Erik Prytz

Intracorporeal suturing: Transfer from Fundamentals of Laparoscopic Surgery to cadavers results in substantial increase in mental workload.

INTRODUCTION A spatial secondary task developed by the authors was used to measure the mental workload of the participant when transferring suturing skills from a box simulator to more realistic surgical conditions using a fresh cadaver. We hypothesized that laparoscopic suturing on genuine bowel would be more challenging than on the Fundamentals of Laparoscopic Surgery (FLS)-simulated bowel as reflected in differences on both suturing and secondary task scores. METHODS We trained 14 surgical assistant students to FLS proficiency in intracorporeal suturing. Participants practiced suturing on the FLS box for 30 minutes and then were tested on both the FLS box and the bowel of a fresh cadaver using the spatial, secondary dual-task conditions developed by the authors. RESULTS Suturing times increased by >333% when moving from the FLS platform to the cadaver F(1,13) = 44.04, P < .001. The increased completion times were accompanied by a 70% decrease in secondary task scores, F(1,13) = 21.21, P < .001. CONCLUSION The mental workload associated with intracorporeal suturing increases dramatically when trainees transfer from the FLS platform to human tissue under more realistic conditions of suturing. The increase in mental workload is indexed by both an increase in suturing times and a decrease in the ability to attend to the secondary task.

The relationship between Workload, Teamwork, Situation Awareness, and Performance in Teams: A microworld study

In modern military organizations teamwork performance is central, yet the underlying factors contributing to such performance are debated. The purpose of this paper was to investigate how several known teamwork measures relate to a prior model of operator performance (Nählinder et al, 2004). This study expands this model to the team level and in the command and control domain. Specifically, this paper studies the relationship between individual and team workload measures, situation awareness measures, and performance measures in 18 two-person teams. The study has two major findings: Firstly, the various team cognition measures statistically cluster into four meaningful concepts (workload, teamwork, situation awareness and performance). Secondly, a Structural Equation Model indicates that the relationship between the various individual and team measures can be described in a model resembling the model found in previous studies (Nählinder et al, 2004). In particular, the results show that the general workload in the microworld study has a negative effect on both teamwork and situation awareness. Teamwork, in turn, also affects situation awareness, which has major impact on performance.

Using Fitts’ Law for a 3D Pointing Task on a 2D Display: Effects of Depth and Vantage Point

Laparoscopic surgery requires surgeons to make judgments about three-dimensional movements using a two-dimensional display. This arrangement reduces the available visual feedback information, such as certain depth cues. The current study used Fitts’ (1954) law to examine the relationship between psychomotor movement time, target size and target distance for a psychomotor pointing task using a laparoscopic instrument in three-dimensional space projected on a two-dimensional display from different vantage points. Analyses demonstrate an effect for depth of target on accuracy, internal consistency and movement time. The results demonstrate that Fitts’ law can be utilized to detect differences in conditions when a three-dimensional task must be completed with the visual feedback presented on a two-dimensional display. No reliable results of vantage point were found. Thus, the location of a two-dimensional display may not be critical for the type of laparoscopic pointing tasks examined in the present study.

The Influence of Visual Aids on Detecting Early and Late Decelerations in Maternal-Fetal Heart Rate Patterns

The present study examined how well individuals could differentiate between two different types of signals (early and late decels) in maternal-fetal heart rate tracings with and without the use of a visual aid. Twenty-one undergraduates twice viewed 80 simulated images under four different signal-to-noise (S/N) ratios. Further, the late decels were delayed in 4-sec increments. In one block of trials, the images were presented without a visual aid, and in the other block a visual aid consisting of a large turquoise crosshair was overlaid on the images. The results indicated that lower S/N ratios and shorter onset delays made signals more difficult to distinguish. However, overall levels of accuracy were significantly higher when the visual aid was present. These results provide initial evidence that utilizing visual aids can enhance the ability to detect critical signals in maternal-fetal heart rate patterns.

Designing a Digital Medical Management Training Simulator Using Distributed Cognition Theory

Background. Training of medical professionals is important to improve care during mass-causality events. Therefore, it is essential to extend knowledge on how to design valid and usable simulation-based training environments. Purpose. This article investigates how distributed cognition and simulation theory concepts can guide design of simulation-based training environments. We present the design and user evaluation of DigEmergo, a simulator for training and assessing emergency medicine management. Design approach. A prior Distributed Cognition in Teamwork (DiCoT) analysis of the Emergo Train System (ETS) guided the design process. The design objective of DigEmergo was to be useful, usable, retain distributed cognition features of ETS, and strengthen validity and output reliability. Evaluation. Eight expert ETS instructors participated in a formative system evaluation. The Technology Assessment Model (TAM) questionnaire was used to measure usefulness and ease of use. Observations and post-test interviews were conducted to contextualize the measures. Results. The results showed that DigEmergo was perceived as somewhat to quite useful and somewhat easy to use. Overall, expert users considered DigEmergo promising and successful in retaining core ETS features. Conclusions. The study indicates that a design methodology based on distributed cognition and simulation theory can be successfully combined to guide simulator (re)design and strengthen simulator validity.

Exploring prehospital C2-work during a mass gathering event

Purpose– The purpose of this paper is to explore the workload and shared workload awareness in a staff performing command and control (C2) work during a planned major incident (MI) empirical case in Sweden. Design/methodology/approach– Data on workload and shared awareness were collected during live C2-work using qualitative observations and in-situ interviews mixed with quantitative questionnaires. Findings– A content analysis of the qualitative data revealed categories of workload sources. Quantified workload estimates showed changes in workload levels over time and staff roles, which were also contextualized using the results of the qualitative data. Data on shared awareness indicated that team workload awareness shifted over time according to common patterns. This study demonstrates a promising methodology to study C2-related factors during live EMS work. Research limitations/implications– The observed variations in workload imply that research that relies only on post-task measurements of workload may be inaccurate. Future research could use this method to investigate the connection between workload and performance during different types of MIs. Originality/value– The results can be used to inform future Goteborgsvarvet C2-teams in terms of when, why, and for whom task load changes, which would support predictive allocation of resources.

