Improved patient comfort and the need for better quality diagnostic information provide the motivation for new sensor development for the urinary tract. Optical sensors based on single mode fibre optics offer unique advantages in terms of access and miniaturization. We report the design, manufacture and evaluation of a diaphragm based sensor to give better than 10 mbar pressure sensitivity. The diaphragm is formed from a medically compatible material and it's geometric parameters set to give the desired resolution. The rear surface of the diaphragm has a thin aluminum coating such that an interference signal can be detected between the light reflected from the diaphragm and the distal end of the fibre. A number of approaches have been investigated for the analysis of the signal from the sensor using broadband illumination where minimizing overall system cost has been a major driver as well as achieving the required performance. A comparison of the techniques is given and experimental data presented with validation of sensor deflection from a white light interferometer.