bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Multiple Methods to Explore the Impact of Interruptions on Intravenous (IV) Push Delivery
Authors: McCurdie Tara , Prakash Varuna , Trbovich Patricia
Published: October 2014

Despite the safety-critical nature of healthcare, it is an interrupt-laden domain. Patient safety organizations have long called for a reduction in interruptions to healthcare workers, in an effort to reduce the likelihood of preventable medical error occurring during patient care. The goal of this research was to examine the impact that interruptions have on nurses’ task performance during medication administration, specifically intravenous (IV) push delivery, and the development of appropriately designed interventions to mitigate the potential harmful effects of interruptions on patient safety. IV push administration errors have been found to be common, and occur when doses are administered faster or slower than recommended. Direct observations found that nurses were interrupted every time they administered an IV push, sometimes more than once. Furthermore, the percentage of nurses who made errors when performing IV pushes during simulated scenarios was significantly higher when interrupted than in the uninterrupted condition. Data collected through focus groups qualitatively described perceptions and preferences that led to the design of a successful and appropriate intervention to solve this important patient safety problem.
Building High Performance Surgical Teams
Authors: Xiao Yan , Hallbeck Susan , Blocker Renaldo , Parker Sarah
Published: October 2014

Surgical team members are typically defined by professional roles. In many surgical teams, membership changes as staffing decisions are subject to considerations other than keeping surgical teams consistent. These considerations may include staffing patterns on the day of surgery and at the time of a surgical case. Teamwork skill training and safety culture have been emphasized, although much is known about the contribution to team performance from team consistency. We review the literature on cognitive and psychosocial benefits of consistent surgical teams. Although empirical evidence base for consistent surgical teams is lacking, we believe that the theoretical justifications may lay the groundwork for future research on the impact of deliberate staffing decisions by organizations, to complement the current emphasis on individual teamwork knowledge, skills and attitude. We also outline some of barriers based on our experience in our respective healthcare organizations.
Team Briefings in the Gynecological Operating Room
Authors: Hildebrand Emily A. , Branaghan Russell J. , Hallbeck M. Susan , Blocker Renaldo C.
Published: October 2014

Briefings are suggested to be an important mechanism for establishing and maintaining cohesive teams. However, there is still much to learn about briefings and how best to design and implement them for surgical teams in the operating room. Currently, there are no formally recognized protocols or methodologies for conducting surgical team briefings. This research reports preliminary findings from an effort to develop a model of team briefings for gynecological surgical teams. Semi-structured interviews were conducted using techniques derived from Applied Cognitive Task Analysis (Millitello & Hutton, 1998) with thirteen surgical team members spanning six different roles including surgeon, surgical resident, registered nurse, certified surgical assistant, certified scrub technician, and anesthesia. Findings reveal that informational needs are consistent across the team but also vary by individual role, illustrating the importance of addressing all stakeholders in potential interventions. Implications for the development of a team briefing model are discussed.
Detrimental Effects of an Electronic Health Records System on Musculoskeletal Symptoms among Health Professionals
Authors: Hedge Alan , James Tamara
Published: October 2014

A survey of 204 health professionals (physicians, physicians’ assistants and nurse practitioners) in private diagnostic clinics of a major healthcare system was conducted after the introduction of an electronic health records (EHR) system. Results showed considerable daily use of computers in various configurations and some 90% of respondents said the EHR had substantially increased their daily computer use. Less than half of the health professionals found the EHR easy to use. Almost half of the physicians said that use of the EHR reduced their face-to-face interactions with patients. Around two-thirds of respondents reported increased frequency of neck, shoulder and back discomfort and some 50% reported an increased frequency of right wrist discomfort since introduction of the EHR. Results demonstrate the importance of incorporating ergonomic workstation designs and ergonomics education when an EHR is being implemented.
Using a context-sensitive ranking method to organize reversible causes of cardiac arrest in a digital cognitive aid
Authors: Ramachandran Meera , Greenstein Joel S. , McEvoy Michael , McEvoy Matthew D.
Published: October 2014

Medical doctors typically identify reversible causes associated with cardiac arrest by recalling them from memory, using a mnemonic. External techniques, such as cognitive aids (e.g., iPad-based applications), have been shown to produce an increase in performance in medical diagnosis. We studied two alternative approaches to the traditional method of using mnemonics to identify reversible causes of cardiac arrest. One approach displayed the causes in alphabetical order (alphabetical scheme) while the other approach displayed causes ordered by their relevance to the patient-context (context-sensitive scheme). We recorded performance and usability measures for these two approaches in two simulated cardiac arrest scenarios for each group. It took significantly longer for the participants to identify the causes using the context- sensitive scheme. However, the context-sensitive scheme resulted in significantly fewer unnecessary keystrokes. The two schemes did not differ significantly in terms of their usability ratings.
Towards the Development of a Resilience Engineering Tool to Improve Patient Safety
Authors: Hegde Sudeep , Wreathall John , Hettinger A. Zach , Fairbanks Rollin J. , Wears Robert L. , Bisantz Ann M.
Published: October 2014

