Application of Ergonomic Principles in Computer Workstations to Alleviate Health Risks from Extended Computer Use

A Thesis Presented to the Faculty of the College of Science and Technology Morehead State University in Partial Fulfillment of the Requirements for the Degree Master of Science by John M. Awbrey on April 27, 201

An Assessment of Unmanned Aircraft System Pilot Discomfort and Fatigue

The rapid growth of unmanned aircraft system (UAS) use in both the military and civil sectors has uncovered an array of challenges within the field. In terms of human factors and ergonomics, the influence of the unique physical design of the control stations used to pilot the unmanned aircraft on local muscular fatigue and discomfort are of great concern. This study was conducted to assess the influence of two display configurations, Side-by-Side (SS) and Stacked (ST), and two chairs, Ergonomic (EC) and Captain’s (CC), on mean and median power frequencies, root mean square amplitude, posture, discomfort, workload, and seat pressure. Sixteen participants [age: 24.75 ± 2.96 years; gender: 4 female/ 12 male; height: 177.56 ± 9.09 cm; weight: 81.37 ± 16.43 kg] completed four, 2-hour simulated UAS flights for all chair/display combinations. Eight participants piloted one, 6-hour simulated UAS flight in the display/chair combination which best minimized discomfort and fatigue in the two-hour flights, EC/SS. During the two-hour flights, muscle activity, discomfort, posture, workload, and seat pressure findings indicated increased muscular fatigue and discomfort over time. Generally, the EC/SS condition appeared to best mitigate muscular fatigue and postures associated with increased risk for the development of musculoskeletal disorders. Six-hour flight data failed to provide additional insights on the influence of extended duration flights on the dependent variables of this study. Finally, linear regression analysis revealed muscle activity can likely be predicted during UAS piloting tasks using the dependent variables in this study; however, the study failed to provide evidence that models built from two-hour data can accurately predict muscle activity out to six hours

Complexity Reduction in Image-Based Breast Cancer Care

The diversity of malignancies of the breast requires personalized diagnostic and therapeutic decision making in a complex situation. This thesis contributes in three clinical areas: (1) For clinical diagnostic image evaluation, computer-aided detection and diagnosis of mass and non-mass lesions in breast MRI is developed. 4D texture features characterize mass lesions. For non-mass lesions, a combined detection/characterisation method utilizes the bilateral symmetry of the breast s contrast agent uptake. (2) To improve clinical workflows, a breast MRI reading paradigm is proposed, exemplified by a breast MRI reading workstation prototype. Instead of mouse and keyboard, it is operated using multi-touch gestures. The concept is extended to mammography screening, introducing efficient navigation aids. (3) Contributions to finite element modeling of breast tissue deformations tackle two clinical problems: surgery planning and the prediction of the breast deformation in a MRI biopsy device

Sub-clinical Neck Symptoms, Disability, Posture, and Muscle Function in Computer Users, and the Effect of Education versus Education and Deep Cervical Flexor Exercise

Purpose: 1, to determine effect of education and exercise on neck pain, disability, cervical posture and muscle function in office workers with sub-clinical neck symptoms; 2, to determine differences in forward head posture in preferred and standardized posture, and 3, to explore the influence of time on work posture in a sub-group of office workers. Subjects: Sixty-six office workers with sub-clinical neck symptoms who utilize computers at least 4 hours per day participated. A sub-group of 27 were videotaped to assess posture over a workday. Methods: Videotaping was performed 15 minutes of the first and last hour of the workday for analysis of the craniovertebral angle. Cervical posture using the CROM was measured on all subjects in standardized and preferred positioning of the trunk and lower extremities. Subjects were randomly assigned to one of three groups: education only (EOG), education and exercise (EEG), or control (CG). Pre and post-test measurements of pain (Visual Analog Scale), disability (NeckDisability Index), forward head posture (FHP), and deep cervical flexor muscle function (Craniocervical Flexion Test and Short Neck Flexor Endurance Test) were assessed for change within group as well as differences between groups over the 8 week period. Results: No difference was found for FHP over 8 hours in the subgroup. FHP was greater in preferred position compared to standardized by 7.59 mm (95% CI 6.27-8.92, p\u3c.001). Median and mean scores improved for all 3 groups on pain and disability with greater improvement in intervention groups. FHP was unchanged/slightly worse in the CG and EOG, and improved in the EEG. Muscle function improved for the EEG. Statistical significance was not found for change scores between groups. Posttest scores were statistically significant for the NDI between EEG (20.45) and the CG (34.47), p=.042, and between the EEG and the EOG (34.59), p=.023 using Kruskall Wallis with adjusted significance for pairwise comparisons. Discussion/Conclusions: Posture over the workday did not change, differences were found based on preferred and standardized positions. Exercise and education intervention for those with sub-clinical neck symptoms show promise but did not demonstrate significance improvement over controls in this study

