Gaze training enhances laparoscopic technical skill acquisition and multi-tasking performance: a randomized, controlled study

Eye-tracking in surgery: a systematic review

BACKGROUND

Surgery is constantly evolving with the assistance of rapidly developing novel technology. Eye-tracking devices provide opportunities to monitor the acquisition of surgical skills, gain insight into performance, and enhance surgical practice. The aim of this review was to consolidate the available evidence for the use of eye-tracking in the surgical disciplines.

METHODS

A systematic literature review was conducted in accordance with PRISMA guidelines. A search of OVID Medline, EMBASE, Cochrane library, Scopus, and Science Direct was conducted January 2000 until December 2022. Studies involving eye-tracking in surgical training, assessment and technical innovation were included in the review. Non-surgical procedures, animal studies, and studies not involving surgical participants were excluded from the review.

RESULTS

The search returned a total of 12 054 articles, 80 of which were included in the final analysis and review. Seventeen studies involved eye-tracking in surgical training, 48 surgical assessment, and 20 were focussing on technical aspects of this technology. Twenty-six different eye-tracking devices were used in the included studies. Metrics such as the number of fixations, duration of fixations, dwell time, and cognitive workload were able to differentiate between novice and expert performance. Eight studies demonstrated the effectiveness of gaze-training for improving surgical skill.

CONCLUSION

The current literature shows a broad range of utility for a variety of eye-tracking devices in surgery. There remains a lack of standardization for metric parameters and gaze analysis techniques. Further research is required to validate its use to establish reliability and create uniform practices.

Gaze behavior is related to objective technical skills assessment during virtual reality simulator-based surgical training: a proof of concept

PURPOSE

Simulation-based training allows surgical skills to be learned safely. Most virtual reality-based surgical simulators address technical skills without considering non-technical skills, such as gaze use. In this study, we investigated surgeons' visual behavior during virtual reality-based surgical training where visual guidance is provided. Our hypothesis was that the gaze distribution in the environment is correlated with the simulator's technical skills assessment.

METHODS

We recorded 25 surgical training sessions on an arthroscopic simulator. Trainees were equipped with a head-mounted eye-tracking device. A U-net was trained on two sessions to segment three simulator-specific areas of interest (AoI) and the background, to quantify gaze distribution. We tested whether the percentage of gazes in those areas was correlated with the simulator's scores.

RESULTS

The neural network was able to segment all AoI with a mean Intersection over Union superior to 94% for each area. The gaze percentage in the AoI differed among trainees. Despite several sources of data loss, we found significant correlations between gaze position and the simulator scores. For instance, trainees obtained better procedural scores when their gaze focused on the virtual assistance (Spearman correlation test, N = 7, r = 0.800, p = 0.031).

CONCLUSION

Our findings suggest that visual behavior should be quantified for assessing surgical expertise in simulation-based training environments, especially when visual guidance is provided. Ultimately visual behavior could be used to quantitatively assess surgeons' learning curve and expertise while training on VR simulators, in a way that complements existing metrics.

Eye-tracking during simulation-based echocardiography: a feasibility study

INTRODUCTION

Due to the technical progress point-of-care ultrasound (POCUS) is increasingly used in critical care medicine. However, optimal training strategies and support for novices have not been thoroughly researched so far. Eye-tracking, which offers insights into the gaze behavior of experts may be a useful tool for better understanding. The aim of this study was to investigate the technical feasibility and usability of eye-tracking during echocardiography as well as to analyze differences of gaze patterns between experts and non-experts.

METHODS

Nine experts in echocardiography and six non-experts were equipped with eye-tracking glasses (Tobii, Stockholm, Sweden), while performing six medical cases on a simulator. For each view case specific areas of interests (AOI) were defined by the first three experts depending on the underlying pathology. Technical feasibility, participants' subjective experience on the usability of the eye-tracking glasses as well as the differences of relative dwell time (focus) inside the areas of interest (AOI) between six experts and six non-experts were evaluated.

RESULTS

Technical feasibility of eye-tracking during echocardiography was achieved with an accordance of 96% between the visual area orally described by participants and the area marked by the glasses. Experts had longer relative dwell time in the case specific AOI (50.6% versus 38.4%, p = 0.072) and performed ultrasound examinations faster (138 s versus 227 s, p = 0.068). Furthermore, experts fixated earlier in the AOI (5 s versus 10 s, p = 0.033).

CONCLUSION

This feasibility study demonstrates that eye-tracking can be used to analyze experts and non-experts gaze patterns during POCUS. Although, in this study the experts had a longer fixation time in the defined AOIs compared to non-experts, further studies are needed to investigate if eye-tracking could improve teaching of POCUS.

Enhancing surgeons' gaze strategies in endoscopic surgery during simulated surgical emergency situations thanks to computer vision. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38083476 DOI: 10.1109/embc40787.2023.10340430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Deficient visualization in minimally invasive surgery often causes misperceptions, which can lead to an increase of iatrogenic lesions and complications. This is especially critical for novice surgeons, who are prone to adopt inadequate switching gaze strategies, thereby increasing the chance of unforeseen complications. In this paper the use of an additional computer-aided vision system was tested for improvement of the reaction of the surgeons to unforeseen complications. Gaze patterns were analyzed using a gaze tracker, as well as other metrics such as task completion time or reaction time to sudden bleeding. While completion time did not show significant difference between tested modalities (p<0.1), the reaction time showed a downward trend as more auxiliary computer-aided vision systems were added (p<0.005). These results support the benefits of including additional vision systems for minimally invasive surgery processes.Clinical Relevance- This work assesses the advantages of including an additional computer vision system to prevent unforeseen complications during minimally invasive surgeries.

A Review of the Essential Visual Skills Required for Field Hockey: Beyond 20-20 Optometry

Context: Field hockey is a very technical and tactical sport, requiring immense levels of visual concentration on moving and stationary targets, which can improve visual and team performance. However, in literature, this area of specialty remains underutilized, with most studies seeking to improve physical and physiological performance. Essential visual skills cannot only be attributed to field hockey but to other ball-playing sports and activities of daily living, which allow humans to coexist. The essential visual skills reduce the propensity of making poor decisions, ill preparations, and the exclusion of potent and capable players. Objectives: This review novelly aims to not only compile a comprehensive list of essential visual skills for field hockey players but also to create a starting point for future studies to add to this list, to aid in player talent identification, and eventually create sport-specific visual exercise programs and testing batteries. Discussion: The skills identified in this review preface a platform for human performance professionals to include in their training regimens, with an intent to maximize performance and talent identification and to aid in the formulation of visuospatial test batteries. Even though this list is comprehensive, this is only a starting point for future research to find more visual skills that are essential to field hockey, as well as provide the opportunity to develop the performance of the visual skills of these athletes in ways that have not been done before.

Gaze patterns reflect and predict expertise in dynamic echocardiographic imaging

Purpose

Echocardiography is the most important modality in cardiac imaging. Rapid valid visual assessment is a critical skill for image interpretation. However, it is unclear how skilled viewers assess echocardiographic images. Therefore, guidance and implicit advice are needed for learners to achieve valid image interpretation.

Approach

Using a signal detection approach, we compared 15 certified experts with 15 medical students in their diagnostic decision-making and viewing behavior. To quantify attention allocation, we recorded eye movements while viewing dynamic echocardiographic imaging loops of patients with reduced ejection fraction and healthy controls. Participants evaluated left ventricular ejection fraction and image quality (as diagnostic and visual control tasks, respectively).

Results

Experts were much better at discriminating between patients and healthy controls (d ' of 2.58, versus 0.98 for novices). Eye tracking revealed that experts fixated diagnostically relevant areas earlier and more often, whereas novices were distracted by visually salient task-irrelevant stimuli. We show that expertise status can be almost perfectly classified either based on judgments or purely on eye movements and that an expertise score derived from viewing behavior predicts diagnostic quality.

Conclusions

Judgments and eye tracking revealed significant differences between echocardiography experts and novices that can be used to derive numerical expertise scores. Experts have implicitly learned to ignore the salient motion cue presented by the mitral valve and to focus on the diagnostically more relevant left ventricle. These findings have implications for echocardiography training, objective characterization of echocardiographic expertise, and the design of user-friendly interfaces for echocardiography.

