Patient-specific modelling of pulmonary airflow using GPU cluster for the application in medical practice

Abstract

In this paper, we propose a novel patient-specific method of modelling pulmonary airflow using graphics processing unit (GPU) computation that can be applied in medical practice. To overcome the barriers imposed by computation speed, installation price and footprint to the application of computational fluid dynamics, we focused on GPU computation and the lattice Boltzmann method (LBM). The GPU computation and LBM are compatible due to the characteristics of the GPU. As the optimisation of data access is essential for the performance of the GPU computation, we developed an adaptive meshing method, in which an airway model is covered by isotropic subdomains consisting of a uniform Cartesian mesh. We found that 4(3) size subdomains gave the best performance. The code was also tested on a small GPU cluster to confirm its performance and applicability, as the price and footprint are reasonable for medical applications.

Capture event of platelets by bolus flow of red blood cells in capillaries

“…In our simulation, the volume error was always lower than 1.0×10 −3 %, as tested and validated in our previous study on cell adhesion (Takeishi, et al, 2016). All procedures were fully implemented on a graphics processing unit (GPU) to accelerate the numerical simulations (Miki, et al, 2012). Our coupling method has been successfully applied to numerical analyses of cellular flow (Takeishi, et al, 2014;Takeishi, et al, 2015;Takeishi and Imai, 2017) and cell adhesion (Takeishi, et al, 2016).…”

Cell adhesion during bullet motion in capillaries

“…Cell volume was maintained constant using the method of Freund (18). All procedures were fully implemented using graphics processing unit (GPU) to accelerate numerical simulation (39). Our method was validated using test problems including the deformation of healthy red blood cells in shear flow and the thickness of cell-depleted peripheral layers in channel flow (56), and was successfully applied to simulate the flow of leukocytes and circulating tumor cells (57).…”

Deposition of micrometer particles in pulmonary airways during inhalation and breath holding

“…The CT data was taken from Aquilion 64 (Toshiba Medical Systems Corp., Japan) in Tohoku University Hospital for medical purposes. Airway geometry was extracted by using a region growing method (Nakamura et al, 2008), and morphometric analysis was conducted with a diffusionbased topological analysis algorithm (Miki, 2011). A geometric model with airways up to the thirteenth generation (G0-G13) was obtained and the morphometric data is summarized in Table 1.…”