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  • 1.
    Almén, Lena
    et al.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Larsson, Tore J
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Possibilities for designers to reduce the risk of work injury in the production phase of a building project2010In: On the Road to Vision Zero?: Construction, 2010Conference paper (Refereed)
    Abstract [en]

    (71) Possibilities for designers to reduce the risk of work injury in the production phase of a building project. Lena Almén, Tore J Larsson, (School of Technology and Health, Royal Institute of Technology (KTH), Sweden) Work related injuries and diseases are more frequent among construction workers than the labour market in average. Thus, there is a need of more preventive work during the design and planning phase. Two building projects, both productions of new apartment buildings with a design and construct contractor, were studied. Unsafe conditions were identified by workers and managers at the construction sites. The unsafe conditions were presented to the designers and planners. They were asked to describe the correlated decisions during the design and planning phase; when they were taken, why and by whom.

    Influence from outside the company was related to the clients, the town planning department, laws, a trade association and to the design of building products. The managers at the construction sites did not get any information, from the designers and planners, of what occupational risks there were in any of the projects. The routines for how to identify and handle hazards in the designing and planning phase were not sufficient. Furthermore, the designers explained, that they did not have enough competence in construction methods to be able to foresee occupational consequences at the construction sites when they designed rare constructions. The designers and planners did not follow up occupational risks at any of the construction sites. In order to get a safer working environment at construction sites, the top managers in the building companies need to define the acceptable safety level and put the safety issue on the agenda for all employees in the company, along with quality, costs and time schedule. Safety need to be communicated with those outside the company who have an influence on the working environment, and included in contracts with consultants, subcontractors and suppliers.

  • 2.
    Asplund, Maria
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Nyberg, Tobias
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Inganäs, Olle
    Electroactive polymers for neural interfaces2010In: Polymer chemistry, ISSN 1759-9954, Vol. 1, no 9, 1374-1391 p.Article, review/survey (Refereed)
    Abstract [en]

    Development of electroactive conjugated polymers, for the purpose of recording and eliciting signals in the neural systems in humans, can be used to fashion the interfaces between the two signalling systems of electronics and neural systems. The design of desirable chemical, mechanical and electrical properties in the electroactive polymer electrodes, and the means of integration of these into biological systems, are here reviewed.

  • 3.
    Ayas, Ebru
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Jörgen, Eklund
    KTH, School of Technology and Health (STH), Ergonomics.
    Identifying trigger feeling factors2010In: International Conference on Kansei Engineeringand Emotional Research (KEER), Paris, France, 2010Conference paper (Refereed)
    Abstract [en]

    Trigger mechanism design in power hand tools is of great importance for communicating with the operator and for providing feedback on operational functioning. Therefore, for a successful power hand tool design, knowledge about how the trigger mechanism feels is required.

    This study aims to define and investigate the design factors related with trigger tactile feeling for electrical right angled nutrunners. A Kansei Engineering (Affective Engineering) study has been conducted for a comparison between users´ (operators that work at an automotive assembly plant) and product developers´ (product development group of a power hand tool manufacturer) to find common and differing semantic expression dimensions for that. 124 Kansei words (descriptors) were collected from literature, interviews and workshops. These words were reduced to 52 by affinity analysis and evaluated by operators and product developers using semantic differential technique.

    From the operator group`s responses six factors (explain 87% of variation ) were extracted as, “professional performance”, “safety and tactile feeling”, “usability”, “smooth operation”, ”communication and durability”, “convenient and comfortable” to define trigger feeling. Correspondingly, five factors (explain 89% of variation) “robust and appealing”, “ergonomics and operator performance”, “controllability and predictability”, “creativity and modern” and“powerful” were distinguished for the product development group. Results showed that the start phase and especially quick start of trigger mechanism is more important to operators, while end feedback is more important to product developers. Soft start of the trigger is correlated with ergonomics, optimal, clear operation and performance for product developers while soft start together with end feedback are associated with well-built, convenient and safe trigger characteristics for operators. According to the results from average ratings the Kansei word “ergonomic” has been rated as the most important descriptor for trigger feeling together with “user-friendly”, “easy to use”, “long life time” and “comfortable” for both groups. By developing a questionnaire using the factors and variables identified; this questionnaire can be used to assess views of operators about trigger functioning and to know how do operators feel about new types of trigger mechanisms.

  • 4. Azar, J.C.
    et al.
    Hamid Muhammed, Hamed
    KTH, School of Technology and Health (STH), Medical Engineering.
    Automated Tracking of the Carotid Artery in Ultrasound Image Sequences Using a Self Organizing Neural Network2010In: Proceedings of 20th International Conference on Pattern Recognition (ICPR 2010), Istanbul, Turkey, Istanbul, Turkey, 2010, 2548-2551 p.Conference paper (Refereed)
    Abstract [en]

    An automated method for the segmentation and tracking of moving vessel walls in 2D ultrasound image sequences is introduced. The method was tested on simulated and real ultrasound image sequences of the carotid artery. Tracking was achieved via a self organizing neural network known as Growing Neural Gas. This topology-preserving algorithm assigns a net of nodes connected by edges that distributes itself within the vessel walls and adapts to changes in topology with time. The movement of the nodes was analyzed to uncover the dynamics of the vessel wall. By this way, radial and longitudinal strain and strain rates have been estimated. Finally, wave intensity signals were computed from these measurements. The method proposed improves upon wave intensity wall analysis, WIWA, and opens up a possibility for easy and efficient analysis and diagnosis of vascular disease through noninvasive ultrasonic examination.

  • 5.
    Bjällmark, Anna
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Nowak, Jacek
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Hayashi, Shirley
    Mazza do Nascimento, Marcelo
    Riella, Miquel
    Seeberger, Astrid
    Effects of hemodialysis on the cardiovascular system: Quantitative analysis using wave intensity wall analysis and tissue velocity imaging2010In: Heart and Vessels, ISSN 0910-8327, E-ISSN 1615-2573Article in journal (Refereed)
    Abstract [en]

    Cardiovascular disease is the leading cause of death in patients with end stage renal disease (ESRD). The aim of this study was to investigate the changes in cardiovascular function induced by a single session of hemodialysis (HD) by the analysis of cardiovascular dynamics using wave intensity wall analysis (WIWA) and of systolic and diastolic myocardial function using tissue velocity imaging (TVI). Grey-scale cine loops of the left common carotid artery, conventional echocardiography and TVI images of the left ventricle were acquired before and after HD in 45 patients (17 women, mean age 54) with ESRD. The WIWA indexes, W1 preload-adjusted W1, W2 and preload-adjusted W2, and the TVI variables, isovolumic contraction velocity (IVCV), isovolumic contraction time (IVCT), peak systolic velocity (PSV), displacement, isovolumic relaxation velocity (IVRV), isovolumic relaxation time (IVRT), peak early diastolic velocity (E’) and peak late diastolic velocity (A’), were compared before and after HD. The WIWA measurements showed significant increases in W1 (p < 0.05) and preload-adjusted W1 (p < 0.01) after HD. W2 was significantly decreased (p < 0.05) after HD, whereas the change in preload-adjusted W2 was not significant. Systolic velocities, IVCV (p < 0.001) and PSV (p < 0.01), were increased after HD, whereas the AV-plane displacement were decreased (p < 0.01). For the measured diastolic variables, E’ was significantly decreased (p < 0.01) and IVRT was significantly prolonged (p < 0.05), after HD. A few correlations were found between WIWA and TVI variables. The WIWA and TVI measurements indicate that a single session of HD improves systolic function. The load dependency of the diastolic variables seems to be more pronounced than for the systolic variables. Preload-adjusted wave intensity indexes may contribute in the assessment of true LV contractility and relaxation.

