Hirano, Harutoyo http://orcid.org/0000-0002-0634-1805
Takama, Renjo
Matsumoto, Ryo
Tanaka, Hiroshi
Hirano, Hiroki
Soh, Zu http://orcid.org/0000-0001-7182-9383
Ukawa, Teiji
Takayanagi, Tsuneo
Morimoto, Haruka
Nakamura, Ryuji http://orcid.org/0000-0001-8074-4787
Saeki, Noboru http://orcid.org/0000-0002-1967-0878
Hashimoto, Haruki
Matsui, Shogo
Kishimoto, Shinji http://orcid.org/0000-0002-5109-7805
Oda, Nozomu
Kajikawa, Masato
Maruhashi, Tatsuya
Kawamoto, Masashi
Yoshizumi, Masao
Higashi, Yukihito
Tsuji, Toshio
Article History
Received: 22 January 2018
Accepted: 1 June 2018
First Online: 18 June 2018
Competing Interests
: Teiji Ukawa, Tsuneo Takayanagi, Haruka Morimoto and Ryo Matsumoto are employees of Nihon Kohden Corporation. Harutoyo Hirano, Renjo Takama, Hiroshi Tanaka, Hiroki Hirano, Zu Soh, Ryuji Nakamura, Noboru Saeki, Haruki Hashimoto, Shogo Matsui, Shinji Kishimoto, Nozomu Oda, Masato Kajikawa, Tatsuya Maruhashi, Masashi Kawamoto, Masao Yoshizumi, Yukihito Higashi and Toshio Tsuji declare no potential conflict of interest.