Engineers at the Massachusetts Institute of Technology (MIT) have developed a noninvasive monitoring system to measure blood sugar. Typically, people with diabetes have to prick a finger to measure their blood sugar. This new technology could potentially replace traditional monitoring devices.
The standard method diabetes patients use to measure their blood sugar levels is by drawing blood and testing it with a glucometer. Some patients use a wearable monitor, which has a sensor that is inserted just under the skin. The interstitial fluid from within the sensors provide continuous blood sugar measurements. However, the downside of using this device is that they may cause skin irritation and need to be replaced every 10 to 15 days.
Back in 2010, researchers at the Laster Biomedical Research Center indirectly calculated blood sugar levels based on a comparison between Raman signals from the interstitial fluid that bathes skin cells and a reference measurement of blood sugar levels. The results produced were reliable measurements, but it wasn’t practical as an actual monitor to measure blood sugar.
The MIT team further developed this device with Raman spectroscopy. This is a technique that reveals the chemical composition of tissues by shining near-infrared or visible light on them. Typically, this signal is too small to pick out from all the other signals generated by molecules in the tissue. However, the MIT researchers discovered a way to filter out any unwanted signals by shining near-infrared light onto the skin at different angles from which they collected the resulting Raman signal. They used this technique to develop a shoebox-sized device that can measure blood-sugar level without the need of needles or finger-pricking.
Over a four-hour period, researchers tested the device on healthy volunteers. The device works like this, the patient rests their arm on top of the device and a near-infrared beam shines through a small glass window onto the skin to calculate the measurements. It takes a little over 30 seconds for each measurement and the researchers took a new reading every five minutes.
The subjects were told to consume two 75-gram glucose drinks after. Researchers then monitored if they had any significant changes in blood sugar concentration.
Based on the results of their tests, researchers found that the measurements from their device were similar to traditional blood-sugar monitoring devices that required a wire to be implanted under the skin to draw blood.
Since that study, the researchers have developed a small prototype, about the size of a cellphone. The researchers are also working towards making a device as small as a watch. Additionally, they’re exploring ways to obtain accurate readings from people with different skin tones.
