Non-Invasive Glucose Monitoring

Researchers continue to make exciting progress in developing new options for measuring glucose levels. For decades, they have been studying non-invasive glucose monitors for people living with diabetes.

This is a method of measuring glucose levels without needles or inserting devices into the body. Developers can then build the technology into a device like a smartwatch. Where does the technology stand today, and what could we see in the future?

Glucose monitoring with your smartwatch

Right now, the only way to use a smartwatch to monitor glucose levels is by connecting it to an app that pairs with your continuous glucose monitor (CGM).¹

Your CGM and the smartwatch connect through the use of Bluetooth technology. The smartwatch then shows your real-time glucose numbers. And you can see how they are trending so you can take steps to regulate your blood sugar if necessary.¹

The future of non-invasive glucose monitoring

Researchers continue to study non-invasive methods to monitor glucose. To date, the U.S. Food and Drug Administration (FDA) has not approved a non-invasive glucose monitoring device. In fact, at this time, the FDA does not recommend using smartwatches or smart rings that claim to measure blood glucose levels without piercing the skin.  However, there are technologies that could one day offer other options for people living with diabetes.^2,3

Monitoring glucose with bodily fluids

Researchers and companies are looking into whether your body's fluids can be used to monitor glucose levels. They are developing wearable sensors that are placed on the skin. The sensors wirelessly monitor glucose levels in the fluid between cells called interstitial fluid.^4,5

The idea is that the sensor could then be integrated into a watch, which would display real-time blood glucose levels on a screen. Levels could then also be checked with a smartphone app.⁵

Researchers tested one smartwatch prototype in a small study with 23 volunteers. It showed 84 percent accuracy in analyzing blood glucose levels compared to standard methods. Companies could develop the prototype into a commercial product for non-invasive glucose monitoring.⁴

Researchers are also studying saliva, sweat, tears, or breath vapor for non-invasive glucose monitoring.²

Optical technology

This type of technology uses electromagnetic radiation or light to detect certain substances in a fluid, such as blood. The idea is that a device, such as a smartwatch, would shine a beam of light through your skin. Glucose then reflects a unique pattern distinct from other elements in your blood. This helps the sensor to figure out your glucose level.²

Most non-invasive glucose monitoring devices being developed today use optical technology. It is a similar type of light-reflecting and absorbing technology used in smartwatches and fitness trackers. These devices measure metrics like your heart rate and blood oxygen level.⁶

The challenges of non-invasive glucose monitoring

Optical technology has been successful in measuring some health metrics. But, gauging blood glucose levels is more complex. The glucose signal from an optical sensor is small. This makes it difficult to isolate it from other components in the blood. It is one of the most difficult challenges device makers face in developing a non-invasive glucose monitor.^2,3

Advances in computing have brought us closer than ever to non-invasive glucose monitoring. Researchers are using artificial intelligence and machine learning algorithms to separate glucose signals from other components. However, some experts still question whether optical technology is precise enough to measure blood glucose.^2,3