  • 6.
    Bjällmark, Anna
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Peolsson, Michael
    KTH, School of Technology and Health (STH).
    Shahgaldi, Kambiz
    KTH, School of Technology and Health (STH), Medical Engineering.
    Nowak, Jacek
    Ultrasonographic strain imaging is superior to conventional non-invasive measures of vascular stiffness in the detection of age-dependent differences in the mechanical properties of the common carotid artery2010In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 11, no 7, 630-636 p.Article in journal (Refereed)
    Abstract [en]

    Aims: Elastic properties of large arteries have been shown to deteriorate with age and in the presence of atherosclerotic vascular disease. In this study, the performance of ultrasonographic strain measurements was compared to conventional measures of vascular stiffness in the detection of age-dependent differences in the elastic properties of the common carotid artery.

    Methods and results: In 10 younger (25-28 years, 4 women) and 10 older (50-59 years, 4 women) healthy individuals, global and regional circumferential and radial strain variables were measured in the short-axis view of the right common carotid artery using ultrasonographic two-dimensional (2D) strain imaging with recently introduced speckle tracking technique. Conventional elasticity variables, elastic modulus (Ep) and β stiffness index, were calculated using M-mode sonography and non-invasive blood pressure measurements. Global and regional circumferential systolic strain and strain rate values were significantly higher (p < 0.001, p < 0.01 for regional late systolic strain rate) in the younger individuals, whereas the values of conventional elasticity variables in the same group were lower (p < 0.05). Among all strain and conventional elasticity variables, principal component analysis and its regression extension identified only circumferential systolic strain variables as contributing significantly to the observed discrimination between the younger and older age groups.

    Conclusion: Ultrasonographic 2D-strain imaging is a sensitive method for the assessment of elastic properties in the common carotid artery, being in this respect superior to conventional measures of vascular elasticity. The method has potential to become a valuable non-invasive tool in the detection of early atherosclerotic vascular changes.

  • 7. Blogg, L
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Direct comparison of audio Doppler ultrasound scores and 2D ultrasound images of venous gas emboli.2010Conference paper (Refereed)
  • 8. Borsbo, Bjorn
    et al.
    Gerdle, Bjorn
    Peolsson, Michael
    KTH, School of Technology and Health (STH).
    Impact of the interaction between self-efficacy, symptoms and catastrophising on disability, quality of life and health in with chronic pain patients2010In: Disability and Rehabilitation, ISSN 0963-8288, E-ISSN 1464-5165, Vol. 32, no 17, 1387-1396 p.Article in journal (Refereed)
    Abstract [en]

    Purpose. To investigate the interactions between self-efficacy - including subcomponents - and symptoms (pain, depression and anxiety), catastrophising, disability, quality of life and health in a population of patients with chronic pain. Method. The study used 433 patients with chronic pain including 47 patients with spinal cord injury-related pain, 150 patients with chronic whiplash-associated disorders and 236 patients with fibromyalgia. The participants answered a postal questionnaire that provided background data, pain intensity and duration and psychological- and health-related variables. Results. In the multivariate context, depression, anxiety, catastrophising and disability were intercorrelated. Self-efficacy correlated positively with variables of quality of life and general health. These two groups of variables were negatively correlated. The pain variables - duration of pain, pain intensity and spreading of pain - formed a third group of variables. Self-efficacy function was negatively correlated to these three pain variables. When regressing disability, quality of life and health, we found that self-efficacy had a positive impact whereas symptoms, catastrophising and pain had a negative influence on these aspects. Different patterns of influencing variables were discerned for the three different analyses, and specific patterns of the subscales of self-efficacy corresponded to specific patterns of negative factors for the outcome of disability, quality of life and health. Conclusion. There is a complex interaction of psychological factors and symptoms and their positive and negative influence on disability, quality of life and health. The results indicate that it might be important to assess and influence both enhancing and detoriating factors to ensure an effective pain management programme.

  • 9.
    Brännmark, Mikael
    KTH, School of Technology and Health (STH), Ergonomics.
    Interaktiv forskning: Gemensamt kunskapande för allas nytta2010In: FALF2010: Arbetsliv i förändring, Malmö: FALF , 2010Conference paper (Refereed)
    Abstract [sv]

    Utvärdering är ett mycket vanligt redskap för kontroll och uppföljning inom olika verksamheter, exempelvis projekt och program. Den traditionella ”summativa” utvärderingen har dock ett flertal brister, som gjort att intresset för formativa utvärderingar ökat. Ett exempel på dessa är de s.k. lärande utvärderingarna, men också forskning i olika former kan användas för att utvärdera projekt och program. I det offentliga programmet Produktionslyftet har det förekommit ett flertal utvärderingsformer, bl.a. två summativa måluppföljelseutvärderingar och ett interaktivt forskningsprojekt. I detta paper presenteras en fallstudie kring dessa utvärderingsformer, samt vilka interna respektive externa spridningseffekter (av programmets erfarenheter), samt också vilken form av utvecklingsstöd, som dessa har möjliggjort för Produktionslyftet. Resultaten pekar på att ett summativa utvärderingsprojekt kan användas för både intern spridning av erfarenheter och för att skapa utvecklingsstöd, förutsatt att halvtidsutvärderingar används. Detta kan också ett interaktivt forskningsprojekt bidra med, samt en lärande utvärdering, men det interaktiva forskningsprojektet tycks vara överlägset när det gäller extern spridning av resultaten från programmet – även om det också är den mest resurskrävande formen av utvärdering. Uttryckt på ett annat sätt, så skapar det interaktiva forskningsprojektet underlag för gemensam diskussion, reflektion och analys för programmet, samt gör också programmet/projektet mer transparent, genom extern spridning av gjorda erfarenheter.

  • 10.
    Brännmark, Mikael
    KTH, School of Technology and Health (STH), Ergonomics.
    Is Lean No Longer Mean?: A Study of the Consequences for Working Conditions in Companies Implementing Lean2010In: FALF2010: Arbetsliv i förändring, Malmö: FALF , 2010Conference paper (Refereed)
    Abstract [en]

    Lean is today becoming increasingly popular in Swedish manufacturing industry, and the concept has also started to spread to other sectors, such as administration, healthcare and the municipal sector. However, previous studies have suggested that Lean can become “mean”, creating working conditions that are bad for the employees. Conversely, other studies instead suggest that this has less to do with Lean, than with the implementation of Lean. Thus, this paper aims at studying the implementation of Lean in eight medium sized companies over a two year period, using qualitative and quantitative data. First, the results from the qualitative data suggest that these companies implementation of Lean is characterized by Lean coordinators, pilot projects and improvements groups, while the Lean tools mostly used are 5S, SMED, standardization and means to improve the production flow. Second, the perceived effects on working conditions, based on the quantitative data, suggest an improvement in the working environment, an increase in the work with safety and some degree of increase in stress for the workers. Consequently, the implementation structure of these companies does not indicate a “mean” production system, although the long term effects on working conditions cannot be determined, based on these data.

  • 11.
    Brännmark, Mikael
    KTH, School of Technology and Health (STH), Ergonomics.
    Lean Working Environments: An Empirical Study of 24 CompaniesImplementing Lean2010In: NES2010: Proactive Ergonomics: Implementation of ergonomics in planning of jobs, tasks, systems and environments., Stavanger, 2010Conference paper (Refereed)
    Abstract [en]

    This paper studies the perceived effects on the working conditions in 24 medium sized manufacturing companies, approximately 1.5 year into their implementation of Lean. This is studied quantitatively based on four stakeholders’ perceptions (the workers, the managers, the production supervisors and the white-collar workers), based on three factors; changes in the working environment, work with safety for the personnel and level of stress. The results indicate that the physical work environments have improved and the workers and production supervisors report a slight increase in stress. Lastly, all groups report an increase in the work with safety for the personnel.