Over the last few years, patient safety research has seen a paradigm-shift marked by the advent of Resilience Engineering (RE). Findings from the team’s previous research on the efficacy of root-cause analysis in improving patient safety revealed the potential to analyze existing resilient system properties and leverage the same in system-design and improvement. A multi-phase research plan to develop a lessons-learned system for resilience engineering in healthcare is described. The focus of this paper is the first phase, which involved critical-incident interviews to elicit detailed information from frontline health care workers regarding real-life examples of resilience. 14 interviews were conducted with clinicians and nurses from a large, multi-hospital medical system. Multiple examples of resilience and factors pertinent to patient safety were extracted and aligned with system capabilities which are the cornerstones of resilience – learning, responding, anticipating and monitoring. Resilience was also seen to manifest at various levels of the work organization. These results demonstrate the feasibility of using the critical incident interviewing method to analyze resilience in a healthcare organization. The data from the interviews will further be used to develop a Resilience Engineering Tool to Improve Patient Safety (RETIPS) that can be implemented organization-wide for reporting and analysis of resilience-based cases.
Managing Interruptions in Healthcare
Authors: Ratwani Raj , Hettinger Zachary , Brixey Juliana , Rivera A. Joy , Colligan Lacey
Published: October 2014

While there are several theoretical accounts of interruptions and numerous empirical studies that have examined the impact of interruptions in laboratory settings, our understanding of interruptions in healthcare is in its infancy. Understanding and managing interruptions in healthcare can be particularly challenging because of the diversity of clinical environments and the importance of interruptions in delivering effective care in some settings. Our expert panel will review the theoretical and practical aspects of interruptions and facilitate a meaningful discussion on how to advance the study of interruptions in healthcare. The discussion will focus on patient safety implications of interruptions and methods to better manage interruptions in complex clinical environments.
Usability Testing of Medication Packaging in a Pharmacy Environment
Authors: Cluff Kevin , Mathieu Mary , Schreiber Anke , Schulz Denise , Weller Amanda , Zhou Ji
Published: October 2014

To better understand the pharmacy medication dispensing process and its relationship with packaging and labeling, two studies were conducted: one was a contextual inquiry involving the interview of 13 experienced pharmacists and pharmacy technicians; the other was a usability test of 30 pharmacists and pharmacy technicians specifically related to a particular product family in a simulated pharmacy environment. The interviews of the contextual inquiry provided the basic understanding of the prescription’s journey from doctor to patient in the US. The usability study also provided information about a prescription’s journey and the importance of safeguards that exist in a real pharmacy environment to prevent dispensing errors.
User Placement of a Visual Aid for Detecting Critical Signals in Fetal-Heart Rate Tracings
Authors: Ashdown Amanda J. , Scerbo Mark W. , Anderson-Montoya Brittany L. , Belfore Lee A. , Abuhamad Alfred Z. , Davis Stephen S.
Published: October 2014

The present study examined the ability of participants to detect critical signals embedded within dynamic fetal-heart rate (FHR) tracings using a visual aid. Participants inspected tracings for deviations in the FHR under different levels of heart rate variability. One group was given control over placement of the visual aid. A second yoke-control group monitored the same presentation of critical signals and aid placements but could not alter the visual aids. In phase 1, student participants placed the aid and in phase 2 the experimenter placed the aid. Performance was compared to a control group that had no aids. The results showed that no group detected all critical signals but those who placed the aid performed better than those who had no aid across all levels of heart rate variability. However, the benefit of the visual aid for the yoke-control participants was limited to the condition where the experimenter placed the aid. These results suggest that a visual aid can improve performance, but that it does not completely overcome the challenge detecting critical signals in FHR tracings.
Mechanical and Cardiopulmonary Responses To The Use of a Newly Designed Leg Simulator
Authors: Radwan Ahmed , Scalise-Smith Dale
Published: October 2014

Axillary crutches are convenient for use but they impose certain physical and cardiovascular demands that not everyone can tolerate. ED LegsimTM is a newly designed assistive device considered as a viable alternative for assisted ambulation. In this study, Twenty-seven normal participants walked using the ED leg simulator, axillary crutches and unassisted. Participants reported that the simulator had less cardiopulmonary impact, as indicated by heart rate response and perceived exertion, when the six-minute walk test was performed. Participants exhibited similar impact patterns and vertical ground reaction force values to that of normal walking as measured by force plates. Given these important findings, practitioners should examine the effectiveness of the ED LegsimTM for individuals with lower extremity impairments, restricted weight-bearing status, particularly those with a compromised cardiopulmonary system.
Comparison of Force Matching Performance in Conventional and Laparoscopic Force-Based Task
Authors: Raghu Prasad M.S. , Manivannan M.
Published: October 2014

