An Overview of Medical Devices and Medical Equipment
As defined by the Federal Food, Drug, and Cosmetic Act, 21 United States Code, 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.
Medical Devices In The 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 labeling, 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 post-market 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 Pre-market 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 pre-market 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 pre-market 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 (EU) and European Free Trade Association (EFTA)
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 (including Is & Im)
- Class IIa
- Class IIb
- Class III
The authorization of medical devices is guaranteed by a Certificate of Conformity. This certificate is issued by the manufacturer itself, but for products in Class Is, Im, IIa, IIb or III, it should be backed by a so-called Notified Body, i.e. a test organization accredited to validate the compliance of the device to the European 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 harmonized pictograms and ISO standardized logos to indicate essential features such as instructions for use, expiry date, manufacturer, sterile, don't reuse, etc.
Medical Equipment
Medical equipment is designed to aid in the diagnosis, monitoring or treatment of medical conditions. These devices are usually designed with rigorous safety standards.
There are several basic types:
- Diagnostic equipment includes medical imaging machines, used to aid in diagnosis. Examples are ultrasound and MRI machines, PET and CT scanners, and x-ray machines.
- Therapeutic equipment includes infusion pumps, medical lasers and LASIK surgical machines.
- Life support equipment is used maintain a patient's bodily function. These include medical ventilators, heart-lung machines, ECMO, and dialysis machines.
- Medical monitors allow medical staff to measure a patient's medical state. Monitors may measure patient vital signs and other parameters including ECG, EEG, blood pressure, and dissolved gases in the blood.
- Medical laboratory equipment automates or help analyze blood, urine and genes.
- Diagnostic Medical Equipment may also be used in the home for certain purposes, e.g. for the control of diabetes mellitus
A Biomedical equipment technician or BMET is a vital component of the healthcare delivery system. Employed primarily by hospitals, BMETs are the people responsible for maintaining a facility's medical equipment.
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