Validation of the National Aeronautics and Space Administration Task Load Index as a tool to evaluate the learning curve for endoscopy training

Validation and motion analyses of laparoscopic radical nephrectomy with Thiel-embalmed cadavers

PURPOSE

Our aim was to develop practical training for laparoscopic surgery using Thielembalmed cadavers. Furthermore, in order to verbalize experts' motion characteristics and provide objective feedback to trainees, we initiated motion capture analyses of multiple surgical instruments simultaneously during the cadaveric trainings. In the present study, we report our preliminary results.

METHODS

Participants voluntarily joined the present cadaveric simulation trainings, and performed laparoscopic radical nephrectomy. After the trainings, scores for tissue similarity (face validity) and impression of educational merit (content validity) were collected from participants based on a 5-point Likert scale (tissue similarity: 5: very similar, 3: average, 1: very different; educational merit: 5: very high, 3: average, 1: very low). In addition, after the additional IRB approval, we started motion capture (Mocap) analyses of 6 surgical instruments (scissors, vessel sealing system, grasping forceps, clip applier, right-angled forceps, and suction), using an infrared trinocular camera (120-Hz location record). Mocap-metrics were compared according to the previous surgical experiences (experts: ≧50 laparoscopic surgeries, intermediates: 10-49, novices: 0-9), using the Kruskal-Wallis test.

RESULTS

A total of 9 experts, 19 intermediates, and 15 novices participated in the present study. In terms of face validity, the mean scores were higher than 3, other than for the Vena cava(mean score of 2.89). Participants agreed with the training value (usefulness for future skill improvement: mean score of 4.57). In terms of Mocap analysis, faster speed-related metrics (e.g., velocity, the distribution of tip velocity, acceleration, and jerk) in the scissors and vessel sealing system, a shorter path length of grasping forceps, and fewer dimensionless squared jerks, which indicated more purposeful motion of 4 surgical instruments (vessel sealing system, grasping forceps, clip applier and suction), were observed in the more experienced group.

CONCLUSIONS

The Thiel-embalmed cadaver provides an excellent training opportunity for complex laparoscopic procedures with participants' high level of satisfaction, and may become a promising tool for a better objective understanding of surgical dexterity. In order to enrich formative feedback to trainees, we are now proceeding with Mocap analysis.

Linked color imaging improves colorectal lesion detection especially for low performance endoscopists: An international trial in Asia

BACKGROUND AND AIM

Linked color imaging (LCI) is an image-enhanced endoscopy technique that accentuates the color difference between red and white, potentially improving the adenoma detection rate (ADR). However, it remains unclear whether LCI performance in detecting colorectal lesions differs based on endoscopists' experience levels. We aimed to evaluate the differences in LCI efficacy based on the experience levels of endoscopists by conducting an exploratory analysis.

METHODS

In this post hoc analysis of an international randomized controlled trial comparing the detection of adenoma and other lesions using colonoscopy with LCI and high-definition white light imaging (WLI), we included patients from 11 institutions across four countries/regions: Japan, Thailand, Taiwan, and Singapore. We retrospectively reviewed differences in the lesion detection of LCI according to endoscopists' colonoscopy history or ADR.

RESULTS

We included 1692 and 1138 patients who underwent colonoscopies performed by 54 experts (experience of ≥ 5000 colonoscopies) and by 43 non-experts (experience of < 5000 colonoscopies), respectively. Both expert and non-expert groups showed a significant improvement in ADR with LCI compared to WLI (expert, 61.7% vs 46.4%; P < 0.001; non-expert, 56.6% vs 46.4%; P < 0.001). LCI had no effect on sessile serrated lesion detection rate in non-experts (3.1% vs 2.5%; P = 0.518). LCI significantly improved detection rates in endoscopists with relatively low detection performance, defined as an ADR < 50%.

CONCLUSIONS

This exploratory study analyzed data from a previous trial and revealed that LCI is useful for both experts and non-experts and is even more beneficial for endoscopists with relatively low detection performance using WLI.

