To reduce the risk of medical accidents and litigation, it is required to perform management such that the built-in clocks of ME devices are always accurate. However, there are no laws and guidelines concerning time management of ME devices, and there is concern about the reliability and adequacy of medical manuals in our facility regarding this type of device.

Therefore, in this study, we performed quantitative analysis with actual time error data using statistical analysis, clarified "to what extent time error is acceptable", and examined how time management should be performed from the viewpoint of a medical device safety management officer.

Based on the analysis results, considering the balance between benefit and risk regarding medical safety, we propose that tolerance should be within ± 30 seconds per month, and that ME devices exceeding their period of endurance undergo intensive maintenance or equipment updates.

Further, the effectiveness and safety of ME devices need to be evaluated by scientific risk analysis. The MDIC must collect evidence from both medical institutions and industries and perform safety risk management, and guidelines defining a standard tolerance range should be formulated by the medical industry.