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

Fiber Bragg grating sensors (FBGs) are considered a valid sensing solution for a variety of medical applications. The last decade witnessed the exploitation of these sensors in applications ranging from minimally invasive surgery to biomechanics and monitoring physiological parameters. Recently, preliminary studies investigated the potential impact of FBGs in the management of epidural procedures by detecting when the needle reaches the epidural space with the loss of resistance (LOR) technique. In this article, we propose a soft and flexible FBG-based system capable of detecting the LOR, we optimized the solution by considering different designs and materials, and we assessed the feasibility of the optimized soft sensor (SS) in clinical settings. The proposed SS addresses some of the open challenges in the use of a sensing solution during epidural punctures: it has high sensitivity, it is non-invasive, the sensing element does not need to be inserted within the needle, and the clinician can follow the standard clinical practice. Our analysis highlights how the material and the design impact the system response, and thus its performance in this scenario. We also demonstrated the system’s feasibility of detecting the LOR during epidural procedures.

Epidural Steroid Injections for Low Back Pain: A Narrative Review

Low back pain represents a significant socioeconomic burden. Several nonsurgical medical treatments have been proposed for the treatment of this disabling condition. Epidural steroid injections (ESIs) are commonly used to treat lumbosacral radicular pain and to avoid surgery. Even though it is still not clear which type of conservative intervention is superior, several studies have proved that ESIs are able to increase patients' quality of life, relieve lumbosacral radicular pain and finally, reduce or delay more invasive interventions, such as spinal surgery. The aim of this narrative review is to analyze the mechanism of action of ESIs in patients affected by low back pain and investigate their current application in treating this widespread pathology.

Soft System Based on Fiber Bragg Grating Sensor for Loss of Resistance Detection during Epidural Procedures: In Silico and In Vivo Assessment

Epidural analgesia represents a clinical common practice aiming at pain mitigation. This loco-regional technique is widely used in several applications such as labor, surgery and lower back pain. It involves the injections of anesthetics or analgesics into the epidural space (ES). The ES detection is still demanding and is usually performed by the techniques named loss of resistance (LOR). In this study, we propose a novel soft system (SS) based on one fiber Bragg grating sensor (FBG) embedded in a soft polymeric matrix for LOR detection during the epidural puncture. The SS was designed to allow instrumenting the syringe's plunger without relevant modifications of the anesthetist's sensations during the procedure. After the metrological characterization of the SS, we assessed the capability of this solution in detecting LOR by carrying it out in silico and in clinical settings. For both trials, results revealed the capability of the proposed solutions in detecting the LOR and then in recording the force exerted on the plunger.

Novice and Expert Anesthesiologists' Eye-Tracking Metrics During Simulated Epidural Block: A Preliminary, Brief Observational Report

Introduction

Eye tracking is the process of measuring an individual’s eye movements to register their attentional behavior by using a device called an eye-tracker. Studies conducted using eye-tracking techniques have demonstrated a number of differences in eye movement parameters and patterns between experts and novices. The aim of this preliminary study was to evaluate if there are any differences in eye-tracking metrics between novice and expert anesthesiologists during the performance of an epidural block using an epidural simulator.

Methods

Seven experts and seven novices who gave their consent to this preliminary study were asked to perform an epidural technique using an epidural simulator while wearing a pair of Tobii Pro glasses. Number of fixations, fixation duration, heat maps and scan-paths were examined by Tobii Pro Lab Software. Duration of the procedure was also recorded.

Results

The observation of the attentional heat map and gaze plot showed different gaze dispersion between experts and novices. The mean total duration of fixations during needle insertion and advancement and catheter introduction was lower in experts than trainees (respectively, 0.18 vs 3.56 sec; P<0.05 and 0.73 vs 2.48 sec; P<0.05). The mean fixation count was greater in experts vs trainees (5 vs 2; P<0.05). The mean duration of the epidural procedure was 104.16 (41) (trainees) vs 65.3 (32.6) seconds (experts) (P<0.05). Expert anesthesiologists spent more time fixating a more specific target location (eg, the point of the epidural needle rather than the syringe’s barrel) whilst novices split their attention between tracking their tools and the target location.