Eye-controlled endoscopy - a benchtop trial of a novel robotic steering platform - iGAZE2

The endoscopic control system has remained similar in design for many decades The remit of advanced therapeutic endoscopy continues to expand requiring precision control and high cognitive workloads. Robotic systems are emerging, but all still require bimanual control and expensive and large new systems. Eye tracking is an exciting area that can be used as an endoscope control system. This is a study to establish the feasibility of an eye-controlled endoscope and compare its performance and cognitive demand to use of a conventional endoscope. An eye gaze-control system consisting of eye-tracking glasses, customised software and a small motor unit was built and attached to a conventional endoscope. Twelve non-endoscopists used both the eye gaze system and a conventional endoscope to complete a benchtop task in a simulated oesophagus and stomach. Completion of tasks was timed. Subjective feedback was collected from each participant on task load using the NASA Task Load Index. Participants were significantly quicker completing the task using iGAZE2 vs a conventional endoscope (65.02 ± 16.34s vs 104.21 ± 51.31s, p = 0.013) Participants were also significantly quicker completing retroflexion using iGAZE2 vs a conventional endoscope (8.48 ± 3.08 vs 11.38 ± 5.36s, p = 0.036). Participants reported a significantly lower workload (raw NASA-TLX score) when using iGAZE2 vs the conventional endoscope (152.1 ± 63.4 vs 319.6 ± 81.6, p = 0.0001) (Fig. 7). Users found iGAZE2 to have a significantly lower temporal demand, mental demand, effort, mental demand, physical demand, and frustration level. The eye gaze system is an exciting, small, and retrofittable system to any endoscope. The system shows exciting potential as a novel endoscopic control system with a significantly lower workload and better performance in novices suggesting a more intuitive control system.

Debriefer cognitive load during Traditional Reflective Debriefing vs. Rapid Cycle Deliberate Practice interdisciplinary team training

BACKGROUND

Cognitive load impacts performance of debriefers and learners during simulations, but limited data exists examining debriefer cognitive load. The aim of this study is to compare the cognitive load of the debriefers during simulation-based team training (SbTT) with Rapid Cycle Deliberate Practice (RCDP) debriefing and Traditional Reflective Debriefing (TRD). We hypothesize that cognitive load will be reduced during RCDP compared to TRD.

METHODS

This study was part of a large-scale, interdisciplinary team training program at Children's Healthcare of Atlanta Egleston Pediatric Emergency Department, with 164 learners (physicians, nurses, medical technicians, paramedics, and respiratory therapists (RTs)). Eight debriefers (main facilitators and discipline-specific coaches) led 28 workshops, which were quasi-randomized to either RCDP or TRD. Each session began with a baseline medical resuscitation scenario and cognitive load measurement using the NASA Task Load Index (TLX), and the NASA TLX was repeated immediately following either TRD or RCDP debriefing. Raw scores of the NASA TLX before and after intervention were compared. ANOVA tests were used to compare differences in NASA TLX scores before and after intervention between the RCDP and TRD groups.

RESULTS

For all debriefers, mean NASA TLX scores for physical demands and frustration significantly decreased (- 0.8, p = 0.004 and - 1.3, p = 0.002) in TRD and mean perceived performance success significantly increased (+ 2.4, p < 0.001). For RCDP, perceived performance success increased post-debriefing (+ 3.6, p < 0.001), time demands decreased (- 1.0, p = 0.04), and frustration decreased (- 2.0, p < 0.001). Comparing TRD directly to RCDP, perceived performance success was greater in RCDP than TRD (3.6 vs. 2.4, p = 0.04). Main facilitators had lower effort and mental demand in RCDP and greater perceived success (p < 0.001).

CONCLUSION

RCDP had greater perceived success than TRD for debriefers. Main facilitators also report reduced effort and baseline mental demand in RCDP. For less experienced debriefers, newer simulation programs, or large team training sessions such as our study, RCDP may be a less mentally demanding debriefing methodology for facilitators.

Development of performance and learning rate evaluation models in robot-assisted surgery using electroencephalography and eye-tracking

The existing performance evaluation methods in robot-assisted surgery (RAS) are mainly subjective, costly, and affected by shortcomings such as the inconsistency of results and dependency on the raters' opinions. The aim of this study was to develop models for an objective evaluation of performance and rate of learning RAS skills while practicing surgical simulator tasks. The electroencephalogram (EEG) and eye-tracking data were recorded from 26 subjects while performing Tubes, Suture Sponge, and Dots and Needles tasks. Performance scores were generated by the simulator program. The functional brain networks were extracted using EEG data and coherence analysis. Then these networks, along with community detection analysis, facilitated the extraction of average search information and average temporal flexibility features at 21 Brodmann areas (BA) and four band frequencies. Twelve eye-tracking features were extracted and used to develop linear random intercept models for performance evaluation and multivariate linear regression models for the evaluation of the learning rate. Results showed that subject-wise standardization of features improved the R2 of the models. Average pupil diameter and rate of saccade were associated with performance in the Tubes task (multivariate analysis; p-value = 0.01 and p-value = 0.04, respectively). Entropy of pupil diameter was associated with performance in Dots and Needles task (multivariate analysis; p-value = 0.01). Average temporal flexibility and search information in several BAs and band frequencies were associated with performance and rate of learning. The models may be used to objectify performance and learning rate evaluation in RAS once validated with a broader sample size and tasks.