Differences in gaze behaviors between trainees and experts during endovascular therapy for cerebral aneurysms: a preliminary study using a cerebral aneurysm model

In the neuroendovascular field, the training of operators has become an important issue. Recently, eye-tracking technology has been introduced into various fields of medical education. This study aimed to apply eye-tracking technology to the training of neuroendovascular therapy. Six neurosurgeons, including three neuroendovascular specialists and three trainees, at our institution and related facilities participated in the study. Eye movement was recorded by the eye-tracking device during the microcatheter navigation and coil placement into the silastic aneurysm model under biplane X-ray fluoroscopy. Eye-tracking analysis during neuroendovascular therapy was feasible in all six subjects. In microcatheter navigation, specialists tended to more frequently switch their attention between frontal and lateral images than trainees. In coil embolization, the overall gaze frequency tended to increase, and the average fixation duration tended to decrease as the number of experienced cases increased. Inexperienced operators tend to fix their gaze when they are operators than when they are assistants. More experienced operators tended to look at the microcatheter longer in the coil insertion task. The eye-tracking analysis may be useful for operator training in neuroendovascular therapy. Experts may have moved their eyes more frequently than trainees to gaze at the right place. In the future, it will be necessary to collect gaze data for more operators in various tasks.

SaFiDe: Detection of saccade and fixation periods based on eye-movement attributes from video-oculography, scleral coil or electrooculography data

In this work we present SaFiDe, a deterministic method to detect eye movements (saccades and fixations) from eye-trace data. We developed this method for human and nonhuman primate data from video- and coil-recorded eye traces and further applied the algorithm to eye traces computed from electrooculograms. All the data analyzed were from free-exploration paradigms, where the main challenge was to detect periods of saccades and fixations that were uncued by the task. The method uses velocity and acceleration thresholds, calculated from the eye trace, to detect saccade and fixation periods. We show that our fully deterministic method detects saccades and fixations from eye traces during free visual exploration. The algorithm was implemented in MATLAB, and the code is publicly available on a GitHub repository.•The algorithm presented is entirely deterministic, simplifying the comparison between subjects and tasks.•Thus far, the algorithm presented can operate over video-based eye tracker data, human electrooculogram records, or monkey scleral eye coil data.

Training and proficiency level in endoscopic sinus surgery change residents' eye movements

Nose surgery is challenging and needs a lot of training for safe and efficient treatments. Eye tracking can provide an objective assessment to measure residents' learning curve. The aim of the current study was to assess residents' fixation duration and other dependent variables over the course of a dedicated training in functional endoscopic sinus surgery (FESS). Sixteen residents performed a FESS training over 18 sessions, split into three surgical steps. Eye movements in terms of percent fixation on the screen and average fixation duration were measured, in addition to residents' completion time, cognitive load, and surgical performance. Results indicated performance improvements in terms of completion time and surgical performance. Cognitive load and average fixation duration showed a significant change within the last step of training. Percent fixation on screen increased within the first step, and then stagnated. Results showed that eye movements and cognitive load differed between residents of different proficiency levels. In conclusion, eye tracking is a helpful objective measuring tool in FESS. It provides additional insights of the training level and changes with increasing performance. Expert-like gaze was obtained after half of the training sessions and increased proficiency in FESS was associated with increased fixation duration.

Gaze Behaviors of Neurosurgeon in Performing Gross Movements under Microscope

BACKGROUND

Frequent intermittent bleeding control and suction are often necessary during microneurosurgical procedures. We compared the visual searching strategy that guides these types of gross hand movements between expert surgeons and neurosurgical residents.

METHODS

A total of 70 trials of a microsurgical task consisting of moving a cotton ball with bipolar forceps and a suction instrument under the microscope were recorded. Based on surgical videos, we extracted total task time, boarding time, gaze-tool time gap, number of fixations during the boarding time, and target-locked fixation duration. A comparison of these measures between experts and resident surgeons were performed.

RESULTS

No significant difference was found for total task time, boarding time, and number of fixations during the boarding time between the 2 groups of surgeons. However, we found significant differences in the measure of gaze-tool time gap (P < 0.001, partial η² = 0.54) and the target-locked fixation (P < 0.001, partial η² = 0.24). Specifically, expert microsurgeons' eyes move to the target board earlier before their tools in hands move (1.01 ± 0.30 seconds) compared with resident microsurgeons (0.44 ± 0.17 seconds). The target-locked fixation duration was also longer among experts comparing to residents (experts: 1.16 ± 0.82 seconds, residents: 0.40 ± 0.30 seconds).

CONCLUSIONS

Task time analysis for this basic microsurgical task is not sufficient to evaluate participants' level of expertise. Gaze behavior analysis helps to reveal hidden differences between experts and residents. This research provides more evidence that supports the use of gaze analysis for assessing surgeons' skills in microsurgery.

Measuring the Quality of Learning in a Human–Robot Collaboration: A Study of Laparoscopic Surgery

Robot-Assisted Laparoscopic Surgery (RALS) is now prevalent in operating rooms. This situation requires future surgeons to learn Classic Laparoscopic Surgery (CLS) and RALS simultaneously. Therefore, along with the investigation of the differences in performance between the two techniques, it is essential to study the impact of training in RALS on the skills mastered in CLS. In this article, we study comanipulated RALS (Co-RALS), one of the two designs for RALS, where the human and the robot share the execution of the task. We use a rarely used in Human–Robot Interaction measuring tool: gaze tracking and time recording to measure for the acquisition of skills in CLS when training in Co-RALS or in CLS and time recording to compare the learning curves between Co-RALS and CLS. These metrics allow us to observe differences in Co-RALS and CLS. Training in Co-RALS develops slightly better but not significantly better hand–eye coordination skills and significantly better timewise performance compared with training in CLS alone. Co-RALS enhances timewise performance in laparoscopic surgery on specific types of tasks that require precision rather than depth perception skills compared with CLS. The results obtained enable us to further define the Human–Robot Interaction quality in Co-RALS.

Assessment of changes in gaze patterns during training in point-of-care ultrasound

BACKGROUND

Point-of-care ultrasound (POCUS) is a core skill in emergency medicine (EM), however, there is a lack of objective competency measures. Eye-tracking technology is a potentially useful assessment tool, as gaze patterns can reliably discriminate between experts and novices across medical specialties. We aim to determine if gaze metrics change in an independent and predictable manner during ultrasound training.

METHODS

A convenience sample of first-year residents from a single academic emergency department was recruited. Participants interpreted 16 ultrasound videos of the focused assessment with sonography for trauma (FAST) scan while their gaze patterns were recorded using a commercially available eye-tracking device. The intervention group then completed an introductory ultrasound course whereas the control group received no additional education. The gaze assessment was subsequently repeated. The primary outcome was total gaze duration on the area of interest (AOI). Secondary outcomes included time to fixation, mean duration of first fixation and mean number of fixations on the AOI.

RESULTS

10 EM residents in the intervention group and 10 non-EM residents in the control group completed the study. After training, there was an 8.8 s increase in the total gaze time on the AOI in the intervention group compared to a 4.0 s decrease in the control group (p = .03). EM residents were also 3.8 s quicker to fixate on the AOI whereas the control group became 2.5 s slower (p = .04). There were no significant interactions on the number of fixations (0.43 vs. 0.18, p = .65) or duration of first fixation on the AOI (0.02 s vs. 0.06 s, p = .63).

CONCLUSIONS

There are significant and quantifiable changes in gaze metrics, which occur with incremental learning after an ultrasound course. Further research is needed to validate the serial use of eye-tracking technology in following a learner's progress toward competency in point-of-care ultrasound image interpretation.

Patterns of Skills Acquisition in Anesthesiologists During Simulated Interscalene Block Training on a Soft Embalmed Thiel Cadaver: Cohort Study

BACKGROUND

The demand for regional anesthesia for major surgery has increased considerably, but only a small number of anesthesiologists can provide such care. Simulations may improve clinical performance. However, opportunities to rehearse procedures are limited, and the clinical educational outcomes prescribed by the Royal College of Anesthesiologists training curriculum 2021 are difficult to attain. Educational paradigms, such as mastery learning and dedicated practice, are increasingly being used to teach technical skills to enhance skills acquisition. Moreover, high-fidelity, resilient cadaver simulators are now available: the soft embalmed Thiel cadaver shows physical characteristics and functional alignment similar to those of patients. Tissue elasticity allows tissues to expand and relax, fluid to drain away, and hundreds of repeated injections to be tolerated without causing damage. Learning curves and their intra- and interindividual dynamics have not hitherto been measured on the Thiel cadaver simulator using the mastery learning and dedicated practice educational paradigm coupled with validated, quantitative metrics, such as checklists, eye tracking metrics, and self-rating scores.

OBJECTIVE

Our primary objective was to measure the learning slopes of the scanning and needling phases of an interscalene block conducted repeatedly on a soft embalmed Thiel cadaver over a 3-hour period of training.

