Investigational Device

Investigational device is the FDA regulatory status a medical device holds when it is “the object of an investigation” — that is, when it is being studied in a clinical investigation to develop safety and effectiveness data, rather than being used strictly within the labeling FDA has already cleared, approved, or authorized. The definition comes from 21 CFR 812.3(g), part of the Investigational Device Exemptions (IDE) regulation, 21 CFR Part 812. A device does not need to be entirely novel to be “investigational” — a marketed, FDA-cleared device becomes investigational again the moment it is studied for a new indication, a new patient population, or any use outside its cleared/approved labeling that the study is designed to support.

The Investigational Device Exemption (IDE) itself is the regulatory mechanism, not the device — an approved IDE exempts a sponsor from certain requirements (such as premarket approval) that would otherwise apply to a device in commercial distribution, so that the device can lawfully be shipped and used in a clinical study before FDA has cleared or approved it for that use. Whether a full IDE application and FDA approval are required before the study starts depends on how the device is classified under 812.3(m).

Significant risk (SR) vs. nonsignificant risk (NSR)

Under 21 CFR 812.3(m), an investigational device is a significant risk (SR) device if it meets any one of four criteria: it is intended as an implant and presents a potential for serious risk to a subject’s health, safety, or welfare; it is purported or represented for use in supporting or sustaining human life and presents a potential for serious risk; it is of substantial importance in diagnosing, curing, mitigating, or treating disease and presents a potential for serious risk; or it otherwise presents a potential for serious risk.

• SR devices require a full IDE application (21 CFR 812.20) and FDA approval before the investigation may begin, in addition to Institutional Review Board (IRB) approval and informed consent.
• NSR devices qualify for abbreviated IDE requirements: appropriate device labeling under 812.5, IRB approval of the investigation, monitoring, recordkeeping, and informed consent — but no separate FDA approval is required unless FDA has specifically notified the sponsor that approval is needed.

The SR/NSR determination is initially made by the sponsor but is reviewed by the IRB, and FDA retains authority to overrule an NSR determination. Because the classification drives whether FDA approval is required at all, it is typically one of the first regulatory questions a sponsor and IRB resolve when designing a device study.

What falls outside Part 812 entirely

Not every study involving a device triggers IDE requirements. 21 CFR 812.2(c) exempts several categories from Part 812, including: devices in commercial distribution immediately before May 28, 1976 (or later devices FDA has found substantially equivalent to a pre-1976 device), used per their labeling in effect at that time; certain noninvasive diagnostic devices; devices used solely for consumer preference testing unrelated to safety or effectiveness; devices intended solely for veterinary use or research on laboratory animals; and custom devices, unless being used to determine safety or effectiveness for commercial distribution. A device used strictly within its FDA-cleared or -approved labeling in a study that is not evaluating that device’s own safety or effectiveness (for example, as a comparator or as approved standard-of-care treatment) is likewise not “investigational” for IDE purposes.

Worked examples

Example 1 — SR device. A novel implantable cardiac defibrillator being studied to support a future Premarket Approval (PMA) application meets the “implant” prong of 812.3(m) and presents potential for serious risk. The sponsor must submit a full IDE application and obtain FDA approval, plus IRB approval and informed consent, before enrolling subjects.

Example 2 — NSR device. A new software-based diagnostic algorithm running on already-cleared imaging hardware, evaluated non-invasively against a reference standard with no direct patient-management decisions made on study data alone, may be determined nonsignificant risk by the IRB. The sponsor still follows abbreviated IDE requirements (labeling, IRB approval, informed consent, monitoring, recordkeeping) but does not need a separate FDA approval before starting, absent an FDA notification to the contrary.

Counter-example

A hospital bed rail that is FDA-cleared and used strictly according to its cleared labeling in a study comparing two already-approved drug regimens — where the bed rail itself is incidental to the study and not the object of the investigation — is not an “investigational device” under 812.3(g), even though it appears in the study. The device only becomes investigational when the study is designed to generate safety or effectiveness data about the device itself, for a use FDA has not already cleared or approved.

Related terms

• Humanitarian Use Device (HUD) — a related but distinct FDA designation for devices addressing rare conditions (≤8,000 U.S. patients/year), which leads to the Humanitarian Device Exemption (HDE) marketing pathway rather than an IDE study.
• Investigational Medicinal Product (IMP) — the drug-side analog: the IND/IMP framework (21 CFR Part 312) governs investigational drugs and biologics the way Part 812 governs investigational devices.
• Institutional Review Board (IRB) — reviews and approves both SR and NSR device investigations, and makes the binding risk-determination review.
• Informed Consent — required for subjects in any IDE study regardless of SR/NSR classification.
• ICH E6(R3) (Good Clinical Practice Guideline) — the international GCP framework that applies alongside Part 812 for device trials conducted under ICH-adhering sponsors.