The association between workload and quality of work life of nurses taking care of patients with COVID-19

BACKGROUND

The COVID-19 epidemic has brought significant changes and complexities to nurses' working conditions. Given the crucial role of health workers, particularly nurses, in providing healthcare services, it is essential to determine the nurses' workload, and its association with the quality of work life (QWL) during COVID-19 epidemic, and to explain the factors predicting their QWL.

METHODS

A total of 250 nurses, who provided care for patients with COVID-19 in Imam Hossein Hospital of Shahrud, and met the inclusion criteria, were considered the samples in the present cross-sectional study in 2021-2022. Data were collected using the demographic questionnaire, NASA Task Load Index (TLX), and Walton's QWL questionnaire, which were analyzed using SPSS26 and based on descriptive and inferential statistical tests. A p-value less than 0.05 was considered significant for all cases.

RESULTS

The nurses' mean scores of workload and QWL were 71.43 ± 14.15 and 88.26 ± 19.5, respectively. Pearson's correlation test indicated a significant inverse relationship between workload and QWL (r=-0.308, p < 0.001). The subscales with the highest perceived workload scores were physical demand and mental demand (14.82 ± 8.27; 14.36 ± 7.43), respectively, and the subscale with the lowest workload was overall performance (6.63 ± 6.31). The subscales with the highest scores for QWL were safety and health in working conditions and opportunity to use and develop human capabilities (15.46 ± 4.11; 14.52 ± 3.84), respectively. The subscales with the lowest scores were adequate and fair compensation, work and total living space (7.46 ± 2.38; 6.52 ± 2.47), respectively. The number of children (β = 4.61, p = 0.004), work experience (β= -0.54, p = 0.019), effort (β = 0.37, p = 0.033) and total workload (β= -0.44, p = 0.000) explained 13% of the variance of nurses' QWL.

CONCLUSIONS

The study's findings showed that a higher workload score is associated with nurses' lower perception of QWL. In order to improve the QWL of nurses, reducing the physical and mental demands of their workload and strengthening overall performance is necessary. Additionally, when promoting QWL, adequate and fair compensation and the work and living space should be considered. The researchers suggest that hospital managers should make more significant efforts to develop and promote the QWL of nurses. To achieve this goal, organizations can pay attention to other influential factors, primarily by increasing organizational support.

Endoscopy training in Australia during COVID-19: Efficacy and knowledge assessment of gastroenterology and general surgery trainees

BACKGROUND AND AIM

During COVID-19, restrictions to elective endoscopy were introduced worldwide. A reduction in procedures may impact trainees' endoscopy learning. This study aims to assess Australian advanced gastroenterology and general surgery trainees' self-perceived efficacy and knowledge in endoscopy during the pandemic.

METHODS

All Australian gastroenterology and general surgery trainees in their last 2 years of accredited training were invited to participate through email (2020-2021 and 2021-2022 training cycles). The primary outcome was to assess trainees' self-efficacy and knowledge regarding gastrointestinal endoscopy. Secondary outcomes included subgroup analysis between gastroenterology and general surgery trainees. Self-perceived efficacy was assessed with Likert-scale questions on 20 endoscopy procedures and knowledge was assessed through 21 endoscopy-related multiple choice questions.

RESULTS

Eighty-one trainees responded to a self-efficacy questionnaire and 77 responded to the knowledge questionnaire. Over 90% of the trainees were confident or extremely confident in diagnostic endoscopy, but only half demonstrated similar efficacy for therapeutic endoscopy. The efficacy for basic endoscopy procedures was higher for gastroenterology trainees (64.0% vs 51.1%, P < 0.001). Last-year trainee achievement of conjoint committee requirements for upper gastrointestinal endoscopy was achieved in 95.8% of gastroenterology trainees versus 22.2% of surgical trainees (P < 0.001). The median score on the knowledge questionnaire was also higher for the gastroenterology subset (90.5% vs 71.4%, P < 0.001).

CONCLUSION

During COVID-19, endoscopy trainees' self-efficacy in endoscopic diagnostic procedures was achieved for most trainees. The differences in self-perceived efficacy and knowledge between gastroenterology and surgical trainees may be reflective of the different opportunities for learning between the two groups.

