expected to pose an unreasonable risk of illness or injury. (21 USC 360c(a)(1)(A))

Class II medical devices.

Devices that present more risk than Class I devices (see above). For these devices, general controls are not by themselves sufficient to provide reasonable assurance of safety and effectiveness, but sufficient information is available to develop “special controls” (for example, guidelines) for that purpose (21 USC 360(c)(a)(1)). For a Class II device to be legally marketed, the manufacturer must usually submit a notification of intent to market and receive FDA clearance under 510(k) provisions (referring to the applicable section of the Medical Device Amendments of 1976. (21 USC 360(k))

Class III medical devices.

Devices that are intended to support or sustain life or play an important role in preventing impairment or that are considered to pose an unreasonable risk of illness or injury. For devices in this class, FDA has determined that general controls are inadequate to reasonably assure safety and effectiveness and that available information is insufficient to develop adequate special controls. (21 USC 360(c)(a)(1)) Class III devices usually require FDA approval.


A process for FDA to authorize a device for marketing based on a review of evidence of safety and equivalence to certain previously marketed devices; clinical evidence of safety and effectiveness is not usually required.

Clinical trial.

A prospective study involving human subjects that is designed to evaluate a health care intervention (e.g., device therapy, diagnostic test).

Close call

(see Near miss).

Combination product.

A product that (1) is comprised of two or more regulated components, i.e., drug/device, biologic/device, drug/biologic, or drug/device/biologic, that are physically, chemically, or otherwise combined or mixed and produced as a single entity; (2) is comprised of two or more separate products packaged together in a single package or as a unit and comprised of drug and device products, device and biological products, or biological and drug products; or (3) is packaged separately that according to its investigational plan or proposed labeling is intended for use only with an approved individually specified drug, device, or biological product where both are required to achieve the intended use, indication, or effect and where upon approval of the proposed product the labeling of the approved product would need to be changed, e.g., to reflect a change in intended use, dosage form, strength, route of administration, or significant change in dose. (21 CFR 3.2(e))

Compassionate use.

A mechanism for securing FDA permission for the use with an individual patient of a medical device that has not been approved or cleared for marketing. (See also Emergency use.)

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