METHODS

A total of 30 anesthesiologists, with a wide range of experience, conducted up to 60 ultrasound-guided interscalene blocks over 3 hours on the left side of 2 soft embalmed Thiel cadavers. The duration of the scanning and needling phases was defined as the time taken to perform all the steps correctly. The primary outcome was the best-fit linear slope of the log-log transformed time to complete each phase. Our secondary objectives were to measure preprocedural psychometrics, describe deviations from the learning slope, correlate scanning and needling phase data, characterize skills according to clinical grade, measure learning curves using objective eye gaze tracking and subjective self-rating measures, and use cluster analysis to categorize performance irrespective of grade.

RESULTS

The median (IQR; range) log-log learning slopes were -0.47 (-0.62 to -0.32; -0.96 to 0.30) and -0.23 (-0.34 to -0.19; -0.71 to 0.27) during the scanning and needling phases, respectively. Locally Weighted Scatterplot Smoother curves showed wide variability in within-participant performance. The learning slopes of the scanning and needling phases correlated: ρ=0.55 (0.23-0.76), P<.001, and ρ=-0.72 (-0.46 to -0.87), P<.001, respectively. Eye gaze fixation count and glance count during the scanning and needling phases best reflected block duration. Using clustering techniques, fixation count and glance were used to identify 4 distinct patterns of learning behavior.

CONCLUSIONS

We quantified learning slopes by log-log transformation of the time taken to complete the scanning and needling phases of interscalene blocks and identified intraindividual and interindividual patterns of variability.

Eye Tracking Use in Surgical Research: A Systematic Review

INTRODUCTION

Eye tracking (ET) is a popular tool to study what factors affect the visual behaviour of surgical team members. To our knowledge, there have been no reviews to date that evaluate the broad use of ET in surgical research. This review aims to identify and assess the quality of this evidence, to synthesize how ET can be used to inform surgical practice, and to provide recommendations to improve future ET surgical studies.

METHODS

In line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic literature review was conducted. An electronic search was performed in MEDLINE, Cochrane Central, Embase, and Web of Science databases up to September 2020. Included studies used ET to measure the visual behaviour of members of the surgical team during surgery or surgical tasks. The included studies were assessed by two independent reviewers.

RESULTS

A total of 7614 studies were identified, and 111 were included for data extraction. Eleven applications were identified; the four most common were skill assessment (41%), visual attention assessment (22%), workload measurement (17%), and skills training (10%). A summary was provided of the various ways ET could be used to inform surgical practice, and three areas were identified for the improvement of future ET studies in surgery.

CONCLUSIONS

This review provided a comprehensive summary of the various applications of ET in surgery and how ET could be used to inform surgical practice, including how to use ET to improve surgical education. The information provided in this review can also aid in the design and conduct of future ET surgical studies.

Video Learning of Surgical Procedures: A Randomized Comparison of Microscopic, 2- and 3-Dimensional Endoscopic Ear Surgery Techniques

BACKGROUND

Video learning of surgical procedures helps trainees gain an initial understanding of the complex anatomy and the surgical procedure. Because no comparative studies have yet examined which microsurgical approach to the middle ear is most suitable for video learning, the authors investigated objective and subjective outcomes for medical trainees observing microscopic, 2-dimensional (2D) endoscopic, and 3- dimensional (3D) endoscopic ear surgeries.

METHODS

Sixty-two medical students (min. 3rd year) from the University Hospital of Bern watched three standardized videos of a type I tympanoplasty surgery recording, conducted with a microscope, a 2D endoscope, and a 3D endoscope, respectively. The authors measured participants' learning outcome, eye movements, cognitive load, and subjective preferences.

RESULTS

Of the 62 participants included in the study, 14 were male (22.58%), and mean age was 24.44 years (range: 21-29). Learning outcome was highest after watching the 3D endoscopic video (mean [SD], 59.48% [20.57%]). Differences in score were statistically significant: 2D endoscopic video (mean difference: -6.56%, 95% CI: -13.02 to -0.10%), microscopic video (mean difference: -13.82%, 95% CI: -20.27 to -7.36%). Participants showed lowest average eye fixation duration when watching the 3D endoscopic video (mean [SD], 307 ms [109 ms]), with statistically significant differences to the 2D endoscopic video (mean difference: -139 ms, 95% CI: -185 to -93 ms), and the microscopic video (mean difference: -264 ms, 95% CI: -310 to -218 ms). Participants reported lowest cognitive load for the 2D and 3D endoscopic videos. Ratings on discomfort, usability, naturalness, depth perception, and image quality were in favor of the 3D endoscopic video.

CONCLUSION

The 3D endoscopic technique offers many advantages for video learning in terms of knowledge gain, visual field exploration, and subjective evaluation. To optimize learning effects in trainees, the authors recommend the use of endoscopes in middle ear surgery and, if available, using 3D technology.

A scoping review of the application of motor learning principles to optimize myoelectric prosthetic hand control

Although prosthetic hand rejection rates remain high, evidence suggests that effective training plays a major role in device acceptance. Receiving training early in the rehabilitation process also enhances functional prosthetic use, decreases the likelihood of developing an overreliance on the intact limb, and reduces amputation-related pain. Despite these obvious benefits, there is a current lack of evidence regarding the most effective training techniques to facilitate myoelectric prosthetic hand control, and it remains unknown whether training is effective in facilitating the acquisition and transfer of prosthetic skill. In this scoping review, we introduced and summarized key motor learning principles related to attentional focus, implicit motor learning, training eye-hand coordination, practice variability, motor imagery, and action observation, and virtual training and biofeedback. We then reviewed the existing literature that has applied these principles for training prosthetic hand control before outlining future avenues for further research. The importance of optimizing early and appropriate training cannot be overlooked. While the intuition and experience of clinicians holds enormous value, evidence-based guidelines based on well-established motor learning principles will also be crucial for training effective prosthetic hand control. While it is clear that more research is needed to form the basis of such guidelines, it is hoped that this review highlights the potential avenues for this work.

Correlating Personal Resourcefulness and Psychomotor Skills: An Analysis of Stress, Visual Attention and Technical Metrics

Modern surgical education is focused on making use of the available technologies in order to train and assess surgical skill acquisition. Innovative technologies for the automatic, objective assessment of nontechnical skills are currently under research. The main aim of this study is to determine whether personal resourcefulness can be assessed by monitoring parameters that are related to stress and visual attention and whether there is a relation between these and psychomotor skills in surgical education. For this purpose, we implemented an application in order to monitor the electrocardiogram (ECG), galvanic skin response (GSR), gaze and performance of surgeons-in-training while performing a laparoscopic box-trainer task so as to obtain technical and personal resourcefulness' metrics. Eight surgeons (6 nonexperts and 2 experts) completed the experiment. A total of 22 metrics were calculated (7 technical and 15 related to personal resourcefulness) per subject. The average values of these metrics in the presence of stressors were compared with those in their absence and depending on the participants' expertise. The results show that both the mean normalized GSR signal and average surgical instrument's acceleration change significantly when stressors are present. Additionally, the GSR and acceleration were found to be correlated, which indicates that there is a relation between psychomotor skills and personal resourcefulness.

The Influence of Experience on Gazing Patterns during Endovascular Treatment: Eye-Tracking Study

Objective

In various fields, differences in eye-gazing patterns during tasks between experts and novices have been evaluated. The aim of this study was to investigate gazing patterns during neuro-endovascular treatment using an eye-tracking device and assess whether gazing patterns depend on the physician's experience or skill.

Methods

Seven physicians performed coil embolization for a cerebral aneurysm in a silicone vessel model under biplane X-ray fluoroscopy, and their gazing patterns were recorded using an eye-tracking device. The subjects were divided into three groups according to experience, highly experienced (Expert) group, intermediately experienced (Trainee) group, and less experienced (Novice) group. The duration of fixation on the anterior-posterior (AP) view screen, lateral (LR) view, and out-of-screen were compared between each group.

Results

During microcatheter navigation, the Expert and Trainee groups spent a long time on fixation to AP, while the Novice group split their attention between each location. In coil insertion, the Expert group gazed at both the AP and the LR views with more saccades between screens. In contrast, the Trainee group spent most of their time only on the AP view screen and the Novice group spent longer out-of-screen.

Conclusion

An eye-tracking device can detect different gazing patterns among physicians with several experiences and skill levels of neuroendovascular treatment. Learning the gazing patterns of experts using eye tracking may be a good educational tool for novices and trainees.

Years of experience is more effective in defining experts in the gaze analysis of laparoscopic suturing task than task duration

In this study, the relationship between gaze patterns, task duration, and years of experience, which are commonly used to define and evaluate expert surgeons in laparoscopic surgery, was identified. Ten surgeons with 1-28 years of experience and six inexperienced students were included. Subjects used forceps to repeat the task of suturing a suture pad. Each subject wore an eye-marking recorder, and gaze points were recorded and analyzed. No significant relationship between task duration and gaze pattern was observed. However, there was a significant relationship between a surgeon's years of experience and the percentage of time spent gazing at the forceps. Subjects with more years of experience operated without looking at the forceps and fixed their gaze on the operational target. Therefore, when analyzing laparoscopic gazing patterns, it may be more appropriate to define an "expert" based on the years of experience rather than task duration.

