N P Smith's research while affiliated with University of Auckland and other places

... 7,11,27 All these mathematical models, which describe different physical processes, interact one another, leading to a highly coupled system. 3,6,16,54,55,59,61 Computational strategies for the resulting cardiac EM models have made significant developments in recent years. 3,12,28,33,63 However, as mentioned above for EP models, the computational costs typically remain still very large. ...

... Cardiac clinical imaging data was leveraged to derive models of the LA and LV prescribed with patient-specific myocardial motion. Each component of Virchow's triad was assessed through biophysical modelling using the finite-element solver, CHeart [16]. ...

... where w ¼ {w i } is the velocity of the moving ALE frame. Through this relation, the rate of change in momentum may be considered in an ALE frame of reference by substitution, yielding the ALE form of Cauchy's first law (Nordsletten et al., 2007), ...

... Moreover, the inverse association between the blood [K + ] and ARI duration was observed. It can be explained by the suppression of K + channels conductance at lowering the extracellular [K + ], specifically IK1 inhibition (Bouchard et al. 2004) and reduced Na + /K + -ATPase currents (Aronsen et al. 2015) resulting in the prolongation of the repolarization phase. As it has been already mentioned above, the ARI shortening in the ischemic zone might be expected to be determined not by the blood [K + ] level but by the local rise of extracellular [K + ]. ...

... Surgery and interventions aim to restore this to the greatest extent possible. Computational Fluid Dynamics (CFD) simulation enables the flow of blood in the heart to be computed before being visualised and analysed [23], and so aids treatment planning. CFD data are fundamentally 3D and often complex, so VR could provide an aid in their understanding by improving visualisation and interaction. ...

... More recently, ref. [4] proposed a framework for the simulation of cardiac perfusion using Darcy's law using the idea of multicompartments to represent the different blood vessels' spatial scale. In medical image analysis, ref. [5] proposed quantifying the behavior of contrast agents in MR perfusion imaging. The work used a simplified model of contrast agent transport and provided interesting insights on the design and selection of the appropriate CA for specific imaging protocols and postprocessing methods. ...

... Simulations of both continuous [25] and pulsatile flow pumps [26,27] have been performed to assess the impact of circulatory devices in HFpEF and optimize their design. Furthermore, advanced LVAD models that use realistic geometries [28][29][30] have also been developed to study their effect on ventricular pressure. Granegger et al. [31] have recently used lumped parameter models to compare several device-based methodologies for HFpEF, including various pacemaker-like devices and an interatrial shunt. ...

... Bioengineering Institute of the University of Auckland (Hunter & Pullan 2002). The animated model is integrated into a web site using the ZINC plug-in and adapts to user input such as heart rate, state of the arteries (e.g., no plaque), and structure and number of capillaries. ...

... where σf along the fiber and σcf across fiber. In some three-dimensional simulation works, directions of sheet of fiber and cross-sheet of fiber are treated differently [22, 30]. ...

... Stretch-induced changes in the Ca 2ϩ affinity of TnC have been studied extensively, using computational simulations to understand effects on cardiac electrical activity (617). In the context of MEC, simulations have shown that with constant stretch, changes in TnC-Ca 2ϩ affinity would be expected to delay repolarization, due to elevated Ca 2ϩ buffering by TnC causing an increase in total SR Ca 2ϩ release and a delay in reuptake that leads to an increase and prolongation of I NCX (312,429,598). These stretch-induced AP changes differ from those predicted to arise from SAC activation, which, as described above, tends to cause AP shortening or crossover of the repolarization curve. ...