Disclaimer: This blog is independently written and published by me. The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.

The Surprising Reality Behind “FDA Clearance”

Most people assume that if a medical device is on the market—especially something as serious as an implant or monitoring system—it must have gone through rigorous human testing and FDA scrutiny before being used on patients. But in reality, many moderate and high-risk devices receive little to no clinical testing before they are cleared for use.

In the U.S., medical-grade devices are regulated differently than consumer health tools like Fitbits or smartwatches. They fall under the purview of the FDA and must be “cleared” or “approved” before hitting the market. But these terms mean very different things—and most devices fall under the former.

FDA “Clearance” vs. “Approval”: What’s the Difference?

The two main regulatory pathways are:

Premarket Approval (PMA) – the gold standard. Like a new drug, a device goes through human trials and is approved based on demonstrated safety and effectiveness. Only about 2% of devices go through PMA.
510(k) Clearance – the most common route. Used for 98% of devices, this pathway does not require human testing. A manufacturer only needs to show that their device is “substantially equivalent” to an existing one on the market—called a predicate.

The result? A device can be cleared without ever being tested in humans, based on the assumption that it’s similar to something already out there. In fact, some cleared devices trace back through multiple layers of predicates in a long “daisy chain”—sometimes to devices that are decades old or even recalled for safety concerns.

The “De Novo” Pathway

There’s also a lesser-used route for novel, low-to-moderate risk devices: the De Novo pathway. This doesn’t require predicate equivalence and allows more flexibility in marketing. However, De Novo devices often become the predicate for future 510(k) submissions, making them vulnerable to copycat devices with even less oversight.

Apple’s EKG feature on the Apple Watch, for example, was granted De Novo classification—it was novel, but still not subject to the rigorous testing required for a PMA-approved device.

Lack of Clinical Testing: A Common Reality

I’ve spoken to medical device companies who admitted their “testing” amounted to little more than a few people doing jumping jacks for a few minutes. Many startups can’t afford full-scale human trials before getting to market. And because hospitals typically won’t test devices that aren’t FDA-cleared, most companies focus first on securing 510(k) clearance—then look for opportunities to validate the device afterward.

Even PMA, the more rigorous route, typically requires only one clinical study—often with small participant numbers. In contrast, drugs require two large-scale trials. In many cases, devices reach patients with open questions about safety and performance still unanswered.

A Real-World Example: Patient Status Engine

Take the Patient Status Engine (PSE), a Class II device cleared in 2018. It monitors six vital signs in real-time and transmits the data to clinicians. Its FDA clearance was based not on new clinical evidence, but on its similarity to earlier devices. Following its predicate devices reveals a long chain—eventually leading back to products cleared with minimal or no human data.

Here’s a summary of what was found in its 510(k) filing:

Clinical Testing: Not required.
Predicate Device Used: VitalPatch (which itself was cleared based on limited internal studies).
Substantial Equivalence: Confirmed, despite known flaws in how predicate chains work.

This is a textbook example of how new devices can legally enter the market riding on the back of old, often untested (or under-tested) predecessors.

Reporting Device Problems: A Broken System?

You might think that adverse events would be swiftly flagged. Unfortunately, that system is also flawed.

Reporting is voluntary. Physicians aren’t required to report device-related complications.
Manufacturers are supposed to report, but have every incentive not to.
Only 3% of adverse events ever make it to the FDA’s database.
A study found that the more severe the complication, the less likely it was to be reported by manufacturers.

It often takes months—or even years—for post-market risks to surface. By then, hundreds of thousands of patients may already be affected.

What This Means for You

Medical device innovation is crucial, but the pathway to market is often less rigorous than many assume. FDA clearance is not the same as approval, and neither guarantees a device is well-tested or safe.

If you or someone you love is being offered a new medical device, here are some questions to ask:

Is this device FDA approved or cleared?
Has it been tested in humans? If so, how many?
What is its predicate device, and has that device ever been recalled?
Does your physician understand the regulatory pathway the device took?

In Summary

New medical devices can offer enormous benefits—but many reach the market without the kind of testing that consumers would expect. The 510(k) system, while efficient, is deeply reliant on legacy assumptions and honor-based compliance. As patients and caregivers, we must be informed, ask hard questions, and not equate regulatory clearance with a guarantee of safety.