Development of a Photoacoustic Platform for Blood Glucose Monitoring and a Comparative Study between Signal Propagation delay and Peak-to-Peak Amplitude

Achieving noninvasive glucose monitoring is a critical goal for diabetes management, and photoacoustic (PA) technology has emerged as a promising pathway. However, conventional PA-glucose models based on the peak-to-peak amplitude (V_PP) are often compromised by environmental interference. While the signal propagation delay (T_P) has shown empirical promise for more stable measurements, a foundational theoretical analysis of its robustness has been absent. This study fills this gap, first by presenting a theoretical analysis concluding that T_P is inherently more robust against environmental noise than V_PP, and then by providing experimental validation on a custom-built PA platform. Linear regression models for both features were established over a 0-1452 mg/dL concentration range. The resulting T_P model demonstrated a significantly better goodness-of-fit (R²=0.874) compared to the V_PP model (R²=0.671). Furthermore, validation on an independent dataset confirmed the T_P's superiority: Clarke Error Grid (CEG) analysis showed 100% of readings in the clinically acceptable A+B zones, starkly outperforming the 70% from the V_PP-based approach. Our findings provide the first theoretical and experimental evidence for the superiority of T_P, positioning it as a more robust feature for reliable noninvasive PA-based glucose monitoring.