Epidural catheter with integrated light guides for spectroscopic tissue characterization

Abstract

Epidural catheters are used to deliver anesthetics and opioids for managing pain in many clinical scenarios. Currently, epidural catheter insertion is performed without information about the tissues that are directly ahead of the catheter. As a result, the catheter can be incorrectly positioned within a blood vessel, which can cause toxicity. Recent studies have shown that optical reflectance spectroscopy could be beneficial for guiding needles that are used to insert catheters. In this study, we investigate the whether this technique could benefit the placement of catheters within the epidural space. We present a novel optical epidural catheter with integrated polymer light guides that allows for optical spectra to be acquired from tissues at the distal tip. To obtain an initial indication of the information that could be obtained, reflectance values and photon penetration depth were estimated using Monte Carlo simulations, and optical reflectance spectra were acquired during a laminectomy of a swine ex vivo. Large differences between the spectra acquired from epidural adipose tissue and from venous blood were observed. The optical catheter has the potential to provide realtime detection of intravascular catheter placement that could reduce the risk of complications.

Smart Optical Catheters for Epidurals

“…In fact, once that the catheter is correctly placed, by simply pulling off the fiber from the catheter lumen, it is possible to administer the anesthetic drugs through the catheter itself, as required by the current clinical procedure. Future catheter realizations could incorporate the optical fiber in the catheter walls in order to allow injection drugs without the need for removing the fiber probe [ 17 ]. Although the above discussed results are still preliminary, and further experimental tests are needed for improving the statistical significance of our observations, this study sets the stage for a new complete approach for epidurals, that guarantees the ES placement of both the needle and the catheter.…”

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver

“…To achieve greater ultrasound detection sensitivity, a plano-concave Fabry-Pérot cavity could be used in the future 17 . Ultimately, ultrasonic tracking could be combined with other modalities in a single optical fiber, such as reflectance spectroscopy 18 19 20 21 22 23 , Raman spectroscopy 24 , optical coherence tomography 25 26 , and photoacoustic imaging 27 28 29 30 31 32 33 .…”

Smart Optical Catheters for Epidurals

“…In fact, once that the catheter is correctly placed, by simply pulling off the fiber from the catheter lumen, it is possible to administer the anesthetic drugs through the catheter itself, as required by the current clinical procedure. Future catheter realizations could incorporate the optical fiber in the catheter walls in order to allow injection drugs without the need for removing the fiber probe [17].…”