Fiber Optic Sensors for Biomedical Applications

Biomedicine is surely the area where the optical fibre sensors can play an important role. Thanks to their potential miniaturisation and their easy handling they are offering unique performances in invasive or minimally invasive applications. The immunity to electromagnetic interference and the absence of electrical contact make the optical fibres useful also in the case of non invasive applications for the setting of the interrogation optoelectronic unit in a safer location, keeping only the sensing element close to the patient’s bedside. As a matter of fact, there are many optical fibre sensors designed for biomedical applications and described in the literature, but the greater part of them stops at the prototype level, without entering the hospital. The clinical validation, which is the necessary step after the characterisation of the laboratory prototype, is often an insurmountable obstacle due to the requirements of compliance with the European Directives on Medical Devices or with the regulations of the Food and Drug Administration. The strategy followed for the clinical validation in the case of optical fibre sensors developed at the Institute of Applied Physics for the detection of bile-containing refluxes, gastric carbon dioxide and interstitial pH is described. An example for potential non-invasive applications in point of care testing is also given with a novel optical platform for the interrogation of optical biochips.