Classification MDD

Article 11 of the MDD gives the routes that are available for manufacturers to demonstrate that their devices are in compliance with the European directive, which allows them to apply the CE mark. Medical devices are categorized, based on their properties, function and intended use, in one of the four risk classes: 
Class I
devices with low risk.
sterile devices which are in class I are indicated as Class Is.
class I devices with a measuring function are indicated as class
Cass II(a) and Class II(b)
devices with an average risk
Class III
devices with a high risk
The main goal is to apply the most strict controls to devices with the biggest risk to health or safety.
The classification rules are focused on the type of product:
Non-invasive devices   Rules 1, 2, 3, 4
Invasive devices Rules 5, 6, 7, 8
Active devices Rules 9, 10, 11, 12
Special rules Rules 13, 14, 15, 16, 17, 18
There is a guidance document created (MEDDEV) which gives further clarification on the classification of medical devices: MEDDEV 2.4/1 – GUIDELINES FOR THE CLASSIFICATION OF MEDICAL DEVICES (see the EU website for the most recent version).