bluuebunny/crossref_metadata_2025 huggingface dataset:
Why Healthcare is Not like Aviation: Control of Natural and Technical Systems
Authors: Drews Frank A. , Fawcett David
Published: January 2012

System control is a challenge in many everyday activities and professional contexts. Unfortunately, it is not clear how much of the cognitive demand of controlling a system depends on the specific type of the system under control. This question is especially important for comparisons between natural and technical systems. The current study examines tracking performance and cognitive demand when controlling different systems. Similar to Durso and Drews (2010) we distinguish between natural and technical systems. Control performance was evaluated using four different conditions that representing aspects of different system types. Control performance was worst when controlling a system that had features of a natural system, where control performance of a technical system was best. Overall, the results of this study indicate that the design of displays to support controllers in a wide range of domains needs to specifically incorporate features that are specific to a systems nature.
Exploring the Dynamics of Resilience
Authors: Wears Robert L
Published: January 2012

Resilience is a complex of behaviours seen in complex work systems, whereby they are able to largely meet their fundamental goals despite threats and challenges to their work and even their existence. It is not something a system has, but rather something a system does. Because resilient behaviour (or lack thereof) is manifested over time, the dynamics of resilience are of interest. Studies of resilience to date have been largely descriptive, but understanding of how resilient performance comes about, and especially how we might enhance it, or recognize that a system is losing it, has been difficult. This work uses system dynamics models to develop inductively a theory of activities resulting in resilient performance in complex systems, and to elaborate on previous representations of system resilience. Such models might be useful in two ways: explaining how resilient behaviours observed might come about; and exploring the temporal dynamics of changes in state (for example, suggesting leading rather than lagging indicators of performance).
The AlphaACT Decision Support System for Emergency Responders
Authors: Oskarsson An T. , Hodgin C. Reed
Published: January 2012

We first present cognitive psychological theories relevant to crisis decision making. Next we describe the AlphaACT™ (Alpha Advanced Crisis Technology) decision support system, a software application designed to support a range of military and civilian emergency responders. The essential components of the system are as follows: (a) a user interface that walks the decision maker through a multi-step decision process inspired by the recognition-primed decision model and case-based reasoning theory; (b) a pattern recognition engine that prompts the user for diagnostic information and retrieves similar cases; and (c) a community-wide shared knowledge base of cases that grows as the system is used. AlphaACT's objective is to train and enable responders in crisis situations to think like experienced decision makers, and to quickly build their store of available experiences. The first AlphaACT application under development will support key decisions made by first responders managing a hazardous materials emergency.
What makes Real-World Interruptions Disruptive? Evidence from an Office Setting
Authors: Cades David M. , Werner Nicole E. , Boehm-Davis Deborah A. , Arshad Zara
Published: January 2012

With the constant barrage of cell phone calls, emails, instant messages, calendar reminders, and more, interruptions have become a common and consistent occurrence in our daily lives. The majority of the literature on interruptions to date has been based on controlled laboratory experiments and it is not yet completely clear how these results will translate into naturalistic settings and/or if there are certain features of interruptions and resumption that are not observable in the controlled setting. The current study is an exploratory study of how interruptions manifest in the naturalistic environment. We found that when working on computer-based tasks in real-world environments, external interruptions are more disruptive than internal interruptions. However, no reliable difference was shown in resumption time when resuming from multiple interruptions as opposed to single interruptions, and when resuming a different task as opposed to resuming the same task that was interrupted.
Voluntary versus Forced Task Switching
Authors: Panepinto Marie P.
Published: January 2012

Research on task switching has focused on the relatively well known task switching cost, an increase in RT on a trial directly following a switch. Two main issues with previous studies raise concerns about their external validity (1) they typically use short and arbitrary tasks in comparison to real work situations and (2) the vast majority force participants to switch rather than allowing them to do so voluntarily. The current experiment utilized two longer lasting tasks (document proofreading and a Sudoku puzzle) to more closely resemble real world situations and four task switching groups. One group switched voluntarily, one was forced without warning, one was forced with a cue that a switch would be coming, and one served as a no switch control group. Performance, reaction time, and mental workload (NASA-TLX) were measured. Task switch groups did not differ on these dependent variables, and no task switching cost was observed. The failure to find a task switching cost lends support to the proposition that previous lab studies may not adequately resemble real world scenarios, and that micromanaging small tasks may not be comparable to switching between comparatively longer lasting tasks.
Assessing the Performance of Common Tasks on Handheld Mobile Computers
Authors: Tossell Chad C. , Kortum Philip T. , Shepard Clayton W. , Rahmati Ahmad , Zhong Lin
Published: January 2012

