Cleared Traditional

SubtleMR (K191688) - FDA 510(k) Clearance

Class II Radiology device cleared through predicate-based substantial equivalence - typically does not require clinical trials.

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Sep 2019
Decision
84d
Days
Class 2
Risk

K191688 is an FDA 510(k) clearance for the SubtleMR. Classified as System, Image Processing, Radiological within the LLZ classification (a category encompassing advanced image processing and PACS-adjacent software), Class II - Special Controls.

Submitted by Subtle Medical, Inc. (Menlo Park, US). The FDA issued a Cleared decision on September 16, 2019 after a review of 84 days - a notably fast clearance cycle.

This device falls under the Radiology FDA review panel, regulated under 21 CFR 892.2050 - the FDA radiology and imaging software oversight framework. The Traditional 510(k) pathway establishes clearance through substantial equivalence to a legally marketed predicate device, without requiring clinical trial data.

Device pattern: Incremental AI imaging tool. Moderate equivalence dependency. Overall, this clearance reflects a predicate-aligned approval typical of modern AI radiology extensions - not a novel clinical breakthrough, but a validated iteration within an established regulatory category.

View all Subtle Medical, Inc. devices

Submission Details

510(k) Number K191688 FDA.gov
FDA Decision Cleared Substantially Equivalent - Traditional 510(k) (SESE)
Date Received June 24, 2019
Decision Date September 16, 2019
Days to Decision 84 days
Submission Type Traditional
Review Panel Radiology (RA)
Summary Summary PDF
Third-party Review No - reviewed directly by FDA
Combination Product No
PCCP Authorized No
Regulatory Context
Review time vs. panel average
23d faster than avg
Panel avg: 107d · This submission: 84d
Pathway characteristics
Predicate-based equivalence. No clinical trials required.

Device Classification

Product Code LLZ System, Image Processing, Radiological
Device Class Class 2 - Special Controls
CFR Regulation 21 CFR 892.2050
What this classification means

Class II devices require demonstration of substantial equivalence to a legally marketed predicate device. This pathway does not require clinical trials - it relies on engineering equivalence and performance data. Most Radiology devices follow this clearance model.

Regulatory Consultant

Enzyme Corporation
Jared Seehafer

The regulatory consultant manages the 510(k) submission process on behalf of the applicant - coordinating technical documentation, predicate strategy and FDA communications. Identifying the consultant behind a submission is a key signal for competitive regulatory intelligence.

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