- any instrument, apparatus, or other article that is recognized in the official National Formulary, or the USP, or any supplement to them, or that is intended to be used to prevent, diagnose, mitigate, or treat a disease or to affect the structure or function of the body, with the exception of drugs. For example, a medical device may include, but is not limited to ventilators, monitors, dialyzers, and any other medical electronic equipment, implants, thermometers, patient restraints, syringes, catheters, in vitro diagnostic test kits and reagents, disposable components, parts, accessories, and related software.