Differing Visual Behavior Between Inexperienced and Experienced Critical Care Nurses While Using a Closed-Loop Ventilation System-A Prospective Observational Study

Introduction: Closed-loop ventilation modes are increasingly being used in intensive care units to ensure more automaticity. Little is known about the visual behavior of health professionals using these ventilation modes. The aim of this study was to analyze gaze patterns of intensive care nurses while ventilating a patient in the closed-loop mode with Intellivent adaptive support ventilation® (I-ASV) and to compare inexperienced with experienced nurses.

Materials and Methods: Intensive care nurses underwent eye-tracking during daily care of a patient ventilated in the closed-loop ventilation mode. Five specific areas of interest were predefined (ventilator settings, ventilation curves, numeric values, oxygenation Intellivent, ventilation Intellivent). The main independent variable and primary outcome was dwell time. Secondary outcomes were revisits, average fixation time, first fixation and fixation count on areas of interest in a targeted tracking-time of 60 min. Gaze patterns were compared between I-ASV inexperienced (n = 12) and experienced (n = 16) nurses.

Results: In total, 28 participants were included. Overall, dwell time was longer for ventilator settings and numeric values compared to the other areas of interest. Similar results could be obtained for the secondary outcomes. Visual fixation of oxygenation Intellivent and ventilation Intellivent was low. However, dwell time, average fixation time and first fixation on oxygenation Intellivent were longer in experienced compared to inexperienced intensive care nurses.

Discussion: Gaze patterns of intensive care nurses were mainly focused on numeric values and settings. Areas of interest related to traditional mechanical ventilation retain high significance for intensive care nurses, despite use of closed-loop mode. More visual attention to oxygenation Intellivent and ventilation Intellivent in experienced nurses implies more routine and familiarity with closed-loop modes in this group. The findings imply the need for constant training and education with new tools in critical care, especially for inexperienced professionals.

Analyzing the Eye Gaze Behaviour of Students and Experienced Physiotherapists during Observational Movement Analysis

Purpose: Physiotherapists use observational movement analysis (OMA) to inform clinical reasoning. This study aimed to (1) determine the feasibility of characterizing eye gaze behaviour during OMA with eye-tracking technology, (2) characterize experienced neurological physiotherapists' and physiotherapy students' eye gaze behaviour during OMA, and (3) investigate differences in eye gaze behaviour during OMA between physiotherapy students and experienced physiotherapists. Method: Eight students and eight physiotherapists wore an eye-tracking device while watching a video of a person with a history of stroke and subsequent concussion perform sit to stand. Feasibility criteria were (1) successful calibration of the eye tracker, and successful collection of data, for 80% of the participants and (2) moderate interrater reliability of the investigators, measured by intra-class correlation coefficients (ICCs). Three investigators independently recorded the participants' foveal fixations. Differences between physiotherapists and students in number of fixations, duration per fixation, and total duration of fixations were evaluated using unpaired t-tests, mean differences, and 95% CIs. Results: Data were collected for all participants. ICCs ranged from 0.64 to 0.78. Fixations by physiotherapists were shorter (mean 368.5 [SD 80.8] ms) and greater in number (mean 18.9 [SD 2.2]) than those by students (mean 459.0 [SD 64.2] ms, p = 0.03, and mean 15.9 [SD 2.7], p = 0.03), respectively. Conclusions: Measuring eye gaze behaviour during OMA using eye tracker technology is feasible. Physiotherapists made more fixations of shorter duration than students. Further investigation of how experienced therapists perform OMA and apply it to clinical reasoning may inform the instruction of OMA.

Eye-Hand Coordination of Neurosurgeons: Evidence of Action-Related Fixation in Microsuturing

OBJECTIVE

We examined performance differences between expert and novice neurosurgeons under a surgical microscope with the goal to evaluate surgical expertise.

METHODS

The Tobii eye-tracker was used to record surgeons' eye movements while they performed a microsuturing task. A total of 19 expert and 18 novice trials were recorded under the microscope. Surgical videos were annotated to label subtasks and critical actions. Total suturing time and subtask times were also compared between novice and expert surgeons. At 3 critical and discrete surgical actions (needle piercing into tissue, exiting, and thread cutting) we examined eye fixation that was directly coupled to each of these actions.

RESULTS

Compared with novices, expert surgeons completed the suture with shorter total time (258.52 ± 102.14 seconds vs. 330.02 ± 96.52 seconds, P = 0.038), penetration time (17.15 ± 3.50 seconds vs. 26.26 ± 18.58 seconds, P = 0.043), and knot-tying time (194.63 ± 94.55 seconds vs. 262.52 ± 79.05 seconds, P = 0.025). On average, experts displayed longer fixation (1.62 seconds) and preaction fixation time (1.3 seconds) than novices (fixation time = 1.24 seconds, P = 0.048; preaction fixation = 0.82 seconds, P = 0.005)). Experts maintained their visual engagement constantly over the 3 levels of subtasks while novices required a longer fixation time for the challenging piercing action than for the exiting and cutting action.

CONCLUSIONS

The action-related fixation can be used to evaluate microsurgeons' level of expertise and in surgical education for gaze training.

Neurosurgical performance between experts and trainees: Evidence from drilling task

BACKGROUND

Lumbar laminectomy is a common neurosurgery that requires precise manipulation of power drills. We examined the fine movement controls of novice neurosurgeons in drilling tasks and compared its accuracy to expert surgeons' performance.

METHODS

Four experts and three novice neurosurgeons performed a lumbar laminectomy on a three-dimensional printed spine model. Scene video and surgeons' eye movements were recorded. Independent sample t-Tests were conducted on the number of jump, total fixation durations, pre-jump fixation durations, post-jump fixation durations and jump distances over novice and expert surgeons.

RESULTS

No statistically significant differences were recorded in terms of total fixations and pre-jump fixation durations. However, novices had more jumping events, greater jump distances and longer post-jump fixation durations when compared to expert neurosurgeons.

CONCLUSION

Differences in movement accuracy and eye measures were found between expert and novice neurosurgeons during a simulated microscopic lumbar laminectomy. A more comprehensive understanding of surgeon's fine movement control mechanism and eye-hand coordination in microsurgery is essential for us before building an enhanced training protocol for surgical residents in neurosurgery.

An algorithmic approach to determine expertise development using object-related gaze pattern sequences

Eye tracking (ET) technology is increasingly utilized to quantify visual behavior in the study of the development of domain-specific expertise. However, the identification and measurement of distinct gaze patterns using traditional ET metrics has been challenging, and the insights gained shown to be inconclusive about the nature of expert gaze behavior. In this article, we introduce an algorithmic approach for the extraction of object-related gaze sequences and determine task-related expertise by investigating the development of gaze sequence patterns during a multi-trial study of a simplified airplane assembly task. We demonstrate the algorithm in a study where novice (n = 28) and expert (n = 2) eye movements were recorded in successive trials (n = 8), allowing us to verify whether similar patterns develop with increasing expertise. In the proposed approach, AOI sequences were transformed to string representation and processed using the k-mer method, a well-known method from the field of computational biology. Our results for expertise development suggest that basic tendencies are visible in traditional ET metrics, such as the fixation duration, but are much more evident for k-mers of k > 2. With increased on-task experience, the appearance of expert k-mer patterns in novice gaze sequences was shown to increase significantly (p < 0.001). The results illustrate that the multi-trial k-mer approach is suitable for revealing specific cognitive processes and can quantify learning progress using gaze patterns that include both spatial and temporal information, which could provide a valuable tool for novice training and expert assessment.

The Application of a System of Eye Tracking in Laparoscopic Surgery: A New Didactic Tool to Visual Instructions

Introduction: Laparoscopic surgery is an increasingly used technique, but it requires a high degree of learning, and communication between the operating room crew is considerably difficult. The use of eye tracking has been proposed as a didactic and evaluation tool in several settings, including in laparoscopy in simulators.

Objectives: This study aimed to evaluate the usefulness of the use of eye tracking systems (Tobii glasses 2) in laparoscopic surgery as a didactic and assessment tool to improve communication in the operating room and improve patients' security.

Methodology: An anonymous survey was sent to the students and medical teachers of a faculty of medicine and practicing doctors and residents. The message contained an explanation about the use of the Tobii glasses, a link to watch the video showing its use in a laparoscopic surgery, and the survey to complete after watching the video.

