Low drift and high resolution miniature optical fiber combined pressure- and temperature sensor for cardio-vascular and other medical applications

A fiber optic Extrinsic Fabry-Perot Interferometer (EFPI) including an internal fully integrated Fibre Bragg Grating (FBG) for application in cardiovascular pressure detection is presented. The combination of EFPI and FBG sensing elements allows the measurement of temperature and pressure at the same time, as well as the compensation of cross-effects. This sensor is entirely fabricated of quartz glass and is a result of a novel design and fabrication process. The sensor was tested in simulated in-vivo biomedical pressure devices, i.e. a cardiovascular pressure simulator that replicates human pressure patterns related to heartbeat. A resolution of 0.1mmHg and a drift of <; 1mmHg in over 1hour at a frequency of 50Hz was achieved. Tests were performed at the Polymer Core Center, within Cleveland Clinic (Ohio, USA). The small sensor overall diameter of 200μίη allows in-vivo application for temperature-compensated pressure detection of aortic, arterial and ventricular pressure patterns.