Laparoscopic instruments have limited haptics feedback. Hence, novices tend to exert excessive force which leads to tissue trauma. In laparoscopic surgery, no external information is available on the magnitude of excessive force. Therefore, novices should be trained to accurately perceive their own force output. This study analyzed the force perception of 18 novices in the absence of external information, by comparing the isometric force matching performance of index finger (i.e. used in conventional procedures) in extended arm posture with that of laparoscopic instrument in a force-based probing task. The study also examined the effect of handedness on force perception. A contra-lateral force matching paradigm was employed to analyze the matching performance of the novice subjects. Interestingly, matching error was found to be lower for laparoscopic instrument. An effect of handedness was visible for laparoscopic instrument only. The dominant hand overestimated the forces of non-dominant hand. The results can be used as a performance metric to evaluate the force perception of novices in laparoscopic force skills-training tasks.
Supporting Procedural and Perceptual Learning in Laparoscopic Surgery
Authors: Lou Y. , Flinn J. T. , Ganapathy S. , Weyhrauch P. , Niehaus J. , Myers B. , Cao C. G. L.
Published: October 2014

Expertise in surgical performance requires mastery of both technical skills such as suturing, and nontechnical skills such as perceptual and procedural knowledge. “Refresher-training” after skill decay due to nonuse should consider the fact that non-technical skills often decay faster than technical skills. To support the re-learning of perceptual and procedural knowledge, this study examined the effectiveness of different design factors for digital training material. The factors considered included modality/fidelity of representation (illustration/cartoon vs. realistic/video images) and task difficulty (easy, medium, and difficult). Results suggest that low fidelity images are better for perceptual learning, and are equally effective as high fidelity images for procedural learning. The level of difficulty of the procedures did not affect performance in this study of novices, but may be an important factor with more experienced trainees. Time and error results indicate that refresher training in perceptual and procedural knowledge should begin with a procedural task to review surgical steps, followed by a perceptual task, to achieve greater efficiency and effectiveness.
Influence of altered visual feedback on neck movement for a virtual reality rehabilitative system
Authors: Chen Karen B. , Ponto Kevin , Sesto Mary E. , Radwin Robert G.
Published: October 2014

This paper investigates altering visual feedback during neck movement through control-display (C-D) gain for a head-mounted display, for the purpose of determining the just noticeable difference (JND) for encouraging individuals with kinesiophobia (i.e. fear avoidance of movement due to chronic pain) to effectively perform therapeutic neck exercises. The JND was defined as .25 probability of detecting a difference from unity C-D gain (gain=1). A target-aiming task with two consecutive neck moves per trial was presented; one neck move had varying C-D gain and the other had unity gain. The VR system was able to influence neck moves without changing locations of the target. Participants indicated whether the two neck movements were the same or different. Logistic regression revealed that the JND gains were 0.903 (lower bound) and 1.159 (upper bound) as the participants could not discriminate a 55° turn, ranging from 49.7° to 63.7°. This preliminary study shows that immersive VR with altered visual feedback influenced movement. The feasibility for rehabilitation of individuals with kinesiophobia will next be assessed.
Development and Usability Testing of Dr. Liver™
Authors: Yang Xiaopeng , Yu Hee Chul , Choi Younggeun , Lee Wonsup , Yang Jaedo , Hwang Hongpil , Kim Ji Hyun , Cho Baik Hwan , You Heecheon
Published: October 2014

The present study developed a user-centered 3D virtual liver surgery planning system called Dr. Liver™ to assist surgeons in preoperative planning of liver surgeries such as living donor liver transplantation and tumor resection. Use scenarios of Dr. Liver were developed through literature review, benchmarking, and interviews with surgeons. The major functions of Dr. Liver include (1) 3D reconstruction of the liver, vessels, and tumors from abdominal CT images, (2) virtual resection simulation for liver surgery planning, and (3) volumetric measurement of the liver, vessels, tumors, remnant, and/or graft. Novel image processing algorithms were developed and implemented into Dr. Liver for accurate and efficient liver surgery planning. Various user-friendly features such as a hierarchical interface were integrated into Dr. Liver for better usability. The usability of Dr. Liver was systematically evaluated with eight medical doctors from three different medical centers using various performance and preference measures. Dr. Liver received a high score of user satisfaction (6.1 ± 0.2) as measured using a 7-point Likert scale. Dr. Liver will be used in preoperative liver surgery planning for safe and rational liver surgery.
A Comprehensive Methodology for Examining the Impact of Surgical Team Briefings and Debriefings on Teamwork
Authors: Law Katherine E. , Hildebrand Emily , Oliveira-Gomes Joao , Hallbeck Susan , Blocker Renaldo C.
Published: October 2014