The goal of this study was to examine three interfaces for handheld mobile computing (HMC) on the iPhone and then assess against a standard personal computer (PC) interface. While designers originally envisioned similar performance between HMC and PC, our results indicate differences between these platforms. However, specialized mobile sites and applications (Apps) greatly enhanced HMC performance on the iPhone. In particular, mobile content that required larger amounts of data entry benefited much more from these sorts of interfaces than mobile content for data acquisition.
Scaling Usability in Terms of Requirements: A Method for Evaluating User Interfaces
Authors: Fracker Martin L.
Published: January 2012

Software usability should be scaled in terms of the probability that a user interface will meet established usability requirements. This paper describes a scaling procedure that first estimates the distribution of common usability metrics and then calculates the probability that a user interface will meet a specific requirement. A series of Monte Carlo simulations showed that even with a small sample of usability test participants, the scaling procedure remained unbiased and could accurately differentiate usable from unusable user interfaces.
Disability and Orientation-Specific Performance during a Reciprocal Tapping Task
Authors: Irwin C.B. , Duff S.N. , Skye J.L. , Wiegmann D.A. , Sesto M.E.
Published: January 2012

Reciprocal tapping tasks have frequently been used to quantify user performance and motor control system function. This experiment used a reciprocal tapping task to examine differences in performance for participants oriented both in front and to the side of a touch screen. Evaluating performance in different orientations for touch screen users is important because public spaces and workplaces may have barriers which preclude touch screens from always being operated from directly in front. Additionally, building design standards may require a wheelchair user in a public building to operate a touch screen from the side because there may not be enough clearance to orient their wheelchair in a manner which allows them to only operate the screen from the front. Participants with motor control impairments affecting the upper extremity and participants without upper extremity motor control impairments completed a study examining reciprocal tapping performance while using a touch screen. Both groups included wheelchair users. Results indicate the orientation of the user, with respect to the touch screen, influences the number of taps which can be completed in five seconds and the amount of force used to activate the buttons. Both variables are negatively affected when the touch screen is oriented to the side of the user. Additionally, users with motor control impairments affecting the upper extremity completed fewer taps and had longer dwell times on the buttons than participants with non-impaired upper extremities. This experiment helps us begin to understand the impact of user-interface position but more research, including more ecologically valid tasks for the user, is needed.
An Analysis of Game Controller and Touchscreen Devices for Input into a Complex High-Information Display
Authors: Ogren Lauren , Wong Jason H.
Published: January 2012

Recently, there has been rapid growth in different methods of providing input into a computer system. Increased familiarity with the unique button layouts of game controllers and direct manipulation touchscreen devices has afforded an opportunity to evaluate how these new input methods can increase efficiency of computer systems that involve the display of complex, densely-packed information. Here, alternative button layouts (through various game controllers) and touchscreen devices were used to navigate through a simulated workflow in a submarine contact management task. Task completion time and errors were recorded, and results show that only some of the alternative input devices sped up the time it takes to cycle through a commonly used workflow. Implications for integration of these devices with already-existing systems are discussed along with future research directions.
Teaching Healthy Computing Skills to High School Students via Participatory Ergonomics
Authors: Korkmaz Sahika Vatan , Sommerich Carolyn M.
Published: January 2012

When today's students graduate from college and start their first job, many have close to twenty years of computer use exposure and some of them also have discomfort associated with this exposure. This discomfort may be due, in part, to a lack of training, from schools or other sources, in healthy computing habits (such as taking breaks, reducing awkward postures and postural fixity, etc.). A long-term goal of this line of research is to improve the health of students. In this study students were introduced to the concept and principles of healthy computing. The specific aim of this study was to recruit a small group of students to learn, in a participatory fashion, about healthy computing and then to assist them to develop means for effectively conveying their knowledge to other students. The objective of this paper is to explain the methodology that was utilized in the study and to provide evidence of its effectiveness.
Restricted vs. Unrestricted Space for L-Turns: A Debate in Environmental Design
Authors: Nasarwanji Mahiyar , Joseph Caroline , Paquet Victor
Published: January 2012

Wheeled mobility device users face challenges in terms of access to the built environment and maneuverability within the built environment has received limited attention. As the wheeled mobility device user population has changed drastically in the recent years, there is a need to update accessibility standards and develop reliable methods for testing user performance in the built environment. This paper presents a comparison of restricted and unrestricted space requirements for angle turns (L-turns) with the aim of highlighting differences between space requirements in these situations and comparing the results to current accessibility standards. One hundred forty wheeled mobility device users completed L-turns to the best of their ability in a restricted space environment, and thirteen performed the same maneuver in an unrestricted space environment. Data indicates that although entrance dimensions of the turns are similar between the restricted space and unrestricted space groups, there is a significant difference between exit dimensions. This suggests that when unrestricted space is utilized, users may adopt different strategies and paths when executing their turns. Additionally, a comparison of the study results, both in the restricted and unrestricted conditions, to current accessibility standards indicates that a large proportion of individuals may not be able to successfully complete L-turns in compliant built environments. In the design of the built environment, researchers and designers should consider space requirements, ease of execution and time of execution simultaneously to create comfortable and accessible environments for normal and urgent circumstances.
The Effect of Image Orientation on a Dynamic Laparoscopic Task
Authors: Zhang Likun , Cao Caroline G.L.
Published: January 2012

