Work

A Keyhole-Shaped Microwave Resonator for Hematocrit Sensing Toward Dengue Monitoring

Year: 2026

Type: article

Abstract: Rapid and continuous monitoring of blood hematocrit (HCT) levels is critical for detecting hemoconcentration and plasma leakage associated with dengue virus progression. This paper presents a label-free, metamaterial-based microwave sensor designed to detect dielectric variations corresponding to changes in HCT. The proposed structural design utilizes a keyhole-shaped resonator. The sensor’s transmission coefficients (S21) were numerically evaluated using simulated dielectric properties representing an extended modelled HCT range of 0% to 80%. The simulated analysis demonstrates a systematic response, linear in resonance frequency (R2 = 0.996) and curved in magnitude (R2 = 0.812), achieving a resonance shift sensitivity of 4.5 MHz/%HCT and a magnitude sensitivity of 0.0599 dB/%HCT. Based on these simulations, a 20% relative rise from a patient’s baseline HCT (assuming = 50%) corresponds to a 45 MHz resonance shift and a −0.599 dB magnitude deviation. As an initial proof of concept, the prototype was tested with alcohol–water mixtures. Over 0–40% alcohol the resonance moved to lower frequencies, whereas above 60%, it reversed. This compact microwave sensor is a candidate framework for point-of-care HCT monitoring, subject to validation on blood.

Source: Biosensors

DOI: 10.3390/bios16110614

Authors: Suhail Asghar Qureshi, Zuhairiah Zainal Abidin, Gameel Saleh

Institutions: Tun Hussein Onn University of Malaysia, Imam Abdulrahman Bin Faisal University

Language: English

Topic: Microwave and Dielectric Measurement Techniques

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,654