The adoptions of briefing and debriefing protocols have evolved from the Joint Commission’s initiative to improve communication and safety in the operating room. Briefing normally occurs prior to incision and is used to discuss and confirm critical information, while debriefing occurs during or after surgery. Debriefing provides a unique opportunity for individuals and teams to immediately reflect on their performance, allowing them to more easily identify errors and develop plans to improve their next performance. Studies have shown that using briefings and debriefings improve communication and teamwork. However, there is still much to learn about the value of both for surgical teams. This paper presents a robust methodology for examining and measuring the impacts of surgical team briefings and debriefings on teamwork. The methodology includes (1) audio/video recording the surgical care process, (2) prospective observations using a validated electronic data collection tool, (3) pre- and post-surgery surveys, and (4) individual surgical team member interviews. The current paper describes the methodology to obtain a robust and comprehensive data set for analyzing the impacts of briefing and debriefing on teamwork; the results of the surgeries recorded using this methodology will be presented in subsequent papers.
Challenges in the Electronic Consult Process for Diabetes Treatment
Authors: Harrell Stephen , Gallimore Jennie , Zoll Brian , Mowrey Corinne , Parikh Pratik , Benson Steed , Burke Brian
Published: October 2014

The United States Department of Veterans Affairs (VA) created an electronic consult to increase access to specialty care. This system has the potential to improve access, reduce the number of face-to-face appointments, reduce travel and decrease chronic disease expense. Evaluation of the process is occurring at the same time as implementation. The purpose of this research was to perform a systems and human factors engineering analysis of the e-consult system. Using a mixed method approach we decomposed the e-consult process by analyzing the e-consults and interviewed system users. The e-consult program supports diabetes treatment but the system requires improvement. We describe seven areas of focus for system improvement. The recommendations provided serve as a requirements framework for electronic health record system upgrades.
A Cognitive Architectural Account of Two-Channel Speech Processing
Authors: Kieras David E. , Wakefield Gregory H. , Thompson Eric , Iyer Nandini , Simpson Brian D.
Published: October 2014

An important application of cognitive architectures is to provide human performance models that capture psychological mechanisms in a form that can be “programmed” to predict task performance of human-machine system designs. While many aspects of human performance have been successfully modeled in this approach, accounting for multi-talker speech task performance is a novel problem. This paper presents a model for performance in a two-talker task that incorporates concepts from the psychoacoustic study of speech perception, in particular, masking effects and stream formation.
Modeling the Effect of Loudness and Semantics of Speech Warnings on Human Performances
Authors: Zhang Yiqi , Wu Changxu
Published: October 2014

The quantitative prediction and understanding of human performances in the responses to speech warnings is an essential component to improve warning effectiveness. Queuing network-model human processor (QN-MHP), as a computational architecture, enables researchers to model dual-task information processing. The current study enhanced QN-MHP by modelling the effect of loudness and semantics on human responses to speech warning messages. The model predictions of crash rate were validated with two empirical studies in collision warning systems with resultant R squares of 0.73 and 0.77, respectively. The developed mathematical model could be further utilized in optimizing the design of speech warnings to achieve most safety benefits.
An Approach to Model Checking the Perceptual Interactions of Medical Alarms
Authors: Hasanain Bassam , Boyd Andrew D. , Bolton Matthew L.
Published: October 2014

The perceptibiliy of auditory medical alarms is critical to patient health and safety. Unfortunately concurrently sounding alarms can interact in ways that can mask one or more of them: render them imperceptible. Masking may only occur in extremely speciﬁc and/or rare situations. Thus, experimentation is insufﬁcient for detecting it in all of the potential alarm conﬁgurations used in medicine. Therefore, there is a real need for computational methods capable of determining if masking exists in medical alarm conﬁgurations. In this work, we present such a method. Using a combination of formal modeling, psychoacoustic modeling, temporal logic speciﬁcation, and model checking, our method is able to prove whether a conﬁguration of alarms can interact in a way that produces masking. This paper motivates and presents this method, describes its implementation, demonstrates its power with an application, and outlines future developments.
Integrating Behavior Modeling with Data Mining to Improve Human Error Prediction in Numerical Data Entry
Authors: Lin Cheng-Jhe , Wu Changxu , Chaovalitwongsec Wanpracha Art
Published: October 2014

