Received: 8 March 2021
Accepted: 1 June 2021
First Online: 12 June 2021
: We obtained informed consent from all participants. This study was approved by the institutional Review Board of Tsukuba University (IRB approval No. H29–253) and was performed in accordance with the Declaration of Helsinki.
: Patients signed informed consent regarding publishing their data.
: A commercial party having a direct financial interest in the results of the research supporting this article has conferred or will confer a financial benefit on one or more of the authors. YS is a professor of University of Tsukuba, a founder, a shareholder, and the chief executive officer of University venture company “CYBERDYNE Inc.”, Ibaraki, Japan. HK is an associate professor of University of Tsukuba, a co-founder, a shareholder, and an outside director of University venture company CYBERDYNE. YY is a Ph.D. student at the University of Tsukuba and the general manager of sales and director of the university’s venture company “CYBERDYNE, Inc.” in Ibaraki, Japan. COI is managed by University of Tsukuba according to National university rules and guidelines and by board of directors of CYBERDYNE. The patent royalty is paid to University of Tsukuba from CYBERDYNE and a part of the royalty is paid to YS from University of Tsukuba according to National university rules. CYBERDYNE is a R&D company and the manufacturer of the HAL. The present study was proposed by the authors. CYBERDYNE was not directly involved in the study design; collection, analysis, or interpretation of data; writing the report; or the decision to submit the paper for publication. Other authors report they have no conflict of interest to disclose.