Expert surgeon's quiet eye and slowing down: expertise differences in performance and quiet eye duration during identification and dissection of the recurrent laryngeal nerve

The use of the eye-fixation-related potential to investigate visual perception in professional domains with high attentional demand: a literature review

INTRODUCTION

Visual attention is a cognitive skill related to visual perception and neural activity, and also moderated by expertise, in time-constrained professional domains (e.g., aviation, driving, sport, surgery). However, the contribution of both perceptual and neural processes on performance has been studied separately in the literature.

DEVELOPMENT

We defend an integration of visual and neural signals to offer a more complete picture of the visual attention displayed by professionals of different skill levels when performing free-viewing tasks. Specifically, we propose to zoom the analysis in data related to the quiet eye and P300 component jointly, as a novel signal processing approach to evaluate professionals' visual attention.

CONCLUSION

This review highlights the advantages of using portable eye trackers and electroencephalogram systems altogether, as a promising technique for a better understanding of early cognitive components related to attentional processes. Altogether, the eye-fixation-related potentials method may provide a better understanding of the cognitive mechanisms employed by the participants in natural settings, revealing what visual information is of interest for participants and distinguishing the neural bases of visual attention between targets and non-targets whenever they perceive a stimulus during free viewing experiments.

Objective assessment of visual attention in orthognathic surgery training based on eye tracking

The aim of this study was to investigate the differences in visual attention between novices and orthognathic experts, as well as to provide evidence for use in developing and optimizing training strategies for orthognathic surgery. Novice and orthognathic experts were recruited, and their distributions of visual attention were monitored via an eye-tracking device while they watched orthognathic surgery videos. The percentages of visual fixation duration devoted to the areas of interest - surgical objects, instruments controlled by the main surgeon, and instruments controlled by the assistants - in each orthognathic surgery section were analyzed and compared between the two groups using repeated-measures factorial analysis of variance (ANOVA). In total, there were 18 participants, comprising both novices (n = 9) and experts (n = 9). For all sections of orthognathic surgery, the percentage of fixation duration on surgical objects was significantly higher for the novices than for the experts (p = 0.031, p = 0.005, p = 0.026, p = 0.047, p = 0.047, p = 0.031, p = 0.027, p = 0.034, p = 0.008, and p = 0.016). During the maxillary segment separation as part of Le Fort I osteotomy and the splitting of the mandible as part of bilateral sagittal split osteotomy, the novices also had a higher percentage of fixation duration on the instruments controlled by the main surgeon, as compared with the experts (p = 0.007 and p = 0.048, respectively). Novices invested great cognitive effort into the surgical objects in each section of orthognathic surgery, including the instruments controlled by the main surgeon in the maxillary segment separation and the splitting of the mandible. Strengthening this aspect of instruction could help novices reduce their cognitive load and achieve mastery more efficiently.

Exploring the distribution of visual attention in genioplasty trainees using eye-tracking technology

PURPOSE

This study aimed to investigate the visual attention of genioplasty trainees using eye-tracking technology, with the goal of providing insights for optimizing genioplasty training strategies.

METHODS

Trainees were recruited for the study, and their visual attention distribution was monitored with an eye-tracking device while they watched a genioplasty procedure video. The percentage of fixation durations dedicated to areas of interest (surgical objects, instruments manipulated by the primary surgeon, and instruments controlled by assistants) were analyzed for each phase of the procedure.

RESULTS

A total of 20 surgical trainees (8 males, 12 females; mean age, 27.8 years; range, 22-35 years) participated in the study. During the soft tissue reflection phase, trainees' percentage fixation durations on instruments controlled by the primary surgeon were higher than on surgical objects, but the difference was not significant (p > 0.05). The percentage fixation durations on instruments controlled by assistants were significantly lower than on those controlled by the primary surgeon or on surgical objects (p < 0.05). In the osteotomy, bone fixation, and suturing phases, the percentage fixation durations on surgical objects were highest, followed by instruments manipulated by the primary surgeon and those controlled by assistants, with significant differences (p < 0.05).

