Microwave

Quantum mechanics

Continuous glucose monitoring

Biomedical engineering

Materials science

Computer graphics (images)

Real-time computing

Endocrinology

Telecommunications

Power (physics)

Response time

Computer science

Acoustics

Insulin

Split-ring resonator

Physical chemistry

Physics

Organic chemistry

Glycemic

Resonator

Medicine

Chemistry

Electrode

Electrolyte

Optoelectronics

Chipless RFID

Ring (chemistry)

Scientific Reports

This paper reports a highly sensitive, non-invasive sensor for real-time glucose monitoring from interstitial fluid. The structure is comprised of a chip-less tag sensor which may be taped over the patient's skin and a reader, that can be embedded in a smartwatch. The tag sensor is energized through the established electromagnetic coupling between the tag and the reader and its frequency response is reflected on the spectrum of the reader in the same manner. The tag sensor consumes zero power as there is no requirement for any active readout or communication circuitry on the tag side. When measuring changes in glucose concentrations within saline replicating interstitial fluid, the sensor was able to detect glucose with an accuracy of ~ 1 mM/l over a physiological range of glucose concentrations with 38 kHz of the resonance frequency shift. This high sensitivity is attained as a result of the proposed new design and extended field concentration on the tag. The impact of some of the possible interferences on the response of the sensor's performance was also investigated. Variations in electrolyte concentrations within the test samples have a negligible effect on the response of the sensor unless these variations are supra-physiologically large.

Non-invasive continuous-time glucose monitoring system using a chipless printable sensor based on split ring microwave resonators