Two in-fibre Bragg grating based optical pressure sensors were developed to address the limitations of conventional solid-state electronic biomedical sensors. The first sensor, developed for intervertebral disc pressure measurements varying over several MPa, had a major diameter of only 400 μm and sensing area of 0.03 mm². This sensor was validated in spine biomechanics studies and was shown to: give accurate and repeatable measurements, be compatible with the small (e.g. cervical) discs, and alter disc mechanics less than the current alternative sensor. This sensor is also the smallest, most mechanically compliant disc pressure sensor presented to date.
The second FBG sensor was developed to measure sub-kPa pressure variations and had a major diameter and sensing area of only 200 μm and 0.02 mm², respectively. This sensor achieves sub-kPa repeatability through a novel design that is approximately 100 times smaller than other FBG sensors presented with sub-kPa pressure repeatability.