Norio Tanaka1, Yoshikazu Masuda2, Satoshi Nakatani3. 1. National Cerebral and Cardiovascular Center, Suita, Japan. 2. Yoshida Onohara Higashi Clinic, Minoo, Japan. 3. Department of Health Sciences, Division of Functional Diagnostics, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita, Osaka, 565-0871, Japan. nakatani@sahs.med.osaka-u.ac.jp.