  • 12.
    Buendia, Ruben
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Gil-Pita, Roberto
    Department of Theory of the Signal and Communications, University of Alcala, Madrid, Spain.
    Experimental validation of a method for removing the capacitive leakage artifact from electrical bioimpedance spectroscopy measurements2010In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 21, no 11Article in journal (Refereed)
    Abstract [en]

    Often when performing electrical bioimpedance (EBI) spectroscopy measurements, the obtained EBI data present a hook-like deviation, which is most noticeable at high frequencies in the impedance plane. The deviation is due to a capacitive leakage effect caused by the presence of stray capacitances. In addition to the data deviation being remarkably noticeable at high frequencies in the phase and the reactance spectra, the measured EBI is also altered in the resistance and the modulus. If this EBI data deviation is not properly removed, it interferes with subsequent data analysis processes, especially with Cole model-based analyses. In other words, to perform any accurate analysis of the EBI spectroscopy data, the hook deviation must be properly removed. Td compensation is a method used to compensate the hook deviation present in EBI data; it consists of multiplying the obtained spectrum, Z meas (ω), by a complex exponential in the form of exp(–jωTd). Although the method is well known and accepted, Td compensation cannot entirely correct the hook-like deviation; moreover, it lacks solid scientific grounds. In this work, the Td compensation method is revisited, and it is shown that it should not be used to correct the effect of a capacitive leakage; furthermore, a more developed approach for correcting the hook deviation caused by the capacitive leakage is proposed. The method includes a novel correcting expression and a process for selecting the proper values of expressions that are complex and frequency dependent. The correctness of the novel method is validated with the experimental data obtained from measurements from three different EBI applications. The obtained results confirm the sufficiency and feasibility of the correcting method.

  • 13.
    Buendia, Ruben
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Harris, Matthew
    Phillips Research.
    Caffarel, Jeniffer
    Phillips Research.
    Gil-Pita, Roberto
    Department of Theory of the Signal and Communications, University of Alcala, Madrid, Spain.
    Hook Effect correction & resistance-based Cole fitting prior Cole model-based analysis: Experimental validation2010In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2010, IEEE Engineering in Medicine and Biology , 2010, 6563-6566 p.Conference paper (Refereed)
    Abstract [en]

    The analysis of measurements of Electrical Bioimpedance (EBI) is on the increase for performing non-invasive assessment of health status and monitoring of pathophysiological mechanisms. EBI measurements might contain measurements artefacts that must be carefully removed prior to any further analysis. Cole model-based analysis is often selected when analysing EBI data and might lead to miss-conclusion if it is applied on data contaminated with measurement artefacts. The recently proposed Correction Function to eliminate the influence of the Hook Effect from EBI data and the fitting to the real part of the Cole model to extract the Cole parameters have been validated on experimental measurements. The obtained results confirm the feasible experimental use of these promising pre-processing tools that might improve the outcome of EBI applications using Cole model-based analysis.

  • 14.
    Burmeister, Jens
    et al.
    University of Dresden, Germany.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lundberg, Stefan
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Contention-Based Wireless Sensor Networks: A case study for ambient assisted living2010In: Active Ageing, Smart Solutions, New Markets, 2010Conference paper (Refereed)
    Abstract [en]

    Wireless personal area networks have emerged as an important communication infrastructure in areas such as at-home healthcare and home automation, independent living and assistive technology. Initiatives towards interoperability and standardization are taken by several players. Zigbee Alliance has launched a profile for “Zigbee wireless sensor applications for health, wellness and fitness” [1]. The Continua Health Alliance promotes “an interoperable personal healthcare ecosystem”. They have published “design guidelines for the telehealth ecosystem” including the interface to personal area network health devices and electronic health record devices ([2], [3]). These examples show that wireless personal area networks, including body sensor networks, are becoming more mature and are considered to be a realistic alternative as communication infrastructure for demanding services. However, to transmit vital sign parameters from ECGs, pulse-oximeters, EEGs etc in wireless networks is also a challenge, especially if multiple sensors compete for access. Contention-based access networks offer simplicity and utilization advantages, but the drawback is unpredictable performance due to loss of transmitted packets.

    We have used the SHIMMER wireless sensor platform developed at Intel [4] in the living lab at the Centre for Health and Building at KTH in a case study to identify and evaluate performance problems. The full-scale living lab consists of two apartments especially equipped with modern technique for healthcare at home and assisted living.

    Our paper focuses on continuous monitoring of the heart activity using a wireless ECG based on the wireless personal area network (WPAN) standard IEEE 802.15.4. Results from performance tests in the living lab will be presented e.g. influence of equipment such as micro wave ovens. Since contention-based wireless access has no guarantees for the quality of the delivered service it is interesting to determine to what extent the received ECG signal is sensitive to loss of information. We have recorded ECG signals as well as emulated packet loss in existing ECG records from official databases. The result of two cardiologists´ assessment of ECGs with different loss ratio levels and patterns will be reported in the paper. One interesting conclusion is that a diagnosis is fully possible for ECGs with packet loss ratio up to at least 5%. This project is part of research at the School of Technology and Health at KTH.

  • 15.
    Cheng, Kimberley
    et al.
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Ivanova, Natalia
    Biomedicinskt centrum, Uppsala.
    Scheres, Sjores
    CSIC, Natl Biotechnol Ctr, Biocomp Unit, E-28049 Madrid, Spain .
    Pavlov, Michael Y
    Biomedicinskt centrum, Uppsala.
    Maria Carazo, Jose
    Lund Univ, Mol Biophys KILU.
    Hebert, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Ehrenberg, Måns
    Biomedicinskt centrum, Uppsala.
    Lindahl, Martin
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    tmRNA-SmpB complex mimics native aminoacyl-tRNAs in the A site of stalled ribosomes2010In: Journal of Structural Biology, ISSN 1047-8477, E-ISSN 1095-8657, Vol. 169, no 3, 342-348 p.Article in journal (Refereed)
    Abstract [en]

    Bacterial ribosomes stalled on faulty, often truncated, mRNAs lacking stop codons are rescued by trans-translation. It relies on an RNA molecule (tmRNA) capable of replacing the faulty mRNA with its own open reading frame (ORF). Translation of tmRNA ORF results in the tagging of faulty protein for degradation and its release from the ribosome. We used single-particle cryo-electron microscopy to visualize tmRNA together with its helper protein SmpB on the 70S Escherichia coli ribosome in states subsequent to GTP hydrolysis on elongation factor Tu (EF-Tu). Three-dimensional reconstruction and heterogeneity analysis resulted in a 15 A resolution structure of the tmRNA-SmpB complex accommodated in the A site of the ribosome, which shows that SmpB mimics the anticodon- and D-stem of native tRNAs missing in the tRNA-like domain of tmRNA. We conclude that the tmRNA-SmpB complex accommodates in the ribosomal A site very much like an aminoacyl-tRNA during protein elongation. (C) 2009 Elsevier Inc. All rights reserved.

  • 16.
    Cloots, Rudy J.H.
    et al.
    Eindhoven University of Technology, Department of Mechanical Engineering.
    van Dommelen, JAW
    Eindhoven University of Technology, Department of Mechanical Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Geers, Marc
    Eindhoven University of Technology, Department of Mechanical Engineering.
    Traumatic Brain Injury at Multiple Length Scales: Relating Diffuse Axonal Injury to Discrete Axonal Impairment2010In: 2010 INTERNATIONAL IRCOBI CONFERENCE ON THE BIOMECHANICS OF INJURY PROCEEDINGS, 2010, 119-130 p.Conference paper (Refereed)
  • 17. Debevec, T
    et al.
    Amon, Mojca
    Keramidas, Michail E.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Kounalakis, S.N.
    Pisot, R
    Mekjavic, I.B.
    Normoxic and hypoxic performance following four weeks of normobaric hypoxic training2010In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 81, no 4, 387-393 p.Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION:

    Although training in hypoxia has been suggested to improve sea level and altitude performance, most studies have only evaluated its effect on maximal aerobic capacity in either normoxia or hypoxia. The present study evaluated the effect of a live low-train high training regimen on both normoxic and hypoxic endurance performance and aerobic capacity.