Effectiveness of simulation-based training for obstetric internal medicine: Impact of cognitive load and emotions on knowledge acquisition and retention

Background

Simulation-based training’s impact on learning outcomes may be related to cognitive load or emotions during training. We evaluated the association of validated measures of cognitive load and emotion with learning outcomes in simulation-based obstetric internal medicine cases.

Methods

All internal medicine learners (n = 15) who completed the knowledge test pre-training, post-training (knowledge acquisition), and at 3–6 months (knowledge retention) for all three simulation cases were included.

Results

Mean knowledge scores differed over time in all three cases (p < 0.0001 for all). Knowledge retention scores were significantly higher only for cases 1 and 3. Cognitive load associated with frustration was positively associated with knowledge acquisition for case 2 (beta = 5.18, P = 0.007), while excitement was negatively associated with knowledge retention in case 1 (beta = –33.07, p = 0.04).

Conclusion

Simulation-based education for obstetric internal medicine can be effective in select cases. Attention to cognitive load and emotion may optimize learning outcomes.

Endoscopic simulators: training the next generation

PURPOSE OF REVIEW

To provide a review of current evidence evaluating endoscopic simulators as teaching platforms in gastroenterology training, with emphasis on upper gastrointestinal anatomy.

RECENT FINDINGS

Endoscopic simulators have leveraged mechanical, virtual reality and ex-vivo or live animal platforms to deliver training in both general and therapeutic endoscopy. Simulators have demonstrated their greatest utility in training novice endoscopists. Intermediate and expert endoscopists may additionally benefit from simulator exposure when learning advanced therapeutic techniques including large tissue resection or natural orifice transluminal endoscopic surgery.

SUMMARY

Simulator-based learning offers promise to complement conventional endoscopic training modalities for novice trainees. Nevertheless, additional evidence demonstrating a clear benefit is required for simulators to become an integral part of gastroenterology training. As novel advanced endoscopic therapies are developed, endoscopic simulators may assume a larger role in training prior to clinical practice.

A novel gaze-controlled flexible robotized endoscope; preliminary trial and report

Background

Interventional endoluminal therapy is rapidly advancing as a minimally invasive surgical technique. The expanding remit of endoscopic therapy necessitates precision control. Eye tracking is an emerging technology which allows intuitive control of devices. This was a feasibility study to establish if a novel eye gaze-controlled endoscopic system could be used to intuitively control an endoscope.

Methods

An eye gaze-control system consisting of eye tracking glasses, specialist cameras and a joystick was used to control a robotically driven endoscope allowing steering, advancement, withdrawal and retroflexion. Eight experienced and eight non-endoscopists used both the eye gaze system and a conventional endoscope to identify ten targets in two simulated environments: a sphere and an upper gastrointestinal (UGI) model.

Completion of tasks was timed. Subjective feedback was collected from each participant on task load (NASA Task Load Index) and acceptance of technology (Van der Laan scale).

Results

When using gaze-control endoscopy, non-endoscopists were significantly quicker when using gaze-control rather than conventional endoscopy (sphere task 3:54 ± 1:17 vs. 9:05 ± 5:40 min, p = 0.012, and UGI model task 1:59 ± 0:24 vs 3:45 ± 0:53 min, p < .001).

Non-endoscopists reported significantly higher NASA-TLX workload total scores using conventional endoscopy versus gaze-control (80.6 ± 11.3 vs 22.5 ± 13.8, p < .001). Endoscopists reported significantly higher total NASA-TLX workload scores using gaze control versus conventional endoscopy (54.2 ± 16 vs 26.9 ± 15.3, p = 0.012). All subjects reported that the gaze-control had positive ‘usefulness’ and ‘satisfaction’ score of 0.56 ± 0.83 and 1.43 ± 0.51 respectively.

Conclusions

The novel eye gaze-control system was significantly quicker to use and subjectively lower in workload when used by non-endoscopists. Further work is needed to see if this would translate into a shallower learning curve to proficiency versus conventional endoscopy. The eye gaze-control system appears feasible as an intuitive endoscope control system. Hybrid gaze and hand control may prove a beneficial technology to evolving endoscopic platforms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08556-1.

Development and validation of a porcine organ model for training in essential laparoscopic surgical skills

OBJECTIVES

To develop a wet laboratory training model for learning core laparoscopic surgical skills and evaluating learners' competency level outside the operating room.