Results: The survey was answered by 113 participants (51.3% medical students, 27.4% medical teachers, 18.6% practicing doctors, and 2.7% medicine residents). Eighty-three percent agreed with the usefulness of the “Tobii glasses” in the operating room for improving communication between the main surgeon and the assistant, for learning complex surgery techniques, for obtaining didactic videos, and for indicating anatomical structures. The item scored worst was the price of the glasses.

Conclusions: It is possible to record and project expert gaze patterns in the operating room in real time using the Tobii glasses. This device allows improving communication among the surgical crew and the learning of residents and also improving the security of surgical patients.

Umbilical two-port laparoscopic percutaneous extraperitoneal closure for patent processus vaginalis in boys: incision-hiding and solo-like surgery

Background

Transumbilical two-port laparoscopic percutaneous extraperitoneal closure for the treatment of processus vaginalis patency in boys has been practising recent years. The applicable instruments and skills are still evolving. In this study, we used a self-made needle assisted by a disposable dissecting forceps to practise this minimal invasive method for patent processus vaginalis in boys. Its safety and effectiveness were studied. The methods for depth and orientation perceptions were analyzed.

Methods

From January 2020 to November 2020, boys characteristic of symtomatic patency of processus vaginalis were performed open surgery consecutively. From December 2020, the authors begun to propose transumbilical two-port laparoscopic percutaneous extraperitoneal closure for this kind of boy patients. The open group included fifteen boys and the laparoscopic group included ten ones. The data of the patients age, constituent ratios of unilateral and bilateral patency, operating time, postoperative stay in hospital, follow-up time, conversion, postoperative complications were assessed. Throughout the laparoscopic process, the parallel and synchronous movements of lens pole and dissecting forceps were maintained. Vas deferens protrude was imagined as one of the point to form the triangular manipulation plane.

Results

There were no statistically significant difference between the laparoscopic group and the open group for the following items: age, operating time, the constituent ratios of unilateral or bilateral patency of processus vaginalis (P > 0.05). Postoperative stay in hospital and follow-up time of the laparoscopic group was significantly shorter than that of the open group (P = 0.0000). No laparoscopic case was converted to open surgery. After 10 cases of laparoscopic practice, orientation perception was established. There were no postoperative complications for all the patients.

Conclusion

Our preliminary experience suggested that umbilical two-port laparoscopic percutaneous extraperitoneal closure is safe and convenient for patent processus vaginalis treatment in boys. It has the advantage of incision-hiding and can be manipulated like a solo-like surgery.

The evaluation of eye gaze using an eye tracking system in simulation training of real-time ultrasound-guided venipuncture

PURPOSE

Real-time ultrasound (RTUS)-guided central venipuncture using the short-axis approach is complicated and likely to result in losing sight of the needle tip. Therefore, we focused on the eye gaze in our evaluation of the differences in eye gaze between medical students and experienced participants using an eye tracking system.

METHODS

Ten medical students (MS group), five residents (R group) and six pediatric surgeon fellows (F group) performed short-axis RTUS-guided venipuncture simulation using a modified vessel training system. The eye gaze was captured by the tracking system (Tobii Eye Tacker 4C) and recorded. The evaluation endpoints were the task completion time, total time and number of occurrences of the eye tracking marker outside US monitor and success rate of venipuncture.

RESULT

There were no significant differences in the task completion time and total time of the tracking marker outside the US monitor. The number of occurrences of the eye tracking marker outside US monitor in the MS group was significantly higher than in the F group (MS group: 9.5 ± 3.4, R group: 6.0 ± 2.9, F group: 5.2 ± 1.6; p = 0.04). The success rate of venipuncture in the R group tended to be better than in the F group.

CONCLUSION

More experienced operators let their eye fall outside the US monitor fewer times than less experienced ones. The eye gaze was associated with the success rate of RTUS-guided venipuncture. Repeated training while considering the eye gaze seems to be pivotal for mastering RTUS-guided venipuncture.

Eye tracking metrics and leader's behavioral performance during a post-partum hemorrhage high-fidelity simulated scenario

BACKGROUND

The use of eye tracking in the simulated setting can help improve our understanding of what sources of information clinicians are using as they deliver routine patient care. The aim of this simulation study was to observe the differences, if any, between the eye tracking patterns of leaders who performed best in a simulated postpartum hemorrhage (PPH) high-fidelity scenario, in comparison with those who performed worst.

METHODS

Forty anesthesia trainees from the University of Catania Medical School were divided into eight teams, to enact four times the same scenario of a patient with postpartum hemorrhage following vaginal delivery. Trainees who were assigned the leader's role wore the eye tracking glasses during the scenario, and their behavioral skills were evaluated by two observers, who reviewed the video recordings of the scenarios using a standardized checklist. The leader's eye tracking metrics, extracted from 27 selected areas of interest (AOI), were recorded by a Tobii Pro Glasses 50 Hz wearable wireless eye tracker. Team performance was evaluated using a PPH checklist. After completion of the study, the leaders were divided into two groups, based on the scores they had received (High-Performance Leader group, HPL, and Low-Performance Leader group, LPL).

RESULTS

In the HPL group, the duration and number of fixations were greater, and the distribution of gaze was uniformly distributed among the various members of the team as compared with the LPL group (with the exception of the participant who performed the role of the obstetrician). The HPL group also looked both at the patient's face and established eye contact with their team members more often and for longer (P < .05). The team performance (PPH checklist) score was greater in the HPL group (P < .001). The LPL group had more and/or longer fixations of technical areas of interest (P < .05).

CONCLUSIONS

Our findings suggest that the leaders who perform the best distribute their gaze across all members of their team and establish direct eye contact. They also look longer at the patient's face and dwell less on areas that are more relevant to technical skills. In addition, the teams led by these best performing leaders fulfilled their clinical task better. The information provided by the eye behaviors of "better-performing physicians" may lay the foundation for the future development of both the assessment process and the educational tools used in simulation.

TRIAL REGISTRATION

Clinical.Trial.Gov ID n. NCT04395963 .

Implicit and Explicit Motor Learning Interventions Have Similar Effects on Walking Speed in People After Stroke: A Randomized Controlled Trial

OBJECTIVE

Clinicians may use implicit or explicit motor learning approaches to facilitate motor learning of patients with stroke. Implicit motor learning approaches have shown promising results in healthy populations. The purpose of this study was to assess whether an implicit motor learning walking intervention is more effective compared with an explicit motor learning walking intervention delivered at home regarding walking speed in people after stroke in the chronic phase of recovery.

METHODS

This randomized, controlled, single-blind trial was conducted in the home environment. The 79 participants, who were in the chronic phase after stroke (age = 66.4 [SD = 11.0] years; time poststroke = 70.1 [SD = 64.3] months; walking speed = 0.7 [SD = 0.3] m/s; Berg Balance Scale score = 44.5 [SD = 9.5]), were randomly assigned to an implicit (n = 38) or explicit (n = 41) group. Analogy learning was used as the implicit motor learning walking intervention, whereas the explicit motor learning walking intervention consisted of detailed verbal instructions. Both groups received 9 training sessions (30 minutes each), for a period of 3 weeks, targeted at improving quality of walking. The primary outcome was walking speed measured by the 10-Meter Walk Test at a comfortable walking pace. Outcomes were assessed at baseline, immediately after intervention, and 1 month postintervention.

RESULTS

No statistically or clinically relevant differences between groups were obtained postintervention (between-group difference was estimated at 0.02 m/s [95% CI = -0.04 to 0.08] and at follow-up (between-group difference estimated at -0.02 m/s [95% CI = -0.09 to 0.05]).

CONCLUSION

Implicit motor learning was not superior to explicit motor learning to improve walking speed in people after stroke in the chronic phase of recovery.

IMPACT

To our knowledge, this is the first study to examine the effects of implicit compared with explicit motor learning on a functional task in people after stroke. Results indicate that physical therapists can use (tailored) implicit and explicit motor learning strategies to improve walking speed in people after stroke who are in the chronic phase of recovery.