Human errors in numerical data entry can lead to serious consequence but it is difficult to predict those errors because mechanisms of human errors vary and no contextual clues are available. This study suggests integrating human behavior modeling and data mining as an advanced method to predict human errors. Human behavior modeling utilized top-down inference to transform interactions between task characteristics and conditions into general inclination of an average operator to make errors, while data mining parsed psychophysiological measurements into individual’s likeliness of making errors on a trial-by-trial basis through bottom-up analysis. Specifically, an enhanced Queuing Network-Model Human Processor (QN-MHP) generated modeling features to be combined with real-time EEG features that were collected in a realistic numerical typing experiment, and potential errors were predicted by detecting error-associated features by linear discriminant analysis (LDA) classifiers before responses. The detection could be made as early as 300 milliseconds beforehand, and the results showed that integration improved the LDA classifiers’ performance by 31.7% in keenness ( d') and by 12.5 % in area under ROC curve (AUC) from that of using EEG only. The integration may help implement future adaptive augmented system to prevent cognitive breakdown by determining appropriate automation/augmentation levels.
Effects of information access cost, confidence judgment and overconfidence bias on information retrieval strategy and task performance
Authors: Yang Jessie X. , Park Taezoon , Wickens Christopher D. , Helander Martin G.
Published: October 2014

Information access cost has been reported to be one determinant of one’s information retrieval strategy. However, the “expected gain” of an information retrieval strategy has not received much attention. The present study aimed to examine the effects of confidence judgment and overconfidence bias, besides the information access cost, on the choice of information retrieval strategy and task performance. The results showed that both information access cost and confidence judgment of memory accuracy affected information access attempts, and overconfidence bias harmed information retrieval performance.
Evidence for a fundamental property of steering
Authors: Benderius Ola , Markkula Gustav
Published: October 2014

In this paper, a general and fundamental property of steering is demonstrated: It is shown that steering corrections generally follow bell-shaped proﬁles of steering rate. The ﬁnding is strongly related to what is already known about reaching movements. Also, a strong linear relationship was found between the maximum steering wheel rate and the steering wheel deﬂection, something that indicates a constant movement time for the correction. Furthermore, by closer examination of those corrections that cannot be described by a single bell-shaped rate proﬁle, it was found that they typically can be described using two or, in some cases three or four, overlapping proﬁles, something which relates to superposition of motor primitives.
Statistical modelling of team training in a microworld study
Authors: Berggren Peter , Johansson Björn JE , Svensson Erland , Baroutsi Nicoletta , Dahlbäck Nils
Published: October 2014

A command and control environment is a dynamic and complex setting with complicated technical systems where teams of operators interact to reach shared goals. This study presents an experiment in which we, by means of Structural Equation Modeling (SEM), explain the relations between basic concepts of command and control environments: mental workload, frustration, situational awareness, and performance. This paper reports a LISREL analysis of the Baroutsi, Berggren, Nählinder, & Johansson (2013) data. From that data, a new latent variable “Frustration” emerges, which now can be included in the model.
Catastrophe Models for Cognitive Workload and Fatigue
Authors: Guastello Stephen J.
Published: October 2014

The cusp catastrophe models for cognitive workload and fatigue and their supporting research program evolved in response to numerous difficulties encountered in previous research. The two cusp models separate the two processes, which have the same temporal dynamic structure but different contributing variables, using an integrated experimental design that tests them both in the same situation. This presentation describes the structural models, experimental tasks, and principles of elasticity-rigidity, compensatory ability, minimum entropy, and the performance-variability paradox. Results from the series of six studies are summarized and discussed.
An ACT-R Process Model of the Signal Duration Phenomenon of Vigilance
Authors: Gartenberg Daniel , Veksler Bella Z. , Gunzelmann Glenn , Trafton J. Gregory
Published: October 2014

Performance on tasks that require sustained attention can be impacted by various factors that include: signal duration, the use of declarative memory in the task, the frequency of critical stimuli that require a response, and the event-rate of the stimuli. A viable model of the ability to maintain vigilance ought to account for these phenomena. In this paper, we focus on one of these critical factors: signal duration. For this we use results from Baker (1963), who manipulated signal duration in a clock task where the second hand moved in a continuous swipe motion. The critical stimuli were stoppages of the hand that lasted for 200, 300, 400, 600, or 800 ms. The results provided evidence for an interaction between condition and time-on-task, where performance declined at a faster rate as the signal duration decreased. In this paper, we describe an ACT-R model that uses fatigue mechanisms from Gunzelmann et al. (2009) that were proposed to account for the impact of sleep loss on sustained attention performance. The research demonstrates how those same mechanisms can be used to understand vigilance task performance. This illustrates an important foundation for predicting and tracking vigilance decrements in applied settings, and validates a mechanism that creates a theoretical link between the vigilance decrement and sleep loss.
Identification of Motion Sick Individuals
Authors: Matsangas Panagiotis , McCauley Michael E.
Published: October 2014

