Article History
Received: 4 June 2019
Accepted: 29 August 2019
First Online: 6 September 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Our research was approved by the Institutional Review Board of Teikyo university (registration number: TUIC‐COI 17‐188).
: Formal consent is not required for this type of study.