A medical device is any device intended to be used for medical purposes.
Because potential for hazards are inherent when using a device for medical purposes, medical devices must be proved safe and effective with reasonable assurance before regulating agencies allow marketing of the device.
As the associated risk of the device increases the amount of testing required to establish safety and efficacy also increases.
As associated risk of a medical device increases, the potential benefit to the patient must also increase.
In the United States the Federal Food, Drug, and Cosmetic Act (FD&C Act) in 1938 regulated medical devices, later updated in 1976.
Medical devices vary in both their intended use and indications for use.
Medical devices range from simple, low-risk devices such as tongue depressors, medical thermometers, disposable gloves, and bedpans to complex, high-risk devices that are implanted and sustain life.
The design of medical devices constitutes a major segment of the field of biomedical engineering.
Food and Drug Administration defines a device as 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 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 its primary intended purposes”.
Under the Food, Drug, and Cosmetic Act, the U.S. Food and Drug Administration recognizes three classes of medical devices, based on the level of control necessary to assure safety and effectiveness.
Class I
Class II
Class III
Device ClassRiskFDA Regulatory Control
Class I Low Risk General Controls Tongue, Electric Toothbrush, Bandages, Hospital Beds
Class II Medium Risk General Controls + Pre-Market Notification Catheters, Contact Lenses, Pregnancy Test Kits
Class III High Risk General Controls + Special controls + Pre-Market Approval Pacemakers, Defibrillators, Implanted prosthetics, Breast implants
Class I devices are subject to the least regulatory control and are not intended to help support or sustain life or be substantially important in preventing impairment to human health, and may not present an unreasonable risk of illness or injury.
Examples of Class I devices include elastic bandages, examination gloves, and hand-held surgical instruments.
Class II devices are subject to special labeling requirements, mandatory performance standards and postmarket surveillance.
Examples of Class II devices include acupuncture needles, powered wheelchairs, infusion pumps, air purifiers, surgical drapes, stereotaxic navigation systems, and surgical robots.
Class III devices are usually those that support or sustain human life, are of substantial importance in preventing impairment of human health, or present a potential, unreasonable risk of illness or injury and require premarket approval.
Examples of Class III devices include implantable pacemakers, pulse generators, HIV diagnostic tests, automated external defibrillators, and endosseous implants.
Reports from 2017 and 2018 reveal more than 18,000 manufacturers produced an estimated 190,000 distinct medical devices regulated by the US FDA.