Article 51 requires all medical devices to be classified into one of four classes. The classification determines the conformity assessment route for the device. While classification is primarily the concern of the manufacturer, if the device falls into Classes IIa, IIb or III it has implications for the Notified Body. Article 51 confirms that if a Manufacture and Notified Body cannot agree on the classification, the Competent Authority of the Manufacturer is the body that makes the final determination.

Before attempting to classify any device, it is recommended to first develop the following documented statements required for the Technical Documentation (Annex II, 1.1):

(a) general description of the device including its intended purpose and intended users;

(c) the intended patient population and medical conditions to be diagnosed, treated and/or monitored and other considerations such as patient selection criteria, indications, contra-indications, warnings;

(d) principles of operation of the device and its mode of action, scientifically demonstrated if necessary;

Annex VIII contains the rules to be followed to determine the classification of the device and the three chapters are intended to be read and applied in sequence. Therefore, referring as necessary to the documents (a), (c) and (d) listed above, perform the following steps:

  1. Start by reviewing the definitions (Chapter I): For example; duration, invasive, active. Identify those that are relevant to the device under consideration.
  2. Next, read through the implementing rules (Chapter II) and decide if any are applicable to the device under consideration. For example, if the device is intended to be used in different parts of the body or conditions, which is the most critical intended use.
  3. Next, work through the twenty two classification rules (Chapter III) step by step in order to arrive at a classification for the device under consideration. In the unusual case that it is not possible to classify the device with certainty, the Competent Authority can be asked to make a final decision. Procedures exist for the Competent Authorities to consult and in exceptional cases achieve a consensus decision on the classification of a device.

Finally, it is important to document the decision on the classification and the supporting justification. It is another required item in the Technical Documentation (Annex II, 1.1):

(f) the risk class of the device and the justification for the classification rule(s) applied in accordance with Annex VIII;