    METHODS:

    There were 18 male subjects who performed 20 training sessions in either a normoxic (F(IO2) = 0.21) or hypoxic (F(IO2) = 0.12) environment. Both the Control (N = 9) and Hypoxic (N = 9) group subjects trained at an intensity that maintained their heart rate at a level corresponding to that elicited at 50% of peak power output attained in normoxia or hypoxia, respectively. Before, during, upon completion, and 10 d after the protocol, subjects' aerobic capacity (VO2 peak) and endurance performance (80% of VO2 peak) were determined under normoxic and hypoxic conditions.

    RESULTS:

    Mean +/- SD normoxic VO2 peak increased significantly only in the Control group from 45.7 +/- 6.1 to 53.9 +/- 3.9 (ml x kg(-1) x min(-1)), whereas hypoxic VO2 peak did not improve in either group. The Control group exhibited significant improvements in normoxic, but not hypoxic peak power output (PPO) and time to exhaustion, whereas the Hypoxic group only exhibited improvements in normoxic time to exhaustion. During each testing period, we also assessed pulmonary function, selected hematological variables, and anthropometry. There were no significant changes in these variables in either group after the training protocol.

    CONCLUSION:

    The hypoxic training regimen used in the present study had no significant effect on altitude and sea level performance.

  • 18.
    Eklund, Jörgen
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Kihlstedt, Annika
    Engkvist, Inga-Lill
    Sorting and disposing of waste at recycling centres: A users perspective2010In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 41, no 3, 355-361 p.Article in journal (Refereed)
    Abstract [en]

    This paper investigates Swedish recycling centres from the users' perspective. The aim was to describe the characteristics and experiences of the users and their activities when sorting and disposing of waste, and to identify improvements for the users. The typical recycling centre user is a recently retired man, living in a house with a garden, having travelled 5 km alone in his own car. The users requested longer opening hours and better information available at home and at the recycling centre. The major difficulty for the users is to understand which fraction their waste belongs to, and consequently into which container they should throw it. The most important sources of sorting information, in addition to experience from earlier visits, are signs and asking the personnel. Although the service at recycling centres is perceived positively by a majority of users. substantial improvements can still be made, and a number of such suggestions are given.

  • 19.
    Elmlund, Dominika
    et al.
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Davis, Ralph
    Elmlund, Hans
    Ab initio structure determination from electron microscopic images of single molecules coexisting in different functional states2010In: Structure, ISSN 0969-2126, E-ISSN 1878-4186, Vol. 18, no 7, 777-786 p.Article in journal (Refereed)
    Abstract [en]

    We have developed methods for ab initio three-dimensional (3D) structure determination from projection images of randomly oriented single molecules coexisting in multiple functional states, to aid the study of complex samples of macromolecules and nanoparticles by electron microscopy (EM). New algorithms for the determination of relative 3D orientations and conformational state assignment of single-molecule projection images are combined with well-established techniques for alignment and statistical image analysis. We describe how the methodology arrives at homogeneous groups of images aligned in 3D and discuss application to experimental EM data sets of the Escherichia coli ribosome and yeast RNA polymerase II.

  • 20. Engkvist, I. L.
    et al.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Krook, J.
    Björkman, M.
    Sundin, E.
    Svensson, R.
    Eklund, M.
    Joint investigation of working conditions, environmental and system performance at recycling centres: Development of instruments and their usage2010In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 41, no 3, 336-346 p.Article in journal (Refereed)
    Abstract [en]

    Recycling is a new and developing industry, which has only been researched to a limited extent. This article describes the development and use of instruments for data collection within a multidisciplinary research programme "Recycling centres in Sweden - working conditions, environmental and system performance". The overall purpose of the programme was to form a basis for improving the function of recycling centres with respect to these three perspectives and the disciplines of: ergonomics, safety, external environment, and production systems. A total of 10 instruments were developed for collecting data from employees, managers and visitors at recycling centres. including one instrument for observing visitors. Validation tests were performed in several steps. This, along with the quality of the collected data, and experience from the data collection, showed that the instruments and methodology used were valid and suitable for their purpose.

  • 21.
    Eriksson, Martin
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Bresin, Roberto
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Improving running mechanics by use of interactive sonification2010In: Proceedings of the Interaction Sonification workshop (ISon) 2010 / [ed] Bresin, Roberto; Hermann, Thomas; Hunt, Andy, Stockholm, Sweden: KTH Royal Institute of Technology, 2010, 95-98 p.Conference paper (Refereed)
    Abstract [en]

    Running technique has a large effect on running economy interms of consumed amount of oxygen. Changing the naturalrunning technique, though, is a difficult task. In this paper, a method based on sonification is presented, that will assist the runner in obtaining a more efficient running style. The system is based on an accelerometer sending data to a mobile phone.Thus the system is non-obtrusive and possible to use in theeveryday training. Specifically, the feedback given is based on the runner’s vertical displacement of the center of mass. As this is the main source of energy expenditure during running, it is conjectured that a reduced vertical displacement should improve running economy.

  • 22. Falkmer, Marita
    et al.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Falkmer, Torbjörn
    The importance of the eye area in face identification abilities and visual search strategies in persons with Asperger syndrome2010In: Research in Autism Spectrum Disorders, ISSN 1750-9467, Vol. 4, no 4, 724-730 p.Article in journal (Refereed)
    Abstract [en]

    Partly claimed to explain social difficulties observed in people with Asperger syndrome, face identification and visual search strategies become important. Previous research findings are, however, disparate. In order to explore face identification abilities and visual search strategies, with special focus on the importance of the eye area, 24 adults with Asperger syndrome and matched controls viewed puzzle pieced photos of faces, in order to identify them as one of three intact photos of persons. Every second puzzle pieced photo had the eyes distorted. Fixation patterns were measured by an eye tracker. Adults with Asperger syndrome had greater difficulties in identifying faces than controls. However, the entire face identification superiority in controls was found in the condition when the eyes were distorted supporting that adults with Aspergers syndrome do use the eye region to a great extent in face identification. The visual search strategies in controls were more effective and relied on the use of the 'face information triangle', i.e. the two eyes and the mouth, while adults with Asperger syndrome had more fixations on other parts of the face, both when obtaining information and during the identification part, suggesting a less effective use of the 'face information triangle'.

  • 23.
    Flisberg, A.
    et al.
    Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital-Östra.
    Kjellmer, I.
    Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital-Östra.
    Löfhede, J.
    School of Engineering, University of Borås.
    Löfgren, N.
    Neoventa Medical AB, Göteborg.
    Rosa-Zurera, M.
    Department of Signal Theory and Communications, University of Alcalá.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Thordstein, M.
    Department of Clinical Neurophysiology, Institute of Neuroscience and Physiology, Sahlgrenska University Hospital, Göteborg, Sweden.
    Does indomethacin for closure of patent ductus arteriosus affect cerebral function?2010In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227, Vol. 99, no 10, 1493-1497 p.Article in journal (Refereed)
    Abstract [en]

    Objective: To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by Electroencephalograms (EEG) evaluated by quantitative measures. Study design: Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function. Results: Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion. Conclusion: Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.

