Development of Human Body Simulator in Medical Use for the Next-Generation Supercomputer in Japan

Shu Takagi, University of Tokyo

The next generation supercomputer of 10 Peta flops speed is now under the development as a national project in Japan. Not only the hardware development but also the software development is emphasized and the software development for the human body simulator is assigned as a grand challenge program for the effective use of the super-computer. In this program, the multiscale and multi-physics natures of the living matter are discussed. Under this concept, we are developing the simulation tools for organ and body scales with the continuum mechanics approach.

The software development using the patient specific data is highly expected for the next-generation medical treatment. In the preset talk, two kinds of simulators are introduced. First, as a medical application of ultrasound therapy, HIFU ( High Intensity Focused Ultrasound ) simulator is explained with the application of brain tumor treatment. Due to the presence of skull, the focus control of ultrasound field becomes considerably difficult without using the information of skull shape and thickness. Here, we utilize the CT data for skull and the time reversal method for wave equations is introduced to control the focal point. The numerical results illustrates that the simulation can be utilized to design the HIFU therapy. Next, a novel numerical method suitable for using medical images is explained. The method is based on the finite difference discretization of fluid-structure interaction problem by the fully Eulerian description. Although the developed method requires a relatively complicated mathematical treatment, it does not require mesh-generation procedure which is a big advantage when the software is introduced in medical institutions. Some examples of numerical simulations are shown with the detail validation of the method. Furthermore, the multiscale thrombosis simulator is explained with the current stage of the development of the numerical methods. In the present talk, the numerical model simulating the initial stage of thrombus formation is explained. The molecular scale interaction between platelets and vascular endothelium is taken into account through the stochastic Monte Carlo simulations. Then, the interacting force obtained from the Monte Carlo simulation is coupled with the continuum scale blood flow simulation using the above-mentioned FSI method. The results illustrate that platelets are much easier to aggregate on the wall in the presence of red blood cells and the effect of molecular interaction force are quantitatively discussed on the aggregation of platelets.

Finally, future direction of our research and development is also discussed.

Speaker Biography

  • 1995, Doctor of Engineering, The University of Tokyo
  • 1998-2002, Assistant Professor, Dept. of Mechanical Engng, The University of Tokyo
  • 2002-2010, Associate Professor, Dept. of Mechanical Engng, The University of Tokyo
  • (2007- , Team Leader, Computational Science Research Program, RIKEN)
  • 2010- , Professor, Dept. of Mechanical Engineering, The University of Tokyo