During laparoscopic surgery, the surgeon's hand-eye coordination is often disrupted by the incongruent mapping between the orientation of the endoscopic view and the actual operative field. This can lead to higher mental load and deteriorated performance for the surgeon. This study investigated the effect of visual-motor misalignment on laparoscopic surgery performance. Twenty-four subjects participated in a dynamic point-and-touch task, with 8 image rotations under different optical axes and different endoscope locations in a simulated laparoscopic surgery environment. Performance was best when the endoscopic image was perfectly aligned with the actual task space (0° image rotation), but degraded progressively as a function of deviation from perfect alignment. Subjects' performance maintained a consistent pattern across 8 image rotations regardless of optical axis orientation and endoscope location. Therefore, it is recommended that any solution to restore the visuomotor congruency in laparoscopic surgery should first align the image with the task space.
Human Centric Environmentalism: Opportunities for the Human Factors Community to Contribute to Global Environmental Solutions
Authors: Phillips Elizabeth , Sellers Brittany , Fiore Stephen M.
Published: January 2012

Previous psychological research into human induced causes of environmental change has stemmed largely from a behavior modification approach and has shown only modest results. We suggest that the lack of long term success in this area may be due to the lack of attention toward the underlying design dimensions to these problems. In this paper, we attempt to illustrate that by using our understanding of design principles related to human behavior and performance, the human factors community has the unique potential to make significant strides in improving these underlying design dimensions. Along these lines, applicable research areas include cognitive decision making, product design, surface transportation, and environmental design. We argue that, by shaping technologies in a way that is both user friendly and environmentally benign, the science of human factors has the potential to grow in new areas of research – areas that are not only theoretically relevant but also of societal importance.
Distractions and Interruptions in the Intensive Care Unit: A Field Observation and a Simulator Experiment
Authors: Grundgeiger T. , Sanderson P.M. , Orihuela C. Beltran , Thompson A. , MacDougall H.G. , Nunnink L. , Venkatesh B.
Published: January 2012

Distractions and interruptions are frequently mentioned as sources of errors in healthcare research, and laboratory research has shown that they can disrupt cognition. However, the current evidence that distractions and interruptions cause patient harm is mixed. In two studies in an intensive care unit, we investigated whether and when distractions and interruptions might lead nurses to forget critical care tasks. Study 1 was an observational study using a mobile eye tracker. It investigated which properties of an interruption influence resumption times and how nurses manage distractions and interruptions. Study 2 was a controlled experiment in a full-scale patient simulator. It investigated whether reminders improve nurses' ability to remember routine tasks when multitasking and resume interrupted routine tasks. We discuss theoretical and practical implications of the studies.
Supporting Physicians' Practice-Based Learning and Improvement (PBLI) and Quality Improvement through Exploration of Population-Based Medical Data
Authors: Baumgart Leigh A. , Bass Ellen J. , Lyman Jason A. , Springs Sherry , Voss John , Hayden Gregory F. , Hellems Martha A. , Hoke Tracey R. , Schlag Katharine A. , Schorling John B.
Published: January 2012

Participating in self-assessment activities may stimulate improvement in practice behaviors. However, it is unclear how best to support the development of self-assessment skills, particularly in the health care domain. Exploration of population-based data is one method to enable health care providers to identify deficiencies in overall practice behavior that can motivate quality improvement initiatives. At the University of Virginia, we are developing a decision support tool to integrate and present population-based patient data to health care providers related to both clinical outcomes and non-clinical measures (e.g., demographic information). By enabling users to separate their direct impact on clinical outcomes from other factors out of their control, we may enhance the self-assessment process.
Patient Safety in the Operating Theatre
Authors: Manser Tanja , Flin Rhona
Published: January 2012

The aim of this symposium is to present and discuss recent research on the factors shaping safe and efficient performance in the operating theatre. Ten years ago, it was not generally accepted that a significant number of surgical patients were harmed not as a result of underlying illness or disease but as a result of their treatment. Detailed incident analyses and studies of behavior in the operating theatre revealed that factors such as decision making, situation awareness, coordination and leadership play a contributory role in the multifaceted nature of adverse events.

