Continuous spectroscopic monitoring of urinary catheter output: advancements and clinical implications

Urine diagnostics are crucial for identifying urological disorders and systemic diseases. Monitoring bladder catheters for urine output and early signs of urinary tract infections (UTIs) is essential but labor-intensive and prone to documentation errors. Recent advances in electronic monitoring and spectroscopy offer potential improvement in this process. This study introduces a novel smart sensor system for urinary catheters, enabling digital, continuous, automated real-time spectroscopic urine monitoring. A prototype consisting of a mini-spectrometer integrated with a custom lens array and hyperspectral illumination source was developed for urine analysis. It measures light intensity across 288 channels (340-850 nm) from multiple angles and exposure times, capturing detailed spectral data. Analyzing 401 urine samples from 168 patients, statistical models in R software were used to assess the dependency between spectral data and clinical laboratory values. The prototype accurately detected response variables like bilirubin, erythrocytes, pH, protein, specific gravity, and urobilinogen, with AUC values indicating good to very good discrimination. Response variables like glucose and nitrite, which do not absorb within the measured spectrum, showed minimal correlation. Our smart catheter system presents the potential for a significant advancement in urine monitoring, providing continuous, accurate analysis of parameters absorbing within the visible light spectrum.