A Study on Large Scale Analysis of Cardiomyocyte Coupling Electrical, Chemical and Mechanical Phenomena Based on Triphasic Theory

Abstract

Triphasic theory has been proposed to integrate mechanical, electrical and chemial phenomena for hydrated soft tissues. Though having been applied to biomaterials such as cardiomyocyte and cartilage, the following two difficulties have prevented the theory from wide range of applications. The first is huge calculation cost; ”multiphysics” makes degree of freedoms large, and chemical or electrical phenomena limit the time step. The second is difficulty of parallelization due to interaction complexity. Therefore size of the model is restricted to unproductively small. To achieve large-scale analysis, we propose an effective algorithm on time discretization and parallelization. We separated mechanical, electrical and chemical variables and updated with different timesteps, sufficient for each phenomenon. Separate time discretization and incorporation of properly updated interaction terms achieved low-calculation-cost interactive analysis. With regard to parallelization, the whole analysis was partitioned based on spatial segmentation of mechanical mesh. Electrical and chemical meshes are generated after separation so as to use communication methods commonly and to access other physical quantity directly within each processor. Finally, the algorithm was applied to cardiomyocyte model of 17 million degree of freedoms and a parallel computation with 256 processor cores was presented.