The papers included in this symposium address these issues applying a spectrum of theoretical and methodological approaches. The emergent findings of these studies have important implications for future research as well as training and organizational design. For design recommendations to be useful in clinical practice they require an in-depth understanding of the strengths and vulnerabilities pertaining to the clinical work environment. This is reflected by the fact that this symposium brings together teams of clinicians and human factors experts in discussing their most recent research.
Thinking Ahead of the Surgeon: Developing a Behavioural Rating System for Scrub Practitioners' Non-Technical Skills (SPLINTS)
Authors: Mitchell Lucy , Flin Rhona , Yule Steven , Mitchell Janet , Coutts Kathy , Youngson George
Published: January 2012

Efforts to reduce adverse event rates in healthcare have revealed the importance of identifying the essential non-technical (cognitive and social) skills for safe and effective performance and developing tools for rating and training those skills. The focus of studies to date has been surgeons, anaesthetists, or the whole team, with less attention paid to other professionals. The aim of the study was to develop a behavioural rating system for non-technical skills of the scrub practitioner (nurse/technician). This paper reports an interview study, as part of a task analysis, to identify the critical non-technical skills for this role, and the development of a prototype behavioural rating system. Experienced scrub practitioners (n = 25) and consultant surgeons (n = 9), from four Scottish teaching hospitals, were interviewed using a semi-structured design. Data that described generic non-technical skills were extracted from the interview transcripts and thereafter, psychologists and panels of perioperative practitioners (n = 4) used an iterative process to develop a skills taxonomy. Three categories of non-technical skills were identified as critical for safe and effective scrub practitioner performance. These were; situation awareness, communication and teamwork, task management. Three underlying skill elements for each of the three categories were labeled by the expert panels and they provided examples of good and poor behaviours for each of these skill elements, drawing on their domain knowledge. The reliability and psychometric properties of the prototype skills taxonomy and behaviour rating system are currently being tested using standardized, simulated scenarios.
Identification and Classification of Flow Disruptions in the Operating Room during Two Types of General Surgery Procedures
Authors: Duff Sacha N. , Windham T. Christopher , Wiegmann Douglas A. , Kring Jason , Schaus Jennifer D. , Malony Robert , Boquet Albert
Published: January 2012

The operating room is one of the most complex work environments in healthcare; it is estimated that at least 7% of adverse events due to medical error occur in the operating room. Flow disruptions are events that cause a “break” in the primary surgical task, or the loss of any team member's situational awareness. From the “systems” perspective, flow disruptions are often a symptom of a latent failure somewhere within the system. An empirical link between flow disruptions and surgical errors in the OR has been established; therefore, identifying and classifying the specific flow disruptions present during different types of procedures should facilitate the development of evidence-based interventions. The goal of this study was to identify and classify flow disruptions during laparoscopic cholecystectomy (camera-assisted gallbladder removal) and open inguinal and umbilical hernia repair procedures. Results of this study include revealed seven categories of disruption that emerged inductively from the data collected. These were: communication, coordination, external/extraneous source, training/supervisory, equipment/supplies, patient factors, and environment.
Anthropometric Assessment of the da Vinci Surgical Robot
Authors: Marshall Matthew , Lux Matthew , Joseph Jean
Published: January 2012

The purpose of this paper is to describe an ergonomic assessment of a da Vinci Surgical Robot. The use of surgical robots has significantly enhanced the surgeon's control and visualization during minimally invasive surgery. In turn, these technological advances have translated into significant benefits to the patients compared to traditional laparoscopic techniques. However, use of surgical robots requires that surgeons sit for extended periods at a surgical console from which they control the robotic arms and view the surgical procedure through a high resolution viewer. This can lead to sustained trunk and neck flexion, resulting in discomfort in those regions. The system was analyzed through observational assessment and anthropometric modeling. The results of the analysis indicate that the current adjustability of the da Vinci console is sufficient for a large majority of the population, but individuals shorter than 60“ or taller than 72” face challenges in using the system.
Design of a New Epinephrine Auto-Injector to Minimize Use Errors
Authors: Guerlain Stephanie , Edwards Evan T. , Edwards Eric S.
Published: January 2012

Currently marketed epinephrine auto-injectors, designed for single-use in an allergic emergency, are prone to unintentional use errors (e.g., holding the device upside down, causing injury to the administrator and, more importantly, no dose for the patient). A simulated use study showed that two alternative designs for a new epinephrine auto-injector, developed using human factors engineering, can reduce such hazards and were significantly preferred by subjects in all age groups tested. Further clinical testing is required before such a pharmaceutical device can be introduced into the market.
Supportive Living Resident Suite Evaluation: Using Simulation to Evaluate a Mock-up
Authors: Shultz Jonas , Chisholm Susan
Published: January 2012

