Smart contact lens that measure glucose
Diabetes mellitus (DM), or diabetes, is a group of disorders associated with high blood sugar levels over a long period of time. People with diabetes have to carefully monitor their food intake and blood sugar levels. Some may be under oral prescriptions while others with type 1 insulin-dependent diabetes mellitus have to take insulin injections.
Accurate blood sugar monitoring is a must as a spike or a drop in blood sugar level should be treated accordingly. Blood glucose testing involves either a simple finger prick or blood extraction from a vein. Another option would be to have a continuous glucose monitoring (CGM) system wherein a glucose sensor is inserted under the skin to measure glucose in tissue fluids.
Those who are afflicted with DM have to undergo any of these procedures repeatedly in their lifetime, that’s why lots of researchers and medical companies are trying to develop a needleless and non-invasive approach in measuring blood glucose levels.
Korean researchers from Ulsan National Institute of Science and Technology in South Korea designed a smart contact lens with the capability to measure blood sugar level without the use of a needle. This contact lens is made of a material similar to that of soft contact lenses. The electronics is composed of a glucose sensor, a small green light-emitting diode (LED), an antenna and a rectifier. All are connected by minute, flexible wires.
The components are small enough not to make any discomfort for the wearer.They are only about 1/100 the thickness of the soft lens that they are embedded. They are also arranged around the edge of the lens to be far away from the pupil so it won’t affect the vision.
No human testing has been conducted to date. The study was done on rabbits, wherein the glucose level was measured through the rabbit’s tears. The continuously on LED turns off once the glucose level spikes above a certain level. The tests on the rabbits were conducted by applying a glucose solution on the rabbit’s eye. And during these trials the LED did turn off during the glucose spikes as it was intended to function. The idea is to alert the wearer of an elevated blood sugar level once the LED turns off. The study concluded that the lens accurately monitored the glucose levels of the rabbits.
The findings from the prototype study make a very promising future for a human version. There were also no adverse reactions seen on the rabbits during the tests. So far it has been the latest advancement in developing a needleless glucose monitoring procedure.
Yet a question that remains is how accurate the reading will be as glucose in tears isn’t a very reliable basis of blood glucose level as glucose in tears is less concentrated. The researchers are currently teaming up with a hospital to start clinical trials with human subjects. Until human testing is concluded, it is not yet clear whether something as crucial as a blood glucose monitoring can be relied on this smart contact lens.