Status and future development of distributed optical fiber sensors for biomedical applications

In recent years, fiber sensing technology has become more and more important in many fields of applied science. The versatility of the fiber sensors to obtain reliable and precise measurements while maintaining compact size and reduced costs has no comparison in sensing technology. However, the most intriguing property of optical fiber sensors is represented by the possibility to extend the sensing area to the whole length of the optical device. A direct consequence of this property is the capability to achieve a higher density of sensing points, thus making the optical fiber a perfect platform for implementing distributing sensing paradigm. In this context, distributed fiber sensing represents a new opportunity for biomedical applications, where the spatial density of sensing points is fundamental to achieve precise mapping of physical measurands. In this contribution we aim to review the main technologies that achieve higher density of sensing points and distributed sensing, in particular optical frequency domain reflectometry based on Rayleigh scattering. We focus our attention on the key aspects of distributing sensing that enable innovative applications in biomedical field such as, temperature mapping during thermo-therapies, guidance reconstruction of needles and catheters, shape sensing of medical device and other emerging application in the field.