Recently, the U.S. Food and Drug Administration (FDA) issued a warning advising consumers not to purchase or use smartwatches or smart rings that claim to use non-invasive methods to measure blood glucose levels. The agency noted that these smart devices, which claim to be able to detect blood sugar without piercing the skin, could lead to diabetics not being able to properly manage their condition, potentially leading to over- or under-dosing on medication.
(Apple Watch Ultra 2 image source: screenshot from Apple’s website)
According to a report by tech media outlet MacRumors, no smartwatch or smart ring claiming to non-invasively test blood glucose levels has been authorised, approved or licensed by the US Food and Drug Administration (FDA). These non-invasive devices are different from continuous glucose monitoring (CGM) devices that deliver data via a smartwatch app. (Note: Continuous glucose monitoring (CGM) is a minimally invasive glucose monitoring technology that indirectly reflects blood glucose levels by implanting microelectrodes in subcutaneous tissues to record electrical signals generated by glucose oxidation reactions in interstitial fluids.)
Currently, there are several smartwatches and smart rings that claim to be able to monitor blood glucose levels without the need for a blood prick or integration with a continuous glucose monitoring (CGM) device. However, the U.S. Food and Drug Administration has cautioned patients to avoid such devices and warned doctors to be aware of the potential risks posed by unauthorised blood glucose measurement products.
If Apple eventually releases an Apple Watch equipped with this feature, Apple will need to get approval from the FDA before it can sell it in the US market. Other companies such as Samsung are working on similar technology, but there is currently no proven and approved method of non-invasive blood glucose monitoring on the market.
In February 2023, it was revealed by Bloomberg’s Mark Gurman that Apple is working on an Apple Watch that measures blood glucose non-invasively, but it could be years before the device hits the market. Apple is developing a silicon photonic chip that uses optical absorption spectroscopy to shine light from a laser under the skin to determine blood glucose concentrations in the body. The technology is at a viable “proof of concept” stage, but needs to be scaled down to fit a wearable device.
According to Gurman, the prototype device is similar in size to an iPhone and can be attached to a person’s arm. The prototype is smaller than previous versions, which were so large that they even needed to be placed on a desktop.
According to MacRumors, TSMC developed a main chip to power the prototype. Previously, Apple partnered with Rockley Photonics to develop sensors and chips for blood glucose monitoring.Rockley Photonics released a digital sensor system in 2021 that reportedly monitors body temperature, blood pressure, blood glucose trends, alcohol levels, lactic acid concentration, and more.Rockley Photonics said that Apple is the company’s largest customer. However, Apple eventually ended the relationship.
According to Bloomberg, Apple has an Exploratory Design Group (XDG) with hundreds of engineers working on a non-invasive glucose testing programme, but it will take years for the technology to mature.The XDG is similar to Google’s X Research and Development programme, and is considered to be Apple’s most secretive department. Apple has invested hundreds of millions of dollars in developing non-invasive glucose monitoring technology.
In 2010, under the leadership of Steve Jobs, Apple acquired a non-invasive glucose monitoring development company called RareLight and began exploring alternatives to traditional glucose testing methods. Later, before transitioning to XDG, Apple utilised a startup called Avolante Health LLC to work on the project in a secret facility.
Over the past decade or so, Apple has tested the blood glucose monitoring technology on hundreds of people. The company applied the technology to people who were unsure if they had diabetes, as well as pre-diabetics and type 2 diabetics, and compared it to invasive glucose monitoring results.