METHODS

Participants completed three tasks (task 1: tissue dissection around the aorta; task 2: tissue dissection and division of the renal artery; task 3: renal parenchymal closure). Each performance was video recorded and subsequently evaluated by two experts, according to the Global Operative Assessment of Laparoscopic Skills and task-specific metrics that we developed (Assessment Sheet of Laparoscopic Skills in Wet Lab score). Mean scores were used for analyses. The subjective mental workload was also assessed (NASA Task Load Index).

RESULTS

The 54 participants included 32 urologists, eight young trainees and 14 medical students. A total of 13 participants were categorized as experts (≥50 laparoscopic surgeries), eight as intermediates (10-49) and 33 as novices (0-9). There were significant differences in the Global Operative Assessment of Laparoscopic Skills and Assessment Sheet of Laparoscopic Skills in Wet Lab scores among the three groups in all three tasks. Higher NASA Task Load Index scores were observed in novices, and there were significant differences in tasks 1 (Kruskal-Wallis test, P = 0.0004) and 2 (P = 0.0002), and marginal differences in task 3 (P = 0.0745) among the three groups.

CONCLUSIONS

Our training model has good construct validity, and differences in the NASA Task Load Index score reflect previous laparoscopic surgical experiences. Our findings show the ability to assess both laparoscopic surgical skills and mental workloads, which could help educators comprehend trainees' level outside the operating room. Given the decreasing opportunity to carry out pure laparoscopic surgeries because of the dissemination of robotic surgery, especially in urology, our model can offer practical training opportunities.

[The "National Aeronautics and Space Administration-Task Load Index" (NASA-TLX) - an instrument for measuring consultation workload within general practice: evaluation of psychometric properties]

OBJECTIVE

The aims of the study were the translation and a first reflection of the psychometric properties of the Aeronautics and Space Administration-Task Load Index (NASA-TLX), a multidimensional instrument to measure workload in general practice.

METHODS

During April and September 2015, the NASA-TLX was translated and evaluated. For this purpose, a questionnaire composed of the NASA-TLX items and others items related to demographic data, was developed. Postgraduate family medicine trainees and family physicians were then asked to assess patient consultations by applying the questionnaire. The psychometric properties of the NASA-TLX were identified using explorative and confirmatory factor analysis. Reliability was assessed using Cronbach's α.

RESULTS

Overall, 16 participants completed 769 surveys after a single patient consultation. The highest average was observed for the item 'mental demand' (mean 6.9 ± 5.4), followed by the item 'effort' (mean 6.6 ± 5.5). Factor analysis revealed a one-factor solution with an explained variance of 56.9 %. The German version of NASA-TLX demonstrated a high internal consistency (Cronbach's α = 0.84). Confirmatory factor analysis showed that there was an acceptable consistency between the expected unidimensional structure and the data.

CONCLUSIONS

The German version of NASA-TLX provides preliminary indications of psychometric properties and presents an important tool to evaluate family physicians' workload in direct patient contact.

Cognitive load theory for training health professionals in the workplace: A BEME review of studies among diverse professions: BEME Guide No. 53

AIM

Cognitive load theory (CLT) is of increasing interest to health professions education researchers. CLT has intuitive applicability to workplace settings, yet how CLT should inform teaching, learning, and research in health professions workplaces is unclear.

METHOD

To map the existing literature, we performed a scoping review of studies involving cognitive load, mental effort and/or mental workload in professional workplace settings within and outside of the health professions. We included actual and simulated workplaces and workplace tasks.

RESULT

Searching eight databases, we identified 4571 citations, of which 116 met inclusion criteria. Studies were most often quantitative. Methods to measure cognitive load included psychometric, physiologic, and secondary task approaches. Few covariates of cognitive load or performance were studied. Overall cognitive load and intrinsic load were consistently negatively associated with the level of experience and performance. Studies consistently found distractions and other aspects of workplace environments as contributing to extraneous load. Studies outside the health professions documented similar findings to those within the health professions, supporting relevance of CLT to workplace learning.

CONCLUSION

The authors discuss implications for workplace teaching, curricular design, learning environment, and metacognition. To advance workplace learning, the authors suggest future CLT research should address higher-level questions and integrate other learning frameworks.

Comparative Analysis of Emergency Medical Service Provider Workload During Simulated Out-of-Hospital Cardiac Arrest Resuscitation Using Standard Versus Experimental Protocols and Equipment

INTRODUCTION

Protocolized automation of critical, labor-intensive tasks for out-of-hospital cardiac arrest (OHCA) resuscitation may decrease Emergency Medical Services (EMS) provider workload. A simulation-based assessment method incorporating objective and self-reported metrics was developed and used to quantify workloads associated with standard and experimental approaches to OHCA resuscitation.

