Classification in European Union

This is the framework the rest of the site measures against, so there is no divergence to report — but there is a shape worth understanding. The MDR classifies by asking what the device does to the body and for how long, not what technology it uses. Four questions carry most of the weight: is it invasive, and if so how; how long is the contact; is it active; and does it fall into one of the special categories. Everything else is refinement. A device that looks unremarkable can land in Class III because one of those answers changed, which is why the reasoning matters more than the letter.

Class I, IIa, IIb and III are MDR labels and mean nothing outside the EU framework. Australia uses the same four labels under different rules; Canada, Brazil and India use I to IV; the United States uses I to III on an entirely different basis. Reading a class across a border by matching the label is the most common way to reach a confident wrong answer.

The intended purpose, applied to the 22 rules in Annex VIII. Invasiveness, duration of contact, whether the device is active and the special categories carry most of the weight. Where several rules apply, the strictest one decides.

The manufacturer. Under Article 10 of Regulation (EU) 2017/745, classifying the device correctly and documenting the rationale is the manufacturer's responsibility. A Notified Body reviews that rationale during conformity assessment and can challenge it, but does not assign the class.

It can, because the class follows the intended purpose. Narrowing it to what the device actually does is a legitimate exercise, done in the technical documentation. Writing an intended purpose that contradicts how the device is marketed is not: a Notified Body reads the website alongside the file.