Abstract
Functional near-infrared spectroscopy (fNIRS) is widely used in academia and medicine, especially in human brain science. The international standard for the basic safety and essential performance of the fNIRS equipment as a medical device was established by the International Electrotechnical Commission (IEC) and published as IEC 80601-2-71. In this review, the authors, who are experienced project leaders in developing and revising the fNIRS standard, provide information on the development of the standard, including the process to date and expectations for the research community. The review will guide future experts in fNIRS standard revisions and relevant standard development.