How to classify medical devices according to the EU MDR

With the new Medical Device Regulation, it is important for medical device manufacturers to understand how the new classification rules apply to the different types of medical devices. These new EU MDR classification rules can be a bit confusing, and because they affect what you have to do before selling your product, you will want to understand them to ensure you do not delay your time to market with unnecessary work or setbacks.

What are the criteria for classifying medical devices into MDR classes?

The MDR medical device classification is based on the perceived risk – impact that a medical device has on the human body, regardless of whether it is a patient and/or user body. The medical device classes are described in Article 51 of the MDR, which separates medical devices into four classes based on medical device types: class I, class IIa, class IIb, and class III. While determining the class is the responsibility of the manufacturer, the class determination also identifies responsibilities for the notified body for all classes except class I.

What are Class I, II, and III medical devices?

MDR device classification is driven by the level of risk that is posed by the medical device on patient safety. MDR classification separates medical devices into the following classes; some EU medical device classification examples are provided:

• Class I (low risk) – These are devices that pose almost no risk to patient safety. Class I examples include bandages, wheelchairs, and surgical instruments.
• Class IIa (medium risk) – Class IIa medical device examples include surgical clamps, and this classification requires regular assessment by a notified body.
• Class IIb (medium/high risk) – Class IIb medical devices include, e.g., bone fixation devices, and regular conformity assessments are mandated with notified bodies.
• Class III (high risk) – Class III medical devices include machinery that is important to patient health or to sustaining the life of a patient.

Low risk, Class I medical devices are further sub-divided into four sub-classes:

• Class I – Non-sterile devices, or products without a measurement function (e.g., facial mask, gauze, gel for ultrasound).
• Class Is – Product that is delivered sterile and must be either transported in a sterile condition or sterilised on receipt (e.g., sterile gauze, sterile gown for the surgeon, sterile syringe).
• Class Im – Device with a measuring function (e.g., syringe with measurement function, spoon for giving antibiotics).
• Class Ir – Reprocessed or reused products (e.g., instruments for dental examination, surgical instruments such as scissors, tweezers, lancets).

The risk level of the assigned classification of the medical device will determine which conformity assessment path must be followed for that medical device.

How do you classify a medical device in Europe?

In order to help with classification, there are 22 EU MDR classification rules in Annex 8 for guidance. While there is still no common EU medical device nomenclature (Article 26), the rules are intended to sort out the medical devices into their proper classifications.

The classification of medical devices is based on the following parameters:

• how long the device is in contact with the patient / user
• on which part of the body the product acts
• whether the product is invasive or not
• whether the product is active or not

Considering the duration of use, the MDR differentiates the following concepts:

• “Transient” is continuous use for less than an hour,
• “short term” is continuous use between an hour and 30 days, and
• “long term” is continuous use over 30 days.

Classification of invasive and active devices depends on which part of the body they are in contact with:

• surface (intact skin),
• any natural opening in the body (body orifice), or
• penetrating into the body.

There are no strict rules that would say that if a device is, for example, invasive, it will be in class IIa. Once you define the type of device (invasive, non-invasive, active, or special), you need to check its other parameters: the longer the duration of use, or the more “invasive” in terms of part of the body, the higher risk class (with respect to MDR classification rules). For example, invasive devices with respect to body orifices (other than surgical invasive devices) are classified as class I if they are intended for transient use, class IIa if they are intended for short-term use, or class IIb if they are intended for long-term use. Surgically invasive devices intended for short-term use are classified as class IIa; if they are intended specifically to control, diagnose, monitor, or correct a defect of the heart or of the central circulatory system, they are classified as class III.

Invasive vs. non-invasive devices

Non-invasive devices are all devices that do not enter the body through any opening or through the surface of the body itself. Non-invasive devices correspond to the first four MDR classification rules:

• Rule 1 – Non-invasive devices
• Rule 2 – Non-invasive devices intended for channeling or storing blood, body liquids, cells or tissues, liquids or gases
• Rule 3 – Non-invasive devices intended to modify biological or chemical composition of human tissues or cells, blood, body liquids, other liquids and cells
• Rule 4 – Non-invasive devices in contact with injured skin or mucous membrane

Invasive devices are devices that enter the body in whole or in part, either through an opening of the body or through the surface of the body. Invasive devices are covered by the classification rules 5–8:

• Rule 5 – Devices that enter body orifices
• Rule 6 – Surgical devices for transient/impermanent use
• Rule 7 – Surgical devices for short-term use
• Rule 8 – Surgical devices for long-term use and implantable devices

Is the product active?

Active devices are all devices that need any source of energy to work. Active devices are covered by the classification rules 9–13:

• Rule 9 – Active therapeutic devices intended to exchange or administer energy
• Rule 10 – Active devices for diagnosis and monitoring that emit ionising radiation
• Rule 11 – Software intended to provide information that is used to make decisions with diagnosis or therapeutic purposes (from class I to class III)
• Rule 12 – Active devices intended to administer and/or remove medicinal products, body liquids, or other substances
• Rule 13 – All other active devices

Special products

The MDR has recognised that there are combined medical devices that can be both invasive and active, or that combine a medical device with an in-vitro diagnostic device or a drug (medicinal). For combined medical devices, classification depends on the determination of the main purpose – whether the main purpose is realised as a medical device, or as a medicine or in-vitro diagnostic device.

Furthermore, the MDR has recognised some new technologies like nanomaterials that also need special attention. For all of those types of devices, the MDR has prepared the following classification rules 14–22 that cover special devices:

• Rule 14 – Devices incorporating a medicinal substance, including human blood or plasma
• Rule 15 – Contraception or prevention of the transmission of sexually transmitted diseases
• Rule 16 – Specific disinfecting, cleaning, and rinsing devices
• Rule 17 – Devices specifically intended for recording of diagnostic images generated by X-ray radiation
• Rule 18 – Devices utilising non-viable tissues or cells of human origin, or tissues of animals or derivatives
• Rule 19 – Devices incorporating or consisting of nanomaterial
• Rule 20 – Invasive devices with respect to body orifices to administer medicinal products by inhalation
• Rule 21 – Substances or combinations of substances that are intended to be introduced into the human body via a body orifice or applied to the skin and that are absorbed
• Rule 22 – Active therapeutic devices with an integrated or incorporated diagnostic function that significantly determines the patient management

Three steps for classifying a medical device under the EU MDR

To classify your product, follow these steps:

1. Decide what type of device you have: non-invasive, invasive, active, or special product.
2. Look at each classification rule from the first to the last (Rules 1–22). If you think multiple rules apply, you should go with the one with the highest risk (which classifies the product into a higher class).
3. If your product is combined (a medical device with medicine), you must determine the main purpose – whether the main purpose is realised as a medical product or as a medicine.

Make sure you update to the new MDR classification

It is critical that you assess your medical devices against these new classifications to ensure that you meet the critical assessment criteria for your medical device as per the new MDR regulations. Failure to properly classify your medical device could prevent your introduction into the EU market, through delays or outright refusal. Even though the interpretation of the rules is changing, it is vital that you keep up to date on these changes to avoid problems with your medical device classification.

To learn more about how the classification of medical devices in Europe differs from that in the U.S., download this free white paper: FDA vs. MDR technical documentation.

FDA vs. EU MDR Technical Documentation Matrix

Free white paper that describes the differences between FDA and MDR requirements

Download now

FDA vs. EU MDR Technical Documentation Matrix

Free white paper that describes the differences between FDA and MDR requirements

Download now

FDA vs. EU MDR Technical Documentation Matrix

Free white paper that describes the differences between FDA and MDR requirements

Download now