The identification of “motion sick” individuals is a challenge because of “misreported” motion sickness, i.e. symptoms developed from reasons unrelated to the nauseogenic stimulus. A behavioral method is proposed to address the confounding effect of the non-specificity associated with motion sickness and sopite syndrome symptoms. The proposed method is based on a within-subject approach with three classification groups; symptoms occurring in static conditions are used as normative to classify whether an individual is motion sick in motion conditions. Participants without any symptoms in both static and motion conditions are classified as “Asymptomatic.” If symptom severity in motion conditions is greater than the static, the participant is identified as motion sick (Symptomatic). If symptom severity in motion is less than or equal to the static condition, it is considered that the individual is reporting symptoms not attributable to motion sickness and is excluded from analysis. As part of a broader study, the proposed method was applied in a laboratory experiment and the corresponding results are compared against two alternative methods. The utility and problems of the proposed method are discussed.
Ergonomic Aspects of Clinical and Surgical Procedures
Authors: Armstrong T. , Cao C. , Hallbeck S. , Radwin R. , Rempel D.
Published: October 2014

This discussion panel aims to identify ergonomic concerns, solutions and research needs, physical stresses, and outcomes related to clinical and surgical procedures. This session will begin with formal presentations to demonstrate current ergonomic concerns and research initiatives associated with clinical and surgical procedures to frame the panel discussion for the second part of the session. Discussion of different procedures will help to identify solutions and research needs that relate to a broad range of ergonomic problems. Questions will be collected from the attendees and speakers and organized so as to guide the panel discussion and to engage all of the speakers in the discussion to achieve the symposium aims.
Research of a Kinect-Based Dhm to Capture and Simulate the Human Behavior
Authors: Zhang Xiaomin , Li Zhelin , Huang Yurun , Jiang Lijun
Published: October 2014

In order to conduct ergonomic assessments of product using real-time data of human behavior in the digital virtual systems, this study developed a real-time acquisition and simulation of human behavior system based on Kinect. This paper studied joint point matching, digital human data structure and motion data calculation. Combining with Open Inventor graphics engine, the research used human behavior data to conduct the dynamic simulation in DHM. The accuracy between the data processing method of Kinect and manual measurement also was analyzed. The results show that the method can achieve accurate real-time acquisition of human behavior. This method has been integrated into the human factors analysis software SAMMIE conducted case studies and achieved good result.
Combined Task and Physical Demands Analyses towards a Comprehensive Human Work Model
Authors: Farrell Philip S. E. , Tack David W. , Nakaza Edward T. , Bray-Miners Jordan , Farrell Cristopher M.
Published: October 2014

Task analyses and physical demands analyses are combined to identify common and extreme postures and postural sequences, durations, frequency, and forces for Griffon Helicopter aircrew tasks, mission phases, and whole missions. The result is a comprehensive model of tasks and associated physical demands from which one can estimate the accumulative neck loads and moments caused by Night Vision Googles usage. Combining task and physical demands analyses yields a methodology for building a model of human work where information processing and physical demands are equally important for finding effective solutions to work issues.
Human Factors Simulation Using Demographically Tuned Biomechanical Models
Authors: De Sapio Vincent , Earl Darren , Green Rush , Saul Katherine
Published: October 2014

We have developed a set of tools based on the OpenSim simulation framework that allows for input of anthropometry, muscle geometry, and measured strength capability to generate demographically tuned models from a core generic musculoskeletal model. The strength tuning capability exploits an algorithm that adaptively tunes muscle parameters in generic Hill-type muscle models to generate performance data consistent with ergonomic subject studies of specific demographic populations (e.g. elderly populations). Following the tuning of the generic model to generate a demographic-specific model, human performance in a variety of scenarios can then be analyzed. Currently, the model is in a prototype phase and has been applied to scenarios modeling elderly passengers interacting with airplane interior features including overhead bins and lavatories. The next phase of development will include manufacturing scenarios with input based on motion capture and worker demographics, including strength measurements.
A Prototype Toolkit for Sensing and Modeling Individual and Team State
Authors: Bracken Bethany K. , Palmon Noa , Romero Victoria , Pfautz Jonathan , Cooke Nancy J.
Published: October 2014

