8.1: Introduction to Medical Devices and Classifications
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Introduction to Medical Devices
Defining what a medical device is can be a bit complex. A medical device can range from a Band-Aid to a tongue depressor, to a clinical testing kit, to a replacement hip. Due to the functional complexity of devices and combination applications (for example, birth control implants), the regulations can also be very complex and specialized as well. The Medical Device Product Classification database lists over 6,000 types of medical devices regulated by FDA's Center for Medical Devices and Radiological Health (CDRH) and the classification assigned to each type. Depending on the device classification, along with other factors, federal regulations (such as the Code of Federal Regulations, Title 21) define requirements that must be fulfilled for CDRH to approve or clear devices sold in the United States. In this chapter, we will look at a broad overview of medical device regulation, including different categories of devices, regulations that apply, and the approval process.
As defined by 201(h) of the FD&C Act, a medical device is "an instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article 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…" (fda.gov)
Explore!
Explore at the FDA website examples of medical devices: www.fda.gov/medicaldevices/device-approvals-denials-and-clearances/recently-approved-devices. What are some examples of items you didn't know are classified as devices? (look at the left-hand tabs)
The FDA began regulating medical devices in 1938 under the FD&C Act. Under this act, the FDA focused on adulteration but not safety. It was not until the 1960s where the FDA began looking at areas of safety and effectiveness and was amended in 1976 to include setting standards and premarket approval.
The Center for Devices and Radiological Health (CDRH)
The Center for Devices and Radiological Health (CDRH) oversees the regulation of medical devices and radiation-emitting products. However, in 1991, the FDA created an inter-center agreement that gave the Center for Biologics Evaluation and Research (CBER) full responsibility to devices related to blood and cellular products. Later on, combination products. Medical devices must be registered and listed with the FDA. Even if they do not sell the device here in the US, they still must register with the FDA. The CDRH department has an entire website dedicated to medical device training called CDRHLearn. https://www.fda.gov/training-and-continuing-education/cdrh-learn
CDRH Organization
Medical Device Registration (21 CFR 807)
All medical devices (both domestic and foreign) must be registered and listed with the FDA.
Explore!
Go to CDRHLearn and Click on "Start here," click on "Overview of Regulatory Requirements" video, and watch this comprehensive 30min video on medical device regulation. Provide any interesting notes below
Classification of a Medical Device (21 CFR 860)
Medical devices are regulated based on the relative risk posed by the product and organized by class. A Class I device is the lowest risk device, Class II is an intermediate risk and, Class III are high-risk devices.
- Class I: A Class I device is a relatively low-risk device with minimal safety considerations for the consumer; safety is assured through a general set of guidelines called "general controls." Examples of a Class I device include prescription sunglasses or elastic bandages. There are currently approximately 780 Class I devices on the market. General Controls include Adulteration/Misbranding, Electronic Establishment, Registration, Electronic Device Listing, Premarket Notification [510(k)], Quality Systems, Labeling, and Medical Device Reporting (MDR).
- Class II: Most devices are classified as Class II, an intermediate-risk device that is subject to "special controls" to assure safety. The majority of Class II devices are subject to premarket review and clearance by FDA through the 510(k)-pre-market notification process and may have rigorous review requirements in-line with a Class III device. Examples include pregnancy tests and motorized wheelchairs. There are currently over 800 Class II devices on the market.
- Class III: A Class III device is a high-risk device and includes devices that may be implanted or support life. Also, devices that are new in technology, and there is no substantially equivalent device currently available, must follow Class III regulations. Examples of a class III device include a pacemaker. Class III devices are subject to the most rigorous review process that includes general controls, special controls, and premarket approval. There are fewer than 120 Class III devices currently on the market.
Explore!
Learn More! Classify your medical device! Go into the Classification database and search for "wheelchair."
What classification comes up? Search for a device you’re curious about.
Medical Device Classification: 21 CFR 862-892
"Most medical devices can be classified by finding the matching description of the device in Title 21 of the CFR, Parts 862-892. FDA has classified and described over 1,700 distinct types of devices and organized them in the CFR into 16 medical specialty panels such as cardiovascular devices or in vitro diagnostics”
862 = Chemistry/Toxicology
864 = Hematology/Pathology
866 = Immunology/Microbiology
868 = Anesthesiology
870 = Cardiovascular
872 = Dental
874 = Ear, Nose and Throat
876 = Gastro/Urology
878 = General Plastic Surgery
880 = General Hospital
882 = Neurological
884 = Obstetrical/Gynecological
886 = Ophthalmic
888 = Orthopedic
890 = Physical Medicine
892 = Radiology Regulations
For each of the devices classified, the CFR provides a description, which includes intended use, class the device belongs (i.e., Class I, II, or III), and marketing requirements.