  • 24.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Ericsson, M.
    Larsson, Å.
    Lindholm, P.
    Investigation of a Halcyon RB80 semiclosed rebreather in connection with a diving accident2010Conference paper (Refereed)
  • 25.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Blogg, L.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Mekjavic, I.
    Comparison between mild dehydration and body temperature on decompression bubble formation2010Conference paper (Refereed)
  • 26. Granåsen, G.
    et al.
    Grönlund, C.
    Öhberg, F.
    Lindberg, Frida
    KTH, School of Technology and Health (STH), Medical Engineering.
    Karlsson, J. S.
    Comparison between ultrasonic muscle strain and electromyography during an isometric ramp contraction2010In: World Congress on Medical Physics and Biomedical Engineering, September 7 - 12, 2009, Munich, Germany, Springer Berlin/Heidelberg, 2010, Vol. 25/4, 1565-1567 p.Conference paper (Refereed)
    Abstract [en]

    This study aims to explore multi modal relationships between ultrasonic muscle strain and electromyography (EMG). Canonical Correlation Analysis (CCA) is technique which can be used to explore multivariate associations between sets of variables. Multi-channel EMG and a spatial differentiated Tissue Velocity Imaging (TVI)-strain signal was compared from measurements on biceps brachii on eight subjects. A data analysis using CCA was then applied to obtain useful information of the relationship between signals.

  • 27.
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical Engineering.
    Comments on "The equations of motion for a standing human reveal three mechanisms for balance" (A. Hof, Vol. 40, pp. 451-457)2010In: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 43, no 16, 3244-3247 p.Article in journal (Refereed)
  • 28.
    Hamid Muhammed, Hamed
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Bergholm, Fredrik
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Sensitivity Analysis of Multichannel Images Intended for Instantaneous Imaging Spectrometry Applications2010In: SIAM Journal on Imaging Sciences, ISSN 1936-4954, E-ISSN 1936-4954, Vol. 3, no 1, 79-109 p.Article in journal (Refereed)
    Abstract [en]

    This paper presents a sensitivity analysis of using instantaneous multichannel two-dimensional (2D) imaging to achieve instantaneous 2D imaging spectroscopy. A simulated multiple-filter mosaic was introduced and used to acquire multichannel data which were transformed into spectra. The feasibility of two different transformation approaches (the concrete pseudoinverse approach and a statistical approach) was investigated through extensive experimental tasks. A promising statistical method was identified to be used for accurate estimation of spectra from multichannel data. Comparison between estimated and measured spectra shows that higher estimation accuracy can be achieved when using a larger number of usable multiple-filter combinations in the mosaic.

  • 29. Hemphala, Hillevi
    et al.
    Kihlstedt, Annika
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Vision ergonomics at recycling centres2010In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 41, no 3, 368-375 p.Article in journal (Refereed)
    Abstract [en]

    All municipalities in Sweden offer their inhabitants a service for disposing of large-size and hazardous waste at local recycling centres. Opening hours at these centres include hours of darkness. The aims of this study were to 1) describe user and employee experiences of lighting and signs at Swedish recycling centres, 2) measure and assess the lighting system at the two recently built recycling centres in Linkoping and to assess the legibility and visibility of the signs used and 3) propose recommendations regarding lighting and signs for recycling centres. Interviews and questionnaires were used to assess experiences of employees and users, and light measurements were performed. By observing users, activities with different visual demands at different areas within the recycling centres were identified. Based on the literature, standards and stakeholder experiences, recommendations regarding lighting systems and sign design, illuminance, luminance and uniformity are proposed for recycling centres.

  • 30. Henareh, Loghman
    et al.
    Jedefors, Camilla
    Jogestrand, Tomas
    Brodin, Lars Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Agewall, Stefan
    Intima-Media Thickness of Common Carotid and Brachial Arteries and Prothrombin Fragment 1+2 Are Associated with Left Ventricular Diastolic Dysfunction in Patients with Myocardial Infarction2010In: Echocardiography, ISSN 0742-2822, E-ISSN 1540-8175, Vol. 27, no 6, 651-658 p.Article in journal (Refereed)
    Abstract [en]

    Aims: To investigate the association between intima-media thickness of brachial and common carotid arteries and factors of the coagulation- and fibrinolysis-system with left ventricular diastolic dysfunction in patients with a previous myocardial infarction. Patients and methods: One hundred and twenty three patients, men (76%) and women (24%) aged between 32and 81 years with a history of previous acute myocardial infarction were included. B-mode ultrasound of common carotid and brachial arteries and echocardiography with tissue Doppler imaging (TDI) were evaluated. Factors of the coagulation- and fibrinolysis-system were also measured. Results: In patients with previous myocardial infarction, late diastolic filling time was significantly and positively associated with log Prothrombin fragment 1 + 2 (P < 0.001) and with calculated intima-media area (cIMa) of the both common carotid and brachial arteries (P < 0.05). Mitral early-to-late flow velocity ratio (E/A) was significantly and negatively associated with log Prothrombin fragment 1 + 2 (P < 0.001), total cholesterol and cIMa of the both common carotid and brachial arteries (P < 0.05). Moreover both late diastolic filling time and mitral E/A correlated significantly with age and systolic blood pressure. In stepwise multiple regression analysis, log Prothrombin fragment 1 + 2 remained the only variable with independent significant correlation to late diastolic filling time and mitral E/A. Conclusions: In a population sample of patients with myocardial infarction, late diastolic filling time and mitral E/A were associated with cIMa of common carotid and brachial arteries, systolic blood pressure, and prothrombin fragment 1 + 2, suggesting a relationship between diastolic dysfunction, thrombin generation and atherosclerosis. (Echocardiography 2010;27:651-658).

  • 31. Henje Blom, E
    et al.
    Olsson, E M
    Serlachius, E
    Ericson, Mats
    KTH, School of Technology and Health (STH), Ergonomics (Closed 20130701).
    Ingvar, M
    Heart rate variability (HRV) in adolescent females with anxiety disorders and major depressive disorder2010In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227, Vol. 99, no 4, 604-611 p.Article in journal (Refereed)
    Abstract [en]

    AIM: The aim of this study was to investigate heart rate variability (HRV) in a clinical sample of female adolescents with anxiety disorders (AD) and/or major depressive disorder (MDD) compared with healthy controls and to assess the effect of selective serotonin reuptake inhibitors (SSRI) on HRV.

    METHODS: Heart rate variability was measured in adolescent female psychiatric patients with AD and/or MDD (n = 69), mean age 16.8 years (range: 14.5-18.4), from 13 out-patient clinics and in healthy controls (n = 65), mean age 16.5 years (range: 15.9-17.7). HRV was registered in the sitting position during 4 min with no interventions.

    RESULTS: Logarithmically transformed high frequency HRV (HF), low frequency HRV (LF) and standard deviation of inter beat intervals (SDNN) were lower in the clinical sample compared with the controls (Cohen's d for HF = 0.57, LF = 0.55, SDNN = 0.60). This was not explained by body mass index, blood pressure or physical activity. Medication with SSRI explained 15.5% of the total variance of HF, 3.0% of LF and 6.5% of SDNN.

    CONCLUSIONS: Adolescent female psychiatric patients with AD and/or MDD show reduced HRV compared with healthy controls. Medication with SSRI explained a part of this difference.

