Page 47 - Biomedical Engineering and Design Handbook Volume 2, Applications

26 MEDICAL DEVICE DESIGN

Class I Class II Class III
Low risk Moderate risk High risk
General controls General controls/special controls General controls
Exempt 510(k) PMA

FIGURE 2.3 Medical device class hierarchy.

Congress decided to control this wide range of medical devices by a classification system.
A hierarchy of three classes was established (Fig. 2.3).
Note that the classes are always referenced by their Roman numerals, for example, Class III
medical devices.
The classes are risk based, with Class I being the lowest risk and Class III the highest. The statu-
tory definitions are as follows:
Class III
(C) Class III, Premarket Approval.—A device which because—
(i) it
(I) cannot be classified as a Class I device because insufficient information exists to determine
that the application of general controls are sufficient to provide reasonable assurance of the
safety and effectiveness of the device, and
(II) cannot be classified as a Class II device because insufficient information exists to determine
that the special controls described in subparagraph (B) would provide reasonable assurance
of its safety and effectiveness, and
(ii)
(I) is purported or represented to be for a use in supporting or sustaining human life or for a
use which is of substantial importance in preventing impairment of human health, or
(II) presents a potential unreasonable risk of illness or injury,
is to be subject, in accordance with section 360e of this title, to Premarket Approval to provide reasonable
assurance of its safety and effectiveness.
If there is not sufficient information to establish a performance standard for a device to provide reason-
able assurance of its safety and effectiveness, the Secretary may conduct such activities as may be neces-
sary to develop or obtain such information.
(2) For purposes of this section and sections 360d and 360e of this title, the safety and effectiveness of a
device are to be determined—
(A) with respect to the persons for whose use the device is represented or intended,
(B) with respect to the conditions of use prescribed, recommended, or suggested in the labeling of
the device, and
(C) weighing any probable benefit to health from the use of the device against any probable risk of
injury or illness from such use.
(3)
(A) Except as authorized by subparagraph (B), the effectiveness of a device is, for purposes of this
section and sections 360d and 360e of this title, to be determined, in accordance with regulations
promulgated by the Secretary, on the basis of well-controlled investigations, including 1 or more
clinical investigations where appropriate, by experts qualified by training and experience to eval-
uate the effectiveness of the device, from which investigations it can fairly and responsibly be
concluded by qualified experts that the device will have the effect it purports or is represented to
have under the conditions of use prescribed, recommended, or suggested in the labeling of the
device.
(B) If the Secretary determines that there exists valid scientific evidence (other than evidence derived
from investigations described in subparagraph (A))—
(i) which is sufficient to determine the effectiveness of a device, and
(ii) from which it can fairly and responsibly be concluded by qualified experts that the device
will have the effect it purports or is represented to have under the conditions of use pre-
scribed, recommended, or suggested in the labeling of the device,