See Like an Expert: Gaze-Augmented Training Enhances Skill Acquisition in a Virtual Reality Robotic Suturing Task

Introduction: The da Vinci Skills Simulator (DVSS) is an effective platform for robotic skills training. Novel training methods using expert gaze patterns to guide trainees have demonstrated superiority to traditional instruction. Portable head-mounted eye-trackers (HMET) offer the opportunity for eye tracking technology to enhance surgical robotic simulation training. Objective: To evaluate if training guided by expert gaze patterns can improve trainee performance over standard movement training techniques during robotic simulation. Methods: Medical students were recruited and randomized into gaze training (GT, n = 9) and movement training (MT, n = 8) groups. First, the participants reviewed an instructional video, with the GT group emulating expert gaze patterns and the MT group (n = 8) standard movement-based instruction. Training consisted of 10 repetitions of "Suture Sponge 3" on the DVSS while wearing HMET; the first three repetitions were followed by group-appropriate video coaching (gaze vs movement feedback), while the remaining repetitions were without feedback. Finally, two multitasking repetitions with a secondary bell-counting task were completed. Primary outcomes included DVSS scores during training and multitasking. Secondary outcomes included metrics collected from the HMET (gaze patterns and gaze entropy). Results: Total score, efficiency, and penalties improved significantly over the training in both groups; the GT group achieved higher scores on every attempt. Total scores in the GT group were higher than the MT group postvideo review (20.3 ± 21.8 vs 3.0 ± 6.2, p = 0.047), after coaching repetitions (61.8 ± 18.8 vs 30.1 ± 26.2, p = 0.01), and at the last training attempt (73.0 ± 16.5 vs 63.1 ± 17.4, p = 0.247). During multitasking, the GT group maintained higher total scores (75 ± 10.1 vs 63.3 ± 15.3, p = 0.01), efficiency (86.3 ± 7.4 vs 77.4 ± 11.2, p = 0.009), and superior secondary task performance (error: 6.3% ± 0.06 vs 10.7% ± 0.11, p = 0.20). Gaze entropy (cognitive-load indicator) and gaze pattern analysis showed similar trends. Conclusion: Gaze-augmented training leads to more efficient movements through adoption of expert gaze patterns that withstand additional stressors.

HoloPointer: a virtual augmented reality pointer for laparoscopic surgery training

PURPOSE

In laparoscopic surgery training, experts guide novice physicians to desired instrument positions or indicate relevant areas of interest. These instructions are usually given via verbal communication or using physical pointing devices. To facilitate a sterile work flow and to improve training, new guiding methods are needed. This work proposes to use optical see-through augmented reality to visualize an interactive virtual pointer on the laparoscopic.

METHODS

After an interdisciplinary development, the pointer's applicability and feasibility for training was evaluated and it was compared to a standard condition based on verbal and gestural communication only. In this study, ten surgical trainees were guided by an experienced trainer during cholecystectomies on a laparoscopic training simulator. All trainees completed a virtual cholecystectomy with and without the interactive virtual pointer in alternating order. Measures included procedure time, economy of movement and error rates.

RESULTS

Results of standardized variables revealed significantly improved economy of movement (p = 0.047) and error rates (p = 0.047), as well as an overall improved user performance (Total z-score; p = 0.031) in conditions using the proposed method.

CONCLUSION

The proposed HoloPointer is a feasible and applicable tool for laparoscopic surgery training. It improved objective performance metrics without prolongation of the task completion time in this pre-clinical setup.

Cognitive Load in Electromagnetic Navigational and Robotic Bronchoscopy for Pulmonary Nodules

Background: Electromagnetic navigational bronchoscopy (ENB) and robotic-assisted bronchoscopy (RB) require a high degree of decision-making and psychomotor skill. Cognitive load theory is the overall effort expended by individuals in response to a task and is closely related to the usability of devices for medical procedures. High cognitive workload leads to poor surgical outcomes and represents a bottleneck for learning that affects performance.

Objective: To analyze the cognitive load associated with ENB and RB in experienced ENB practitioners learning RB.

Methods: Six experienced ENB bronchoscopists performed ENB and RB on a human cadaver model of peripheral pulmonary nodules. To assess cognitive load, we used the Surgery Task Load Index (SURG-TLX) and biometric changes. The SURG-TLX questionnaire was given to the provider after every peripheral pulmonary nodule biopsy with ENB and RB. Pupillary dilation and screen changes were continuously measured throughout the procedure for each biopsy attempt to collect biometric measures of cognitive load. Procedural time and biopsy outcome were also recorded.

Results: Forty procedures (ENB and RB) were analyzed. Task complexity (23%) and mental demand (21.4%) were the highest contributors to cognitive load in ENB and RB. The cumulative SURG-TLX was significantly lower for the RB (69.25 vs. 101.25; P < 0.01). Total procedure time was greater for ENB (6.7 min; SD 1.5) compared with RB (4.4 min; SD 1.5; P = 0.01). Pupillary diameter was similar across the modalities (RB vs. ENB), but the diameter was higher during the biopsy portion (4.25 mm) than the navigation portion (4.01 mm).

Conclusion: The intrinsic cognitive load of RB was highly manageable by existing ENB practitioners, and in this study, RB appeared to be less mentally demanding. Future development and training should focus on task complexity and mental demand for RB. The biopsy portion, regardless of bronchoscopic modality, should be a focus for education and training.

Eye-Tracking Metrics Predict Perceived Workload in Robotic Surgical Skills Training

OBJECTIVE

The aim of this study is to assess the relationship between eye-tracking measures and perceived workload in robotic surgical tasks.

BACKGROUND

Robotic techniques provide improved dexterity, stereoscopic vision, and ergonomic control system over laparoscopic surgery, but the complexity of the interfaces and operations may pose new challenges to surgeons and compromise patient safety. Limited studies have objectively quantified workload and its impact on performance in robotic surgery. Although not yet implemented in robotic surgery, minimally intrusive and continuous eye-tracking metrics have been shown to be sensitive to changes in workload in other domains.

METHODS

Eight surgical trainees participated in 15 robotic skills simulation sessions. In each session, participants performed up to 12 simulated exercises. Correlation and mixed-effects analyses were conducted to explore the relationships between eye-tracking metrics and perceived workload. Machine learning classifiers were used to determine the sensitivity of differentiating between low and high workload with eye-tracking features.

RESULTS

Gaze entropy increased as perceived workload increased, with a correlation of .51. Pupil diameter and gaze entropy distinguished differences in workload between task difficulty levels, and both metrics increased as task level difficulty increased. The classification model using eye-tracking features achieved an accuracy of 84.7% in predicting workload levels.

CONCLUSION

Eye-tracking measures can detect perceived workload during robotic tasks. They can potentially be used to identify task contributors to high workload and provide measures for robotic surgery training.

APPLICATION

Workload assessment can be used for real-time monitoring of workload in robotic surgical training and provide assessments for performance and learning.

Multiple processes independently predict motor learning

Background

Our ability to acquire, refine and adapt skilled limb movements is a hallmark of human motor learning that allows us to successfully perform many daily activities. The capacity to acquire, refine and adapt other features of motor performance, such as visual search, eye-hand coordination and visuomotor decisions, may also contribute to motor learning. However, the extent to which refinements of multiple behavioral features and their underlying neural processes independently contribute to motor learning remains unknown. In the current study, we used an ethological approach to test the hypothesis that practice-related refinements of multiple behavioral features would be independently predictive of motor learning.

Methods

Eighteen healthy, young adults used an upper-limb robot with eye-tracking to practice six trials of a continuous, visuomotor task once a week for six consecutive weeks. Participants used virtual paddles to hit away 200 “Targets” and avoid hitting 100 “Distractors” that continuously moved towards them from the back of the workspace. Motor learning was inferred from trial-by-trial acquisition and week-by-week retention of improvements on two measures of task performance related to motor execution and motor inhibition. Adaptations involving underlying neural processes were inferred from trial-by-trial acquisition and week-by-week retention of refinements on measures of skilled limb movement, visual search, eye-hand coordination and visuomotor decisions. We tested our hypothesis by quantifying the extent to which refinements on measures of multiple behavioral features (predictors) were independently predictive of improvements on our two measures of task performance (outcomes) after removing all shared variance between predictors.

Results

We found that refinements on measures of skilled limb movement, visual search and eye-hand coordination were independently predictive of improvements on our measure of task performance related to motor execution. In contrast, only refinements of eye-hand coordination were independently predictive of improvements on our measure of task performance related to motor inhibition.

Conclusion

Our results provide indirect evidence that refinements involving multiple, neural processes may independently contribute to motor learning, and distinct neural processes may underlie improvements in task performance related to motor execution and motor inhibition. This also suggests that refinements involving multiple, neural processes may contribute to motor recovery after stroke, and rehabilitation interventions should be designed to produce refinements of all behavioral features that may contribute to motor recovery.

Preliminary study of eye tracking to investigate the differences in gaze behaviors depending on the experience of neuroendovascular therapy

Background

Neuroendovascular therapy is now the choice for the management of many neurovascular pathologies, and physicians with endovascular skills are in high demand. In addition to the traditional method of practicing hand movements to learn skills, a new strategy of practicing eye movements to learn skills is also attracting attention. This preliminary study explored the differences in gaze behavior depending on experience with endovascular procedures to be facilitated in future skill training in neuroendovascular therapy.

Methods

Four physicians with experience of 3-412 neuroendovascular procedures wore eye-tracking devices during coil embolization of swine cervical arteries. Gaze metrics with direct correlations to the expertise of endovascular procedures were explored.