Teams of individuals working together toward a common goal must be skilled at multi-tasking to perform their own work while maintaining shared attention across the team. Experimenters who study team performance can use cutting edge methods to assess physiological, neurophysiological, and behavioral underpinnings of optimal performance; however, this requires an adequate understanding of how these signals correlate with individual and team performance. We designed a toolkit to support experimenters in evaluating individual and team performance in a laboratory setting, in testing and validating models of performance, and in developing and validating augmentation strategies to improve performance. Our toolkit provides a framework that flexibly integrates current and emerging sensors. The data fusion tool fuses time-synchronized sensor data to assess performance. The model-building and execution toolset enables experimenters to choose previously entered models, adapt these models according to the current experiment, or develop new models to test. The real-time assessment tool enables experimenters to monitor the state of individual subjects and the team as a whole (e.g., stress, workload, focused attention) throughout the experiment, and how these states relate to performance. This information is then used by the real-time augmentation tool, which suggests augmentations to optimize that performance. Together, these tools provide a proof-of-concept prototype of a flexible modeling tool that would allow sensor inputs to be used to model and predict both individual and team performance.
The Robustness of Affect Manipulations in Vigilance Paradigms
Authors: Phillips Rachel R. , Madhavan Poornima
Published: October 2014

Previous research has shown that vigilance tasks result in decreased affect ratings. However, studies have not examined the effectiveness of valence manipulations presented in discrete manipulation sessions over the course of a vigilance task, nor how repeated exposure to an affect manipulation would impact the perceptions or effectiveness of the manipulations. To that end, 109 participants from a large southeastern university completed three affect manipulations (of either positive, negative, or neutral valence) over the course of a 700 image visual search task and rated the manipulation stimuli and their own experiences in terms of valence and arousal. Results revealed no changes in the perceptions or effectiveness of the negative manipulations over time. However, those in the positive condition perceived their stimuli as less positive over time and were resistant to affect restoration at the end of the experiment. Results are discussed in relation to implications for experimental design when attempting to examine the effects of affect over a vigilance task.
The Effects of Individual Differences on Vigilance Training and Performance in a Dynamic Vigilance Task
Authors: Teo G. , Schmidt T. , Szalma J. , Hancock G. , Hancock P.
Published: October 2014

Efforts to mitigate the vigilance decrement include training with feedback in the form of knowledge of results (KR). However, the influences of individual differences on vigilance training and performance are not well understood. Based on previous studies on individual differences in vigilance, the present study investigates the impact of feedback, as well as six individual differences variables (i.e. Attentional Control, Boredom Proneness, Cognitive Failures, Extraversion, Conscientiousness, and Neuroticism) on several performance measures. Results indicated that, in general, individual differences did not affect performance or training effectiveness. Hence, KR training may be effective for most operators confronted with monitoring tasks.
Variability in Human Performance – the Roles of Context Specificity and Closed-Loop Control
Authors: Smith Thomas J.
Published: October 2014

Objective: This report briefly addresses sources of variability in five different domains of human performance: movement behavior, cognition and learning, performance under displaced feedback, human error performance, and social and team performance. Results: In every case: (1) context specificity makes a key contribution to variability observed with these domains; and (2) a control systems interpretation can be applied to account for the basis of these effects. Conclusion: This analytical approach can readily be extended to other performance domains, such as variability in complex sociotechnical systems. Application: Given that HF/E science is primarily concerned with performance-design interaction, it can be argued that an emphasis on the contribution of design (context) to performance variability has a scientific and practical significance for the field that far exceeds the possible influence of innate biological factors on such variability.
Individual Differences in Cognitive Strategy During Reactive Task-Set Switching
Authors: Martini Molly C. , Gonzalez Christian A. , Youmans Robert J.
Published: October 2014

Researchers who employ traditional laboratory task-set switching paradigms often assume that their participants are using only one strategy to complete switch moves. In the current study, we hypothesized that real world task-set switching behaviors are facilitated by multiple processing strategies, including fast “heuristic” strategies that are employed when switching is routine, and slower “reasoned” strategies that are used less often when heuristic strategies fail. In this study, 151 undergraduate students from George Mason University volunteered to complete the Youmans Cognitive Flexibility Assessment (YCFA), a computer-based, reactive task-set switching paradigm that takes the form of a simple puzzle game. Participants’ reaction time data suggests that they tried to utilize both heuristic and reasoned strategies to make task-set switches, and that they only used reasoned strategies when heuristic strategies failed. The data also revealed that participants quickly abandoned reasoned strategies when heuristic strategies once again become successful. We conclude by providing some guidance for system designers regarding the speed with which humans who are employing reasoned approaches to task-set switching will abandon them once heuristic approaches again become successful, and by discussing the implications of our findings for safe system design.
The Generalized Intelligent Framework for Tutoring (GIFT) as a Tool for Human Factors Professionals
Authors: Sinatra Anne M. , Goldberg Benjamin S. , Sottilare Robert A.
Published: October 2014