CONCLUSION

Surgical trainees need to invest significant cognitive effort in focusing on the instruments manipulated by the primary surgeon and the surgical objects during the soft tissue reflection phase, as well as on surgical objects during the osteotomy, fixation, and suturing phases. Emphasizing these elements during instruction can help trainees reduce their cognitive load and effectively master genioplasty techniques.

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.

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.

Adaptative damping assistance in bimanual laparoscopic surgery

PURPOSE

Laparoscopic surgery has demonstrated various advantages for the patients' care, but also presents some difficulties for the surgeons, such as kinematic restrictions. Robotic comanipulation, in which control of instruments is shared between the robot and the surgeon, can provide adaptative damping assistance which allows stabilisation of movements. The objective of the present study was to determine the contribution of this assistance on a bimanual laparoscopic task.

METHODS

Adaptative damping was studied on Peg Transfer task, performed by eighteen surgery-naive subjects. This exercise was repeated seven times without (Classic repetitions) and seven times with comanipulated robots (Robot repetitions), in a randomised order. We measured task performance, using Peg Transfer score; gesture performance, using hand oscillations and travelled distance; eye-tracking movements as an indicator of emergence of expertise. Participants' perceived workload was assessed by NASA TLX questionnaire, and difference in impression between the two conditions by UEQ questionnaire.

RESULTS

Adaptative damping improved gesture performance (oscillations F(1,17) = 23.473, p < 0.001, η² = 0.580), with a statistically significant simple effect on the tool oscillation for both non-dominant (p < 0.001) and dominant hands (p = 0.005), without influencing task performance (mean Peg Transfer score t(17) = 0.920, p = 0.382, d = 0.29), but deteriorating eye-tracking movements associated with emergence of expertise (mean fixation rate per second F(1,17) = 6.318, p = 0.022, η² = 0.271), at the cost of a high perceived workload (NASA TLX score 59.78/100).

CONCLUSION

Assistance by adaptative damping applied by comanipulated robots improved gesture performance during a laparoscopic bimanual task, without impacting task's performance without allowing the emergence of comportments associated with an expertise, and at the cost of a high perceived workload. Further research should investigate this assistance on more precise and clinical tasks performed by professionals.

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.

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.

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.

Automated tool detection with deep learning for monitoring kinematics and eye-hand coordination in microsurgery

In microsurgical procedures, surgeons use micro-instruments under high magnifications to handle delicate tissues. These procedures require highly skilled attentional and motor control for planning and implementing eye-hand coordination strategies. Eye-hand coordination in surgery has mostly been studied in open, laparoscopic, and robot-assisted surgeries, as there are no available tools to perform automatic tool detection in microsurgery. We introduce and investigate a method for simultaneous detection and processing of micro-instruments and gaze during microsurgery. We train and evaluate a convolutional neural network for detecting 17 microsurgical tools with a dataset of 7500 frames from 20 videos of simulated and real surgical procedures. Model evaluations result in mean average precision at the 0.5 threshold of 89.5-91.4% for validation and 69.7-73.2% for testing over partially unseen surgical settings, and the average inference time of 39.90 ± 1.2 frames/second. While prior research has mostly evaluated surgical tool detection on homogeneous datasets with limited number of tools, we demonstrate the feasibility of transfer learning, and conclude that detectors that generalize reliably to new settings require data from several different surgical procedures. In a case study, we apply the detector with a microscope eye tracker to investigate tool use and eye-hand coordination during an intracranial vessel dissection task. The results show that tool kinematics differentiate microsurgical actions. The gaze-to-microscissors distances are also smaller during dissection than other actions when the surgeon has more space to maneuver. The presented detection pipeline provides the clinical and research communities with a valuable resource for automatic content extraction and objective skill assessment in various microsurgical environments.

