A Miniature Fiber Optic Pressure Sensor for Intervertebral Disc Pressure Measurements of Rodents

摘要

Lower back pain, which continues to be a leading cause of disability in people of all ages, has been associated with degenerative disc disease. It is well accepted that mechanical stress, among other factors, can play a role in the development of disc degeneration. Pressures generated in the intervertebral disc have been measured both in vivo and in vitro for humans and animals. However, thus far it has been difficult to measure pressure experimentally in rodent discs due to their small size. With the prevalent use of rodent tail disc models in mechanobiology, it is important to characterize the intradiscal pressures generated with externally applied stresses. In this paper, a miniature fiber optic Fabry-Perot interferometric pressure sensor with a diameter of 363 μm was developed to measure intradiscal pressures in rat discs. Validation experiments show that owing to the small size, inserting the sensor does not disrupt the annulus fibrosus and will not alter intradiscal pressures generated. In-tail pressure variation measurements also demonstrate the feasibility of using this sensor to quantify external load and intradiscal pressure relationships in small animal discs.