Biomedical Devices and Device Classes

According to the FDA (Food and Drug Administration), "A medical device is an instrument, apparatus, implant, in vitro reagent, or other similar or related article, which is intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, or intended to affect the structure or any function of the body and which does not achieve any of its primary intended purposes through chemical action within or on the body."

Medical devices can be as simple as a bandaid or as complex as pacemakers. Based on the level of complexity and the level of control required to ensure the safety and efficacy of the device, medical devices are classified into three classes. This classification is done by the FDA Classification Panels.

• Class I Device: Minimal potential risk to patient, simple design. Eg: bandages.
• Class II Device: Medium potential risk to patient, design is more complicated than Class I device. Eg: surgical instruments, powered wheelchair.
• Class III Device: Potential high risk to patients, these are often devices that support and/or sustain life, highly complex designs. Eg. Implantable devices like pacemakers, stents, knee or hip implants.

There are no risk-free devices – the goal is to minimize the risk while maximizing benefit to patients. The FDA, therefore, has controls to ensure the safety and efficacy of all devices in the market. This makes the medical device industry a regulated industry. The controls applicable depends upon the class of the device.

• Class I Device: General Controls
• Class II Device: General Controls + Special Controls
• Class III Device: General Controls + Special Controls + Pre-market Approval (PMA).