A device worn by millions could change the equation entirely.
For a decade, the promise of a wearable that could silently watch over one of humanity's most prevalent and underdiagnosed diseases has remained just out of reach. Now, a pendant-sized device called Isaac — which reads the chemical whispers in human breath to detect signs of diabetes — has entered FDA clinical trials at Indiana University, offering the most credible path yet toward non-invasive glucose monitoring. With over ten percent of adults living with diabetes and nearly half unaware of it, the distance between a laboratory trial and a wrist-worn device has rarely carried such weight.
- Diabetes kills millions annually, yet half of those affected don't know they have it — a silent crisis that invasive monitoring tools have never been able to reach at scale.
- Isaac, a breath-analysis device the size of a quarter, is now in human clinical trials, measuring acetone in exhaled air to correlate with blood glucose levels — no needles, no blood, no barrier to entry.
- Indiana University trials began with type 1 adolescents and are expanding to type 2 adults, building the regulatory evidence the FDA will need to grant approval as early as this year.
- The device is currently nearly as large as an Apple Watch itself, meaning miniaturization remains the critical engineering obstacle standing between this breakthrough and a wrist-worn future.
- If FDA approval arrives, it transforms Isaac into a proof of concept — signaling to Apple and the industry that the regulatory and scientific path to Watch-integrated glucose monitoring is finally open.
Apple envisioned blood sugar monitoring as a flagship feature of the very first Apple Watch in 2015. It never arrived. For a decade, the capability cycled through the rumor mill with each new model, always deferred — not for lack of ambition, but for lack of a technology that regulators and biology would both accept.
That may be changing. A device called Isaac has entered human clinical trials, and it works in a way no approved glucose monitor ever has: by analyzing breath. Diabetes leaves a chemical signature in what we exhale — acetone and other volatile compounds — and Isaac, roughly the size of a quarter, measures those biomarkers and translates them into a blood glucose reading in seconds. No needle. No skin puncture. Just a breath.
The stakes behind this development are hard to overstate. More than one in ten adults worldwide has diabetes, and nearly half of them don't know it. The disease is especially dangerous when type 2 develops before age 40 and goes undetected. A non-invasive tool worn by millions could catch what today's devices never reach — the undiagnosed, the unaware, the people whose bodies are already changing.
Indiana University is running the trials, starting with type 1 adolescents and expanding to type 2 adults, building the comparative data regulators will need to see. If the FDA grants approval this year, Isaac becomes something larger than itself: a proof of concept that the science works and the regulatory path exists.
The remaining challenge is size. Isaac is currently almost as large as an Apple Watch. Miniaturization is the engineering distance between a clinical trial and a wrist. But shrinking things elegantly is precisely what Apple does — and for the millions walking around unaware their blood sugar is rising, the urgency of closing that distance could not be more human.
Apple has wanted to put blood sugar monitoring on the Watch since the beginning. A 2023 report revealed that the original Apple Watch, back in 2015, was supposed to launch with non-invasive glucose measurement as a flagship feature. It never happened. Over the past decade, rumors have cycled through the tech press with predictable regularity—each new Watch model was supposedly the one that would finally bring the capability. But the feature remained out of reach, a perpetual promise deferred.
Now there's a reason to think the wait might actually be ending. A small pendant-sized device called Isaac has entered human clinical trials, and if it clears FDA review this year, it could unlock a path forward that Apple has been searching for all along.
The stakes are enormous. The International Diabetes Federation estimates that more than one in ten adults worldwide now has diabetes. The truly staggering part: nearly half of them don't know it. The disease kills millions annually, and the danger is sharpest for people who develop type 2 diabetes before age 40. Early detection saves lives. But the devices that exist today all require the same thing—a needle inserted under the skin. That barrier keeps the technology confined to people who already know they're at risk. A non-invasive option worn by millions could change the equation entirely.
The Isaac works by analyzing breath. Diabetes produces a distinctive chemical signature in what you exhale—acetone, among other volatile organic compounds. The device, about the size of a quarter, measures these biomarkers and correlates them with blood glucose levels. You hold it to your mouth, breathe out, and within seconds you have a reading. It's not continuous monitoring, but it's something you could do daily, and it requires no puncture, no blood, no pain.
Indiana University is running the trials. They started with adolescents who have type 1 diabetes and are expanding to adults with type 2. The goal is to demonstrate that Isaac's measurements match what traditional blood glucose monitors show—the evidence regulators will need to grant approval.
The obvious challenge is size. Isaac is currently almost as large as an Apple Watch itself. Miniaturization is the engineering problem that stands between this technology and a wrist-worn device. But if the FDA signs off this year, it becomes a proof of concept. It shows that the approach works, that regulators will accept it, that the path exists. Apple's engineers would then face a familiar problem: making something smaller, faster, more elegant. That's what they do.
For the millions of people walking around unaware that their blood sugar is climbing, that their body is already changing, the implications are profound. A Watch that could catch diabetes early, without asking anything of the wearer except to breathe—that's not just a feature. It's a different kind of health device entirely.
Notable Quotes
Non-invasive blood sugar monitoring has long been a holy grail in health tech.— reporting from Wired and 9to5Mac
The Hearth Conversation Another angle on the story
Why has this taken so long? Apple's had over a decade to solve this.
Because non-invasive glucose monitoring is genuinely hard. You can't just stick a sensor on skin and read blood sugar. You need a biomarker you can measure without breaking the body. Breath analysis is elegant, but it took years to prove it actually works.
So the Isaac device—is this Apple's work, or someone else's?
Someone else's. A separate team built it. Apple's been waiting for the underlying science to mature. Once it does, once it's FDA-approved, then Apple can license it, miniaturize it, integrate it into the Watch.
And if it gets approved this year, how long until it's in a Watch?
That's the real question. Miniaturization takes time. But the regulatory path opens up. That's the bottleneck that's been holding everything back.
What changes if this actually works? Why does it matter so much?
Right now, half of all diabetics don't know they have it. They're living with a disease that's silently damaging their body. A Watch that could catch it early, without needles, without friction—that reaches people who would never get tested otherwise. That's millions of lives.
But it's just a breath test. How accurate is that really?
That's what the trials are proving. If it matches traditional blood glucose monitors, regulators will accept it. The science has to hold up first. Then everything else follows.