Here’s how Apple Watch manages to monitor blood glucose without drawing blood

Patent application shows how the Apple Watch could monitor blood glucose without drawing blood.

With the launch of its next smartwatch, Apple is hoping in the future, when you glance at your wrist it’ll not just be to check the time. Integrating one among the foremost advanced health tech, the new Apple Watch Series 7 will have blood sugar monitoring. For people with diabetes, it could provide a far easier method of monitoring blood glucose levels than current devices, which require a pin-prick blood sample.

Traditional blood sugar monitors require the patient to use a pin-prick device to draw a drop of blood and transfer this to a test strip, which is then read by a machine. The method isn’t ideal: it’s slightly painful, somewhat fiddly, and requires a constant supply of test strips.

For this reason, many companies are trying to develop non-invasive monitors – one that doesn’t require a drop of blood. Since many diabetics do not like the method of obtaining a reading, the new feature could lead to improved monitoring for these patients and help them control their diabetes better. and therefore the Apple Watch will eventually buy itself since there aren’t any more test strips to buy. 

How does Apple plan on measuring an individual’s blood glucose level without drawing blood?

Apple built an impressively accurate pulse sensor into the very first version of the Apple Watch in 2015 and has continued to expand the device’s heart-monitoring capabilities. Its last major improvement was adding the electrical sensors needed to make an electrocardiogram (ECG), which measures the characteristics of the electrical signals that govern the pumping of the guts muscle. While the Watch’s ECG has already positively affected the lives of some users, it’s not exactly a mainstream feature that applies to all or maybe most watch users.

In the past, Apple worked with companies like Dexcom and OneDrop to supply blood sugar monitoring, However, Dexcom and One Drop currently depend on sampling fluid or blood from the user’s body. Apple is now chasing a contactless means of sampling blood glucose levels.

One method of non-invasive measurement in development uses the skinny flap of skin between the thumb and forefinger. The glucose levels are extracted by a non-invasive technique that transmits low-power radio waves through a part of the user’s body, like the area between the thumb and forefinger. These areas have an adequate blood supply and are thin enough for the waves to go through the tissue. These signals are then received by a sensor on the other side of the GlucoWise device, where the info about the characteristics of the blood within the flesh are collected and analyzed.

But, because the explanation states, the technology works only because the skin is very thin in between the thumb and forefinger. How could an Apple Watch measure blood sugar through the wrist? The solution may be found in a new approach described in Nature, a scientific report journal, within the summer of last year. A skin tag – linked with frequency Identification (RFID) – is taped to the skin, then energized by a reader embedded within the Apple Watch.

This paper reports a sensitive, non-invasive sensor for real-time glucose monitoring from the extracellular fluid. The structure consists of a chipless tag sensor that can be taped over the patient’s skin and a reader, which will be embedded during a smartwatch. It works by measuring the shift in frequency. This shift is proportional to the relative percentages of water and glucose within the blood.

A new application filed by Apple with the United States Patent and Trademark Office explains how. With the long-winded title “Terahertz Spectroscopy and Imaging In Dynamic Environments With Performance Enhancements using Ambient Sensors, “Apple plans on using absorption spectroscopy to get non-invasive blood glucose readings. The goal is to use terahertz electromagnetic waves rather than light passing through a user’s body so as to detect “gas, health/quality of liquid or solid materials.”

Illustration from Apple blood glucose monitoring watch patent application
Illustration from Apple’s patent application

There are some issues though. Apple adds, “Integrating a gas sensor on an electronic device requires an aperture or opening to allow air to flow onto the gas sensor so that the gas can be detected. “The opening used to allow airflow could lessen the device’s protection from water.” Also, the blood glucose reading has got to be accurate. If it’s off by even a little, the user could find himself taking an excessive amount of insulin and be on a hypoglycemic or low blood glucose attack. This might make the user pass out. The system envisioned by Apple is going to be ready to constantly monitor a diabetic’s blood sugar levels, but not at the accuracy available to hospital patients.

Bringing non-invasive blood sugar testing to the Apple Watch could also make the device’s battery drain much faster than usual. For a blood sugar monitor to be available on the Apple Watch, the device will have to monitor more than just gas. There’s also a question, whether the timepiece is large enough to suit all the required components. The price of the new watch will also rise, subsequently. 

The technology discussed within the application could even be used to detect cancer and other skin problems. And while this all sounds quite grand, Apple has been performing non-invasive blood sugar testing for years now and there’s no sign that the tech giant has actually developed anything worthwhile. Still, the possible payoff would be huge for diabetics and for Apple. Especially considering the potential diseases that would be detected with this technology.

Apple would surely use this as a chance to introduce blood glucose notifications. Since the watch’s sensors are active all throughout the day, the watch could provide you with a warning if your blood glucose is just too high or too low. It could offer recommendations for lowering or increasing your blood glucose level, too.

Samsung is also rumored to be ready to include a non-invasive blood glucose monitor with its next smartwatch expected to be released later this year. There are also some infrared approaches in development, which could potentially work with existing Apple Watch models, but the above approach seems brighter in terms of accuracy. All of this remains highly speculative, however. The method would need to be evaluated and approved for use, and it appears this technology is at a very early stage in the process.

Also Read: Apple Watch can detect COVID-19 even before symptoms appear


Please enter your comment!
Please enter your name here

Hot Topics

Related Articles