Pressure Sensor Catheter based on Micromachined Aluminum Nitride Membrane Fiber Tip Fabry-Pérot-Interferometer

This paper introduces an absolute pressure sensor based on an extrinsic fiber-optic Fabry-Pérot-Interferometer molded into a silicone catheter. The interferometer principle is formed between the tip of an optical fiber and a reflective multilayer membrane containing aluminum nitride. The signal analysis is done by a Fiber Bragg Grating interrogation device. First, the optical sensing principle as pressure sensor in an invasive catheter with a diameter of 1 mm is described. Then, the dependence of the optical signal on changes of hydrostatic pressure and ambient temperature is shown. Out of these characteristics it was possible to evaluate the pressure sensor catheter for potential application in the human vascular system.