Approximate Target Pre-Cueing Reduces Programming Quiet Eye and Movement Preparation Time: Evidence for Parameter Pre-Programming?

Purpose: We examined the effect of target pre-cues on quiet eye duration (QED). If quiet eye (QE) represents the initial and only period for the programming of movement parameters, then the precision of target pre-cues should not affect QED. In contrast, shorter QED after pre-cueing of targets implies some initial programming process to have occurred before QE. Method: Sixteen participants threw darts at targets projected onto a soft screen. We manipulated the precision of target pre-cues by highlighting an area within which the target would appear. These pre-cued areas were either the full screen (i.e., no cue), any half, quarter, or sixteenth of the screen. Participants threw eight times in each condition. Dependent measures included QED (programming and online segments), movement preparation time (MPT; from target presentation to initiation of movement), and radial error (cm). Results: Analysis revealed that programming QE was shorter when the target was pre-cued in the most precise sixteenth condition, compared to the no cue condition. Also, MPT was shorter when pre-cued in the sixteenth condition than in either the no cue or half screen conditions. Target pre-cueing conditions did not affect the other dependent variables. Conclusions: Shorter PQE following the most precise target pre-cueing implies that some pre-programming occurred before QE, perhaps through inhibition, but only when the pre-cue was specific enough to make pre-programming possible.

Exploring Eye-tracking Technology as an Assessment Tool for Point-of-care Ultrasound Training

OBJECTIVES

Eye-tracking technology has emerged as a potentially useful learner assessment tool in several medical specialties. In the fields of general surgery and anesthesiology, it has been shown to reliably differentiate between different levels of expertise in procedural skills. In the field of radiology, it has been shown to be a valid assessment tool for diagnostic test interpretation. Current methods of competency assessment in point-of-care ultrasound (POCUS) remain a challenge, because they require significant direct observation time by an instructor. The purpose of this study was to determine if eye-tracking technology can accurately distinguish between novice and experts in the interpretation of POCUS clips, specifically of the focused assessment using sonography in trauma (FAST) scan.

METHODS

A convenience sample of medical students, residents, and emergency physicians from a single academic emergency department were invited to participate. Participants included both novices and experts in POCUS. Each participant completed a baseline questionnaire and viewed 16 video clips of a FAST ultrasound examination while their gaze patterns were recorded by a commercially available eye-tracking device. The primary outcome was total gaze time on the area of interest (AOI). Secondary outcomes included total time to fixation, mean number of fixations, and mean duration of first fixation on the AOI.

RESULTS

Fifteen novices and 15 experts completed this study. For total gaze time on the AOI, experts fixated their gaze significantly longer than novices (75.8 ± 16.2 seconds vs. 56.6 ± 12.8 seconds, p = 0.001). Similarly, experts were significantly faster to fixate on the AOI and had a higher fixation count on the AOI (8.5 ± 4.0 seconds vs. 15.1 ± 6.8 seconds, p = 0.003; and 170 ± 30 vs. 143 ± 28 seconds, p = 0.016). There were no differences on the mean duration of first fixation on the AOI (0.42 ± 0.12 seconds vs. 0.39 ± 0.09 seconds, p = 0.467).

CONCLUSION

Eye-tracking technology shows the potential to differentiate between experts and novices by their gaze patterns on video clips of FAST examinations. The total gaze time on the AOI may be a useful metric to help in the assessment of competency in POCUS image interpretation. In addition, the evaluation of gaze patterns may help educators identify causes of interpretation errors. Future studies are needed to further validate these metrics in a larger cohort.