The importance of eye-contact for collaboration in AR systems

Eye contact is believed to be an important factor in normal human communication and as a result of this a head mounted display (HMD) is often seen as something intrusive and limiting. This can be especially problematic when AR is used in a collaborative setting. The study presented in this paper aims to investigate the effects an HMD-based AR system can have on eye contact behaviour between participants in a collaborative task and thus, in extension, the effects of the HMD on collaboration itself. The focus of the study is on task-oriented collaboration between professionals. The participants worked through three different scenarios alternating between HMDs and regular paper maps with the purpose of managing the crisis response to a simulated major forest fire. Correlations between eye contact between participants and questionnaire items concerning team- and taskwork were analysed, indicating that, for the paper map condition, a high amount of eye contact is associated with low confidence and trust in the artefacts used (i.e. paper map and symbols). The amount of eye-contact in both conditions was very low. It was significantly higher for conditions without HMDs. However, the confidence and trust in the artefacts was generally rated significantly higher with HMDs than without. In conclusion, the decrease in eye contact with HMDs does not seem to have a direct effect on the collaboration in a professional, task-oriented context. This is contrary to popular assumptions and the results are relevant for future design choices for AR systems using HMDs.

Workload Differences Across Command Levels and Emergency Response Organizations During a Major Joint Training Exercise

OBJECTIVE This study reports on an initial test using a validated workload measurement method, the NASA Task Load Index (TLX), as an indicator of joint emergency exercise effectiveness. Prior research on emergency exercises indicates that exercises must be challenging, ie, result in high workload, to be effective. However, this is often problematic with some participants being underloaded and some overloaded. The NASA TLX was used to test for differences in workload between commanders and subordinates and among three different emergency response organizations during a joint emergency exercise. DESIGN Questionnaire-based evaluation with professional emergency responders. SETTING The study was performed in conjunction with a large-scale interorganizational joint emergency exercise in Sweden. PARTICIPANTS A total of 20 participants from the rescue services, 12 from the emergency medical services, and 12 from the police participated in the study (N=44). Ten participants had a command-level role during the exercise and the remaining 34 were subordinates. MAIN OUTCOME MEASURE(S) The main outcome measures were the workload subscales of the NASA TLX: mental demands, physical demands, temporal demands, performance, effort, and frustration. RESULTS The results showed that the organizations experienced different levels of workload, that the commanders experienced a higher workload than the subordinates, and that two out of three organizations fell below the twenty-fifth percentile of average workload scores compiled from 237 prior studies. CONCLUSIONS The results support the notion that the NASA TLX could be a useful complementary tool to evaluate exercise designs and outcomes. This should be further explored and verified in additional studies.

Evaluation of a Novel Method to Study Interorganizational Coordination in Medical Command and Control Centers

Study/Objective: Inter-organizational coordination is key to successful medical command and control (C2) during major incidents. However, evaluating this factor is often problematic, in particular during or after real emergencies as compared to controlled training scenarios. The purpose of this case study was to pilot test a non-intrusive data collection method for evaluating operative inter-organizational coordination during medical C2 situations.Background: This study was conducted during a planned major incident in Sweden. The major incident studied was the Goteborgsvarvet half-marathon, the largest half-marathon event in the world with more than 200 000 attending spectators and over 60 000 runners. The studied C2 center included representatives from local hospitals, Goteborgsvarvet organization, police, fire department, ambulance service, the local traffic and infrastructure management office, and emergency dispatch.Methods: A combination of qualitative and quantitative methods was employed in this study. The qualitative methods included an ethnographic field study with on-site observations and contextual inquiry interviews. The quantitative methods included validated and experimental questionnaires distributed to the command center personnel at pre-determined intervals. These questionnaires aimed at gathering data on workload, stress, and shared and individual situational awareness.Results: The data indicate that the qualitative methods were less intrusive than the quantitative methods. The observations and contextual inquiries could be performed without interruptions while periods of high workload resulted in lower or delayed response rates on the questionnaires. Simple questionnaires produced an 80% response rate, complex questionnaires only 40%.Conclusion: The employed method appears useful to evaluate inter-organizational coordination and showed potential to gather meaningful data without being intrusive or disturbing the operative C2 activities. Due to the time-sensitive nature of emergency C2-work, unobtrusive qualitative methods and short, easy to fill out questionnaires are recommended for future studies. The results from this pilot will inform future operative C2 studies during similar planned major incidents.

The Effects of a Workload Transition on Stress over Time

The present study explored the effects of a workload transition on three dimensions of stress: task engagement, distress, and worry. Previous research on the effects of workload transitions has generated conflicting results. It was suggested that the concept of a continuous stress appraisal process could potentially resolve these prior conflicting results. A digit-processing task with high and low task demands was used to test this suggested explanation. Subjective reports of stress were measured both one minute and six minutes posttransition to show changes over time. The results showed that a workload transition affects each of the three stress dimensions differently such that task engagement declined over time, distress decreased following a high-to-low transition six minutes posttransition, and worry increased following a transition. These results suggest that distress and worry are more sensitive to workload transitions than task engagement. Further, the appraisal process may partially explain the prior conflicting findings by accounting for changes in stress over time.