The medical device technical review is a highly professional work, and the Medical Device Technical Evaluation Center of the State Food and Drug Administration (hereinafter referred to as the "Device Evaluation Center") often encounters recurring common technical problems in the process of consulting services. In order to improve the quality and efficiency of the technical review and consultation work for medical device registration, this edition will open a "review forum" from today, and the relevant personnel of the instrument review center are invited to analyze and interpret these common problems.

　　As the functions of medical devices become more and more complex, there are more and more problems in the use of medical devices, which have seriously affected the safety and effectiveness of medical devices. A survey by the U.S. Food and Drug Administration (FDA) shows that more than one-third of adverse events of medical devices involve use problems; More than 1/2 of the medical device recalls caused by design issues stem from the design of the user interface, and the root cause is also a problem with the usability design of the medical device. For example, a doctor who is untrained to place pacemaker electrodes punctures a patient's heart; The user confuses the button, causing the patient to be exposed to excessive radiation doses; The user misunderstands the icon, selects the wrong function, and causes serious harm to the patient. As a result, the United States and the European Union have gradually strengthened regulatory requirements for the availability of medical devices in recent years.

　　Overview of medical device availability

　　Medical device usability refers to the easy-to-use user interface (how the user interacts with the medical device) features, i.e., the characteristics needed to establish effectiveness, efficiency, and user satisfaction in the intended use environment. Usability engineering, also known as human factors engineering and ergonomics, refers to the use of human knowledge of human behavior, capabilities, limitations, and other characteristics to design medical devices (including software), systems, and tasks to achieve adequate usability.

　　The use of medical devices can be divided into normal use and abnormal use. Among them, normal use refers to the use of the medical device by the user in accordance with the instructions or generally acceptable practices; Abnormal use is defined as intentional or intentional omission by the user that results in actions that exceed all reasonable risk control measures of the manufacturer.

　　Normal use can be divided into correct use and wrong use. Among them, correct use refers to normal use without use errors; A usage error is an action or negligence that results in a medical device response that is different from what the manufacturer expects or the user expects. The latter can be further subdivided into perceptual errors, cognitive errors, and action errors.

　　Medical device usability engineering is used to assess and mitigate risks arising from usability issues related to normal use, such as proper use and use errors, and can be used to identify, but not to assess or mitigate risks associated with abnormal use.