There are a number of pathways available to bring a medical device to market. The regulatory pathway for a specific device depends on the classification of the device, which is based on risk as well as the level of control necessary to mitigate such risks to health.

Medical devices are categorized into one of three classes based on their degree of risk.

There are relatively few class I (lowest risk) neurological devices. Most neurological devices are classified as class II (moderate risk) or class III (high risk) devices. Examples of Class I devices include ventricular needles and anvils used to form skull plates. Examples of Class II devices include neurostimulators, aneurysm clips, and blood clot retrievers. Examples of Class III devices include deep brain stimulators and medical devices for the treatment of brain tumors.

The class to which your device is assigned determines, among other things, the type of premarket submission necessary, if required, to legally market your device. The Center for Devices and Radiological Health's (CDRH) Device Advice web section contains additional information on how to Classify Your Medical Device.

Pre-submission Program

The FDA created a pre-submission program that allows sponsors to engage with FDA staff to determine the most efficient regulatory pathway for bringing a  medical device to the U.S. market.

The FDA encourages sponsors of neurological devices to use the pre-submission program to help determine whether their planned studies present significant risks to patients, whether they require an Investigational Device Exemption (IDE) prior to study, or to obtain further input on what data to collect as the basis for a marketing decision for a future submission.

More information about the pre-submission program is available in the guidance document entitled Requests for Feedback on Medical Device Submissions: The Pre-Submission Program and Meetings with Food and Drug Administration Staff.

Premarket Requirements

There are several steps that must be followed prior to marketing a medical device in the United States. The Device Advice section on How to Study and Market Your Device provides detailed information about premarket requirements, including classifying your device, choosing the correct premarket submission, preparing the appropriate information for a premarket submission to the FDA, sending a premarket submission to the FDA and interacting with FDA staff during review, and completing the establishment registration and device listing.

The most common types of premarket submissions include premarket notification, more commonly referred to as 510(k), premarket approval (PMA), de novo classification, and humanitarian device exemptions. Because many neurological devices are initially used for investigational purposes and are significant risk devices, they often require an Investigational Device Exemption (IDE) submission before they can be used to gather data to help support a PMA or de novo submission.

The following information may be of particular interest to sponsors and developers of neurological devices, particularly those who may need to submit an IDE:

Investigational Device Exemptions (IDEs)

Once the study is approved, an Investigational Device Exemption (IDE) submission allows a device that is not approved or cleared for market, or that is being tested for a new use, to be used in a clinical study to collect safety and effectiveness data to support a marketing application.

During review of an IDE application, the FDA establishes a review team appropriate to the device's technology and intended uses. The review team uses a multidisciplinary approach to assess the potential benefits and risks of the study for study participants. The FDA will generally approve the study if the potential benefits justify the risks, and if remaining risks have been appropriately minimized.

Demonstrating the preliminary safety of the device as it will be used in the clinical trial is important in obtaining FDA approval of an IDE application. Therefore, sponsors should address safety considerations specific to the patient population being studied, as well as those that may be common to the device.

For example, risks associated with active implantable devices, such as deep brain stimulation (DBS) devices, may include some or all of the following aspects: implantation and stimulation-related adverse effects associated with use of the device, risks associated with imaging techniques and electromagnetic interference, and usability of the device technology. Further, there may be additional risks for any given study depending upon the implantation and stimulation site, proposed indication for use, and patient population under study, such as whether children or other vulnerable populations are being included. More information is available in the FDA's guidance Factors to Consider When Making Benefit-Risk Determinations for Medical Device Investigational Device Exemptions.

Humanitarian Device Exemption (HDE)

A Humanitarian Use Device (HUD) is a device that is intended to benefit patients by treating or diagnosing a disease or condition that affects no more than 8,000 patients in the U.S. Because companies might not have a financial incentive to develop devices for use in such small populations, the HUD provisions reduce the regulatory burden on manufacturers of these devices. 

To obtain approval for an HUD, a humanitarian device exemption (HDE) application is submitted to the FDA. The submission is similar in form and content to a premarket approval (PMA) application, but it is exempt from the effectiveness requirements of a PMA.

Several neurological devices such as a deep brain stimulator and an aneurysm treatment device have been approved through humanitarian device exemptions.

More information about Humanitarian Device Exemptions can be found in Device Advice and CDRHLearn.

Postmarket Requirements

Medical device manufacturers and other firms involved in producing devices must follow certain requirements and regulations once their devices are legally on the market. This includes mandatory reporting requirements when manufacturers, importers and device user facilities learn that their devices may have caused or contributed to a death or serious injury. Postmarket requirements may also include such things as device tracking, establishment registration, postmarket surveillance studies required under section 522 of the Food and Drug Cosmetic Act, and post-approval studies. More information can be found in the Device Advice section on Postmarket Requirements.

The FDA is promoting the development of national and international medical device registries. Device registries may be useful to determine, for example, how an implantation method affects outcomes or how a device performs over time. Real-world evidence from such registries could be further refined and used for regulatory decision-making. The FDA has been working with neurological device manufacturers and professional societies such as NeuroPoint Alliance and NIH (StrokeNet) to facilitate the development of robust registries that will help with postmarket surveillance and could also be leveraged to generate data for premarket applications.