Metyos K-Patch: A Novel Biowearable for Real-Time Potassium Level Monitoring

Background: Abnormal serum potassium (K+) levels or dyskalemia are dangerous due to the risk of cardiac rhythm disturbances. The reference method of K+ monitoring based on venous blood sampling is invasive, painful and takes up to several days to provide a result. The ability to dynamically and non-invasively monitor changes in K+ levels could reduce the morbidity and mortality due to dyskalemia in both acute and chronic situations. Methods: Metyos K-Patch is a remote patient monitoring solution integrating a biowearable for monitoring K+ in real time thanks to a microneedle array inserted in the patient's dermis. The sensor sticks to the skin with medical adhesive and is worn for 8 consecutive days. Despite the efficiency of transdermal penetration, microneedles do not exceed 1mm in length and cause no pain upon device’s placement. They are modified with ion selective membrane for specific reaction with K+. The electrochemical sensor generates an electrical response proportional to the concentration of K+ that can be measured as a potential difference. The registered signal is then transmitted via Bluetooth to the patient's smartphone. Results: The potentiometric cell based on the microneedles was sufficiently sensitive for detecting real-time changes in K+ concentrations. It exhibits linear behavior with Nernstian slope 59mV for the complete range of physiological K+ concentrations (2-10mM) when tested in complex matrix. Its analytical performance remains stable during 8 days. No needle deformation or degradation has been registered upon the insertion of the device both in pig skin and volunteers’ skin. General ease of use has been tested by 10 volunteers of age 34-72 y.o. Conclusion: The wearable Metyos K-Patch has shown promising results for continuous K+ tracking. These results pave the way towards remote K+ monitoring in patients with dyskalemia. Funding: Commercial Support - Metyos