Medical device classification
Medical devices are classified into four risk groups, according to the classification rules: I, IIa, IIb, and III (depending on the risk during use).
In Article 51 and in Annex VIII of Regulation (EU) 2017/745, the classification principles are laid down in great detail. The manufacturer is responsible for applying the classification rules, which are determined by the products' intended intent.
MDCG 2021-24 Guidance on classification of medical devices
Article 52 of Regulation (EU) 2017/745 establishes the conformity assessment procedures for the different classes of devices.
Class I Devices: Low risk, non-invasive, everyday devices or appliances are classified as class I devices. The manufacturer is required to issue the EU declaration of conformity and to draw up the technical documentation for such devices.
Class Is Devices: Class I devices placed on the market in sterile condition. These devices also require a technical file, as well as an application to a EU notified body for manufacturing certification in accordance with sterility requirements.
Class Im Devices: Class I devices with a measuring function. The manufacturer must provide a technical file and be certified by a EU notified body for manufacturing in accordance with metrology requirements.
Class Ir Devices: Class I reusable surgical instruments. The manufacturer must provide a technical file and be certified by a EU notified body on the aspects relating to the reuse of the device.
Class IIa Devices: Class IIa devices generally include low to medium risk and refer mainly to devices installed within the body in the short term. Class IIa devices are those which are installed within the body for only between 60 minutes and 30 days. Requirements are the EU declaration of conformity, the technical documentation and a conformity assessment procedure carried out by a EU notified body according to Annex IX or Annex XI.
Class IIb Devices: Slightly more complex than class IIa devices, class IIb devices are generally medium to high risk and will often be devices installed within the body for periods of 30 days or longer. Similar compliance route to class IIa devices with the EU declaration of conformity, the technical documentation and a conformity assessment procedure carried out by a EU notified body according to Annex IX or Annex XI, with an additional requirement on the assessment of the technical documentation for every class IIb implantable device, with certain exceptions.
Class III Devices: Class III devices are strictly high risk devices. The steps to compliance here include the EU declaration of conformity, the technical documentation and a conformity assessment procedure carried out by a EU notified body according to Annex IX or Annex X coupled with Annex XI.