Context Affects Quiet Eye Duration and Motor Performance Independent of Cognitive Effort

Extensive literature has shown the effect of "quiet eye" (QE) on motor performance. However, little attention has been paid to the context in which tasks are executed (independent of anxiety) and the mechanisms that underpin the phenomenon. Here, the authors aimed to investigate the effects of context (independent of anxiety) on QE and performance while examining if the mechanisms underpinning QE are rooted in cognitive effort. In this study, 21 novice participants completed golf putts while pupil dilation, QE duration, and putting accuracy were measured. Results showed that putting to win was more accurate compared with the control (no context) condition, and QE duration was longer when putting to win or tie a hole compared with control. There was no effect of context on pupil dilation. Results suggest that, while the task was challenging, performance scenarios can enhance representativeness of practice without adding additional load to cognitive resources, even for novice performers.

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.

Contemporary training methods in regional anaesthesia: fundamentals and innovations

Over the past two decades, regional anaesthesia and medical education as a whole have undergone a renaissance. Significant changes in our teaching methods and clinical practice have been influenced by improvements in our theoretical understanding as well as by technological innovations. More recently, there has been a focus on using foundational education principles to teach regional anaesthesia, and the evidence on how to best teach and assess trainees is growing. This narrative review will discuss fundamentals and innovations in regional anaesthesia training. We present the fundamentals in regional anaesthesia training, specifically the current state of simulation-based education, deliberate practice and curriculum design based on competency-based progression. Moving into the future, we present the latest innovations in web-based learning, emerging technologies for teaching and assessment and new developments in alternate reality learning systems.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Difference in eye movements during gait analysis between professionals and trainees

INTRODUCTION

Observational gait analysis is a widely used skill in physical therapy. Meanwhile, the skill has not been investigated using objective assessments. The present study investigated the differences in eye movement between professionals and trainees, while observing gait analysis.

METHODS

The participants included in this study were 26 professional physical therapists and 26 physical therapist trainees. The participants, wearing eye tracker systems, were asked to describe gait abnormalities of a patient as much as possible. The eye movement parameters of interest were fixation count, average fixation duration, and total fixation duration.

RESULTS

The number of gait abnormalities described was significantly higher in professionals than in trainees, overall and in limbs of the patient. The fixation count was significantly higher in professionals when compared to trainees. Additionally, the average fixation duration and total fixation duration were significantly shorter in professionals. Conversely, in trunks, the number of gait abnormalities and eye movements showed no significant differences between groups.

CONCLUSIONS

Professionals require shorter fixation durations on areas of interest than trainees, while describing a higher number of gait abnormalities.

Visual behaviour in robotic surgery-Demonstrating the validity of the simulated environment

BACKGROUND

Eye metrics provide insight into surgical behaviour allowing differentiation of performance, however have not been used in robotic surgery. This study explores eye metrics of robotic surgeons in training in simulated and real tissue environments.

METHODS

Following the Fundamentals of Robotic Surgery (FRS), training curriculum novice robotic surgeons were trained to expert-derived benchmark proficiency using real tissue on the da Vinci Si and the da Vinci skills simulator (dVSS) simulator. Surgeons eye metrics were recorded using eye-tracking glasses when both "novice" and "proficient" in both environments. Performance was assessed using Global Evaluative Assessment of Robotic skills (GEARS) and numeric psychomotor test score (NPMTS) scores.

RESULTS

Significant (P ≤ .05) correlations were seen between pupil size, rate of change and entropy, and associated GEARS/NPMTS in "novice" and "proficient" surgeons. Only number of blinks per minute was significantly different between pupilometrics in the simulated and real tissue environments.

CONCLUSIONS

This study illustrates the value of eye tracking as an objective physiological tool in the robotic setting. Pupilometrics significantly correlate with established assessment methods and could be incorporated into robotic surgery assessments.

Does effective gaze behavior lead to enhanced performance in a complex error-detection cockpit task?