To address the growing population of seniors, Alberta Health Services plans to provide 11,700 supportive living resident suites over the next decade. Before finalizing the design standards and guidelines for these facilities, a mock-up residential suite was constructed, outfitted with all necessary furnishings and equipment, and used to evaluate the proposed design. Evaluation of the physical space and accessibility for residents' and clinical tasks were accomplished using simulation, think aloud protocols and extensive debriefing sessions. Scenarios were created that focused on commonly-occurring tasks identified by frontline staff as being problematic for both residents and staff. These scenarios were then carried out by seniors and a variety of healthcare professionals to simulate expected room usage. Evaluation of the scenarios indicated that sufficient space was available in the design; however, areas prone to congestion were also identified. Recommendations to improve the design of the residential suite were made to improve accessibility (of cupboards, light switches and electrical outlets), storage (of power scooters/wheel chairs), and bathroom configuration (of emergency pull cord and grab bar locations).
The Joint Effect of Task Characteristics and Neuroticism on the Performance, Workload, and Stress of Signal Detection
Authors: Szalma James L. , Teo Grace W.L.
Published: January 2012

The present study tests an extension of the Maximal Adaptability Model of Stress (Hancock & Warm, 1989) that incorporated individual differences into the model (Szalma, 2008). The purpose was to investigate how the task characteristics of information rate (event rate) and information uncertainty (number of displays to be monitored) interact with participant personality (Neuroticism) to affect the performance, workload, and stress associated with a cognitive vigilance task. Results supported claim by Szalma (2008) that the maximal adaptability model should be modified to include person characteristics.
The role emotion and gender play in the choice of commuting by bicycle: A preliminary study from Christchurch, New Zealand
Authors: Woo Tak C. , Helton William S. , Russell Paul N.
Published: January 2012

In this study, 35 women and 18 men completed a detailed questionnaire in order to determine the possible role emotion and individual differences have on the decision to commute by bicycle. Measured affect regarding cycling did not significantly correlate with support for pro-cycling policies. There was, however, a significant interaction between affect regarding cycling and gender when predicting actual time spent using bicycles. Positive affect towards cycling was significantly related to riding time for men, r = .56, but not women, r = .03. This result is intriguing given that men expressed less support for pro-cycling policies, less support for the environmental-social benefits of cycling, but actually spent more time commuting by bicycle than women. Marketing bicycle commuting may need to be considered in light of these gender differences. For some users, a lofty pro-sustainability message may not be as persuasive as advertising the thrills associated with bike commuting.
Cognitive Abilities and the Measurement of World Wide Web Usability
Authors: Campbell Susan G. , Norman Kent L.
Published: January 2012

Usability of an interface is an emergent property of the system and the user; it does not exist independently of either one. For this reason, characteristics of the user which affect his or her performance on a task can affect the apparent usability of the interface in a usability study. We propose and investigate, using a Wikipedia information-seeking task, a model relating spatial abilities and performance measures for system usability. In the context of World Wide Web (WWW) site usability, we found that spatial visualization ability and system experience predicted system effectiveness measures, while spatial orientation ability, spatial visualization ability, and general computer experience predicted system efficiency measures. We suggest possible extensions and further tests of this model.
Computer Input Devices — Race and Gender: Is there a mismatch between anthropometry and input device design
Authors: Hwang Sean , Johnson Peter W.
Published: January 2012

Studies have shown an association between intensive computer use and the onset and development of upper extremity musculoskeletal disorders. However, the evidence for possible health effects related to computer input device design and operator anthropometry is limited. The aim of this study was to systematically examine relationships between the current sizing of computer input devices and key anthropometric differences, based on gender and race, in adult computer users. Computer input devices appear to be designed based on anthropometric clearance issues to accommodate the largest users (95th percentile Western males). Based on this current design, less than 6.1% of the worldwide population would “fit” the current pointing device and keyboard design standards. Finger mass is a critical component for determining device activation forces When comparing male and female hand anthropometry, finger mass accounted for the largest anthropometric difference with the 50th percentile females' hand only 73% the mass of the 50th percentile males‘. With respect to similarities, in virtually every aspect of seated workstation anthropometry (i.e. furniture requirements), the 50th percentile Western female very closely approximated the 50th percentile Asian male. The findings of this study indicate that gender and race base differences in workstation design are small relative to the differences in input device activation forces based on hand anthropometry. It appears that the current “one size fits all” paradigm used to design computer input devices may not be optimal. Smaller devices with lower activation forces could benefit a large percentage of the world population.
40 Years of “Human Engineering the Keyboard”
Authors: Kroemer Karl H. E.
Published: January 2012

