Kristina Zvonar Brkic Updated: September 22, 2023.
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 medical device, you will want to understand them to ensure you do not delay your time to market with unnecessary work or setbacks. So, what is medical device classification? Why is it important, and under which regulations do manufacturers need to classify devices? Learn in this article.
Medical device classification examples
- Class I medical devices (low risk) – devices that pose almost no risk to patient safety.
- Class IIa medical devices (medium risk) – require regular assessment by a notified body.
- Class IIb medical devices (medium/high risk) – regular conformity assessments by notified bodies are mandated.
- Class III medical devices (high risk) – includes machinery that is important to patient health or to sustaining the life of a patient.
What is medical device classification?
Medical device classification is a way of categorizing medical devices based on their level of risk and the level of regulatory control needed to ensure their safety and efficacy. It is important because it helps to ensure that medical devices are regulated appropriately, and that patients are protected from potential harm.
The MDR device classification process involves considering factors such as the intended use of the device, its physical characteristics, the part of the body with which it is in contact (intact skin, injured skin, tissues, blood, or bones), and the duration of contact with the human body.
What are the three classifications of medical devices?
There are three classes of medical devices: class I, class II, and class III. Class I devices are considered to be low risk and are subject to the least amount of regulatory control. Class II devices are considered to be moderate risk, and class III devices are considered to be high risk.
The classification of a device can impact the regulatory requirements that a manufacturer must meet in order to bring the device to market. For example, higher-risk devices may require more extensive testing and clinical data before they can be approved for sale.
How to determine medical device classification
The MDR device classification is based on the perceived risk – the potential impact that a medical device has on the human body, regardless of whether it is the patient’s or the user’s 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 medical device classes except class I.
Medical device classification examples
Some of the common questions asked about medical device classification are: What are some examples of class III medical devices, and what is a class II medical device? 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 medical devices (low risk) – These are devices that pose almost no risk to patient safety. Class I medical devices examples include bandages, wheelchairs, and surgical instruments.
- Class IIa medical devices (medium risk) – Class IIa medical device example is surgical clamps, and this classification requires regular assessment by a notified body.
- Class IIb medical devices (medium/high risk) – Class IIb medical devices include, e.g., bone fixation devices, and regular conformity assessments are mandated with notified bodies.
- Class III medical devices (high risk) – Class III medical devices include machinery that is important to patient health or to sustaining the life of a patient.
What is a Class I medical device? A detailed explanation
Low-risk, class I medical devices are further sub-divided into four sub-classes:
- Class I medical devices – Non-sterile devices, or medical devices without a measurement function (e.g., facial mask, gauze, gel for ultrasound).
- Class Is medical devices – Medical devices that are delivered sterile and must be either transported in a sterile condition or sterilized on receipt (e.g., sterile gauze, sterile gown for the surgeon, sterile syringe).
- Class Im medical devices – Devices with a measuring function (e.g., syringe with a measurement function, spoon for giving antibiotics).
- Class Ir medical devices – Reprocessed or reused medical devices (e.g., instruments for a dental examination, or surgical instruments such as scissors, tweezers, and 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 medical device acts
- whether the medical device is invasive or not
- whether the medical device 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.
EU MDR classification rules
Classification rules for medical devices are used to categorize devices based on their potential risks to patients and users. The classification system helps to determine the level of regulatory control required for each device type. The rules take into account factors such as intended use, duration of contact with the body, and the degree of invasiveness.
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 the biological or chemical composition of human tissues or cells, blood, body liquids, or 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 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 medical device active?
Active devices are all devices that need any source of energy to work. Active devices are covered by 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 ionizing radiation
- Rule 11 – Software intended to provide information that is used to make decisions regarding diagnoses 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 medical devices
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 the recording of diagnostic images generated by X-ray radiation
- Rule 18 – Devices utilizing 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
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 medical devices
What are invasive devices? An invasive device is any medical device which, wholly or in part, penetrates the body, either through a body orifice or through the surface of the body. Examples of invasive devices include surgical instruments, catheters, and implants.
What are non-invasive devices? Non-invasive devices are medical devices that do not penetrate the body. These devices are used externally and include things like blood pressure monitors, thermometers, and ultrasound machines.
Three steps for classifying a medical device under the EU MDR
To classify your medical device, follow these steps:
- Decide what type of device you have: non-invasive, invasive, active, or special medical device.
- 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 medical device into a higher class).
- If your medical device is combined (e.g., a medical device with medicine), you must determine the main purpose – whether the main purpose is realized as a medical device 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. EU MDR Technical Documentation Matrix.
