Low-cost miniature fiber-optic extrinsic Fabry-Perot interferometric pressure sensor for biomedical applications

A fiber-optic pressure sensor based in extrinsic Fabry-Perot interferometer (EFPI) is presented and discussed. The sensing probe is based on an inexpensive all-silica biocompatible design, with 0.2 mm outer diameter, suitable for disposable operation in medical catheters. A white-light interrogation system has been implemented, achieving a target accuracy of 1 mmHg and pressure stability of 1 mmHg/hour for long-term operation. A fiber Bragg grating (FBG) is added in proximity of the sensing tip, compensating temperature variations with 0.5°C accuracy. Design, simulation, and preliminary experimental validation are discussed.