EU Medical Device Regulation requirements for all device types, explained

For years, medical devices in the EU were classified under the Medical Device Directive (MDD) system, and manufacturers were familiar with the certification requirements for each device class. The newer Medical Device Regulation (MDR) system has changed how devices are classified and what requirements they must meet to be certified. Whether it's reclassifying an existing device or classifying a new device, it's natural to be unsure about how to meet compliance requirements.

By understanding how medical devices are classified under the new system, which MDR requirements they must meet and how legacy devices are affected, manufacturers can better understand the path to certification. This guide by Kiwa | NQA helps to clarify common points of confusion with the new EU MDR (Regulation 2017/745) requirements. 

Key Takeaways 

• The EU MDR (Regulation 2017/745) assigns all medical devices to one of four risk classes based on intended purpose, invasiveness, duration of use and device type.
• Classification is determined by applying 22 rules set out in Annex VIII, with the highest applicable rule always governing.
• Class I devices generally allow manufacturers to self-certify, with some exceptions.
• Classes IIa, IIb and III typically require the involvement of a notified body, with the level of review depending on the device class and conformity assessment route.
• MDD classifications do not automatically transfer to MDR. Manufacturers must assess classification under Annex VIII, although certain legacy devices may qualify for transitional provisions.

The EU MDR Classification System at a Glance

Under Article 51 of Regulation (EU) 2017/745, medical devices are classified using a risk-based system. This classification is based on the device's intended purpose, as stated by the manufacturer, as well as its invasiveness and intended duration of use. The technology or design alone doesn't determine the device's classification.

The classification a device receives is determined by the 22 rules laid out in Annex VIII. These rules group medical devices into four categories:

1. Noninvasive devices are covered by rules 1-4.
2. Invasive devices are covered by rules 5-8.
3. Active devices are covered by rules 9-13.
4. Special rules devices are covered by rules 14-22.

If multiple rules apply to a device, the rule resulting in the highest classification applies. There are also many rule exceptions, which are part of the reason why classification is often complex.

EU MDR Device Classes and Their Compliance Requirements

A device's classification affects its compliance requirements, including which conformity assessment procedure it must follow. This conformity assessment is how a device meets the necessary medical device regulations.

The conformity assessment route also affects the level of involvement from a notified body, the clinical evidence required and the level of post-market surveillance required. 

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Kiwa | NQA

Class I Devices

Class I is the lowest of the four tiers of EU MDR device classification, with stethoscopes, bandages and examination gloves falling under this classification. Because of the lower risk, most Class I devices can be self-certified by the manufacturer, without a notified body To self-certify, the manufacturer must issue an EU Declaration of Conformity and draw up the technical documentation.

However, there are three instances when a manufacturer can't fully self-certify a Class I device. Instead, a notified body must be involved with certifying a particular aspect of the device, and the required technical documentation must be provided. These devices are classified into three subclasses:

• Class Is: Any Class I device that's placed on the market in a sterile condition is classified as Class Is. These devices require an application to a notified body, which will assess the aspects relating to sterility. 
• Class Im: Class I devices that contain a measuring function, such as a timer, are subclassed as Class Im. A notified body must be involved only for metrological aspects.
• Class Ir: Any Class I reusable surgical instrument falls under Class Ir and must be certified by a notified body. The notified body will only be involved in assessing the reprocessing aspects, such as cleaning, disinfection, sterilization, maintenance and functional testing.

Whether the device is self-certified or not, it must still meet the requirements of Annex I for general safety and performance. A post-market surveillance (PMS) report must also be maintained.

Class IIa Devices

Generally considered low- to medium-risk, Class IIa devices can include certain short-term invasive devices and certain active diagnostic and monitoring devices. Common Class IIa devices include hearing aids and certain urinary catheters. Active diagnosis and monitoring devices, such as ultrasound equipment, can also fall under Class IIa.

Certain software, particularly as a medical device (SaMD), can also be classified as Class IIa under Rule 11 in Annex VIII. This rule states that any software intended to provide information to help clinicians make decisions for diagnostic or therapeutic purposes is generally classified as. There are some exceptions to this rule, such as software that provides information for decisions that may cause a person's death, irreversible deterioration to their health, or serious deterioration in their health or a surgical intervention.

Class IIa devices require technical documentation and the EU Declaration of Conformity. In most Class IIa conformity assessment routes, manufacturers must involve a notified body, though the level and type of notified body review can vary depending on the selected route.

Devices in the Annex IX route may undergo a full Quality Management System audit and technical documentation assessment. Alternatively, the Annex XI route can assess a device in one of two ways. The first is through Annex XI Part A Product Quality Assurance, and the second is through Annex XI Part B Product Conformity Verification. In both cases, the device's technical documentation must be assessed in accordance with Annex II and Annex III. 

Regardless of the conformity assessment route, a representative device can be assessed for each category. Once a Class IIa device has been certified, a periodic safety update report (PSUR) is required at least every two years.

Class IIb Devices

Class IIb devices are considered medium- to high-risk, which is why they're scrutinized closely before receiving certification. These devices can include long-term implantable devices. However, devices that modify the chemical or biological composition of the human body, or are used to store or channel body fluids, can also fall under Class IIb.

