Development and Validation of a Surgical Workload Measure: The Surgery Task Load Index (SURG-TLX)

Background: The 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. Methods: The 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. Results: The 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. Conclusions: The 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. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Developing an objective indicator of fatigue: An alternative mobile version of the Psychomotor Vigilance Task (m-PVT)

Approximately 20% of the working population report symptoms of feeling fatigued at work. The aim of the study was to investigate whether an alternative mobile version of the ‘gold standard’ Psychomotor Vigilance Task (PVT) could be used to provide an objective indicator of fatigue in staff working in applied safety critical settings such as train driving, hospital staffs, emergency services, law enforcements, etc., using different mobile devices. 26 participants mean age 20 years completed a 25-min reaction time study using an alternative mobile version of the Psychomotor Vigilance Task (m-PVT) that was implemented on either an Apple iPhone 6s Plus or a Samsung Galaxy Tab 4. Participants attended two sessions: a morning and an afternoon session held on two consecutive days counterbalanced. It was found that the iPhone 6s Plus generated both mean speed responses (1/RTs) and mean reaction times (RTs) that were comparable to those observed in the literature while the Galaxy Tab 4 generated significantly lower 1/RTs and slower RTs than those found with the iPhone 6s Plus. Furthermore, it was also found that the iPhone 6s Plus was sensitive enough to detect lower mean speed of responses (1/RTs) and significantly slower mean reaction times (RTs) after 10-min on the m-PVT. In contrast, it was also found that the Galaxy Tab 4 generated mean number of lapses that were significant after 5-min on the m-PVT. These findings seem to indicate that the m-PVT could be used to provide an objective indicator of fatigue in staff working in applied safety critical settings such as train driving, hospital staffs, emergency services, law enforcements, etc

The Development of Behavior-Based User Models for a Computer System

This paper examines the development of user models for the graphical user interface of a telecommunication computer system used during service and sales negotiations. User models enhance the requirements gathering phase of system design by capturing the diversity of the user population and capitalizing on the variety of distinguishable and categorizable strategies that affect performance. The CDM method (Categorizing, Describing, and Modeling method) was developed as a technique to generate user models. In the CDM method, the user population is first categorized into a reasonable number of groups. The behaviors for each group are described and then qualitatively and quantitatively modeled. These models are subsequently used during the system design and operational processes to optimize performance of the entire user population

Weighing the importance of drivers’ workload measurement standardization

Workload is an inescapable topic within the context of Human-Machine Interaction (HMI). Evolution dictates that HMI systems will be all the more attractive to users the more intuitive they are. While attempting to create an optimized workload management system, the authors have encountered a difficulty in gathering a homogeneous definition of workload and a standardized manner of measuring it. In fact, some researchers even call into question the fact that maybe different things are being discussed. Could it be the underlying cause of many of the HMI failures so far recorded? Either way, the weight this concept carries is too heavy to be dealt lightly. It is very important that standardized strategies for measurement of workload are developed so that, for one, different results can be compared and contribute to a more robust understanding of the concept and that, for two, the measurement of workload is globalized and able to be adapted to all users.This work has been supported by European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 039334; Funding Reference: POCI-01-0247- FEDER-039334]

Driving workload indicators: the case of senior drivers

The automotive industry is currently focused in the goal of developing advanced autonomous driving systems (ADAS) and its supporting technologies. A main condition for achieving this goal is to ensure drivers’ safety and comfort during the ride. The driving task is often described as complex and dynamic and can be considered as the single most risky task that the individual has to perform on a daily basis. Since the mean age of the population in industrialized countries is gradually increasing, one of the ADAS objective is to enhance mobility of seniors by easing the task of driving to levels with which they are able to comply. This paper aimed at researching present key workload indicators that can be used by the car autonomous driving systems to establish the more efficient means to keep the senior drivers informed about the driving task and surrounding environment, allowing them to benefit from other entertainment applications and safely resume the driving task.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

Mental workload and other causes of different types of fatigue in rail staff

Workload and shift work have been addressed as causes of occupational fatigue in previous research. Fatigue in the workplace has usually been investigated as a single outcome. However, taking into account separate kinds of energy resources, there are different types of fatigue. The present study investigated mental workload and other causes of physical fatigue, mental fatigue, and emotional fatigue in a rail company. Overall, the results confirm the importance of mental workload for different types of work fatigue and reveal other specific causes for each type of fatigue. Prolonged work and insufficient rest resulted in physical fatigue, while poor shift patterns caused mental and emotional fatigue