The purpose of the current study was to examine the relationship between expertise, performance, and gaze behavior in a complex error-detection cockpit task. Twenty-four pilots and 26 non-pilots viewed video-clips from a pilot's viewpoint and were asked to detect malfunctions in the cockpit instrument panel. Compared to non-pilots, pilots detected more malfunctioning instruments, had shorter dwell times on the instruments, made more transitions, visited task-relevant areas more often, and dwelled longer on the areas between the instruments. These results provide evidence for three theories that explain underlying processes for expert performance: The long-term working memory theory, the information-reduction hypothesis, and the holistic model of image perception. In addition, the results for generic attentional skills indicated a higher capability to switch between global and local information processing in pilots compared to non-pilots. Taken together, the results suggest that gaze behavior as well as other generic skills may provide important information concerning underlying processes that can explain successful performance during flight in expert pilots.

Exploiting Three-Dimensional Gaze Tracking for Action Recognition During Bimanual Manipulation to Enhance Human-Robot Collaboration

Human-robot collaboration could be advanced by facilitating the intuitive, gaze-based control of robots, and enabling robots to recognize human actions, infer human intent, and plan actions that support human goals. Traditionally, gaze tracking approaches to action recognition have relied upon computer vision-based analyses of two-dimensional egocentric camera videos. The objective of this study was to identify useful features that can be extracted from three-dimensional (3D) gaze behavior and used as inputs to machine learning algorithms for human action recognition. We investigated human gaze behavior and gaze-object interactions in 3D during the performance of a bimanual, instrumental activity of daily living: the preparation of a powdered drink. A marker-based motion capture system and binocular eye tracker were used to reconstruct 3D gaze vectors and their intersection with 3D point clouds of objects being manipulated. Statistical analyses of gaze fixation duration and saccade size suggested that some actions (pouring and stirring) may require more visual attention than other actions (reach, pick up, set down, and move). 3D gaze saliency maps, generated with high spatial resolution for six subtasks, appeared to encode action-relevant information. The "gaze object sequence" was used to capture information about the identity of objects in concert with the temporal sequence in which the objects were visually regarded. Dynamic time warping barycentric averaging was used to create a population-based set of characteristic gaze object sequences that accounted for intra- and inter-subject variability. The gaze object sequence was used to demonstrate the feasibility of a simple action recognition algorithm that utilized a dynamic time warping Euclidean distance metric. Averaged over the six subtasks, the action recognition algorithm yielded an accuracy of 96.4%, precision of 89.5%, and recall of 89.2%. This level of performance suggests that the gaze object sequence is a promising feature for action recognition whose impact could be enhanced through the use of sophisticated machine learning classifiers and algorithmic improvements for real-time implementation. Robots capable of robust, real-time recognition of human actions during manipulation tasks could be used to improve quality of life in the home and quality of work in industrial environments.

Preliminary Experience Using Eye-Tracking Technology to Differentiate Novice and Expert Image Interpretation for Ultrasound-Guided Regional Anesthesia

OBJECTIVES

Objective measures are needed to guide the novice's pathway to expertise. Within and outside medicine, eye tracking has been used for both training and assessment. We designed this study to test the hypothesis that eye tracking may differentiate novices from experts in static image interpretation for ultrasound (US)-guided regional anesthesia.

METHODS

We recruited novice anesthesiology residents and regional anesthesiology experts. Participants wore eye-tracking glasses, were shown 5 sonograms of US-guided regional anesthesia, and were asked a series of anatomy-based questions related to each image while their eye movements were recorded. The answer to each question was a location on the sonogram, defined as the area of interest (AOI). The primary outcome was the total gaze time in the AOI (seconds). Secondary outcomes were the total gaze time outside the AOI (seconds), total time to answer (seconds), and time to first fixation on the AOI (seconds).

RESULTS

Five novices and 5 experts completed the study. Although the gaze time (mean ± SD) in the AOI was not different between groups (7 ± 4 seconds for novices and 7 ± 3 seconds for experts; P = .150), the gaze time outside the AOI was greater for novices (75 ± 18 versus 44 ± 4 seconds for experts; P = .005). The total time to answer and total time to first fixation in the AOI were both shorter for experts.

