A study that looks into the potential of future wearables to non-invasively measure blood glucose has brought promising results.
Nature published the study, which involved the participation of 50 people with type 2 diabetes.
A Raman spectroscopy device was used to non-invasively monitor their blood glucose over a two day period.
This uses a near-infrared light of 830nm wavelength, positioned over the person’s thumb. An analysis of the reflected light is then performed to glean information over, in this case, 50 seconds of data recording for each “hand placement” in each session.
The recorded results were then compared with those of traditional blood sample testing.
While using non-invasive spectroscopy methods to assess blood glucose are nothing new, this study does move the conversation forward in its use of a “pre-trained calibration model.”
This was derived from a previous study, one featuring 160 participants, and it significantly cut down on the calibration stage required at the start to 10 measurements, recorded over four hours.
The study found that this calibration stage was enough to set up the device for readings “for a minimum of 15 days.”
“These results highlight the ability to reliably track blood glucose levels in people with type 2 diabetes,” the study concludes.
While the testing itself did not involve consumer-grade electronics, the Raman spectroscopy technique employed is exactly that rumoured to be in contention for Apple’s long-discussed Apple Watch implementation of blood glucose readings.
Apple has reportedly been working on blood glucose monitoring in the Apple Watch since as early 2017. But the difficulties in getting reliable results from a non-invasive wearable are substantial, as are the responsibilities for a company like Apple should it offer blood glucose readings.
One remaining key difficulty is in miniaturising the tech required into a form suitable for inclusion in a mainstream wearable device.
For now, the closest alternative for Apple Watch fans is the Dexcom G7, a patch-based blood glucose reader that connects to Apple’s smartwatch.
Apple is not alone in its efforts either.
Early in 2025, Samsung’s senior vice president Dr. Hon Pak announced the company’s work on a non-invasive blood glucose monitor solution, with the help of AI.
“Samsung has been working to develop a sensor algorithm that predicts early signs of diabetes — along with non-invasive blood glucose monitoring technology and continuous glucose monitoring-integrated nutrition coaching,” Dr. Hon Pak wrote in a Samsung blog post.