The Generalized Intelligent Framework for Tutoring (GIFT) is an open-source domain-independent intelligent tutoring system (ITS) framework. It provides the tools and capabilities to design a complete ITS, manage student instruction, and serve as a testbed for experimentation and analysis. GIFT was developed to provide a cost-effective and efficient means for developing ITSs that have interchangeable parts and can be reused. Additionally, GIFT provides the ability for human factors professionals to develop and run complete experiments in a computer-based environment. This demonstration will provide an introduction to GIFT, along with the motivation behind its design. Further, a demonstration of the tools that are useful to human factors practitioners and psychologists will be provided, and examples of courses that have been developed using GIFT will be shown.
Evaluation of a Peripherally-Located Instrument Landing Display with High-Order Control of a Non-Linear Approach and Landing
Authors: Spielman Zach A. , Evans Ryan T. , Holmberg Jordan D. , Dyre Brian P.
Published: October 2014

We compared the precision of simulated-fixed wing aircraft landing approaches with two different head-up display (HUD) formats: a) the MIL-STD-1787B Instrument Landing System and b) a virtual peripherally-located optical flow ILS HUD. Within each display condition we compared a three second quickened display to a real time non-quickened display. Non-pilot participants used simplified controls to guide a landing simulation under night conditions with extremely poor visibility using Instrument Flight Rules (IFR). Participants followed a non-linear flight and approach path under the two display and quickening conditions. While quickening was found to have no significant effect, the peripheral optical flow ILS afforded greater overall precision in flight path control. The findings suggest an increased ability to extract rate-of-change information from the peripheral optical flow ILS affording improved spatial orientation.
Relation between perceived effort and the electromyographic signal in localized low-effort activities
Authors: Korol Gadi , Karniel Amir , Melzer Itzik , Ronen Adi , Edan Yael , Stern Helman , Riemer Raziel
Published: October 2014

Hand-based human–machine interfaces are complex tasks that involve repetitive or sustained movements and postures of the hands that can lead to overuse syndromes of the musculoskeletal system. Consequently, it is important to minimize the physical effort that occurs at these interfaces. The evaluation of physical effort can be performed either by subjective evaluation of the relative perceived effort (e.g., Borg scale) or by objective physiological measurements (e.g., electromyography – EMG). However, the relation between these two measures has not been sufficiently studied for localized low-effort activities. This study investigated the relation between EMG and Borg ratings, as well as the issue of gender differences during low-effort activity of forearm muscles. Nine females and nine males performed eight different hand gestures (localized low-effort activity), during which EMG signals were recorded from six forearm muscles and Borg ratings were obtained. On average, the female subjects rated the gestures as less effortful than the male subjects, and also demonstrated a higher positive correlation between the EMG and Borg ratings. Furthermore, the linear model that was fitted for predicting the Borg ratings based on gender and the combined activity of muscles provided an R-squared value of approximately 0.3.
Muscle Response to Different Socket Wrench Configurations
Authors: Dix Patrick , Campbell-Kyureghyan Naira
Published: October 2014

Evaluation of manual hand tools play an important role in producing better designs that are targeted to fit the user, maximize comfort, and minimize the risk of injury. The goal of this study was to evaluate and quantify the muscle response due to a horizontal wrenching task while using four socket wrench configurations: two handle types and two handle lengths. Eleven participants in this study were instructed to loosen a bolt three times using each of the tool combinations in a random order. Activity from twelve muscles was recorded using wireless surface EMG sensors. Both the handle length and the grip type were observed to have a significant effect on the overall muscle activity. Between 5-32% reduction in muscle activity was seen in all muscles due to the longer handle, and the padded handle further reduced muscle effort by up to 13%. These findings indicate the importance of tool configuration selection in order to reduce the required force application, improve posture and reduce muscle effort required for the wrenching task.
The Effects of Posture on Force Estimations Using Surface Electromyography
Authors: Gall Jessica L. , O’Donnell Callie L. , Dembinski Kimberly A. , Kapellusch Jay M.
Published: October 2014

Surface electromyography (sEMG) has shown promise in estimating grip forces while people are performing tasks; however, equipment and analysis procedures remain complex for use by practitioners in industry. The objective of this study was to quantify error in grip force estimations associated with changes in hand/wrist posture using simple methods and off-the-shelf sEMG equipment. Eight healthy, college-aged females participated in the study. Six sEMG sensors were placed radially around the forearm. Subjects applied 15%, 45%, and 75% of maximum power grip strength in seven different postures (neutral, 15, 30, and 45 degrees extension, and 15, 30, and 45 degrees flexion). sEMG signals were calibrated using linear regression and used to predict grip force. Predicted grip force was statistically compared to applied grip force measured by a digital dynamometer. The results suggest that radial electrode placement can generate reasonably accurate static force estimations regardless of MVC and across most postures, but extreme posture estimations do not appear accurate without corrections.