The compliance route for Class IIb devices is similar to that for Class IIa devices, except that the technical documentation is subject to more stringent assessment. Devices going down the Annex XI route must also undergo an Annex X type examination.

Additionally, rather than assessing a representative device for each category, every implantable Class IIb device must be assessed. Some devices are exempt from this rule, such as sutures, staples and ancillary components like screws and plates. The Summary of Safety and Clinical Performance (SSCP) must be publicly accessible via EUDAMED for applicable implantable Class IIb devices, too.

The PSUR frequency increases from every two years to every year. 

Class III Devices

Class III devices are those with the highest risk, and include devices that: 

• Support life, such as pacemakers and implantable defibrillators.
• Directly contact the heart, such as certain catheters.
• Directly contact the central circulatory system, such as artificial heart valves.
• Directly contact the central nervous system, such as cerebrospinal fluid shunts.
• Incorporate medicinal substances with ancillary action, such as drug-eluting stents.

Class III devices must undergo the most stringent conformity assessments, with two routes available. The first involves the conformity assessment outlined in Annex IX Chapters I and II. The second route involves an Annex X type examination, followed by either an Annex XI Production Quality Assurance assessment or an Annex XI Part B Production Verification assessment. Whichever route is taken, certain devices must also undergo a clinical evaluation consultation.

As with many Class IIb devices, the technical documentation for every Class III device must be assessed, rather than just a representative device. The SSCP must be publicly accessible via EUDAMED for applicable Class III and implantable devices, excluding custom-made and investigational devices.

What Is a Notified Body and When Is It Required Under EU MDR?

A notified body for medical devices is an independent conformity assessment organization designated by an EU member state or a country under specific agreements. These bodies will appear on the European Commission's NANDO database of designated notified bodies. 

Notified bodies carry out the necessary assessments and procedures to confirm that a device conforms with EU MDR requirements before it reaches the market.

For most device classifications, a notified body is required under EU MDR, with standard Class I being the exception. Standard Class I devices don't require a notified body at all, while Class Is, Class Im and Class Ir devices will only need one for a specific aspect. Any device that requires a notified body won't be able to receive CE marking without the body's involvement.

Manufacturers can choose their notified body for a device's certification, but cannot apply to multiple notified bodies at the same time for the same procedure. 

How MDR Reclassification Has Affected Legacy Devices

Legacy devices are those that were certified under the previous system, MDD. These devices must eventually meet the applicable MDR requirements, but the old classifications don't automatically transfer. Instead, each device must go through the MDR classification process. 

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Kiwa | NQA

To give manufacturers time to transition their devices without pulling them from the market, devices can benefit from a transition period, provided they meet certain conditions. However, many manufacturers have found transitioning legacy devices challenging thanks to: 

• Stricter legislation: MDR places greater emphasis on clinical evidence of a device's safety and performance.
• Notified body demand: Fewer notified bodies have been designated under the MDR than under the MDD. Coupled with the large number of devices that need to be recertified, not to mention the new devices that still need to be certified, this has led to long waits for notified body involvement.
• Compliance assumptions: Some manufacturers have mistakenly assumed that their legacy devices will be recertified quickly because they hold legacy certification. Failure to prepare for the new requirements can lead to legacy devices failing to be recertified or requiring more time to meet them.
• Up-classified devices: Some legacy devices fall into higher-risk classifications under MDR, including certain software, reusable surgical instruments and combination products. These changes can increase the level of clinical evidence, technical documentation and notified body involvement required before certification.

Frequently Asked Questions

Questions about EU medical device regulation and classification are common, even among manufacturers with decades of experience. These are some of the most common questions.

What Must the Technical Documentation Include?

The elements required in the technical documentation are detailed in Annex II (Part 1), and include:

• Product name and a general description of the device, including its intended purpose.
• A description of how it should be operated.
• The risk class of the device and a justification for this class.
• A description of any device accessories.

What Defines a Transient Device?

The intended duration of a device's continuous use is a critical variable in its classification, with Annex VIII Section 1 defining the different device durations: 

• Transient devices are intended to be used for under 60 minutes. 
• Short-term devices are intended for use for between 60 minutes and 30 days.  
• Long-term devices are intended for use for more than 30 days. 

How Are Accessories Classified?

Accessories are classified in their own right, and not as part of the same procedure that classifies the device they accompany. This could result in the accessory receiving a different classification than the device it accompanies.

What Happens During a Classification Dispute?

If the manufacturer and the notified body disagree on a device's classification, the dispute will be resolved by the competent authority of the member state in which the manufacturer's place of business is registered. There are several contingencies outlined in Article 51 (2) if the manufacturer does not have a registered place of business in the EU.

How Does ISO 13485 Relate to EU MDR Regulations?

ISO 13485 is the quality management system standard that harmonizes medical device regulatory requirements. By achieving ISO 13485 certification, manufacturers can better support their efforts to meet EU MDR requirements.

Getting EU MDR Classification Right Matters

Medical device classification is the foundation of any regulatory decision under EU MDR. The device's classification affects all aspects of its MDR compliance, including whether a notified body is required and which certification routes are available.

Understanding the new criteria is key to knowing how your device will be classified. If you're reclassifying a legacy device, understanding how MDR differs from MDD can remove friction from the process.

This story was produced by Kiwa | NQA and reviewed and distributed by Stacker.