  • 32.
    Holden, Richard J.
    KTH, School of Technology and Health (STH), Ergonomics.
    Physicians' beliefs about using EMR and CPOE: In pursuit of a contextualized understanding of health IT use behavior2010In: International Journal of Medical Informatics, ISSN 1386-5056, E-ISSN 1872-8243, Vol. 79, no 2, 71-80 p.Article in journal (Refereed)
    Abstract [en]

    Purpose: To identify and describe physicians' beliefs about use of electronic medical records (EMR) and computerized provider order entry (CPOE) for inpatient and outpatient care, to build an understanding of what factors shape information technology (IT) use behavior in the unique context of health care delivery. Methods: Semi-structured qualitative research interviews were carried out, following the beliefs elicitation approach. Twenty physicians from two large Midwest US hospitals participated. Physicians were asked questions to elicit beliefs and experiences pertaining to their use of EMR and CPOE. Questions were based on a broad set of behavior-shaping beliefs and the methods commonly used to elicit those beliefs. Results: Qualitative analysis revealed numerous themes related to the perceived emotional and instrumental outcomes of EMR and CPOE use; perceived external and personal normative pressure to use those systems; perceived volitional control over use behavior; perceived facilitators and barriers to system use; and perceptions about the systems and how they were implemented. EMR and CPOE were commonly believed to both improve and worsen the ease and quality of personal performance, productivity and efficiency, and patient outcomes. Physicians felt encouraged by employers and others to use the systems but also had personal role-related and moral concerns about doing so. Perceived facilitators and barriers were numerous and had their sources in all aspects of the work system. Conclusion: Given the breadth and detail of elicited beliefs, numerous design and policy implications can be identified. Additionally, the findings are a first step toward developing a theory of health IT acceptance and use contextualized to the unique setting of health care.

  • 33.
    Holden, Richard J.
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Patel, Neal R.
    Scanlon, Matthew C.
    Shalaby, Theresa M.
    Arnold, Judi M.
    Karsh, Ben-Tzion
    Effects of mental demands during dispensing on perceived medication safety and employee well-being: A study of workload in pediatric hospital pharmacies2010In: Research in Social and Administrative Pharmacy, ISSN 1551-7411, Vol. 6, no 4, 293-306 p.Article in journal (Refereed)
    Abstract [en]

    Background: Pharmacy workload is a modifiable work system factor believed to affect both medication safety outcomes and employee outcomes, such as job satisfaction. Objectives: This study sought to measure the effect of workload on safety and employee outcomes in 2 pediatric hospitals and to do so using a novel approach to pharmacy workload measurement. Methods: Rather than measuring prescription volume or other similar indicators, this study measured the type and intensity of mental demands experienced during the medication dispensing tasks. The effects of external (interruptions, divided attention, and rushing) and internal (concentration and effort) task demands on perceived medication error likelihood, adverse drug event likelihood, job dissatisfaction, and burnout were statistically estimated using multiple linear and logistic regression. Results: Pharmacists and pharmacy technicians reported high levels of external and internal,mental demands during dispensing. The study supported the hypothesis that external demands (interruptions, divided attention, and rushing) negatively impacted medication safety and employee well-being outcomes. However, as hypothesized, increasing levels of internal demands (concentration and effort) were not associated with greater perceived likelihood of error, adverse drug events, or burnout and even had a positive effect on job satisfaction. Conclusions: Replicating a prior study in nursing, this study shows that new conceptualizations and measures of workload can generate important new findings about both detrimental and beneficial effects of workload on patient safety and employee well-being. This study discusses what those findings imply for policy, management, and design concerning automation, cognition, and staffing.

  • 34.
    Karltun, Johan
    et al.
    Högskolan i Jönköping, JTH.
    Berglund, Martina
    KTH, School of Technology and Health (STH), Ergonomics.
    Contextual conditions influencing the scheduler's work at a sawmill2010In: Production planning & control (Print), ISSN 0953-7287, E-ISSN 1366-5871, Vol. 21, no 4, 359-374 p.Article in journal (Refereed)
    Abstract [en]

    This case study addresses the issue of how contextual conditions influence scheduling work in practice at a sawmill in Sweden. Based on observations and interviews, activity analysis was used to study the work activities of the main scheduler. It is shown how the contextual conditions related to constraints, either in the technical system and the technical scheduling tools used by the scheduler or in the social system, delimit the possible ways for the scheduler to perform his work. It is furthermore illustrated how the scheduler sometimes used the contextual conditions as a means to control the sawmill production. Moreover, the presence of the numerous uncertainties in the production process is shown. Finally, the study demonstrates that the scheduler's thorough knowledge, experience, and skills of both the technical and the social systems had immense influence in his ability to perform during daily scheduling work.

  • 35. Keramidas, Michail E.
    et al.
    Kounalakis, S.
    Debevec, T.
    Norman, B.
    Gustafsson, T.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology (Closed 20130701).
    Mekjavic, I.
    The effect of acute normobaric hyperoxia on EPO concentration in healthy males2010Conference paper (Refereed)
  • 36. Keramidas, Michail E.
    et al.
    Kounalakis, S.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology (Closed 20130701).
    Mekjavic, I.
    The effect of 10-days of hypoxia on muscle and cerebral oxygenation during a submaximal performance test2010In: High Altitude Medicine & Biology, ISSN 1527-0297, E-ISSN 1557-8682, Vol. 11, no 3, 269-269 p.Article in journal (Refereed)
  • 37. Kjellberg, Anders
    et al.
    Toomingas, Allan
    Norman, Kerstin
    Hagman, Maud
    Herlin, Rose-Marie
    Wigaeus Tornqvist, Ewa
    KTH, School of Technology and Health (STH), Ergonomics.
    Stress, energy and psychosocial conditions in different types of call centres2010In: Work: A journal of Prevention, Assesment and rehabilitation, ISSN 1051-9815, E-ISSN 1875-9270, Vol. 36, no 1, 9-25 p.Article in journal (Refereed)
    Abstract [en]

    Objective: To identify risk indicators for high stress and low mental energy as well as to describe psychosocial working conditions at different types of call centres. Participants: 1183 operators from 28 call centres in Sweden, both external and internal, with different levels of task complexity, ownership and geographical location. Method: A cross sectional questionnaire study. Results: The stress level was moderately high and the energy level fairly high. Stress levels tended to be lower and psychosocial conditions better with increasing level of task complexity. Fourteen per cent of the operators were in a state of high stress/low energy ("worn out") and 47% in high stress/high energy ("committed under pressure"). Operators in a state of low stress/high energy ("committed without pressure") were most likely to report a better health status. High stress and lack of energy was mainly associated with time pressure, low decision latitude, and lack of social and supervisor support. Conclusions: Time pressure in combination with lack of support and influence should be seen as a potential high risk situation for the development of a "worn-out" state among call centre operators. Management should make use of this knowledge in order to promote a long lasting efficient and healthy call centre work.

  • 38. Kremer, F.
    et al.
    Rabayah, M.
    Choi, H.F.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    D'hooge, Jan
    Spatial compounding for 2D strain estimation in the mouse heart: a pilot study2010Conference paper (Refereed)
    Abstract [en]

    Estimating cardiac strain in the mouse in the lateral direction usingspeckle tracking with adapted clinical equipment was shown to be challenging dueto the fast heart rate and the large speckle size relative to the wallthickness. Compounding axial motion estimates acquired from different insonationangles can potentially improve lateral strain estimates. Therefore, the aim ofthis study was to test the feasibility of this methodology in the murine heartbased on simulated data sets. A 3D kinematic model of a murine left ventriclewas simulated and filled randomly with scatterers. Ultrasound short-axis images(10mm 6mm) were obtained by assuming a linear array transducer. Beam steeringwas simulated at 3 different angles (22, 0, 22). Axial motion was estimated ineach data set by 1D cross-correlation. A dynamic programming approach wasintegrated in the motion estimation algorithm to avoid discontinuities. Axialcomponents were combined to reconstruct the in-plane motion vector. The 2Ddisplacement fields were subsequently accumulated over the whole cycle. Theprocedure was repeated for 10 different distributions of scatterers to acquire10 different RF data sets (5 for parameter tuning and 5 for comparing themethods). Radial and circumferential RMS strain errors calculated from theaccumulated motion fields were compared with those obtained with 2D speckletracking. Spatial compounding yielded significantly better radial (RMSE: 0.07370.0078 vs. 0.112 0.0094) as well as circumferential strain (RMSE: 0.102 0.0097vs. 0.281 0.054).

