Fiber Optic Distributed Sensing Network for Shape Sensing-Assisted Epidural Needle Guidance

Abstract

Epidural anesthesia is a pain management process that requires the insertion of a miniature needle through the epidural space located within lumbar vertebrae. The use of a guidance system for manual insertion can reduce failure rates and provide increased efficiency in the process. In this work, we present and experimentally assess a guidance system based on a network of fiber optic distributed sensors. The fibers are mounted externally to the needle, without blocking its inner channel, and through a strain-to-shape detection method reconstruct the silhouette of the epidural device in real time (1 s). We experimentally assessed the shape sensing methods over 25 experiments performed in a phantom, and we observed that the sensing system correctly identified bending patterns typical in epidural insertions, characterized by the different stiffness of the tissues. By studying metrics related to the curvatures and their temporal changes, we provide identifiers that can potentially serve for the (in)correct identification of the epidural space, and support the operator through the insertion process by recognizing the bending patterns.

FBG-Based Soft System for Assisted Epidural Anesthesia: Design Optimization and Clinical Assessment

“…Compared to other FBG-based solutions, our SS is the first completely non-invasive approach. Indeed, approaches presented by [ 21 , 22 , 23 , 24 ] suggest instrumenting the Tuohy’s needle or replacing it with a new one. Scientific articles published by Carotenuto et al [ 21 , 22 ] proposed inserting an FBG array inside the Tuohy needle to track pressure variations as it moves through several tissues.…”

“…It consisted of two cylinders made of steel connected by a band that housed in the middle a 3 mm-FBG. More recently, in [ 23 ], authors proposed using a shape-sensing guidance system, including four distributed optical fiber sensors attached to the external surface of the Tuohy needle. These proposals intend to include optical fibers inside the needle, involving the risk of occlusion in the anesthetic flow.…”

“…Several researchers promote the introduction of smart devices to support anesthesiologists during the procedure, allowing more accurate detection of the ES and reducing the risk of adverse events caused by a wrong procedure [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Some of these devices are commercially available and intended to provide visual and/or acoustic feedback to the operator as the ES is reached by measuring pressure during tissue crossing.…”