Developed a lens showing glucose concentrations in tears and algorithms for minimizing measurement errors

Diabetes diagnosis mostly uses an invasive method of pinching a needle at the end of the finger and measuring the glucose concentrations in the blood. However, such a method has disadvantages of triggering psychological stress to patients and possibilities of side effects like an infection.

To solve this problem, the research team sought ways to measure blood sugar levels instead of using blood. The research team confirmed that when the blood sugar level of diabetes patients increases, the glucose concentration in other bodily fluids also increases. Using this information, they studied methods to diagnose diabetes using tears.

As a result, they developed a smart contact lens that can measure the blood sugar level by linking with a smartphone and a lens that changes the nanoparticle colors inside according to the glucose concentration in the tear. Furthermore, the joint research team developed a system to capture the color change scope in detail and an eye-tracking algorithm that can minimize the measurement error that occurs from the eye’s movement. The smart contact lens created with such a method does not require additional electrons, minimizes the burden on the body through quantitative analysis using color changes in nanoparticles harmless to humans, and enables convenient self-diagnosis using smartphones.

Professor Lee said that “After safety evaluations through clinical demonstration, it is expected that self-diagnosis of diabetes that is convenient for patients compared to previous methods is possible.”

Professor Chung said that "Thanks to this technology, invasive methods, which are the biggest disadvantage of previous diabetes diagnosis, can be less used. If deep learning technologies or bio big data are used in the future, it could be a more precise non-invasive method.”

This research was led by Professor Lee Dong-yun and Professor Chung Eui-heon, carried out by Dr. Jeon Hee-jae, and was supported by the National Research Foundation of Korea Biomedicine Technology Development Project. The paper was published in the international academic journal in the nanotechnology field “Nano Letters” online on August 20.