What distinguishes Class III devices from Class I and II devices?

Class III medical devices are notably distinct because they are typically used to support or sustain human life, are involved in significant risk of illness or injury, and require pre-market approval from regulatory bodies such as the FDA. This pre-market approval process necessitates extensive evidence demonstrating the safety and efficacy of the device, reflecting a more stringent regulatory environment compared to Class I and II devices.

Class I devices usually pose the least risk and are subject to the least regulatory control, often requiring minimal oversight and typically not needing pre-market approval. Class II devices, while presenting a higher risk than Class I, still do not require the same level of pre-market scrutiny as Class III devices and are often subject to special controls to ensure their performance and safety.

In summary, the nature of Class III devices as life-sustaining or life-supporting emphasizes their critical role in healthcare, necessitating rigorous verification processes to ensure patient safety before they can be marketed or used clinically. This aspect clearly sets them apart from Class I and II devices.