The basic safety requirement for medical electronic equipment recognized globally is the IEC-60601 series of standards. IEC-60601-1 covers all general provisions, including risks of environment, mechanics, excessive radiation, etc. The risk tolerance assessment is included as well. IEC-60601-1-X series is a parallel standard belonging to IEC-60601-1, specifically for general properties such as electromagnetic compatibility, usability, radiation protection, etc. It should be applied with IEC-60601-1. IEC-60601-2-XX series is used for specific medical equipment, but IEC-60601-1 and IEC-60601-1-X standards are also applicable. The relationship between series is as follows.