In the USA the FDA regulates medical device manufacture and as part of this process classifies medical devices into one of three categories.

Class I: Most Class I devices and a few Class II devices are exempt from the premarket notification [510(k)]. They have only general controls and a few class I devices are even exempt from GMP requirements with the exception of complaint files and general record keeping requirements. Examples of Class I devices include elastic bandages, examination gloves, and hand-held surgical instruments.

Class II: These devices can have General Controls and Special Controls. Devices in class II held to a higher level of assurance than Class I devices, and are designed to perform as indicated without causing injury or harm to patient or user. Examples of Class II devices include powered wheelchairs, infusion pumps, surgical drapes and an implantable radiofrequency transponder system for patient identification and health information.

Class III: This class of devices requires General Controls and Premarket Approval. They are generally the highest risk devices and are therefore subject to the highest level of regulatory control. Examples of Class III devices that currently require a premarket notification include: implantable pacemaker, pulse generators, HIV diagnostic tests, automated external defibrillators, and dental implants.

Courtesy steveblank.com and Wikipedia