Sterile medical devices refer to products free of viable microorganisms. They are supplied in a sterile state by manufacturers and can be used directly by medical institutions and the general public without additional sterilization. Manufacturers of sterile medical devices shall build production clean rooms of different grades in accordance with the Good Manufacturing Practice for Medical Devices. Strict controls are implemented over raw materials, production processes, personnel hygiene, equipment cleanliness, material handling and personnel flow, to keep microbial contamination within the acceptable limits specified by standards. Sterilization means eliminating all viable microorganisms (including pathogenic and non-pathogenic microorganisms, vegetative cells and spores) by physical or chemical means. The sterility of such devices is not absolute; it only reduces the probability of surviving microorganisms to a minimum. The current standard sets the sterility assurance level at 10⁻⁶, meaning a maximum survival probability of one in a million. Common sterilization methods for medical devices include moist heat sterilization, radiation sterilization and ethylene oxide sterilization. All sterilization operations must comply with corresponding national standards.