METHODS

Emergency Medical Services-Basic (EMT-B) and advanced life support (ALS) providers were randomized into two-provider mixed-level teams and fitted with heart rate (HR) monitors for continuous HR and energy expenditure (EE) monitoring. Subjects' resting salivary α-amylase (sAA) levels were measured along with Borg perceived exertion scores and multidimensional workload assessments (NASA-TLX). Each team engaged in the following three OHCA simulations: (1) baseline simulation in standard BLS/ALS roles; (2) repeat simulation in standard roles; and then (3) repeat simulation in reversed roles, ie, EMT-B provider performing ALS tasks. Control teams operated with standard state protocols and equipment; experimental teams used resuscitation-automating devices and accompanying goal-directed algorithmic protocol for simulations 2 and 3. Investigators video-recorded resuscitations and analyzed subjects' percent attained of maximal age-predicted HR (%mHR), EE, sAA, Borg, and NASA-TLX measurements.

RESULTS

Ten control and ten experimental teams completed the study (20 EMT-Basic; 1 EMT-Intermediate, 8 EMT-Cardiac, 11 EMT-Paramedic). Median %mHR, EE, sAA, Borg, and NASA-TLX scores did not differ between groups at rest. Overall multivariate analyses of variance did not detect significant differences; univariate analyses of variance for changes in %mHR, Borg, and NASA-TLX from resting state detected significant differences across simulations (workload reductions in experimental groups for simulations 2 and 3).

CONCLUSIONS

A simulation-based OHCA resuscitation performance and workload assessment method compared protocolized automation-assisted resuscitation with standard response. During exploratory application of the assessment method, subjects using the experimental approach appeared to experience reduced levels of physical exertion and perceived workload than control subjects.

Learner, Patient, and Supervisor Features Are Associated With Different Types of Cognitive Load During Procedural Skills Training: Implications for Teaching and Instructional Design

PURPOSE

Cognitive load theory, focusing on limits of the working memory, is relevant to medical education; however, factors associated with cognitive load during procedural skills training are not well characterized. The authors sought to determine how features of learners, patients/tasks, settings, and supervisors were associated with three types of cognitive load among learners performing a specific procedure, colonoscopy, to identify implications for procedural teaching.

METHOD

Data were collected through an electronically administered survey sent to 1,061 U.S. gastroenterology fellows during the 2014-2015 academic year; 477 (45.0%) participated. Participants completed the survey immediately following a colonoscopy. Using multivariable linear regression analyses, the authors identified sets of features associated with intrinsic, extraneous, and germane loads.

RESULTS

Features associated with intrinsic load included learners (prior experience and year in training negatively associated, fatigue positively associated) and patient/tasks (procedural complexity positively associated, better patient tolerance negatively associated). Features associated with extraneous load included learners (fatigue positively associated), setting (queue order positively associated), and supervisors (supervisor engagement and confidence negatively associated). Only one feature, supervisor engagement, was (positively) associated with germane load.

CONCLUSIONS

These data support practical recommendations for teaching procedural skills through the lens of cognitive load theory. To optimize intrinsic load, level of experience and competence of learners should be balanced with procedural complexity; part-task approaches and scaffolding may be beneficial. To reduce extraneous load, teachers should remain engaged, and factors within the procedural setting that may interfere with learning should be minimized. To optimize germane load, teachers should remain engaged.

Impact of simulated three-dimensional perception on precision of depth judgements, technical performance and perceived workload in laparoscopy

Background

This study compared precision of depth judgements, technical performance and workload using two‐dimensional (2D) and three‐dimensional (3D) laparoscopic displays across different viewing distances. It also compared the accuracy of 3D displays with natural viewing, along with the relationship between stereoacuity and 3D laparoscopic performance.

Methods

A counterbalanced within‐subjects design with random assignment to testing sequences was used. The system could display 2D or 3D images with the same set‐up. A Howard–Dolman apparatus assessed precision of depth judgements, and three laparoscopic tasks (peg transfer, navigation in space and suturing) assessed performance (time to completion). Participants completed tasks in all combinations of two viewing modes (2D, 3D) and two viewing distances (1 m, 3 m). Other measures administered included the National Aeronautics and Space Administration Task Load Index (perceived workload) and the Randot^® Stereotest (stereoacuity).

