Skip Links

Why the iWatch won't measure glucose levels

A multitude of reasons why the iWatch will not monitor user glucose levels.

By Yoni Heisler on Wed, 02/26/14 - 12:28am.

It's widely believed that Apple sometime in 2014 or soon thereafter will introduce what many are calling the "iWatch," a wearable device capable of tracking all sorts of interesting biometric data.

Over the past few months, Apple has hired a formidable team of biomedical experts with deep experience in medical sensor technologies. Notably, many of the folks now working for Apple have done impressive and groundbreaking work in the realm of continuous glucose monitoring (CGM).

Many news outlets, as a result, have reported that Apple's rumored iWatch may be able to non-invasively measure a user's glucose levels. Such a device would be a godsend for diabetics who often have to monitor their blood glucose levels multiple times a day, either by drawing blood from their finger or through an implanted sensor paired with an external monitoring device.

The rumors swirling around the iWatch have grown so unwieldly, the expectations so beyond the realms of modern science, that many are already pegging the iWatch as a revolutionary medical device that will leapfrog competing devices like the Fitbit and the Nike FuelBand by offering unprecedented medical sensor technologies to the masses. Just last week, the San Francisco Chronicle published a report claiming that Apple is researching sensor technologies capable of predicting heart attacks "by studying the sound blood makes at it flows through arteries."

It's time to jump back to reality.

Here, we will specifically focus on the the idea that Apple's iWatch will be able to measure a user's glucose levels.

Recently, well-connected 9to5Mac blogger Mark Gurman reiterated that the iWatch will, in fact, be able to monitor glucose levels.

Our knowledge is reliant upon what Apple is programming the Healthbook app to be capable of and based on the company’s recent hires. Our sources today have reiterated that Healthbook is planned to be able to read glucose-related data...

Given Gurman's impressive track record for accurately breaking Apple news, many outlets have similarly made the leap from "Apple is hiring folks with expertise in continuous glucose monitoring" to "the iWatch will monitor user glucose levels."

A deeper examination of the issue, however, strongly suggests otherwise.

Non-invasive CGM is an incredibly complex problem that presents a number of challenging medical and technological hurdles. Indeed, medical device companies have been trying to solve this problem for decades, with no real success to speak of.

Apple and C8 Medisensors

Over the past few months, Apple has hired a number of scientists and engineers from C8 Medisensors, an innovative California-based company (now defunct) that was singularly focused on developing a non-invasive CGM device called the HG1-c.

To really gauge the feasibility of an iWatch that monitors glucose levels, it's helpful to take a deeper look at the HG1-c's capabilities and limitations. Indeed, doing so brings to light a number of daunting challenges that would arise in bringing the technology to market, let alone embedding it in a wristwatch.

Employing a technology called Raman spectroscopy, the HG1-c was able to measure users' glucose levels by transmitting a pulse of light through the skin, thereby causing glucose molecules to vibrate. An optic sensor then detected the light reflected off of these molecules, whereupon the device analyzed the resulting "fingerprint" and returned a glucose reading.