Smart Optical Catheters for Epidurals

Abstract

Placing the needle inside the epidural space for locoregional anesthesia is a challenging procedure, which even today is left to the expertise of the operator. Recently, we have demonstrated that the use of optically sensorized needles significantly improves the effectiveness of this procedure. Here, we propose an optimized configuration, where the optical fiber strain sensor is directly integrated inside the epidural catheter. The new design allows the solving of the biocompatibility issues and increases the versatility of the former configuration. Through an in vivo study carried out on a porcine model, we confirm the reliability of our approach, which also opens the way to catheter monitoring during insertion inside biological spaces.

Recent Advances in Biomedical Photonic Sensors: A Focus on Optical-Fibre-Based Sensing

“…The system was tested with real tissue [176], providing a preliminary indication of the potential of this technique to localise the epidural space. Some related works can be found in [177,178]. Finally, a multiparameter measurement FBG-based needle is proposed in [179].…”

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

“…In recent years, the availability of low-cost miniaturized sensors has progressively allowed the realization of smart surgical instruments and needles [ 1 ] that combine the detection of biophysical parameters with therapeutic functions such as the delivery of anesthetic fluid [ 2 ], radiating a surrounding tissue with focused electromagnetic waves to deliver cancer therapies [ 3 ], or performing diagnostic tasks through endoscopic and photoacoustic imaging [ 4 ]. Multifunctional surgical devices benefit from having advanced and miniaturized on-board sensors that can either perform or contribute to diagnostic tasks or provide in situ detection of additional parameters to improve efficacy.…”

“…In order to provide quantitative and sensory based assistance to epidural anesthesia, methods based on Fiber Bragg Gratings (FBGs) have been proposed. Carotenuto et al reported [ 13 ] and tested [ 2 ] a method based on an FBG mounted inside the needle that converts the tip force into a detectable strain. Similar work was recently proposed by De Tommasi et al [ 14 ] using a single FBG assembled in the epidural needle.…”

“…In addition, this method does not fully exploit the multipoint sensing capability of the optical fiber, providing a method that estimates whether the epidural space has been reached but without providing a guidance system that can support the clinician to actually reach the target region. Experimental data shown by FBG sensors [ 2 ] show a high variability between each output metric, as the differences in thickness of each layer, and the changes in the angle of insertion of the needle, have substantial impacts on the forces exerted on the needle.…”

Desarrollo de sensores basados en guía de onda plana y fibra óptica

“…Se realizó una prueba de calibración variando la temperatura para cada índice de refracción de Una de las estructuras más utilizadas para generar LMRs es la fibra en forma de D (D-Shaped fiber) en transmisión [32], [33]. Esta configuración no es tan fácil de manejar como una fibra en la configuración de reflexión, la que se puede utilizar como catéter [67], sonda nasogástrica [68] o incluso para mapeo químico de superficies [69]. Por el contrario, esta versatilidad se convierte en un inconveniente cuando el espesor del thin film a lo largo de la fibra no es uniforme, lo que puede ocurrir debido a la distancia e inclinación con la que se coloca la muestra dentro de la máquina de sputtering, o a los parámetros utilizados para rotar la plataforma donde se coloca la muestra en [70]- [72].…”