Results

Gaze metrics with a positive direct correlation to experience included the proportion of fixation durations (PFD) in the screen area and the native images. Those with a negative direct correlation included the PFD in the off-screen area and the roadmap images and the average fixation durations in the off-screen and coil areas. During the parent artery occlusion procedure with detachable coils, more experienced operators preferred to look at native images rather than roadmap images and that less experienced operators tended to look down at their hands more frequently.

Conclusion

This preliminary study demonstrated the feasibility of eye tracking to identify the differences in gaze behavior depending on the experience of endovascular procedures and may guide future eye-tracking studies in neuroendovascular therapy.

Feasibility and Utility of an Eye-Tracking Device for Assessing Teachers of Invasive Bedside Procedures

Patient-related complications from invasive bedside procedures (IBPs) are attributed to the experience and proficiency of the operator. Furthermore, IBP complications by trainees may be due to practice variability and competency among IBP teachers. The use of gaze metrics technology to better understand the behaviors of IBP teachers may aid in the creation of faculty development checklists and, ultimately, reduce procedural complications. Prior research on gaze patterns has focused on the individual performing the procedure, but the goal of this pilot study was to assess gaze behaviors of supervising teachers of IBPs, which is a paradigm shift within procedural education. In this study, pulmonary and critical care medicine fellows placed a central venous catheter on a simulated task trainer as pulmonary and critical care medicine faculty supervised while wearing an eye-tracking device. Both quantitative and qualitative data were obtained. Gaze analysis was divided into 2 areas of interest (ultrasonography and procedure site) and 3 procedural tasks (venous puncture, dilation, and flushing the line). Study findings included the following: (1) calibration was easy and took seconds to complete, (2) the device is relatively comfortable and did not interfere with tasks, (3) a trend toward a higher fixation frequency and dwell time on the ultrasound images during the puncture segment, and (4) variations in fixation frequency on the ultrasound images among supervising IBP teachers. This study documents the feasibility of the eye-tracking device for assessing behaviors of supervisory IBP teachers. There may be a signal suggesting differences in gaze patterns among supervisory teachers, which warrants further study.

Preliminary Study of Eye-Tracking During the Coil Insertion Task in a Silastic Model of Intracranial Aneurysms

OBJECTIVE

Surgical skills are generally acquired by watching the "hand movements" of experts. "Eye movements" are now attracting attention in skill-learning fields. Eye-tracking technology was introduced preliminarily to develop a better skill-learning system for neuroendovascular treatments.

METHODS

During a task to place a detachable coil into a silastic cerebral aneurysm model under biplane X-ray fluoroscopy, gaze points were recorded using a head-mount eye-tracking device.

RESULTS

During the task, 91% of fixations were allocated to the monitor displaying fluoroscopic images, and the others to the hands of operators or unspecified visual targets. More than 80% of fixations were located in frontal or lateral fluoroscopic images. Fixations were placed more frequently around the aneurysm than the microcatheter. One operator failed to recognize the timing when the proximal marker of the coil overlapped that of the microcatheter. The subject allocated most fixations to the frontal fluoroscopic image, whereas other subjects placed most fixations to the lateral fluoroscopic image. Furthermore, that operator put no fixations to the proximal marker of the microcatheter.

CONCLUSIONS

The results of this preliminary study imply the feasibility of the eye tracking-based learning system for neuroendovascular treatments. The eye-tracking analysis has potential in investigating or preventing procedural failures in neuroendovascular treatments.

Eye-tracking during simulation-based neonatal airway management

BACKGROUND

Eye-tracking devices help to understand provider behavior during medical tasks. The aim of this study was to assess participants' gaze behavior and usability of eye-tracking glasses during airway management in a simulated neonatal resuscitation.

METHODS

This study was an observational simulation-based study. The team member assigned to airway management wore head-mounted eye-tracking glasses. Main outcome measures were airway providers' gaze, dwell time (total amount of time a participant fixates certain areas of interest), and usability of eye-tracking glasses.

RESULTS

Data from 13 participants were included. There were significant differences in dwell time during the scenario (p < 0.001), with participants spending twice as much time on the newborn and instruments as on the monitor and other staff. Participants spent about 25% more time focusing on another provider while the provider was inserting the umbilical vein catheter than in all other times of interest (intervals of time with meaningful events) (p = 0.04). The use of the glasses was perceived easy and not disturbing.

CONCLUSIONS

Eye-tracking glasses enhance our understanding of providers' gaze and perspective during simulated neonatal airway management. Future studies will better characterize the ideal use in real situations.

Mobility-Related Gaze Training in Individuals With Glaucoma: A Proof-of-Concept Study

Purpose

Older adults with glaucoma show inappropriate gaze strategies during routine mobility tasks. Furthermore, glaucoma is a risk factor for falling and colliding with objects when walking. However, effective interventions to rectify these strategies and prevent these adverse events are scarce. We designed a gaze training program with the goal of providing proof-of-concept that we could modify mobility-related gaze behavior in this population.

Methods

A total of 13 individuals with moderate glaucoma participated in this study. We taught participants general and task-specific gaze strategies over two 1-hour sessions. To determine the efficacy of this gaze training program, participants performed walking tasks that required accurate foot placement onto targets and circumventing obstacles before and after training. We used a mobile eye tracker to quantify gaze and a motion-capture system to quantify body movement.

Results

After training, we found changes in the timing between gaze shifts away from targets relative to stepping on them (P < 0.05). In the obstacle negotiation task, we found a greater range of gaze shifts early in walking trials and changes in the timing between gaze shifts away from obstacles after training (P < 0.05), each suggesting better route planning. A posttraining reduction in foot-placement error and obstacle collisions accompanied these changes (P < 0.05).

Conclusions

Our results demonstrated that it is possible to modify mobility-related gaze behavior and mobility performance in older adults with glaucoma.

Translational Relevance

This study provides proof-of-concept for a gaze training program for glaucoma. A larger, randomized controlled trial is warranted.

Virtual pointer for gaze guidance in laparoscopic surgery

BACKGROUND

A challenge of laparoscopic surgery is learning how to interpret the indirect view of the operative field. Acquiring professional vision-understanding what to see and which information to attend to, is thereby an essential part of laparoscopic training and one in which trainers exert great effort to convey. We designed a virtual pointer (VP) that enables experts to point or draw free-hand sketches over an intraoperative laparoscopic video for a novice to see. This study aimed to investigate the efficacy of the virtual pointer in guiding novices' gaze patterns.

METHODS

We conducted a counter-balanced, within-subject trial to compare the novices' gaze behaviors in laparoscopic training with the virtual pointer compared to a standard training condition, i.e., verbal instruction with un-mediated gestures. In the study, seven trainees performed four simulated laparoscopic tasks guided by an experienced surgeon as the trainer. A Tobii Pro X3-120 eye-tracker was used to capture the trainees' eye movements. The measures include fixation rate, i.e., the frequency of trainees' fixations, saccade amplitude, and fixation concentration, i.e., the closeness of trainees' fixations.

RESULTS

No significant difference in fixation rate or saccade amplitude was found between the virtual pointer condition and the standard condition. In the virtual pointer condition, trainees' fixations were more concentrated (p = 0.039) and longer fixations were more clustered, compared to the Standard condition (p = 0.008).

CONCLUSIONS

The virtual pointer effectively improved surgical trainees' in-the-moment gaze focus during the laparoscopic training by reducing their gaze dispersion and concentrating their attention on the anatomical target. These results suggest that technologies which support gaze training should be expert-driven and intraoperative to efficiently modify novices' gaze behaviors.

Visual attention, EEG alpha power and T7-Fz connectivity are implicated in prosthetic hand control and can be optimized through gaze training

Background

Prosthetic hands impose a high cognitive burden on the user that often results in fatigue, frustration and prosthesis rejection. However, efforts to directly measure this burden are sparse and little is known about the mechanisms behind it. There is also a lack of evidence-based training interventions designed to improve prosthesis hand control and reduce the mental effort required to use them. In two experiments, we provide the first direct evaluation of this cognitive burden using measurements of EEG and eye-tracking (Experiment 1), and then explore how a novel visuomotor intervention (gaze training; GT) might alleviate it (Experiment 2).

Methods

In Experiment 1, able-bodied participants (n = 20) lifted and moved a jar, first using their anatomical hand and then using a myoelectric prosthetic hand simulator. In experiment 2, a GT group (n = 12) and a movement training (MT) group (n = 12) trained with the prosthetic hand simulator over three one hour sessions in a picking up coins task, before returning for retention, delayed retention and transfer tests. The GT group received instruction regarding how to use their eyes effectively, while the MT group received movement-related instruction typical in rehabilitation.

