Over the last few years, capillary blood sugar measuring devices have improved a lot: they require smaller droplets of blood and they yield faster and more accurate results. But we are still quite far from non-invasive technology that wouldn’t require the insertion of a device underneath the skin or a finger prick. What person with type 1 diabetes (T1D) hasn’t dreamt of being able to measure their blood sugar easily, discreetly and without pain?
Here is an overview of upcoming flash or continuous blood sugar measuring technology that involve no or minimal pain.
Minimally invasive technology
Continuous (Dexcom, Guardian) and flash (Freestyle Libre) glucose monitoring systems that require the insertion of a sensor wire underneath the skin have been on the market for a few years and are constantly updated. This technology involves minimal pain and provides blood sugar results for a prolonged period (currently 10–14 days, and coming soon, for several months). Continuous glucose monitoring (CGM) systems have evolved a lot over the past few years; they are now more accurate, have a lower risk of interference with certain drugs, and most of them no longer require calibration (capillary blood sugar measurement for more accurate results). Upcoming generations (Dexcom G7 and Freestyle Libre 3) are expected to be about 60% smaller. This technology has also come to be considered as an essential tool for people with T1D and is now covered by a growing number of government programs. According to data from the BETTER registry, 79% of registered adults and 73% of registered children (as of October 2021) are using a blood sugar monitoring device. Not to mention, recent recommendations encourage their use when possible.
The most recent CGM device to be approved by the U.S. Food and Drug Administration (FDA) is called Eversense. This new technology must be inserted underneath the skin and removed by a healthcare professional. It can be worn for up to 90 days, and a new 180-day version is currently under development.
Two types of non-invasive technology are currently under development: optical monitoring and fluid sampling.
- Optical monitoring
This technology involves passing a type of harmless, low-energy radiation into a vascular region of the body (e.g., fingers, earlobes, abdominal wall, extremities) and analyzing the signal to estimate blood sugar levels.
Optical monitoring technology is not currently on the market, as it has yet to be improved to take into account elements such as skin pigmentation, thickness and roughness.
- Fluid sampling
Fluid sampling consists in measuring blood sugar levels by extracting fluid without the need for any invasive procedure (e.g., tears, sweat, saliva, urine).
Two types of blood sugar monitoring technology using fluid sampling were approved by the FDA or received the CE (European compliance) certification.
The first consists in measuring glucose in interstitial fluid extracted through a low electrical current applied to the skin. The resulting localized sweat is then used to measure glucose on the skin surface using a sensor. A disposable patch called SugarBEAT uses this technology.
A similar device, GlucoWatch Biographer, was already cleared by the FDA in 2001. However, the blood sugar readings were not accurate enough and the device was short-lived. The products under development use the same foundation, but their accuracy is much better.
There are also studies underway to improve blood sugar readings in saliva or tears, but they have yet to overcome such hurdles as the impact of stress on blood sugar levels and time delays in glucose concentrations between blood and measurement fluids. As for urine glucose testing, one of its challenges are the high blood sugar concentration treshold needed for glucose to appear in the urine (usually 10–15 mmol/L, but varies from one person to another and with the use of certain drugs).
A promising future despite many challenges
According to available data, 65 products use the above-mentioned types of technology, although only 13 are currently on the market. This means that a lot of products are still under development.
We can hope that research will continue to improve new technology that will become key to blood sugar monitoring for people with diabetes.
- Shang, Trisha, et al. “Products for Monitoring Glucose Levels in the Human Body with Noninvasive Optical, Noninvasive Fluid Sampling, or Minimally Invasive Technologies.” Journal of Diabetes Science and Technology, June 2021, doi:10.1177/19322968211007212.