Medical Devices – In a nutshell

Medical Device Definition

The Medical Device Directive defines medical device as:

any instrument, apparatus, appliance, software, material or other article, whether used alone or in combination, including the software intended by its manufacturer to be used specifically for diagnostic and/or therapeutic purposes and necessary for its proper application, intended by the manufacturer to be used for human beings for the purpose of:

  • diagnosis, prevention, monitoring, treatment or alleviation of disease,

  • diagnosis, monitoring, treatment, alleviation of or compensation for an injury or handicap,

  • investigation, replacement or modification of the anatomy or of a physiological process,

  • control of conception,

and which does not achieve its principal intended action in or on the human body by pharmacological, immunological or metabolic means, but which may be assisted in its function by such means.

Regulatory Framework

Medical devices within the EU are currently regulated by the following 3 directives:

In addition, legally non-binding guidance documents, MEDDEVsconsensus statements and informative documents  provide significant help in interpreting and applying the Directives.

On 5 April 2017, 2 new Regulations on medical devices were adopted, and they entered into force on 25 May 2017.

The new rules will only apply after a transitional period. the Regulation on medical devices will apply in spring 2020 and the Regulation on in vitro diagnostic medical devices in spring 2022.

Borderline products

In certain cases, it may not be clear if a product falls under the medical device legislation or whether to classify a device as a medicine, cosmetic, biocide, personal protective equipment (PPE) etc.

The decision will largely depend on the particular intended use of the product, as assigned by the manufacturer, and on the demonstrated mode of action. The manufacturer’s claims must be substantiated by relevant data (scientific/technical/clinical).

At a European level, decisions made on borderline classification issues relating to medical devices are documented in the Manual on Borderline and Classification in the Community Regulatory Framework for Medical Devices.


The MDD covers a vast range of products from first-aid bandages and walking frames to CT scanners and non-active implants. This wide range of medical technology reflects tens of thousands of medical devices. Medical devices are categorised into classes according to the degree of risk inherent in the device

Classification of a medical device depends upon a series of factors, including:

  • how long the device is intended to be in continuous use

  • whether or not the device is invasive or surgically invasive,

  • whether or not the device is implantable

  • whether or not the device is active

  • whether or not the device contains a substance, which in its own right is considered to be a medicinal substance and has action ancillary to that of the device.

The rules governing device classification are listed in Annex IX of Directive 93/42/EEC and are further elaborated on in the MEDDEV guidance ‘MEDDEV 2.4/1 Guidelines for the Classification of Medical Devices. The classification rules are a set of broad statements relating to situations, functions, parts of the body treated, properties etc.

According to these rules, medical devices and accessories are classified into one of the following classes:

Class I – generally regarded as low risk

Class IIa – generally regarded as medium risk

Class IIb – generally regarded as medium risk

Class III – generally regarded as high risk

Further to this, there are subclasses Is (for sterile class I products) and Im (class I products with a measuring function).

The application of classification rules depends on the intended use of the products and therefore the manufacturer bears the whole responsibility for this.

The authorization of medical devices is guaranteed by a Declaration of Conformity. This declaration is issued by the manufacturer, but for products in Class Is, Im, IIa, IIb or III, it must be verified by a Certificate of Conformity issued by a Notified Body.

The classification of a device determines the conformity assessment options that are applicable to the device, with higher risk devices undergoing higher levels of assessment.

Definition of Manufacturer

The Medical Device Directive defines manufacturer as:

the natural or legal person with responsibility for the design, manufacture, packaging and labelling of a device before it is placed on the market under his own name, regardless of whether these operations are carried out by that person himself or on his behalf by a third party.

The obligations of this Directive to be met by manufacturers also apply to the natural or legal person who assembles, packages, processes, fully refurbishes and/or labels one or more ready-made products and/or assigns to them their intended purpose as a device with a view to their being placed on the market under his own name. This subparagraph does not apply to the person who, while not a manufacturer within the meaning of the first subparagraph, assembles or adapts devices already on the market to their intended purpose for an individual patient.

Essential Requirements

Medical devices can only be put on the European Market if they satisfy a set of criteria called “Essential Requirements”, as set out in Annex I of the Medical Device Directive. The essential requirements give particular consideration to:

  • the safety,

  • the technical performance and

  • the medical performance of a medical device

All medical devices must comply, where applicable, with these requirements. Manufacturers are required to check each device against each requirement, determine whether the requirement is applicable, acquire documented evidence of compliance and keep this evidence available in the technical file of the product.

The conformity-assessment procedure is used to show proof that the requirements concerning safety and technical performance have been fulfilled while medical performance is verified in the context of clinical assessment.

The manufacturer demonstrates the conformity of a medical device to the essential requirements by affixing the CE marking to each individual device.