Health maintenance facility system effectiveness testing

The Medical Simulations Working Group conducted a series of medical simulations to evaluate the proposed Health Maintenance Facility (HMF) Preliminary Design Review (PDR) configuration. The goal of these simulations was to test the system effectiveness of the HMF PDR configurations. The objectives of the medical simulations are to (1) ensure fulfillment of requirements with this HMF design, (2) demonstrate the conformance of the system to human engineering design criteria, and (3) determine whether undesirable design or procedural features were introduced into the design. The simulations consisted of performing 6 different medical scenarios with the HMF mockup in the KRUG laboratory. The scenarios included representative medical procedures and used a broad spectrum of HMF equipment and supplies. Scripts were written and simulations performed by medical simulations working group members under observation from others. Data were collected by means of questionnaires, debriefings, and videotapes. Results were extracted and listed in the individual reports. Specific issues and recommendations from each simulation were compiled into the individual reports. General issues regarding the PDR design of the HMF are outlined in the summary report

Human Factors Considerations in System Design

Human factors considerations in systems design was examined. Human factors in automated command and control, in the efficiency of the human computer interface and system effectiveness are outlined. The following topics are discussed: human factors aspects of control room design; design of interactive systems; human computer dialogue, interaction tasks and techniques; guidelines on ergonomic aspects of control rooms and highly automated environments; system engineering for control by humans; conceptual models of information processing; information display and interaction in real time environments

Proceedings of the 1993 Conference on Intelligent Computer-Aided Training and Virtual Environment Technology

The volume 2 proceedings from the 1993 Conference on Intelligent Computer-Aided Training and Virtual Environment Technology are presented. Topics discussed include intelligent computer assisted training (ICAT) systems architectures, ICAT educational and medical applications, virtual environment (VE) training and assessment, human factors engineering and VE, ICAT theory and natural language processing, ICAT military applications, VE engineering applications, ICAT knowledge acquisition processes and applications, and ICAT aerospace applications