Results

Depth judgements were 6·2 times as precise at 1 m and 3·0 times as precise at 3 m using 3Dversus2D displays (P < 0·001). Participants performed all laparoscopic tasks faster in 3D at both 1 and 3 m (P < 0.001), with mean completion times up to 64 per cent shorter for 3Dversus2D displays. Workload was lower for 3D displays (up to 34 per cent) than for 2D displays at both viewing distances (P < 0·001). Greater viewing distance inhibited performance for two laparoscopic tasks, and increased perceived workload for all three (P < 0·001). Higher stereoacuity was associated with shorter completion times for the navigating in space task performed in 3D at 1 m (r = − 0·40, P = 0·001).

Conclusion

3D displays offer large improvements over 2D displays in precision of depth judgements, technical performance and perceived workload.

Many advantages for 3D

Evaluation of a novel tablet application for improvement in colonoscopy training and mentoring (with video)

BACKGROUND AND AIMS

Endoscopic training can be challenging for the trainee and preceptor. Frustration can result from ineffective communication regarding areas of interest. Our team developed a novel tablet application for real-time mirroring of the colonoscopy examination that allows preceptors to make annotations directly on the viewing monitor. The potential for improvement in team proficiency and satisfaction is unknown.

METHODS

The on-screen endoscopic image is mirrored to an Android tablet and permits real-time annotation directly on the in-room endoscopic image display. Preceptors can also "freeze-frame" an image and provide visual on-screen instruction (telestration). Trainees, precepted by a GI attending, were 1:1 randomized to perform colonoscopy on a training phantom using the application with traditional precepting or traditional precepting alone. Magnetized polyps (size < 5 mm) were placed in 1 of 5 preset location scenarios. Each trainee performed a total of 10 colonoscopies and completed each location scenario twice. During withdrawal, the trainee and the attending identified polyps. Outcome measures included number of polyps missed and participant satisfaction after each trial.

RESULTS

Fifteen trainees (6 novice and 9 GI fellows) performed a total of 150 colonoscopies where 330 polyps in total were placed. Fellows missed fewer polyps using the tablet versus traditional precepting alone (4.2% vs 12.5%; P = .04). There was no significant difference in missed polyps for novices (12.5% vs 18.8%; P = .66). Overall, fellows missed fewer polyps when compared with novices regardless of the precepting method (P = .01). The attending and all trainees reported reduced stress with improved communication using the tablet.

CONCLUSIONS

Fellows missed fewer polyps using the tablet when compared with traditional endoscopy precepting. All trainees reported reduced stress, quicker identification of polyps, and improved educational satisfaction using the tablet. Our application has the potential to improve trainee plus attending team lesion detection and to enhance the endoscopy training experience for both the trainee and attending preceptor.

EUS-guided intrahepatic portosystemic shunt with direct portal pressure measurements: a novel alternative to transjugular intrahepatic portosystemic shunting

BACKGROUND AND AIMS

Transjugular intrahepatic portosystemic shunting involves the creation of a low-resistance channel between the portal vein (PV) and the hepatic vein (HV), and is routinely performed under angiography. The aims were to evaluate (1) safety and technical feasibility; (2) procedural duration; and (3) subjective workload assessment of EUS-guided intrahepatic portosystemic shunt (EIPS).

METHODS

Five Yorkshire pigs were used in the study. The HV or inferior vena cava (IVC) was identified using a linear-array echoendoscope and accessed with a 19-G FNA needle preloaded with a digital pressure wire. Mean pressure was recorded. The needle was advanced into the PV, where pressure measurements were again taken, and ultimately exchanged over a guidewire. A lumen-apposing metal stent was deployed under EUS and fluoroscopic guidance, with distal and proximal ends positioned inside the PV and HV (IVC), respectively. Dilation was performed, and pressure measurements repeated. The National Aeronautics and Space Administration (NASA) Task Load Index (TLI) was scored. Animals survived 2 weeks before necropsy.

RESULTS

EIPS was successful in 5 out of 5 pigs. Mean time required for EUS identification, needle access, pressure measurement, and stent placement was 43 (31-55) minutes. NASA TLI scores revealed moderate workload. Mean baseline pressure measurements were PV 7.0 (5-9) and HV/IVC 5.0 (3-7) mm Hg and PV 6.3 (5-7) and HV/IVC 6.0 (4-7) mm Hg after. All animals survived 2 weeks. No bleeding was seen on necropsy.