Results

Experiment 1 revealed that when using the prosthetic hand, participants performed worse, exhibited spatial and temporal disruptions to visual attention, and exhibited a global decrease in EEG alpha power (8-12 Hz), suggesting increased cognitive effort. Experiment 2 showed that GT was the more effective method for expediting prosthesis learning, optimising visual attention, and lowering conscious control – as indexed by reduced T7-Fz connectivity. Whilst the MT group improved performance, they did not reduce hand-focused visual attention and showed increased conscious movement control. The superior benefits of GT transferred to a more complex tea-making task.

Conclusions

These experiments quantify the visual and cortical mechanisms relating to the cognitive burden experienced during prosthetic hand control. They also evidence the efficacy of a GT intervention that alleviated this burden and promoted better learning and transfer, compared to typical rehabilitation instructions. These findings have theoretical and practical implications for prosthesis rehabilitation, the development of emerging prosthesis technologies and for the general understanding of human-tool interactions.

Electronic supplementary material

The online version of this article (10.1186/s12984-019-0524-x) contains supplementary material, which is available to authorized users.

Guiding Low Spatial Ability Individuals through Visual Cueing: The Dual Importance of Where and When to Look

Research suggests that spatial ability may predict success in complex disciplines including anatomy, where mastery requires a firm understanding of the intricate relationships occurring along the course of veins, arteries, and nerves, as they traverse through and around bones, muscles, and organs. Debate exists on the malleability of spatial ability, and some suggest that spatial ability can be enhanced through training. It is hypothesized that spatial ability can be trained in low-performing individuals through visual guidance. To address this, training was completed through a visual guidance protocol. This protocol was based on eye-movement patterns of high-performing individuals, collected via eye-tracking as they completed an Electronic Mental Rotations Test (EMRT). The effects of guidance were evaluated using 33 individuals with low mental rotation ability, in a counterbalanced crossover design. Individuals were placed in one of two treatment groups (late or early guidance) and completed both a guided, and an unguided EMRT. A third group (no guidance/control) completed two unguided EMRTs. All groups demonstrated an increase in EMRT scores on their second test (P < 0.001); however, an interaction was observed between treatment and test iteration (P = 0.024). The effect of guidance on scores was contingent on when the guidance was applied. When guidance was applied early, scores were significantly greater than expected (P = 0.028). These findings suggest that by guiding individuals with low mental rotation ability "where" to look early in training, better search approaches may be adopted, yielding improvements in spatial reasoning scores. It is proposed that visual guidance may be applied in spatial fields, such as STEMM (science, technology, engineering, mathematics and medicine), surgery, and anatomy to improve student's interpretation of visual content. Anat Sci Educ. © 2018 American Association of Anatomists.

Arthroscopic simulation using a knee model can be used to train speed and gaze strategies in knee arthroscopy

PURPOSE

This study aimed to determine the effect of a simulation course on gaze fixation strategies of participants performing arthroscopy.

METHODS

Participants (n = 16) were recruited from two one-day simulation-based knee arthroscopy courses, and were asked to undergo a task before and after the course, which involved identifying a series of arthroscopic landmarks. The gaze fixation of the participants was recorded with a wearable eye-tracking system. The time taken to complete the task and proportion of time participants spent with their gaze fixated on the arthroscopic stack, the knee model, and away from the stack or knee model were recorded.

RESULTS

Participants demonstrated a statistically decreased completion time in their second attempt compared to the first attempt (P = 0.001). In their second attempt, they also demonstrated improved gaze fixation strategies, with a significantly increased amount (P = 0.008) and proportion of time (P = 0.003) spent fixated on the screen vs. knee model.

CONCLUSION

Simulation improved arthroscopic skills in orthopaedic surgeons, specifically by improving their gaze control strategies and decreasing the amount of time taken to identify and mark landmarks in an arthroscopic task.

Looks can be deceiving: Gaze pattern differences between novices and experts during placement of central lines

BACKGROUND

The objective of this study was to determine whether gaze patterns could differentiate expertise during simulated ultrasound-guided Internal Jugular Central Venous Catheterization (US-IJCVC) and if expert gazes were different between simulators of varying functional and structural fidelity.

METHODS

A 2017 study compared eye gaze patterns of expert surgeons (n = 11), senior residents (n = 4), and novices (n = 7) during CVC needle insertions using the dynamic haptic robotic trainer (DHRT), a system which simulates US-IJCVC. Expert gaze patterns were also compared between a manikin and the DHRT.

RESULTS

Expert gaze patterns were consistent between the manikin and DHRT environments (p = 0.401). On the DHRT system, CVC experience significantly impacted the percent of time participants spent gazing at the ultrasound screen (p < 0.0005) and the needle and ultrasound probe (p < 0.0005).

CONCLUSION

Gaze patterns differentiate expertise during ultrasound-guided IJCVC placement and the fidelity of the simulator does not impact gaze patterns.

Spatial cognition in minimally invasive surgery: a systematic review

Background

Spatial cognition is known to play an important role in minimally invasive surgery (MIS), as it was found to enable faster surgical skill acquisition, reduce surgical time and errors made and significantly improve surgical performance. No prior research attempted to summarize the available literature, to indicate the level of importance of the individual spatial abilities and how they impact surgical performance and skill acquisition in MIS.

Methods

Psychological and medical databases were systematically searched to identify studies directly exploring spatial cognition in MIS learning and performance outcomes. Articles written in the English language articles, published between 2006 and 2016, investigating any and all aspect of spatial cognition in direct relation to influence over performance or learning of MIS, were deemed eligible.

Results

A total of 26 studies satisfied this criterion and were included in the review. The studies were very heterogeneous and the vast majority of the participants were novice trainees but with variable degree of skills. There were no clinical studies as almost all studies were conducted on either box trainers or virtual reality simulators. Mental rotation ability was found to have a clear impact on operative performance and mental practice was identified as an effective tool to enhance performance, pre-operatively. Ergonomic set-up of the MIS equipment has a marked influence on MIS performance and learning outcomes.

Conclusions

Spatial cognition was found to play an important role in MIS, with mental rotation showing a specific significance. Future research is required to further confirm and quantify these findings in the clinical settings.

Eye tracking in surgical education: gaze-based dynamic area of interest can discriminate adverse events and expertise

BACKGROUND

Eye-gaze metrics derived from areas of interest (AOIs) have been suggested to be effective for surgical skill assessment. However, prior research is mostly based on static images and simulated tasks that may not translate to complex and dynamic surgical scenes. Therefore, eye-gaze metrics must advance to account for changes in the location of important information during a surgical procedure.

METHODS

We developed a dynamic AOI generation technique based on eye gaze collected from an expert viewing surgery videos. This AOI updated as the gaze of the expert moved with changes in the surgical scene. This technique was evaluated through an experiment recruiting a total of 20 attendings and residents to view 10 videos associated with and another 10 without adverse events.

RESULTS

Dwell time percentage (i.e., gaze duration) inside the AOI differentiated video type (U = 13508.5, p < 0.001) between videos with the presence (Mdn = 16.75) versus absence (Mdn = 19.95) of adverse events. This metric also differentiated participant group (U = 14029.5, p < 0.001) between attendings (Mdn = 15.45) and residents (Mdn = 19.80). This indicates that our dynamic AOIs reflecting the expert eye gaze was able to differentiate expertise, and the presence of unexpected adverse events.

CONCLUSION

This dynamic AOI generation technique produced dynamic AOIs for deriving eye-gaze metrics that were sensitive to expertise level and event characteristics.

Action observation for sensorimotor learning in surgery

Background

Acquiring new motor skills to learn complex movements and master the use of a diverse range of instruments is fundamental for developing expertise in surgery. Although aspects of skill development occur through trial and error, watching the performance of another individual (action observation) is an increasingly important adjunct for the acquisition of these complex skills before performing a procedure. The aim of this review was to examine the evidence in support of the use of action observation in surgery.

Methods

A narrative review of observational learning for surgical motor skills was undertaken. Searches of PubMed and PsycINFO databases were performed using the terms ‘observational learning’ OR ‘action observation’ AND ‘motor learning’ OR ‘skill learning’.

Results

Factors such as the structure of physical practice, the skill level of the demonstrator and the use of feedback were all found to be important moderators of the effectiveness of observational learning. In particular, observation of both expert and novice performance, cueing attention to key features of the task, and watching the eye movements of expert surgeons were all found to enhance the effectiveness of observation. It was unclear, however, whether repeated observations were beneficial for skill learning. The evidence suggests that these methods can be employed to enhance surgical training curricula.

Conclusion

Observational learning is an effective method for learning surgical skills. An improved understanding of observational learning may further inform the refinement and use of these methods in contemporary surgical training curricula.