This paper presents a study of the applicability of clusters of GPUs to high-resolution 3D simulations of cardiac electrophysiology. By experimenting with representative cardiac cell models and ODE solvers, in association with solving the monodomain equation, we quantitatively analyze the obtainable computational capacity of GPU clusters. It is found that for a 501×501×101 3D mesh, which entails a 0.1mm spatial resolution, a 128-GPU cluster only needs a few minutes to carry out a 100,000-time-step cardiac excitation simulation that involves a four-variable cell model. Even higher spatial and temporal resolutions are achievable for such simplified mathematical models. On the other hand, our experiments also show that a dramatically larger cluster of GPUs is needed to handle a very detailed cardiac cell model.

The bioelectric potential of plants is generated by ion concentration difference between inside and outside of plant cells. It has been reported that the bioelectric potential of leaves changes at the beginning of steady irradiation and intensity of the potential response increases with the photosynthetic rate. Although it has been reported that photosynthesis is accelerated by blinking irradiation, the potential response under the blinking irradiation have not been fully clarified. In this study, we measured the bioelectric potential and CO2 consumption of plants under various types of the blinking irradiation. This result showed that the potential response under the blinking irradiation has various behaviors and intensity of the response related to photosynthetic rate. We conclude that our method is suitable for monitoring the biological activity of plants such as photosynthesis.