CONCLUSIONS

This study demonstrates the technical feasibility of EIPS using LAMS, with direct portal pressure measurement, in a survival model. In addition, the procedure was performed quickly with moderate technical demand.

Learning curve for endoscopy training: Is it all about numbers?

Endoscopy training is an important component of postgraduate gastroenterology and general surgery programs. Proficiency in endoscopy requires the development of several tangible and intangible skills. Much attention has traditionally been paid to establishing a threshold, or minimum procedural volume during the training period, which is necessary for a trainee to achieve competence in endoscopy by the conclusion of his or her program. However, despite several attempts to characterize this target, it has become clear in recent years that training programs need to consider other factors rather than relying on this measure as the sole marker of trainee competency. Here, we present a review of general concepts in endoscopy skills acquisition that affect the learning curve, the evolving definition of competency as it relates to procedural volume, the role of simulation in endoscopy training, and the concept of massed versus spaced delivery of endoscopy training.

EUS-guided portal pressure measurement using a digital pressure wire with real-time remote display: a novel, minimally invasive technique for direct measurement in an animal model

BACKGROUND AND AIMS

Hepatic venous pressure gradient (HVPG) currently serves as a surrogate for portal pressure measurement but has many limitations. We developed a novel technique for rapid and direct portal pressure measurements using a digital pressure wire delivered through an EUS-guided 22-gauge FNA needle. Our aims were to evaluate (1) the short-term safety and technical feasibility, (2) procedural duration and subjective workload assessment, and (3) accuracy compared with a transjugular criterion standard approach.

METHODS

The subjects were Yorkshire pigs, weighing 40 to 55 kg. The portal vein was identified by using a linear array echoendoscope and accessed with a commercially available 22-gauge FNA needle preloaded with a digital pressure wire. Access was confirmed by portal venography. Mean digital pressure measurements were recorded over 30 to 60 seconds, and the National Aeronautics and Space Administration Task Load Index was scored. The control measurements were conventional transjugular catheterization with a balloon occlusion catheter to obtain free and wedged hepatic pressures, with subsequent HVPG calculation.

RESULTS

The total time required for EUS identification and needle access of the portal vein, venography, and digital pressure measurement was less than 5 minutes in 5 of 5 pigs. The National Aeronautics and Space Administration Task Load Index scores revealed a low subjective workload. Baseline portal pressure measurements via EUS ranged from 5 mm Hg to 10 mm Hg (mean, 6.4 mm Hg). HVPG measurements were consistently ±1 mm Hg of portal pressure.

CONCLUSIONS

This study is the first report of direct EUS-guided portal pressure measurements by using a digital pressure wire. This method is routinely performed in minutes and provides real-time pressure tracings via wireless transmission. This novel approach for direct portal pressure measurement has the potential to replace traditional indirect HVPG measurements.

Electromagnetic image guidance in gynecology: prospective study of a new laparoscopic imaging and targeting technique for the treatment of symptomatic uterine fibroids

Background

Uterine fibroids occur singly or as multiple benign tumors originating in the myometrium. Because they vary in size and location, the approach and technique for their identification and surgical management vary. Reference images, such as ultrasound images, magnetic resonance images, and sonohystograms, do not provide real-time intraoperative findings.

Methods

Electromagnetic image guidance, as incorporated in the Acessa Guidance System, has been cleared by the FDA to facilitate targeting and ablation of uterine fibroids during laparoscopic surgery. This is the first feasibility study to verify the features and usefulness of the guidance system in targeting symptomatic uterine fibroids—particularly hard-to-reach intramural fibroids and those abutting the endometrium. One gynecologic surgeon, who had extensive prior experience in laparoscopic ultrasound-guided identification of fibroids, treated five women with symptomatic uterine fibroids using the Acessa Guidance System. The surgeon evaluated the system and its features in terms of responses to prescribed statements; the responses were analyzed prospectively.

Results

The surgeon strongly agreed (96 %) or agreed (4 %) with statements describing the helpfulness of the transducer and handpiece’s dynamic animation in targeting each fibroid, reaching the fibroid quickly, visualizing the positions of the transducer and handpiece within the pelvic cavity, and providing the surgeon with confidence when targeting the fibroid even during “out-of-plane” positioning of the handpiece.

Conclusions

The surgeon’s positive user experience was evident in the guidance system’s facilitation of accurate handpiece tip placement during targeting and ablation of uterine fibroids. Continued study of electromagnetic image guidance in the laparoscopic identification and treatment of fibroids is warranted.

ClinicalTrials.gov Identifier: NCT01842789.