Elizabeth Bright

Development and validation of a surgical workload measure: the surgery task load index (SURG-TLX).

BackgroundThe purpose of the present study was to develop and validate a multidimensional, surgery-specific workload measure (the SURG-TLX), and to determine its utility in providing diagnostic information about the impact of various sources of stress on the perceived demands of trained surgical operators. As a wide range of stressors have been identified for surgeons in the operating room, the current approach of considering stress as a unidimensional construct may not only limit the degree to which underlying mechanisms may be understood but also the degree to which training interventions may be successfully matched to particular sources of stress.MethodsThe dimensions of the SURG-TLX were based on two current multidimensional workload measures and developed via focus group discussion. The six dimensions were defined as mental demands, physical demands, temporal demands, task complexity, situational stress, and distractions. Thirty novices were trained on the Fundamentals of Laparoscopic Surgery (FLS) peg transfer task and then completed the task under various conditions designed to manipulate the degree and source of stress experienced: task novelty, physical fatigue, time pressure, evaluation apprehension, multitasking, and distraction.ResultsThe results were supportive of the discriminant sensitivity of the SURG-TLX to different sources of stress. The sub-factors loaded on the relevant stressors as hypothesized, although the evaluation pressure manipulation was not strong enough to cause a significant rise in situational stress.ConclusionsThe present study provides support for the validity of the SURG-TLX instrument and also highlights the importance of considering how different stressors may load surgeons. Implications for categorizing the difficulty of certain procedures, the implementation of new technology in the operating room (man–machine interface issues), and the targeting of stress training strategies to the sources of demand are discussed. Modifications to the scale to enhance clinical utility are also suggested.

Cheating experience: Guiding novices to adopt the gaze strategies of experts expedites the learning of technical laparoscopic skills

BACKGROUND Previous research has demonstrated that trainees can be taught (via explicit verbal instruction) to adopt the gaze strategies of expert laparoscopic surgeons. The current study examined a software template designed to guide trainees to adopt expert gaze control strategies passively, without being provided with explicit instructions. METHODS We examined 27 novices (who had no laparoscopic training) performing 50 learning trials of a laparoscopic training task in either a discovery-learning (DL) group or a gaze-training (GT) group while wearing an eye tracker to assess gaze control. The GT group performed trials using a surgery-training template (STT); software that is designed to guide expert-like gaze strategies by highlighting the key locations on the monitor screen. The DL group had a normal, unrestricted view of the scene on the monitor screen. Both groups then took part in a nondelayed retention test (to assess learning) and a stress test (under social evaluative threat) with a normal view of the scene. RESULTS The STT was successful in guiding the GT group to adopt an expert-like gaze strategy (displaying more target-locking fixations). Adopting expert gaze strategies led to an improvement in performance for the GT group, which outperformed the DL group in both retention and stress tests (faster completion time and fewer errors). CONCLUSION The STT is a practical and cost-effective training interface that automatically promotes an optimal gaze strategy. Trainees who are trained to adopt the efficient target-locking gaze strategy of experts gain a performance advantage over trainees left to discover their own strategies for task completion.

Assessing visual control during simulated and live operations: gathering evidence for the content validity of simulation using eye movement metrics

BackgroundAlthough virtual reality (VR) simulators serve an important role in the training and assessment of surgeons, they need to be evaluated for evidence of validity. Eye-tracking technology and measures of visual control have been used as an adjunct to the performance parameters produced by VR simulators to help in objectively establishing the construct validity (experts vs. novices) of VR simulators. However, determining the extent to which VR simulators represent the real procedure and environment (content validity) has largely been a subjective process undertaken by experienced surgeons. This study aimed to examine the content validity of a VR transurethral resection of the prostate (TURP) simulator by comparing visual control metrics taken during simulated and real TURP procedures.MethodsEye-tracking data were collected from seven surgeons performing 14 simulated TURP operations and three surgeons performing 15 real TURP operations on live patients. The data were analyzed offline, and visual control metrics (number and duration of fixations, percentage of time the surgeons fixated on the screen) were calculated.ResultsThe surgeons displayed more fixations of a shorter duration and spent less time fixating on the video monitor during the real TURP than during the simulated TURP. This could have been due to (1) the increased complexity of the operating room (OR) environment (2) the decreased quality of the image of the urethra and associated anatomy (compared with the VR simulator), or (3) the impairment of visual attentional control due to the increased levels of stress likely experienced in the OR.ConclusionsThe findings suggest that the complexity of the environment surrounding VR simulators needs to be considered in the design of effective simulated training curricula. The study also provides support for the use of eye-tracking technology to assess the content validity of simulation and to examine psychomotor processes during live operations.

