Blood Sugar Measurement Without Drawing Blood... Development of Electromagnetic Wave Sensor

Published 31 Oct.2022 15:08(KST)

Professor Byungjae Byeon’s Team at UNIST

From the left, Seongmun Kim, Researcher in the Department of Electrical and Electronic Engineering at Ulsan National Institute of Science and Technology (UNIST), Professor Youngjae Byun, and Dr. Jagannath Malik (holding the developed devices in their hands).

[Asia Economy Reporter Kim Bong-su] Domestic researchers have developed a technology that can measure blood sugar without drawing blood.

Ulsan National Institute of Science and Technology (UNIST) announced on the 31st that Professor Byun Young-jae's team from the Department of Electrical and Electronic Engineering developed a "body-implantable electromagnetic wave-based blood glucose monitoring system" that measures blood sugar without drawing blood. The sensor, one-fifth the size of a cotton swab, detects changes in blood glucose in the interstitial fluid, the tissue fluid filling the spaces between cells under the skin. It overcomes the short usage period, a drawback of existing continuous glucose monitoring devices, and offers higher accuracy in reflecting blood glucose, making commercialization highly feasible.

Diabetes is a disease in which the blood sugar level in the blood during fasting remains above 126 mg/dL, higher than the normal level (100 mg/dL). Diabetic patients need to maintain normal levels by controlling meals and other factors, so they prick their fingertips several times a day to draw blood and check their blood sugar. More than 400 million diabetic patients worldwide suffer daily pain and inconvenience from blood sampling.

As an alternative, enzyme- or fluorescence-based blood glucose measurement technologies have also been developed. However, the "enzyme-based method," which measures electrons (current) released when glucose in the blood reacts with glucose oxidase producing hydrogen peroxide that converts to oxygen, does not require blood drawing but has a short enzyme lifespan, leading to decreased accuracy over time. The "fluorescence-based method," which is based on the change in wavelength of light in response to varying glucose levels in the blood, also suffers from reduced accuracy as the luminescence decreases over time.

The research team created a semi-permanent body-implantable blood glucose monitoring system using "electromagnetic waves," which have no lifespan limitations. Unlike enzyme-based sensors, it does not require weekly replacement, making it convenient. The cost of using continuous glucose monitoring systems (CGMS) can also be drastically reduced. This technology is expected to increase the CGMS adoption rate, which currently stands at only 5%.

Another strength is that it is "implantable," inserted into subcutaneous fat by making an incision in the skin. This means it is not affected by external environmental factors such as surrounding temperature, humidity, or movement, thereby improving the accuracy of blood glucose measurement. The sensor is designed to be 30 mm in length with a circular circumference of 4 mm and is wrapped in a biocompatible polyolefin-based packaging material.

The sensor in the system links the unique permittivity of blood glucose components with changes caused by electromagnetic waves. When the sensor operates, the electromagnetic wave area generated around it detects changes in permittivity. Verification by attaching the system to animal bodies showed that both intravenous glucose tolerance tests (IVGTT), where glucose is directly injected into veins, and oral glucose tolerance tests (OGTT), where glucose is ingested orally, exhibited trends where blood glucose and frequency matched.

Professor Byun emphasized, "Thanks to the advantages of being implantable, the accuracy of blood glucose measurement can be improved to meet FDA standards. Once implanted, it can be used semi-permanently, and since it operates with low power, blood glucose can be checked anytime using devices with NFC (Near Field Communication) functionality or smartphones."

Kim Sung-moon, first author and integrated master's and doctoral course researcher at UNIST's Department of Electrical and Electronic Engineering, explained, "When blood glucose rises, permittivity decreases, and at this time, the sensor's frequency increases. Using this, real-time blood glucose measurement is possible."

The research results were published in "Scientific Reports" and are currently at the commercialization stage.