Discussion

Eye tracking may have interesting implications for the creation of assessment programs, which distinguish skill level through the use of gaze behavior, and may be a promising tool for monitoring training progress towards the development of expertise.

Epidural Needle Extension through the Ligamentum Flavum Using the Standard versus the CompuFlo®-Assisted Loss of Resistance to Saline Technique: A Simulation Study

Background. The CompuFlo® epidural system has been recently introduced and validated as an objective and sensible tool to detect the epidural space. We aimed to verify whether the high sensitivity of the instrument may help the anesthesiologist to identify the epidural space very early, limiting the extension of the Tuohy needle into the epidural space. Methods. In this prospective, simulation study, we evaluated the Tuohy needle extension through a simulated ligamentum flavum during the epidural procedure performed by 52 expert anesthesiologists by using the CompuFlo® epidural instrument or their standard loss of resistance to saline technique (LORT). Results. The mean (SD) needle extension length was 3.90 (3.71) mm in the standard technique group and 0.68 (0.46) mm in the CompuFlo® group (P<000001). The extremely reduced variability of the data in the CompuFlo® group (F test 0.01) made the results obtained with this instrument highly predictable. Conclusions. Puncturing high-resistance material that simulated the ligamentum flavum, the use of CompuFlo® has determined the arrest of the needle more precociously when compared with the traditional LORT.

Face and construct validity of TU-Delft epidural simulator and the value of real-time visualization

Background and objectives

Learning epidural anesthesia traditionally involves bedside teaching. Visualization aids or a simulator can help in acquiring motor skills, increasing patient safety and steepening the learning curve. We evaluated the face and construct validity of the TU-Delft Epidural Simulator and the effect of needle visualization.

Methods

Sixty-eight anesthesiologists, anesthesia residents, and final-year medical students tested the epidural simulator. Participants performed six epidural simulations with and six without needle visualization. We tested face validity on a Likert scale questionnaire. We collected data with the simulator software (spinal taps, dura contacts, bone contacts, attempts, and time) and tested for correlation with the performer’s experience (construct validity). A visualization aid was tested in a randomized crossover design.

Results

Face validity as rated by the participants was above average, with a mean of 3.7 (2.0–4.8) on a 5-point scale. Construct validity was indicated by significantly more spinal taps (0.4 [0–4) vs 0.07 [0–2], p=0.04) and more dura contacts (0.58 [0–6] vs 0.37 [0–3], p=0.002) by the inexperienced group compared with the expert group. The visualization aid improved performance by reducing the number of bone contacts and the number of attempts, and by decreasing the procedure time. Prior visualization training reduced the total procedure time from 279 s (69–574) to 180 s (53–605) (p=0.01) for the “blind” procedure.

Conclusions

The TU-Delft Epidural Simulator is a useful tool for teaching motor skills during epidural needle placement. Prior use of a visualization tool improves performance even without visual support during consequent simulations.

Artificial Organs 2017: A Year in Review

In this Editor's Review, articles published in 2017 are organized by category and summarized. We provide a brief reflection of the research and progress in artificial organs intended to advance and better human life while providing insight for continued application of these technologies and methods. Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. Peer-reviewed Special Issues this year included contributions from the 12th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Undar, Artificial Oxygen Carriers edited by Drs. Akira Kawaguchi and Jan Simoni, the 24th Congress of the International Society for Mechanical Circulatory Support edited by Dr. Toru Masuzawa, Challenges in the Field of Biomedical Devices: A Multidisciplinary Perspective edited by Dr. Vincenzo Piemonte and colleagues and Functional Electrical Stimulation edited by Dr. Winfried Mayr and colleagues. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.