Medical Device Classifications and Risk Management

By Chad Graham, Electrical Engineering Manager

As with life, the medical industry is a constant balance of risk versus benefit. In the medical device sector, a medical device’s class is used as a means of classifying how risky a device is and, by extension, what level of risk mitigation is required. While something simple like an elastic bandage doesn’t require a lot in terms of risk mitigation, something complex like an invasive surgical laser medical device would require a lot more.

In the United States, the FDA maintains jurisdiction of medical devices and has three tiers of medical device classes.

FDA Medical Device Classifications(1)(2):

Class I – These devices present minimal potential for harm. ~47% of medical devices are considered Class I devices. Examples include enema kits and elastic bandages.
Class II – These devices possess moderate potential for harm. ~43% of medical devices are classified as Class II devices. Examples include powered wheelchairs and some pregnancy test kits.
Class III – These devices are high risk and usually sustain or support life, are implanted, or present potential unreasonable risk of illness or injury. ~10% of medical devices are Class III devices. Examples include implantable pacemakers and breast implants.

cogmedix associate working on medical device In order of risk management requirements, Class I devices are the simplest and only require the general controls as defined by the FDA(2)(3). General controls are the basic authorities of the Medical Device Amendments that provide the FDA with the means of regulating devices to ensure their safety and effectiveness.

Class II devices are more complex and require more risk mitigation to ensure the device’s safety. Class II devices require special controls in addition to general controls. Special controls are usually device-specific and include things like performance standards, premarket data requirements and special labeling requirements.

Class III devices are the most risky and require the most risk mitigation effort to bring them to market. These devices are required to undergo a Premarket Approval (PMA) and are subject to the general controls. PMAs are the most stringent type of device marketing application and the FDA will require substantial evidence to assure the device is safe and effective(4).

It should be noted that any device that is “not substantially equivalent” (NSE) to a pre-existing medical device will be classified as “de novo” device. Also known as the “Evaluation of Automatic Class III Designation, de novo simply means the device will be processed as a Class III device(5). Cogmedix’s proprietary DFcx™ (Design For Compliance and eXcellence) engineering services support all medical device classifications. This, in addition to our ability to support both early phase and late phase design efforts, makes us uniquely suited to reduce device time to market for all customer projects.

Every medical device destined for use in the US will be assigned to one of the three medical device classes defined by the FDA. While Class II and Class III devices will require more risk mitigation than a Class I device, small engineering teams should not be discouraged from attempting them. The Cogmedix DFcx™ group has direct experience with all aspects of the approvals process and can be used as an extension to the existing team. Be it a simple DFcx™ assessment before entering manufacturing, or a complete design effort starting from device concept, our engineering services group is able to help get the product to market quicker, always keeping compliance at the forefront.