CONCLUSIONS

Experts in US-guided regional anesthesia take less time to identify sonoanatomy and spend less unfocused time away from a target compared to novices. Eye tracking is a potentially useful tool to differentiate novices from experts in the domain of US image interpretation.

Eye-tracking technology in medical education: A systematic review

BACKGROUND

Eye-tracking technology is an established research tool within allied industries such as advertising, psychology and aerospace. This review aims to consolidate literature describing the evidence for use of eye-tracking as an adjunct to traditional teaching methods in medical education.

METHODS

A systematic literature review was conducted in line with STORIES guidelines. A search of EMBASE, OVID MEDLINE, PsycINFO, TRIP database, and Science Direct was conducted until January 2017. Studies describing the use of eye-tracking in the training, assessment, and feedback of clinicians were included in the review.

RESULTS

Thirty-three studies were included in the final qualitative synthesis. Three studies were based on the use of gaze training, three studies on the changes in gaze behavior during the learning curve, 17 studies on clinical assessment and six studies focused on the use of eye-tracking methodology as a feedback tool. The studies demonstrated feasibility and validity in the use of eye-tracking as a training and assessment method.

CONCLUSIONS

Overall, eye-tracking methodology has contributed significantly to the training, assessment, and feedback practices used in the clinical setting. The technology provides reliable quantitative data, which can be interpreted to give an indication of clinical skill, provide training solutions and aid in feedback and reflection. This review provides a detailed summary of evidence relating to eye-tracking methodology and its uses as a training method, changes in visual gaze behavior during the learning curve, eye-tracking methodology for proficiency assessment and its uses as a feedback tool.

Quantifying the cognitive cost of laparo-endoscopic single-site surgeries: Gaze-based indices

BACKGROUND

Despite the growing interest concerning the laparo-endoscopic single-site surgery (LESS) procedure, LESS presents multiple difficulties and challenges that are likely to increase the surgeon's cognitive cost, in terms of both cognitive load and performance. Nevertheless, there is currently no objective index capable of assessing the surgeon cognitive cost while performing LESS. We assessed if gaze-based indices might offer unique and unbiased measures to quantify LESS complexity and its cognitive cost. We expect that the assessment of surgeon's cognitive cost to improve patient safety by measuring fitness-for-duty and reducing surgeons overload.

METHODS

Using a wearable eye tracker device, we measured gaze entropy and velocity of surgical trainees and attending surgeons during two surgical procedures (LESS vs. multiport laparoscopy surgery [MPS]). None of the participants had previous experience with LESS. They performed two exercises with different complexity levels (Low: Pattern Cut vs. High: Peg Transfer). We also collected performance and subjective data.

RESULTS

LESS caused higher cognitive demand than MPS, as indicated by increased gaze entropy in both surgical trainees and attending surgeons (exploration pattern became more random). Furthermore, gaze velocity was higher (exploration pattern became more rapid) for the LESS procedure independently of the surgeon's expertise. Perceived task complexity and laparoscopic accuracy confirmed gaze-based results.

CONCLUSION

Gaze-based indices have great potential as objective and non-intrusive measures to assess surgeons' cognitive cost and fitness-for-duty. Furthermore, gaze-based indices might play a relevant role in defining future guidelines on surgeons' examinations to mark their achievements during the entire training (e.g. analyzing surgical learning curves).

The 'Quiet Eye' and Motor Performance: A Systematic Review Based on Newell's Constraints-Led Model

INTRODUCTION

The quiet eye (final fixation to a specific target prior to movement initiation) is a perceptual skill robustly associated with expertise and superior performance. The benefit of the phenomenon has been demonstrated in a range of sporting tasks. The mechanism(s) underpinning this phenomenon are much-debated and are associated with varying assumptions.

OBJECTIVE

This systematic review categorizes previous quiet eye research based on Newell's 1986 model of interacting constraints.