  • 39.
    Kronander, Håkan
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Fischer-Colbrie, Werner
    Nowak, Jacek
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Elmqvist, Håkan
    KTH, School of Technology and Health (STH), Medical Engineering.
    Diagnostic performance and partition values of exercise electrocardiographic variables in the detection of coronary artery disease - improved accuracy by using ST/HR hysteresis2010In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 30, no 2, 98-106 p.Article in journal (Refereed)
    Abstract [en]

    P>Exercise electrocardiography is widely used for initial identification of patients with coronary artery disease (CAD). This study compares the measurements of ST-segment changes during exercise and during early postexercise recovery in terms of diagnostic discrimination capacity and optimal partition values. Data from 1876 patients undergoing a routine bicycle exercise test were analysed. CAD was angiographically verified in 668 patients, and excluded by angiography (n = 119), myocardial scintigraphy (n = 250), and on clinical grounds (n = 839) in 1208 patients. Postexercise ST/HR hysteresis was calculated as normalized for heart rate (HR) ST/HR loop area during the first 3 min of recovery. ST/HR index was obtained by dividing the overall ST amplitude change during exercise by exercise-induced HR change, and ST/HR slope was calculated using linear regression analysis of ST/HR data pairs during exercise. ST-segment depression was measured during, and for 3 min after the exercise. Discriminating capacity of the methods was evaluated in terms of receiver operating characteristic areas and optimal partition values providing the combination of the best sensitivity and specificity were established. The best diagnostic discrimination was provided by ST/HR hysteresis at optimal partition value of -15 mu V, followed by postexercise ST amplitude measurements at gender-specific partition values of -10 to -90 mu V, ST/HR slope [partition value 2 center dot 4 mu V (beats/min)-1], ST/HR index [partition value 1 center dot 6 mu V (beats/min)-1], and ST-segment depression during exercise (partition value 70 mu V in men and 90 mu V in women). The results demonstrate that analysis of postexercise ST/HR hysteresis offers the most accurate and gender indifferent identification of patients with CAD.

  • 40.
    Lanner, Daniel
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Halldin, Peter
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Iraeus, Johan
    Epsilon, Göteborg, Sweden.
    Holmqvist, Kristian
    SAFER, Chalmers University of Technology, Göteborg, Sweden.
    Mroz, Krystoffer
    Autoliv Research, Vårgårda, Sweden.
    Pipkorn, Bengt
    Autoliv Research, Vårgårda, Sweden.
    Jakobsson, Lotta
    Volvo Car Corporation, Göteborg, Sweden.
    Backlund, Maria
    Volvo Car Corporation, Göteborg, Sweden.
    Bolte, John H.
    The Ohio State University, Ohio, USA.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Evaluation of finite element human body models in lateral padded pendulum impacts to the shoulder2010In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 15, no 2, 125-142 p.Article in journal (Refereed)
    Abstract [en]

    Lateral impacts are of great concern for occupant safety. In order to design side protective systems, it is of importance that the timing of the body and the head should be well predicted. Today, experimental and numerical Anthropometric Test Devices (ATDs) are used as human substitutes to predict the human kinematics. As a complement to the ATDs, numerical Human Body Models (HBMs) are used as research tools. The objective of this study is to compare the loading and kinematics of the shoulder complex in three different HBMs with published biological experiments. This study also compares the models with each other and with two numerical ATDs. The results indicate that no HBM can be used for detailed prediction of the kinematics of the human shoulder complex. However, in the presented statistical analysis, all HBMs show a better overall correlation to experiments compared to the numerical ATDs.

  • 41.
    Larsson, Matilda
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Kremer, F.
    Claus, P.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    D'hooge, Jan
    A novel measure to express tracking quality in ultrasound block matching2010In: Proceedings - IEEE Ultrasonics Symposium, 2010, 1636-1639 p.Conference paper (Refereed)
    Abstract [en]

    Speckle de-correlation is a major problem in block matching based ultrasound methodologies as it limits the accuracy of the tracking result. It would be of benefit to have a quantitative measure expressing the local tracking quality as it would allow discarding unreliable motion estimates. We hypothesized that kernels showing sufficient gray scale pattern would more reliably track than kernels with more homogenous gray scale distributions. The aim of this study was to test this hypothesis in-silico. Ultrasound B-mode sequences were simulated from a kinematic model of the carotid artery. Two-dimensional motion was estimated using block matching with the normalized cross-correlation function as similarity measure. For each kernel, two measures of tracking quality were stored: the normalized cross-correlation coefficient (Ccc) and a measure of the amount of edges inside the kernel detected using a canny filter and counted on a pixel-by-pixel basis. As such, a quality measure (Cedge) between 0 (no edges) and 1 (nothing but edges) was obtained. Axial and lateral strains were subsequently obtained by linear regression in regions of interest (ROIs) with best/worst mean tracking quality scores. The root-mean-squared-error (RMSE) was significantly lower in regions with low Ccc (worst ROI) compared to ROIs with high Ccc. However, more edges in the kernel did indeed result in better overall tracking (lower RMSE). Thus, the proposed edge-detection method showed to be a better tracking quality measure than the commonly used Ccc.

  • 42.
    Larsson, Matilda
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Kremer, F.
    Kuznetsova, T.
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    D'hooge, J.
    In-vivo assessment of radial and longitudinal strain in the carotid artery using speckle tracking2010In: 2010 IEEE International Ultrasonics Symposium Proceedings, IEEE , 2010, 1328-1331 p.Conference paper (Refereed)
    Abstract [en]

    Ultrasound-based algorithms are commonly used to assess mechanical properties of arterial walls in studies of arterial stiffness and atherosclerosis. Speckle tracking based techniques used for estimation of myocardial strain can be applied on vessels to estimate strain of the arterial wall. Previous elastography studies in vessels have mainly focused on radial strain measurements, whereas the longitudinal strain has been more or less ignored. However, recently we showed the feasibility of speckle tracking to assess longitudinal strain of the carotid artery in-silico. The aim of this study was to test this methodology in-vivo. Ultrasound images were obtained in seven healthy subjects with no known cardiovascular disease (39 ± 14 years old) and in seven patients with coronary artery disease (CAD), (69 ± 4 years old). Speckle tracking was performed on the envelope detected data using our previous developed algorithm. Radial and longitudinal strains were estimated throughout two cardiac cycles in a region of interest (ROI) positioned in the posterior vessel wall. The mean peak systolic radial and longitudinal strain values from the two heart cycles were compared between the groups using a student's t-test. The mean peak radial strain was -39.1 ± 15.1% for the healthy group and -20.4 ± 7.5% for the diseased group (p = 0.01), whereas the mean peak longitudinal strain was 4.8 ± 1.1% and 3.2 ± 1.6% (p = 0.05) for the healthy and diseased group, respectively. Both peak radial and longitudinal strain values were thus significantly reduced in the CAD patient group. This study shows the feasibility to estimate radial and longitudinal strain in-vivo using speckle tracking and indicates that the method can detect differences between groups of healthy and diseased (CAD) subjects.

