Drift Correction Algorithms for Lifetime-based Transcutaneous Oxygen Measurements

Recently, miniature luminescence-based blood gas monitors have emerged as noninvasive, compact devices for continuous monitoring. Although these sensors demonstrate enhanced stability compared to traditional electrochemical-based sensors, they still face challenges such as photobleaching, temperature fluctuations, and material degradation, albeit at a reduced rate. This study introduces an algorithm aimed at compensating for drift in luminescence-based sensing. We implemented the algorithm on a custom evaluation board, incorporating an STM32WB35CC microcontroller and an ADPD4101 analog front end for luminescence lifetime sampling. The setup utilized a commercial platinum porphyrin-based luminescence sensor film. Experiments measured the partial pressure of oxygen in ambient air over three-day periods, comparing uncompensated measurements with those adjusted in real-time using the proposed compensation algorithm. The results indicated a ±0.3% change in luminescence lifetime over three days with the compensation method, in contrast to a drift of -2.6% to -3.6% without compensation. The proposed method enhances the long-term reliability and accuracy of luminescence-based oxygen sensing, with potential applications in extended home care and clinical monitoring.