Optical Guidance Systems for Epidural Space Identification

Epidurals are the most diffused loco-regional techniques for the relief of operative, postoperative, and chronic pain and are used for about 50% of deliveries. Currently, doctors still identify epidural space relying on subjective perception, by using “blind” manual techniques to which are associated failure rate up to 7%. In the last years, many systems aimed at assisting and guiding the placement of epidural needle have been proposed. In particular, optical systems basically rely on the integration inside the epidural needle lumen of optical fiber probes providing real-time discrimination of differing tissue types during needle penetration. In this study, aside of providing an exhaustive overview on the systems proposed so far, we also report on a novel sensorized medical needle, based on the judicious integration of a fiber Bragg grating sensor inside the epidural needle lumen. Our device, by providing continuous and real-time measurements of the pressure experienced by the needle tip during its advancement, is able to effectively detect the needle passage from one tissue to the other. A pilot study carried out on an epidural training phantom demonstrates the validity of our approach for making the needle placement into the epidural space easier and safer.