DATA SOURCES

Three electronic databases (Web of Science, Scopus, PubMed) were searched from inception until February 2015. Details of relevant studies were also obtained from one literature review and two book chapters.

ELIGIBILITY CRITERIA AND SYNTHESIS METHODS

To frame the discussion of research evidence concerning the quiet eye, previous studies were evaluated based on a classification of manipulating performer, environment, and task constraints. Additionally, associative studies (without specific constraints), and interacting constraints (affecting more than one constraint) were considered.

RESULTS

This review emphasizes that the quiet eye is beneficial for performing aiming tasks and that Newell's constraints model provides a useful framework for organizing knowledge in this area.

CONCLUSION

Despite the robust research on the value of the quiet eye, several gaps in current knowledge exist regarding the mechanism of the quiet eye effect.

Variaciones anatómicas del nervio laríngeo recurrente en una muestra de población colombiana

<p>Introducción. El nervio laríngeo recurrente (NLR), originado en el nervio vago, se encuentra relacionado con diferentes estructuras a nivel del tórax y del cuello, además de estar inmerso en diversos procesos nosológicos y quirúrgicos que pueden resultar en alteraciones funcionales; alteraciones que van desde la disfonía y la afonía hasta la muerte por obstrucción de la vía aérea. Estas complicaciones, específicamente las quirúrgicas, pueden cursar con secuelas permanentes del 0.3% al 3% de los casos y transitorias del 3% al 8%. Objetivo. Analizar el origen, el trayecto, los ramos y las relaciones anatómicas del nervio laríngeo recurrente en una muestra de 58 plastrones cervicocardiopulmonares y digestivos de población colombiana. Materiales y métodos. Estudio descriptivo analítico transversal con disección de 58 plastrones cervicocardiotorácicos seleccionados por muestreo a conveniencia. Resultados. Se determinó que el 100% de los plastrones disecados cuentan con un sitio de llegada usual; de igual modo, la descripción de la relación entre el NLR y la arteria tiroidea inferior (ATI) arrojó que la disposición más frecuente, tanto del NLR derecho como izquierdo, fue posterior a la ATI. Asimismo, se reportó el primer caso en Colombia y el décimo en el mundo del triángulo del nervio laríngeo recurrente (TNLR). Conclusiones. La disposición del NLR derecho e izquierdo es frecuentemente posterior a la ATI; de igual forma, es importante tener en cuenta la existencia del TNLR durante los abordajes quirúrgicos, especialmente en tiroidectomías.</p>

Gaze patterns of gross anatomy students change with classroom learning

Numerous studies have documented that experts exhibit more efficient gaze patterns than those of less experienced individuals. In visual search tasks, experts use fewer, longer fixations to fixate for relatively longer on salient regions of the visual field while less experienced observers spend more time examining nonsalient regions. This study investigates whether changes in gaze patterns reflect learning by students in a medical gross anatomy course. Students were asked to examine photographs of dissections similar to those they experienced in class and to identify the tagged structure in each image. We postulated that, compared to naive behavior (behavior at baseline and when examining unfamiliar content) students would examine familiar content for longer and would direct proportionally more fixation time on cognitively salient regions of the images while using fewer, longer duration fixations. Our students examined familiar images for significantly longer than they did at baseline (P < 0.0001) or for unfamiliar images (P < 0.0001). They also spent significantly longer examining cognitively salient regions of familiar images, as compared to examining those regions at baseline (P < 0.0001) and on unfamiliar images (P < 0.0001). However, these gaze patterns were characterized by more numerous fixations rather than fewer, longer fixations. These individuals are successful learners in a challenging gross anatomy course, but are not experts in anatomy. Therefore we speculate that the gaze pattern they exhibit characterizes an earlier stage of the learning process than has previously been documented in studies of expertise, which have primarily focused on the gaze patterns of true experts.