  • 43.
    Larsson, Tore J
    et al.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Tezic, Kerem
    AFA Swedish Labour Market Insurances.
    Oldertz, Cecilia
    AFA Swedish Labour Market Insurances.
    Threats and violence as a precursor to occupational injury: Text-mining of insurance-based information on police officers and security guards in Sweden 2004-20072010In: Safety Science Monitor, ISSN 1443-8844, Vol. 14, no 2Article in journal (Refereed)
    Abstract [en]

    The full text of all occupational injury claims associated with threats or violence from Police Officers and Security Guards reported to the Swedish National workers’ compensation insurance 2004 –2007 was analysed with the help of text-mining software. The analysis generated clusters of details on hazardous exposures and accident processes, and the level of information in the clusters describing the different scenarios identified possible practical modifications in training, technology and professional operating procedures. The analysis of the textual information in the reporting of traumatic injuries promises to better represent the dynamics and detail of exposure and accident process and, when applied to valid and representative insurance data with the help of a suitable text-mining software, will provide industry groups and local companies with detailed decision support for safety management and prevention.

  • 44.
    Larsson, Tore J
    et al.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Wilson, Kay
    Centralgalaxen Bygg, Sweden.
    Leray, Henri
    Centralgalaxen Bygg, Sweden.
    The Challenge of Health and Safety Promotion at Work: Balance training for fitness and falls prevention among Swedish construction workers2010In: Safety Science Monitor, ISSN 1443-8844, Vol. 14, no 2Article in journal (Refereed)
  • 45.
    Li, Xiaogai
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    Ho, Johnson
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    Three Dimensional Poroelastic Simulation of Brain Edema: Initial studies on intracranial pressure2010In: IFMBE Proceedings, 2010, 2010, 1478-1481 p.Conference paper (Refereed)
    Abstract [en]

    Brain edema is one of the most common consequences of serious head injury because of the enhancement of water content and thus the increased brain volume. Once the brain compensation mechanisms have been exhausted, the intracranial pressure (ICP) will increase exponentially because the brain is enclosed in the rigid skull. Previous research suggests that the poroelastic theory provides a solution for studying the fluid flow in the brain. In this paper, poroelastic theory is used to study the intracranial pressure distribution due to traumatic brain edema by a detailed 3D finite element brain model.

  • 46.
    Lindberg, Frida
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Grönlund, C.
    Granåsen, G.
    Karlsson, J. S.
    Peolsson, Mikael
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Tissue strain from Tissue Velocity Imaging (TVI) during sub-maximal isotonic muscle contractions2010In: World Congress on Medical Physics and Biomedical Engineering, September 7 - 12, 2009, Munich, Germany: Vol. 25/4 Image Processing, Biosignal Processing, Modelling and Simulation, Biomechanics, Springer Publishing Company, 2010, Vol. 25/4, 1554-1556 p.Conference paper (Refereed)
    Abstract [en]

    We have used Tissue Velocity Imaging (TVI) as a method to quantify the deformation of skeletal muscle tissue during contraction. The parameters used to describe tissue dynamics in this study were strain and strain rate, respectively. Eight subjects were evaluated performing submaximal isotonic contractions of biceps brachii before and after muscle fatigue.

  • 47. Lundqvist, Joakim
    et al.
    Elmlund, Hans
    KTH, School of Technology and Health (STH).
    Wulff, Ragna Peterson
    Berglund, Lisa
    Elmlund, Dominika
    KTH, School of Technology and Health (STH).
    Emanuelsson, Cecilia
    Hebert, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Willows, Robert D.
    Hansson, Mats
    Lindahl, Martin
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Al-Karadaghi, Salam
    ATP-Induced Conformational Dynamics in the AAA plus Motor Unit of Magnesium Chelatase2010In: Structure, ISSN 0969-2126, E-ISSN 1878-4186, Vol. 18, no 3, 354-365 p.Article in journal (Refereed)
    Abstract [en]

    Mg-chelatase catalyzes the first committed step of the chlorophyll biosynthetic pathway, the ATP-dependent insertion of Mg2+ into protoporphyrin IX (PPIX). Here we report the reconstruction using single-particle cryo-electron microscopy of the complex between subunits BchD and BchI of Rhodobacter capsulatus Mg-chelatase in the presence of ADP, the nonhydrolyzable ATP analog AMPPNP, and ATP at 7.5 angstrom, 14 angstrom, and 13 angstrom resolution, respectively. We show that the two AAA+ modules of the subunits form a unique complex of 3 dimers related by a three-fold axis. The reconstructions demonstrate substantial differences between the conformations of the complex in the presence of ATIP and ADP, and suggest that the C-terminal integrin-I domains of the BchD subunits play a central role in transmitting conformational changes of BchI to BchD. Based on these data a model for the function of magnesium chelatase is proposed.

  • 48. Manouras, A.
    et al.
    Nyktari, E.
    Sahlen, A.
    Winter, R.
    Vardas, P.
    Brodin, Lärs-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Evaluation of E/Em predictive capacity: Impact of acute load reduction2010In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 31, 733-733 p.Article in journal (Refereed)
  • 49.
    Marquez, Juan Carlos
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Ferreira, Javier
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Buendia, Ruben
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Textile electrode straps for wrist-to-ankle bioimpedance measurements for Body Composition Analysis: Initial validation & experimental results2010In: 2010 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), IEEE Engineering in Medicine and Biology Society , 2010, 6385-6388 p.Conference paper (Refereed)
    Abstract [en]

    Electrical Bioimpedance (EBI) is one of the non-invasive monitoring technologies that could benefit from the emerging textile based measurement systems. If reliable and reproducible EBI measurements could be done with textile electrodes, that would facilitate the utilization of EBI-based personalized healthcare monitoring applications. In this work the performance of a custom-made dry-textile electrode prototype is tested. Four-electrodes ankle-to-wrist EBI measurements have been taken on healthy subjects with the Impedimed spectrometer SFB7 in the frequency range 5 kHz to 1 MHz. The EBI spectroscopy measurements taken with dry electrodes were analyzed via the Cole and Body Composition Analysis (BCA) parameters, which were compared with EBI measurements obtained with standard electrolytic electrodes. The analysis of the obtained results indicate that even when dry textile electrodes may be used for EBI spectroscopy measurements, the measurements present remarkable differences that influence in the Cole parameter estimation process and in the final production of the BCA parameters. These initial results indicate that more research work must be done to in order to obtain a textile-based electrode that ensures reliable and reproducible EBI spectroscopy measurements.

  • 50. Marquez, Juan Carlos
    et al.
    Seoane, Fernando
    Välimäki, Elina
    University of Borås.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Comparison of dry-textile electrodes for electrical bioimpedance spectroscopy measurements2010Conference paper (Refereed)
    Abstract [en]

    Textile Electrodes have been widely studied for biopotentials recordings, specially for monitoring the cardiac activity. Commercially available applications, such as Adistar T-shirt and Textronics Cardioshirt, have proved a good performance for heart rate monitoring and are available worldwide. Textile technology can also be used for Electrical Bioimpedance Spectroscopy measurements enabling home and personalized health monitoring applications however solid ground research about the measurement performance of the electrodes must be done prior to the development of any textile-enabled EBI application. In this work a comparison of the measurement performance of two different types of dry-textile electrodes and manufacturers has been performed against standardized RedDot 3M Ag/AgCl electrolytic electrodes. 4-Electrode, whole body, Ankle-to-Wrist EBI measurements have been taken with the Impedimed spectrometer SFB7 from healthy subjects in the frequency range of 3kHz to 500kHz. Measurements have been taken with dry electrodes at different times to study the influence of the interaction skin-electrode interface on the EBI measurements. The analysis of the obtained complex EBI spectra shows that the measurements performed with textile electrodes produce constant and reliable EBI spectra. Certain deviation can be observed at higher frequencies and the measurements obtained with Textronics and Ag/AgCl electrodes present a better resemblance. Textile technology, if successfully integrated it, may enable the performance of EBI measurements in new scenarios allowing the rising of novel wearable monitoring applications for home and personal care as well as car safety.

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