Design and Performance Test of a Prototype MRI-Compatible Cascaded Pressure Microsensor

Abstract

In this paper, the design, simulation, fabrication and characterization of a prototype single fiber MRI compatible cascaded pressure sensor is presented. This paper represents the extended version of earlier communication on this topic. In addition to the earlier communication, in this paper, we report on a crucial design requirement: the immunity to Electro-Magnetic Interference (EMI). This immunity has been experimentally tested by combining the prototype sensors with a Siemens 1.5T Magnetic Resonance Imaging (MRI) apparatus at Haga Hospital (The Hague). No disturbance was observed during a full MRI imaging cycle. The system allows for long lasting usage in the range -50 mmHg to 300 mmHg without damage to the membrane. A static pressure resolution (averaged over the array) of 3.6 mmHg was found, a performance that needs improvement in the future. Simulations show that the desired resolution of 1.0 mmHg is feasible within this design approach. The dynamical response allows for registration of dynamical features up to 20 Hz, already meeting dynamical requirements of this low-cost sensing system and already exceeding expectations expressed in advance. Future work includes further miniaturization, catheter integration, improvement of static pressure resolution, tackling separation of temperature-pressure crosstalk by implementing alternating independent Fibre Bragg Grating (FBG) temperature sensors in the array and further enhancing dynamical properties.