“Human engineering the keyboard” was the topic of my 1970 technical report (AMRL-TR-69-141), re-printed 1972 in Human Factors 14(1), 51–63. Now, 40 years later, it is of some interest to revisit that topic.
The Impairment and Recovery of Dynamic Walking Stability during Virtual Environment Exposure in the Elderly
Authors: Zhang Xiaoyue , Lockhart Thurmon E.
Published: January 2012

The emerging technology of virtual reality (VR) used in motor rehabilitation might bring in challenges to elderly users' locomotion safety. The objective of this study was to investigate such effects of virtual environment (VE) exposure to the dynamic stability of lower extremities by using a head mounted display (HMD). Twelve healthy elderly were randomly assigned with real world or VR walking conditions. Maximum Lyapunov exponents (maxLE), which served as a general measurement of dynamic stability, were assessed for real world walking, VR walking in the initial phase and VR walking in the habituated phase. Significant degradation of stability at the initial phase and remarkable recovery of stability after VE habituation were found at five lower extremity landmarks out of six, suggesting potential problems for the elderly to accept VR based interventions and the importance of habituation to a new perturbation. Meanwhile, across all walking conditions, dynamic stability was found to be increased from ankles up to hip joints. And a novel method for computing maxLE appeared to be reasonable and feasible for analyzing treadmill walking trials which were relatively short.
Design and Development of a Torque Tool Testing Rig that Simulates Human Operator-Tool-Task Interactions
Authors: Ay Haluk , Luscher Anthony , Sommerich Carolyn
Published: January 2012

For some time now, automobile manufacturers, torque tool manufacturers, and biomechanics researchers have shared a common objective to reduce musculoskeletal injuries associated with DC torque tool use. To attain that goal, a better understanding of factors that contribute to these injuries has been pursued through human subjects laboratory testing, field research, and biomechanical modeling. A testing rig was recently developed that builds upon much of this prior research. The rig provides a means to simulate the effects experienced by an operator using a right angle torque tools, in part, by controlling the stiffness and mass properties of the rig. The rig also uses a database of human biomechanical properties and responses to interpret measured handle force and displacement. This rig will be used to objectively evaluate new tools and identify appropriate tool settings for specific task conditions, such as joint hardness and target torque.
Risk Assessment and Application of Engineering Controls to Reduce the Number of Occupational Related Musculoskeletal Disorders in a Large Pharmaceutical Production Facility
Authors: Yagjian Allen S.
Published: January 2012

The high number of discomfort and lost work time cases in one department of a large pharmaceutical production facility, created a unique opportunity for ergonomics study and intervention. The first step in the project identified the three highest risk tasks using safety incident data. Each task was analyzed for ergonomics risk factors. Interventions were developed and implemented for these tasks. Biomechanical and subjective data were collected before and after all interventions to assess the effectiveness of the interventions. Three-dimensional dynamic flexion of the lower back data were collected using a Lumbar Motion Monitor (LMM). Electrogoniometers were used to measure wrist flexion. We used a force gauge, scale, and a tape measure to assess moments, forces, and weight. Subjective data were collected by questionnaire. A quantitative comparison of the subjective and electronic data showed reduced risk factors for Work-Related Musculoskeletal Disorders (WMSDs) of the wrist and back for all three tasks. All the interventions were shown by empirical methods to reduce the risk factors for WMSDs. The interventions were permanently implemented.
Understanding the Physical Risk Factors Affecting Cervical Musculoskeletal Disorders
Authors: Nimbarte Ashish D. , Aghazadeh Fereydoun , Sun Yun
Published: January 2012

In spite of strong epidemiological evidence associating neck or cervical spine disorders with forceful arm exertions common at workplaces, effect of such exertions as causative of neck musculoskeletal disorders (MSD) is currently not well understood. In this study the effect of isometric lifting tasks at elbow, shoulder and overhead heights on the activities of two major neck muscles, sternocleidomastoid (anterior neck muscle) and upper trapezius (posterior neck muscle), was evaluated by using electromyography (EMG). Thirty healthy participants performed isometric lifting tasks exerting 25%, 50% and 75% of their respective maximum strengths at neutral and extended neck postures. Activities of sternocleidomastoid and upper trapezius increased with the increase in the lifting weights and heights. Extended neck posture caused a higher load on the neck musculature than the neutral posture. In conclusion, this study demonstrates a positive load-response relationship between forceful arm exertions and activation of the neck muscles.
Cognitive Load Assessment of a Vibrotactile Posture Feedback Chair
Authors: Zheng Ying (Jean) , Morrell John B.
Published: January 2012

