1. Department of Medical Engineering and Cardiology, Institute of Development, Aging and Cancer, Sendai, Japan,
2. Graduate School of Engineering, Tohoku University, Sendai, Japan,
3. Department of Thoracic and Cardiovascular Surgery, Tohoku University School of Medicine, Sendai, Japan,
4. Faculty of Engineering, Tohoku‐gakuin University, Sendai, Japan,
5. Kurokawa County Hospital, Sendai, Japan