Wednesday, 5 September 2007

CLASSIFICATION OF MEDICAL DEVICES

EUROPEAN DEFINITION OF MEDICAL DEVICES

COUNCIL DIRECTIVE 93/42/EEC of 14 June 1993 concerning medical devices defines a ‘medical device’ as:

any instrument, apparatus, appliance, material or other article, whether used alone or in combination, including the software 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


The Medicines and Healthcare products Regulatory Agency (MHRA) regulates medical devices in the UK under European legislation. Medical devices must not be mistaken with medicinal products.

USA DEFINITION
(BY FOOD & DRUG ADMINISTRATION)


A medical device is an instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article, including a component part, or accessory which is:
recognized in the official National Formulary, or the United States Pharmacopoeia, or any supplement to them,
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, or
intended to affect the structure or any function of the body of man or other animals, and which does not achieve any of its primary intended purposes through chemical action within or on the body of man or other animals and which is not dependent upon being metabolized for the achievement of any of its primary intended purposes.

as defined by the Federal Food, Drug, and Cosmetic Act, 21 United States Code [321] (h).



CLASSIFICATION OF MEDICAL DEVICES

United States

The Food and Drug Administration has recognized three classes of medical devices based on the level of control necessary to assure the safety and effectiveness of the device. The classification procedures are described in the Code of Federal Regulations, Title 21, part 820 (usually known as 21 CFR 820).

Class I: General Controls

Class I devices present minimal potential for harm to the user and are often simpler in design than Class II or Class III devices. These devices are subject only to general controls. General controls cover such issues as manufacturer registration with the FDA, good manufacturing techniques, proper branding and labelling, notification of the FDA before marketing the device, and general reporting procedures. (Most Class I devices are exempt from the good manufacturing practices and/or the FDA notification regulations.) These controls are deemed sufficient to provide reasonable assurance of the safety and effectiveness of the device; or the device is not life-supporting or life-sustaining and does not present a reasonable source of injury through normal usage. Devices in this category include tongue depressors, bedpans, elastic bandages, examination gloves, and hand-held surgical instruments and other similar types of common equipment.

Class II: General Controls with Special Controls

Class II devices are those for which general controls alone are insufficient to assure safety and effectiveness, and additional existing methods are available to provide such assurances. Therefore, Class II devices are also subject to special controls in addition to the general controls of Class I devices. Special controls may include special labeling requirements, mandatory performance standards, and postmarket surveillance. Devices in Class II are held to a higher level of assurance than Class I devices that they will perform as indicated and will not cause injury or harm to patient or user. Devices in this class are typically non-invasive and include x-ray machines, PACS, powered wheelchairs, infusion pumps, surgical drapes, surgical needles and suture material, and acupuncture needles.

Class III: General Controls and Premarket Approval

A Class III device is one for which insufficient information exists to assure safety and effectiveness solely through the general or special controls sufficient for Class I or Class II devices. Such a device needs premarket approval, a scientific review to ensure the device's safety and effectiveness, in addition to the general controls of Class I. Class III devices are described as those for which "insufficient information exists to determine that general controls are sufficient to provide reasonable assurance of its safety and effectiveness or that application of special controls ... would provide such assurance and if, in addition, the device is life-supporting or life-sustaining, or for a use which is of substantial importance in preventing impairment of human health, or if the device presents a potential unreasonable risk of illness or injury."

Examples of Class III devices which require a premarket approval include replacement heart valves, silicone gel-filled breast implants, implanted cerebral stimulators, implantable pacemaker pulse generators and endosseous (intra-bone) implants (with the exception of root-form endosseous dental implants which were recently reclassified as Class II).

European Union and European Economic Area

The classification of medical devices in the European Union is outlined in Annex IX of DIR 93/42/EEC. There are basically four classes, ranging from low risk to high risk.

Class I
Class IIa
Class IIb
Class III

The authorisation of medical devices is guaranteed by a Certificate of Conformity. This certificate is issued by the manufacturer itself, but for products in classe II until III, it should be backed by a so-called Notified Body, i.e. a test organisation accredited to the validate the compliance of the device with the council directive. Medical devices that pertain to class I (on condition they do not need to be sterilised or are not used to measure a function) can be put on the market purely by self-certification.

The European classification depends on rules that involve the medical device's duration of body contact, its invasive character, its use of an energy source, its effect on the central circulation or nervous system, its diagnostic impact or its incorporation of a medicinal product.

Certified medical devices should have the CE mark on the packaging, insert leaflets, etc.. These packagings should also show harmonised pictograms and ISO standardised logo's to indicate essential features such as instructions for use, expiry date, manufacturer, sterile, don't reuse, etc...

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