Optical comb interrogation of structured FBGs for physiological pressure sensing

Monitoring physiological pressure indices is crucial for diagnosing and monitoring critical health conditions. Key metrics such as intracranial pressure (ICP), instantaneous wave-free ratio (iFR), gastrointestinal pressure, intracolonic pressure, and bladder pressure provide essential information for assessing diseases like traumatic brain injury, coronary artery diseases, and gastrointestinal motility disorders. Optical fiber sensors, particularly structured Fiber Bragg Gratings (sFBGs) interrogated with Dual Optical Frequency Comb (DOFC), offer advantages over electrical sensors due to their biocompatibility and immunity to electromagnetic interference. This study demonstrates that sFBGs significantly enhance spatial and strain resolution, leading to improved pressure sensitivity. The DOFC method increases the limit of detection and signal-to-noise ratio. DOFC-interrogated sFBGs can potentially provide a minimally invasive solution with enhanced resolution (∼10-20mmHg) for in-vivo pressure sensing applications.