Abstract: Old people usually have more complex health problems and use healthcare services more frequently than young people. It is obvious that the increasing old people both in number and proportion will challenge the emergency departments (ED). This paper firstly presents a way to quantitatively predict and explain this challenge by using simulation techniques. Then, we outline the capability of simulation for decision support to overcome this challenge. Specifically, we use simulation to predict and explain the impact of population aging over an ED. In which, a precise ED simulator which has been validated for a public hospital ED will be used to predict the behavior of an ED under population aging in the next 15 years. Our prediction shows that the stress of population aging to EDs can no longer be ignored and ED upgrade must be carefully planned. Based on this prediction, the cost and benefits of several upgrade proposals are evaluated.

Abstract: We present a high-performance computational framework (Hemocell) with validated cell-material models, which provides the necessary tool to target challenging biophysical questions in relation to blood flows, e.g. the influence of transport characteristics on platelet bonding and aggregation. The dynamics of blood plasma are resolved by using the lattice Boltzmann method (LBM), while the cellular membranes are implemented using a discrete element method (DEM) coupled to the fluid as immersed boundary method (IBM) surfaces. In the current work a selected set of viable technical solutions are introduced and discussed, whose application translates to significant performance benefits. These solutions extend the applicability of our framework to up to two orders of magnitude larger, physiologically relevant settings.

Abstract: We develop two-dimensional Brownian dynamics simulations to examine the motion of disks under thermal fluctuations and Hookean forces. Our simulations are designed to be experimental-like, since the experimental conditions define the available time-scales which characterize the solution of Langevin equations. To define the fluid model and methodology, we explain the basics of the theory of Brownian motion applicable to quasi-twodimensional diffusion of optically-trapped microspheres. Using the data produced by the simulations, we propose an alternative methodology to calculate diffusion coefficients. We obtain that, using typical input parameters in video-microscopy experiments, the averaged values of the diffusion coefficient differ from the theoretical one less than a 1%.

Abstract: Simulations of the passage of eukaryotic cells through a constricted channel aid in studying the properties of cancer cells and their transport through the bloodstream. Compound capsules, which explicitly model the outer cell membrane and nuclear lamina, have the potential to improve fidelity of computational models. However, general simulations of compound capsules through a constricted microchannel have not been conducted and the influence of the compound capsule model on computational performance is not well known. In this study, we extend a parallel hemodynamics application to simulate the fluid-structure interaction between compound capsules and fluid. With this framework, we compare the deformation of simple and compound capsules in constricted microchannels, and explore how this deformation depends on the capillary number and on the volume fraction of the inner membrane. The parallel performance of the computational framework in this setting is evaluated and lessons for future development are discussed.