In this paper, we evaluate the cognitive load of using a vibrotactile posture feedback chair while performing standard office tasks. Our specific application is seated posture guidance in the office environment. We have instrumented a standard office chair with sensors and vibrotactile actuators to detect and correct a user's seated posture in real-time. A pilot study with 20 subjects (age 25±3.2 years, weight 71.6±17.7kg) was conducted to determine the impact on performance in a typing task while responding to the vibrotactile feedback. We found that 55% of the subjects showed statistically significant decrease in typing performance ( p<0.05) during the phases with feedback compared to the phases without feedback. However, 70% of the subjects exhibited an improvement in typing speed from the first to last feedback phases. These findings suggest that although the feedback system temporarily induces greater cognitive load, the load decreases with increased familiarity with the feedback system.
Density Guides Visual Search: Sparse Groups are First even when Slower
Authors: Tarling Katherine A. , Brumby Duncan P.
Published: January 2012

How do people efficiently locate content in a display? We investigate the effect of text layout on how people decide which area of a display to search first. Using a visual search paradigm, participants were required to locate a known target within a two-column display, in which items were grouped into semantic clusters, and the physical distance between items varied. For ‘mixed’ trials, the distance between items in each column was varied. Results showed that participants preferred to search the sparser of the two columns first, even though they were faster at locating the target in the denser column. This finding suggests that participants were adopting an inefficient search strategy for locating the target item. Discussion focuses on the implications for models that assume people rationally adapt their search strategy to maximize the gain of task-relevant information over time.
A Comparison of Cerebral Hemovelocity and Blood Oxygen Saturation Levels during Vigilance Performance
Authors: Funke Matthew E. , Warm Joel S. , Matthews Gerald , Riley Michael , Finomore Victor , Funke Gregory J. , Knott Benjamin , Vidulich Michael A.
Published: January 2012

This study compared measures of cerebral blood flow velocity (CBFV) and blood oxygen saturation (rSO2), during the performance of a 40-min vigilance task. Observers monitored a simulated air-traffic control display for flight path deviations which occurred in a unidirectional or a multidirectional context. CBFV and rSO2 measures were secured from the medial cerebral arteries in the left and right cerebral hemispheres and from the corresponding frontal lobes, respectively. Performance efficiency was greater in the unidirectional than the multidirectional condition and declined over time in both conditions, more so in the multidirectional condition. This pattern of results was paralleled in different ways by the two hemodynamic measures. A result of this sort challenges the assumption of a close tie between cerebral blood flow and oxygen saturation (Siesjo, 1978) and supports recent findings (Mintun et al., 2001) that cerebral blood flow and oxygen levels are not tightly coupled in active brain states.
Ocular Activity as a Measure of Mental and Visual Workload
Authors: Jessee M. Sage
Published: January 2012

The mental workload construct is examined along with visual workload in order to discriminate the relationship between the converging constructs. Six ocular activity variables were measured in order to test convergent and discriminant properties with regards to visual and mental workload. Three pilot crews flew six flight scenarios in which subjective and physiological mental workload measures were analyzed across task difficulty and task differences (pilot on-controls versus pilot off-controls). Results indicate less subjective mental workload for the hover task compared to the action on contact task and greater ocular fixation duration variability for the lower difficulty task. Blink interval was greater for the pilot on-controls and saccadic extent was greater for the pilot off-controls. Data suggest that blink interval and saccadic extent are diagnostic of different aspects of visual workload, whereas fixation duration variability is sensitive to mental workload.
Human Habitation in a Lunar Electric Rover during a 14-Day Field Trial
Authors: Litaker Harry , Thompson Shelby , Howard Robert
Published: January 2012

Various military and commercial entities, as well as the National Aeronautics and Space Administration (NASA), have conducted space-cabin confinement studies. However, after an extensive literature search, only one study was found using a simulated lunar rover (LUNEX II), under laboratory conditions, with a crew of two for an 18-day lunar mission. Forty-three years later, NASA human-factors engineers conducted a similar study using the Lunar Electric Rover (LER) in a dynamic real-world lunar simulation at the Black Point Lava Flow in Arizona. The objective of the study was to obtain human-in-the-loop performance data on the vehicle's interior volume with respect to human-system interfaces, crew accommodations, and habitation over a 14-day mission. Though part of a larger study including 212 overall operational elements, this paper will discuss only the performance of fifty different daily habitational elements within the confines of the vehicle carried out by two male subjects. Objective timing data and subjective questionnaire data were collected. Results indicate, much like the LUNEX II study, the LER field study suggest that a crew of two was able to maintain a satisfactory performance of tasks throughout the 14-day field trail within a relative small vehicle volume.
The Importance of Ground Truth: An Open-Source Biometric Repository
Authors: Tear Morgan J. , Thompson Matthew B. , Tangen Jason M.
Published: January 2012