Nociplastic pain in office workers with chronic neck pain

Chronic neck pain is highly prevalent in office workers. For a better treatment management plan is fundamental to classified the pain mechanism. The main aim of this thesis was to assess central sensitization in office workers with chronic neck pain comparing different pain conditions and different pain intensities. Thus, the thesis is presented in five articles format. The first study, a systematic review and meta-analysis found that all the pressure pain threshold measurements were lower in office workers with chronic neck pain compared with healthy workers. These assumptions were based on a small sample of existing studies. Importantly, this study proposed hypersensitivity reference values for localized and extra-segmental assessment of pressure pain thresholds in chronic neck pain. The second article, a structured web-based questionnaire, demonstrated a high prevalence of neck pain and a considerable number of body segments with pain in Portuguese office workers. The third study assessed pressure pain threshold, temporal summation of pain, and conditioned pain modulation, in different pain conditions and pain intensities. Office workers with moderate pain intensity demonstrated signs of sensitization demonstrated by widespread pressure hyperalgesia and enhanced temporal summation of pain. The fourth study added the assessment of maximal voluntary contraction in upper and lower trapezius, which was lower in those workers. The last study further demonstrated signs of sensitization in a higher number of office workers with chronic neck pain which had at least one quantitative sensory testing finding, being associated with pain intensity and pain rumination. It concludes that office workers with chronic neck pain self reporting a moderate pain intensity, demonstrated signals of nociplastic pain. The assessment of the pain mechanism was possible with reference values and cut-off points in the quantitative sensory testing. Moreover, the presence of nociplastic pain was associated with pain intensity, pain rumination, and lower muscle strengthDor crónica na cervical é altamente prevalente em trabalhadores de escritório. Para uma melhor estratégia de tratamento é fundamental classificar-se o mecanismo de dor. O objetivo principal desta tese é avaliar a sensitização central em trabalhadores de escritório com dor crónica cervical, comparando diferentes condições de dor com diferentes intensidades de dor. Esta tese é constituída por cinco estudos. O primeiro estudo, uma revisão sistemática e meta-análise, verificou que o limiar de dor à pressão estava diminuído em trabalhadores de escritório com dor crónica cervical, comparando com trabalhadores saudáveis. Estas suposições foram baseadas em estudos com pequenas amostras. Importante foi propor valores hipersentitivos de referência para pontos locais e extra-segmentares, na avaliação do limiar de dor à pressão em dor crónica cervical. O segundo estudo, um questionário online, demonstrou uma prevalência elevada de dor cervical e um número elevado de áreas com dor em trabalhadores de escritório portugueses. O terceiro estudo, avaliou o limiar de dor à pressão, somação temporal e modulação condicionada de dor, em diferenças condições e intensidades. Trabalhadores com dor moderada demonstraram sinais de sensitização, devidos a uma hiperalgesia por pressão generalizada e uma somação temporal aumentada. O quarto estudo avaliou a contração voluntária máxima do trapézio superior e inferior, que nestes trabalhadores estava reduzida. No último estudo foi demonstrada a existência de sinais de sensitização num número elevado de trabalhadores com dor crónica cervical, que tiveram um teste quantitativo sensorial positivo, com associações entre intensidade e ruminação da dor. Concluiu-se que trabalhadores de escritório com dor cervical, que auto-reportam dor moderada, demonstram sinais de dor nociplástica. A avaliação do mecanismo de dor foi possível através de testes quantitativos sensoriais, usando-se valores de referência e pontos de corte. Além disso, a presença de dor nociplástica foi associada com intensidade da dor, ruminação e redução da força muscular

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 257

This bibliography lists 331 reports, articles and other documents introduced into the NASA scientific and technical information system in March 1984

The Effect of Office Chair Backrest Design on the Body\u27s Metabolic Response to Office Work

Most office chairs have a backrest that is wider at the shoulders than at the hips. Recently, a new office chair was developed that has a backrest that is narrower at the shoulders and wider at the hips (upwardly tapered backrest). The upwardly tapered backrest should allow users to increase their ventilatory efficiency, compared to a conventional, wide backrest. This new backrest design will hypothetically allow a user to retract their scapulae, increase expansion of the chest cavity, thus allowing the lungs more space to expand. Specific measures of improved ventilatory efficiency are an increase in tidal volume (Vt - liters/breath) and a decrease in respiratory rate (RR - breaths/min). Ventilatory and cardiovascular metabolic variables were measured from 31 office workers sitting in 2 chairs (conventional and upwardly tapered). The Cortex Metamax 3B system (Leipzig, Germany) was used to measure VO2 , RR, Vt and heart rate (HR - beats per min). Each participant performed 8 tasks in each chair. The tasks included typing, searching the internet, creating a spreadsheet, and watching a movie. Physiologic data were collected throughout testing. The subjects were blinded to which chair the test chair was. Results indicated no significant differences in users\u27 RR and Vt between the two chairs, but the users did have a significantly lower HR when they sat in the chair with the upwardly tapered backrest (3 to 7 bpm less). Heart rate has been shown to be a risk factor of heart disease, and thus the test chair could reduce the impact of a risk factor of heart disease in office workers. Analysis of subjective assessment data did not show any overall preference for either chair