Non-Reciprocal Whispering-Gallery-Mode Resonator for Sensitive Blood Glucose Monitoring
Bibliographic record
Abstract
In this article, a miniaturized low-cost microwave sensor of high sensitivity is proposed for noninvasive blood glucose monitoring. The traveling waves whispering gallery modes ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WGM</i> ) are excited/launched on a ferrite-made ring resonator when placed nearby a microstrip line (MTL). The sensing structure is designed appropriately to support four distinct <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WGM</i> modes with the desired coupling in the frequency range of 22–32 GHz. A disk of permanent magnet is incorporated beneath the MTL substrate to generate a bias magnetic field necessary to create a nonreciprocal effect in the resonator. This nonreciprocal behavior is demonstrated in the transmission responses <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{12}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{21}$ </tex-math></inline-formula> , where the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WGM</i> resonances of similar modes are triggered at different frequencies over a narrowband. A magneto-static analysis is performed to approximate the internal biasing fields inside the FRR at multiple longitudinal layers. The complex components of the permeability tensor are computed accordingly for each layer, and then integrated into HFSS to simulate the sensor scattering responses. The EM simulations are validated when compared with practical measurements of a magnetized FRR. The latter fabricated prototype is tested in different setups for monitoring the glucose in synthetic blood of concentrations related to diabetes conditions. The proposed sensor shows high detection sensitivity at <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WGM</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">600</sub> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WGM</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">700</sub> to small changes in the dielectric properties of glucose samples as demonstrated by the frequency and phase shifts (0.07 MHz and 0.17° per 1 mg/dL, respectively) of the measured <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{21}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{12}$ </tex-math></inline-formula> with repeatability error of about ±0.2 MHz and ± 0.5°.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".