1 Center for Frontier Medical Engineering, Chiba University, 1-33, Yayoicho, Inage, Chiba, 263-8522, Japan.
2 Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan. taka.nakada@nifty.com.
3 Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan.