EU MDR Classification of medical devices

Medical device:

The device which is intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, in man or other animals.

Classification of medical devices:

• Class I (low risk) – devices that pose almost no risk to patient safety.
• Class IIa (medium risk) – requires regular assessment by a notified body.
• Class IIb (medium/high risk) – regular conformity assessments are mandated with notified bodies.
• Class III (high risk) – includes 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 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.

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.

• 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 recognized 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 realized as a medical device, or as a medicine or in-vitro diagnostic device.

Furthermore, the MDR has recognized 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 realized as a medical product or as a medicine.