1507 LEARNING EFFECTS USING A TURP SIMULATOR ASSESSING CHANGES IN VISUAL CONTROL AND PERFORMANCE

Technology & Instruments: Surgical Education & Skills Assessment/Ureteroscopy II Moderated Poster This work was supported by a bilateral research_x000D_ grant from the Economic and Social Research Council, UK and the Research Grants Council, Hong Kong (RES-000-22-3016). 1507: Learning effects using a TURP simulator: Assessing changes in visual control and performance. Samuel Vine Thomas Dutton Mark Wilson Elizabeth Bright John McGrath Introduction and Objectives Surgical simulators afford trainees the chance to practise skills in a safe environment and without the need for supervision. Although they have been proposed to shorten the learning curve for complex surgical skills, there is concern that they do not prepare trainees for the demanding conditions of the operating room. Research in skill learning (including surgical skills) has shown that experts and novices can be distinguished by differences in their visual control strategies, with experts using fewer fixations of a longer duration. The aim of this study was to assess the learning benefits of a TURP simulator by examining, not only changes in novice performance, but also changes in their visual control.

1516 EXAMINING THE VISUAL CONTROL STRATEGIES OF EXPERTS AND NOVICES TO ESTABLISH THE VALIDITY OF A NOVEL TURP SIMULATOR

INTRODUCTION AND OBJECTIVES: With increasing resource constraints and patient concern, there has been a recent interest in the use of simulators to help surgeons acquire technical skills. Surgical simulators facilitate repetitive practice and performance feedback in a risk-free environment. Previous validation of simulators has focussed on motor proficiency measures. However, studies have shown that expertise in laparoscopic skills is underpinned by an efficient visual control strategy (fixations that are long in duration and low in frequency). Using infrared eye-tracking devices, experts are seen to ‘lock’ their gaze on a target earlier and for longer, improving the accuracy of the subsequent motor skill. The aim of this study was to examine visual control measures and their utility as a novel method to assess the construct validity of a transurethral resection of prostate (TURP) virtual reality simulator (VR; Simbionix, USA Corp). METHODS: 11 novices (no TURP experience) and 7 experts ( 200 TURPS) completed the median lobe resection task on the simulator. All participants wore a gaze registration system that assessed their visual control strategy (recorded as the number of fixations per second and mean duration of fixations). The VR simulator also provided objective measures of performance (% prostate resected per minute) and safety/error (% prostatic capsule perforation and time diathermy active without tissue contact). RESULTS: When compared to novices, experts employed a visual control strategy of fewer fixations per second (mean 1.49 vs 1.12, p 0.05), but a longer mean fixation duration (0.43 vs 0.76, p .005). Differences were also found in performance related measures; experts resected 59.05% of the prostate per minute whereas novices resected only 30.86% (p .001) and experts were more precise with the diathermy than novices (0.32 vs 2.35, p .005). However, both groups had an equal rate of prostatic capsular perforation (13.71 vs 16.91, p 0.31). CONCLUSIONS: Significant differences have been shown in the performance of experts versus novices (proficiency and safety parameters) whilst performing a VR TURP training task. Furthermore, experts and novices displayed the expected differences in visual control strategies. This suggests that the TURP simulator is a valid tool in the replication of this common urological procedure. The study of visual control strategies may be a useful adjunct, alongside assessment of motor performance, in assessing surgeons undergoing simulation training.