FDA Warns of Risks of Inaccurate Wearable ‘Noninvasive Blood Glucose Monitoring’

Recently, wearable manufacturers are focusing on “noninvasive blood glucose monitoring” features. Noninvasive blood glucose monitoring is a feature that allows you to measure blood glucose without pricking the skin.

Blood Glucose Monitoring

Diabetes patients typically have to measure their blood glucose levels at set times. In the past, a small needle called a lancet was used to draw blood from the finger and check the levels with a glucose meter. However, while this method of drawing blood directly to check levels is accurate, it does require causing injury to the skin each time.

To solve this, wearable product manufacturers are actively researching to equip smart watches and smart rings with noninvasive blood glucose monitoring features.

There are various technologies used for noninvasive blood glucose monitoring. According to the “Trends in Noninvasive Continuous Blood Glucose Monitoring Technology” from the Korea Electronics and Telecommunications Research Institute, they are broadly divided into three types depending on the type of specimen. The first is a technology that measures blood glucose using glucose in body fluids such as tears, sweat, and urine. It measures the current when the sugar enzyme of the sensor meets glucose and causes a chemical reaction, thereby understanding changes in blood glucose.

The second and third are technologies that measure blood glucose by transmitting and receiving signals, causing no harm to the body. Depending on the type of specimen, it is divided into interstitial fluid and blood type. The most accurate way to measure blood glucose is to measure the blood in the blood vessels. However, it is not easy to reach the signal beyond the blood vessel wall to the blood.

The alternative for this is the interstitial fluid of subcutaneous fat. The interstitial fluid is where the glucose in the blood stays before entering the cells. By measuring the glucose concentration of the interstitial fluid, you can know the blood glucose level within 5 to 15 minutes.

FDA Warns of “Warning” of Noninvasive Blood Glucose Monitoring in Wearables

However, on February 21st (local time), the U.S. Food and Drug Administration (FDA) warned about the noninvasive blood glucose monitoring feature of wearable devices.

The FDA explains that the noninvasive blood glucose monitoring feature may pose greater risks due to its low accuracy. If the measurement results are not accurate, it may lead to the administration of incorrect doses of insulin or other drugs. In severe cases, it can lead to a coma or death.

Apple and Samsung developing related features

Several IT companies, including Apple, are reported to be developing noninvasive blood glucose monitoring features. Apple uses technology that measures glucose concentration in the body by shining a laser light under the skin.

In 2021, they applied for a patent titled “Terahertz Spectroscopy and Imaging Technology in Dynamic Environments Using Peripheral Sensors” to the U.S. Patent and Trademark Office (USPTO). The patent contains technology that uses absorption spectroscopy to measure blood glucose in a bloodless manner.

Samsung Electronics has also been researching to apply blood glucose monitoring features to the Galaxy Watch. In 2020, they published a paper on “noninvasive blood glucose monitoring technology” in the world-renowned academic journal “Science Advances” in collaboration with a research team from the Massachusetts Institute of Technology (MIT).

On online shopping platforms, you can often find wearable devices equipped with noninvasive blood glucose monitoring features. They are not products of famous companies like Apple or Samsung but are already on sale on shopping platforms like Amazon and AliExpress.

The FDA approves no wearable devices

However, the FDA has warned against purchasing wearable devices with noninvasive blood glucose monitoring features. This is because no products are accurate and safe enough to receive FDA approval yet. Since blood glucose monitoring is a healthcare feature, FDA approval is necessary.

The FDA only approves the Continuous Glucose Monitoring System (CGMS). Continuous glucose monitors allow you to check your blood glucose levels in real time by inserting a thread-like sensor under the skin. It eliminates the need to draw blood each time, a drawback of existing self-blood glucose measurement.

FDA-approved healthcare features

Recently, the FDA approved Samsung Electronics’ Sleep Apnea Feature, which was developed using the Galaxy Watch. With the acquisition of the FDA’s De Novo approval, they can equip future Galaxy Watches with this feature. De Novo approval is the first approval granted after a comprehensive review of the safety and effectiveness of new healthcare technology.

The sleep apnea feature measures the oxygen saturation (SpO2) in the blood during sleep through the “BioActive Sensor” of the Galaxy Watch. Through this, it analyzes the pattern of alternating apnea and hypopnea and calculates the estimated value of the Apnea-Hypopnea Index (AHI) during sleep.