Bio Startup “Thedonee” and Severance Hospital Joint Research

Detecting Dangerous Potassium Levels in One Minute with a Drop of Blood

95% Accuracy Compared to Hospital Equipment – Published in CJASN

Prof. Kang-Won Lee, Seoul National University: “Founded to Save Patients’ Lives”

Gnosis-K, the world’s first self-testing potassium monitor developed by Thedonee [Photo courtesy of Thedonee]

People with diabetes prick their fingers before and after meals to measure their blood sugar levels. This simple act helps prevent many complications. However, for patients with chronic kidney disease, such at-home testing has not been possible. To check their potassium levels—a potentially life-threatening substance that can stop the heart—they have had to visit a hospital, insert a needle into a vein, and draw blood for laboratory testing.

THEDONEE, a biotech venture founded by Professor Kang-Won Lee of Seoul National University’s Graduate School of Convergence Science and Technology, has developed and validated a groundbreaking technology that allows users to easily measure potassium concentration at home using just a single drop of fingertip blood.

In collaboration with Professors Chul-Ho Park and Tae-Hyun Yoo from the Department of Nephrology at Yonsei University Severance Hospital, THEDONEE conducted clinical studies on its portable potassium measuring device, Gnosis-K. The results showed that the device achieved accuracy comparable to that of large, precision laboratory instruments used in hospitals. The findings were published in the latest issue of the Clinical Journal of the American Society of Nephrology (CJASN), a leading international journal in nephrology.

Potassium is an essential electrolyte that supports normal muscle and nerve function and is abundant in foods such as spinach and bananas. In healthy individuals, the kidneys regulate potassium levels by excreting the excess through urine. However, for patients with kidney disease, this regulation does not occur properly. When potassium accumulates excessively in the body—a condition known as hyperkalemia—it can cause muscle paralysis and severe arrhythmia, greatly increasing the risk of sudden cardiac death.

The research team evaluated the performance of Gnosis-K in a clinical study involving 40 patients with end-stage kidney disease undergoing hemodialysis. Using a small sample of capillary blood collected from the fingertip and applied to a disposable test strip, the device produced results with a correlation coefficient of 0.95 compared to potassium levels measured from venous blood in hospital laboratories. A coefficient closer to 1 indicates stronger agreement between the two values. The entire process—from sampling to result—took less than one minute, overcoming a major limitation of traditional testing methods that require lengthy blood draws and analysis times.

This achievement is regarded as a successful case of bridging the so-called “Death Valley” in medical innovation, made possible by cooperation between hospitals that understand clinical needs and a university research lab with advanced engineering solutions.
Professor Kang-Won Lee, founder and CEO of THEDONEE, is also a faculty member at Seoul National University’s Graduate School of Convergence Science and Technology.

Professor Lee stated,

“With the rapidly aging population, national-level management of chronic kidney disease has become increasingly urgent. Patients need the ability to measure and manage potassium levels at home after meals, yet there is currently no such method available anywhere in the world,”

adding that,
“While research and development are actively underway in Europe and the United States, THEDONEE is the only company in Korea developing such a product. Our goal is for Korea to commercialize this technology first and secure a global competitive edge.”

THEDONEE has already registered patents not only in South Korea but also in key international markets including the United States, Europe, China, and Japan. The company plans to launch a multi-analyte device capable of measuring both potassium and glucose simultaneously, aiming to expand into the global healthcare market.

Professor Tae-Hyun Yoo of Severance Hospital emphasized,

“Hyperkalemia often progresses without symptoms but can suddenly lead to fatal cardiac arrest. Continuous monitoring is crucial for survival. Just as diabetics use glucometers, kidney patients will soon be able to monitor their potassium levels themselves and prevent medical emergencies.”

https://n.news.naver.com/article/009/0005632170?type=journalists