 

two different mri scans (3d tagged MR and 3d ssfp) are combined together to personalise patient simulations, displayed here with a segmented left ventricle mesh. 

Incorporating Hemodynamic Load into Biventricular Simulations

To fully understand heart function, one must consider the interaction it has with the circulation system. Using a hemodynamic model developed in-house, we link the ventricular pressure of the left and right ventricles through a 0D representation of the entire circulation system. This model includes time varying descriptions for the valves of the heart, models for the left and right atria and lumped parameter descriptions for the systemic and pulmonary systems.  In addition, this model allows us to consider the effects of disease on the patient and closely examine how pathological changes, such as increased blood pressure or valvular regurgitation, will affect the efficiency of the heart.  

Simulations of Beating Hearts

Biophysically-based electro-mechanical simulations of the bi-ventricular heart model are examined, that reflect each patient's individual anatomy and function. This is done by bringing the above components together into CHeart, our in-house multi-physics engine, where the left and right ventricles deform according to the effects of blood pressure, contractile function and tissue mechanics. These personalised models give a representation for in-depth understanding of physiological and mechanical influences on the patients heart, as well as make it possible to understand how variations in patients can effect disease progression and therapy outcome.