Advances in forensic technologies and procedures seek to produce better and more efficient policing for safer societies. Little is understood, however, about how effectively the human forensic professional employs such technologies, or the cognitive and perceptual processes of judgment and decision making the forensic professional engages in during the course of evidence evaluation. For this, experimenters need materials that approximate the realism of crime scene evidence, while ensuring the ground truth about the source of this information. These two goals are often incompatible. We discuss the development of an open-source biometric repository to address the issue of ground truth. This repository contains a range of crime related materials such as fingerprints and palm-prints, shoe-prints, faces, handwriting, voices, and irises. Our goal is to provide a large, open-source repository of forensic information, where certainty of the source in built into the system, to help advance research on identification by humans and technology.
Poultry Growers' Control Strategies and their Evolution
Authors: Ferrara Patricia R. , Lee John D.
Published: January 2012

This paper presents a model for understanding the evolution of worker strategies in rural northern Mozambique, an industrially developing agricultural region. We reviewed administrative data on grower productivity from an integrated poultry operation, visited three grower chicken houses, and followed-up with informal discussions with the integrator, examining tasks and strategies related to productivity. Defining strategy as a mode of behavior that demands a resource profile and generates a performance profile that depends on the environment, we discuss examples of strategies and their adaptation over three time horizons. These time horizons are exemplified in the poultry growing domain as the critical brooding period following birth, the weekly routine within a growing cycle, and the span of months comprised of several growing cycles. Responding to observed flock characteristics, growers used behavioral indicators of health to adjust temperature; used heuristics to adjust feed based on measured weight; and constructed items to reduce exposure of the flock to disease. Growers adapted strategies according to the work context. Heat control strategies, for example, varied seasonally. Viewing strategy change in the context of a self-regulation model in which growers actively control their work environment reveals interactions over time horizons, which range from minutes to months, and link micro and macro-cognition. The self-regulation model also suggests that strategy change creates experiences that enrich the grower's conceptual models and improve skills, which in turn enable new strategies. Investigating growers' control strategies can reveal interactions between micro and macro-cognition that influence strategy development and change.
A Cognition-Based Control System for Autonomous Robots
Authors: Stacy Webb , Cohn Joseph V. , Geyer Alexandra , Wheeler Tracey
Published: January 2012

Most approaches to controlling autonomous systems require extensive pre-mission preparation, intensive effort by the human operator, or have strong limitations on the range of possible missions that can be accomplished. In this paper we describe an approach called Cognitive Patterns that promises to alleviate these challenges by replicating three key processes of human cognition—pattern generation, perception/action, and adaptation—and instantiating them in a new architecture which can then be embedded into an autonomous system. An early version of this approach connected high-level knowledge representations in an ontology with a robot's sensing and acting abilities. The advantages of this approach were then demonstrated in a simulation environment. A more refined version, based on lessons learned and called Cognitive Patterns Knowledge Generation, can deal with anomalies, unexpected events, and uncertainties, and is also described in terms of its components, their interactions, and benefits.
Stereoscopic Displays for Robot Teleoperation and Simulated Driving
Authors: Chen Jessie Y. C. , Oden Razia N. V. , Kenny Caitlin , Merritt John O.
Published: January 2012

A three-part experiment was conducted to investigate the usefulness of two types of 3D stereoscopic displays (SDs) for simulated indirect-vision driving (with various terrains) and live robot teleoperation. Results showed that, overall, participants completed their tasks significantly faster when they used an SD in 3D mode compared to the baseline 2D/monoscopic mode. They also navigated more accurately with SDs in 3D mode. The results also showed that the system with active 3D shutter glasses appeared to be more effective in supporting faster responses and task completion times than the system using passive polarized 3D glasses. Participants' self-assessed “simulator sickness” and workload after interacting with the two SD systems did not differ significantly between displays or between the 3D vs. 2D modes of operation.
The Influence of Perceived Task Difficulty and Importance on Automation Use
Authors: Schwark Jeremy , Dolgov Igor , Graves William , Hor Daniel
Published: January 2012

Automation use can be analyzed by looking at compliance rates (agreeing with automated alerts) and reliance rates (agreeing with automated nonalerts). The authors investigated how compliance and reliance rates in a target detection task depend on the perceived difficulty and importance of the trials and on the feedback given after each trial. Results show that focusing on trial importance significantly increased participants' compliance rates while reliance rates remained stable. When no feedback was presented, participants were more likely to comply with the automated aid in trials they perceived as difficult, but this trend reversed when importance was introduced and correlated with difficulty.