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  • 1. Aare, Magnus
    et al.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Injuries from motorcycle- and moped crashes in Sweden from 1987 to 1999.2003In: Injury control and safety promotion, ISSN 1566-0974, E-ISSN 1744-4985, Vol. 10, no 3, p. 131-8Article in journal (Refereed)
    Abstract [en]

    The objective of this paper is to study injuries from motorcycle and moped crashes in Sweden from 1987 to 1999. Databases at the National Board for Health and Welfare and codes from both ICD9 and ICD10 systems were used, including patterns of age, gender, E-code and type of injury. Length of hospital stay, type of injuries and trends over time was evaluated. To get a more detailed picture of the age distribution, type of vehicle used and number of killed, data from the Swedish National Road Administration were also used. In Sweden, 27,122 individuals received in-patient care due to motorcycle and moped injuries between 1987 and 1999. The motorcycle and moped injury rate was reduced in the second half of the studied period and so were the total days of treatment per year. Males had eight times the incidence of injuries compared to females. Riders under the age of 26 and in particular those at an age of 15 had the highest incidence rate. Head injuries were the most frequent diagnosis, followed by fractures to the lower limbs. Concussion was the most frequent head injury. Focal and diffuse brain injuries combined showed the same frequency as concussion. It is concluded that more preventative strategies must be presented before the injury rate can be reduced.

  • 2. Aberg, A. C.
    et al.
    Thorstensson, A.
    Tarassova, O.
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH).
    Calculations of mechanisms for balance control during narrow and single-leg standing in fit older adults: A reliability study2011In: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 34, no 3, p. 352-357Article in journal (Refereed)
    Abstract [en]

    For older people balance control in standing is critical for performance of activities of daily living without falling. The aims were to investigate reliability of quantification of the usage of the two balance mechanisms M(1) 'moving the centre of pressure' and M(2) 'Segment acceleration' and also to compare calculation methods based on a combination of kinetic (K) and kinematic (Km) data, (K-Km), or Km data only concerning M(2). For this purpose nine physically fit persons aged 70-78 years were tested in narrow and single-leg standing. Data were collected by a 7-camera motion capture system and two force plates. Repeated measure ANOVA and Tukey's post hoc tests were used to detect differences between the standing tasks. Reliability was estimated by ICCs, standard error of measurement including its 95% Cl, and minimal detectable change, whereas Pearson's correlation coefficient was used to investigate agreement between the two calculation methods. The results indicated that for the tasks investigated, M(1) and M(2) can be measured with acceptable inter- and intrasession reliability, and that both Km and K-Km based calculations may be useful for M(2), although Km data may give slightly lower values. The proportional M(1) :M(2) usage was approximately 9:1, in both anterio-posterior (AP) and medio-lateral (ML) directions for narrow standing, and about 2:1 in the AP and of 1:2 in the ML direction in single-leg standing, respectively. In conclusion, the tested measurements and calculations appear to constitute a reliable way of quantifying one important aspect of balance capacity in fit older people.

  • 3. Aberg, B
    et al.
    Koul, B L
    Liska, J
    Brodin, L A
    KTH, School of Technology and Health (STH).
    Landou, C
    Delayed left ventricular free wall rupture complicating coronary artery bypass surgery. A case report.1985In: Scandinavian journal of thoracic and cardiovascular surgery, ISSN 0036-5580, Vol. 19, no 3, p. 273-7Article in journal (Refereed)
    Abstract [en]

    Rupture of the left ventricular free wall is a not uncommon life-threatening complication of acute myocardial infarction and after prosthetic mitral valve replacement. To our knowledge, no case of left ventricular rupture after coronary artery bypass surgery has been reported. A case is now described in which coronary artery bypass grafting was complicated by delayed rupture, which was successfully repaired. Different etiologic factors are discussed, but the cause considered most likely was trauma from elevation of and traction on the heart in exposure of its posterior aspect.

  • 4.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Patient Safety (Closed 20130701).
    Gyllensten, Illapha Cuba
    KTH, School of Technology and Health (STH).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Software tool for analysis of breathing-related errors in transthoracic electrical bioimpedance spectroscopy measurements2012In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 407, no 1, p. 012028-Article in journal (Refereed)
    Abstract [en]

    During the last decades, Electrical Bioimpedance Spectroscopy (EBIS) has been applied in a range of different applications and mainly using the frequency sweep-technique. Traditionally the tissue under study is considered to be timeinvariant and dynamic changes of tissue activity are ignored and instead treated as a noise source. This assumption has not been adequately tested and could have a negative impact and limit the accuracy for impedance monitoring systems. In order to successfully use frequency-sweeping EBIS for monitoring time-variant systems, it is paramount to study the effect of frequency-sweep delay on Cole Model-based analysis. In this work, we present a software tool that can be used to simulate the influence of respiration activity in frequency-sweep EBIS measurements of the human thorax and analyse the effects of the different error sources. Preliminary results indicate that the deviation on the EBIS measurement might be significant at any frequency, and especially in the impedance plane. Therefore the impact on Cole-model analysis might be different depending on method applied for Cole parameter estimation.

  • 5. Ahlstrom, L.
    et al.
    Dellve, Lotta
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics. University of Borås, Sweden.
    Hagberg, M.
    Ahlberg, K.
    Women with Neck Pain on Long-Term Sick Leave — Approaches Used in the Return to Work Process: A Qualitative Study2016In: Journal of occupational rehabilitation, ISSN 1053-0487, E-ISSN 1573-3688, p. 1-14Article in journal (Refereed)
    Abstract [en]

    Purpose There are difficulties in the process of return to work (RTW) from long-term sick leave, both in general and regarding sick leave because of neck pain in particular. Neck pain is difficult to assess, problematic to rehabilitate, and hard to cure; and it is not always easy to decide whether the pain is work-related. The outcome of RTW could be dependent upon individuals’ approaches, defensive or offensive behaviors, and choices related to their self-efficacy. The aim of this study was to identify approaches used in the RTW process among women with neck pain on long-term sick leave from human service organizations. Methods This is a qualitative descriptive study based on grounded theory. A Swedish cohort of 207 women with a history of long-term sick leave with neck pain from human service organizations answered open-ended written questions at 0, 6, and 12 months, and 6 years; and 16 women were interviewed. Results Individuals expressed their coping approaches in terms of fluctuating in work status over time: either as a strategy or as a consequence. Periods of sick leave were interwoven with periods of work. The women were either controlling the interaction or struggling in the interaction with stakeholders. Conclusions Return to work outcomes may be improved if the fluctuating work status over time is taken into account in the design of rehabilitation efforts for women with a history of long-term sick leave and with chronical musculoskeletal conditions.

  • 6.
    Ahlstrom, L
    et al.
    Sahlgrenska Akademin.
    Hagberg, M
    Sahlgrenska Akademin.
    Dellve, Lotta
    KTH, School of Technology and Health (STH), Ergonomics.
    Workplace Rehabilitation and Supportive Conditions at Work: A Prospective Study2013In: Journal of occupational rehabilitation, ISSN 1053-0487, E-ISSN 1573-3688, Vol. 23, no 2, p. 248-260Article in journal (Refereed)
    Abstract [en]

    Purpose To investigate the impact of rehabilitation measures on work ability and return to work (RTW), specifically the association between workplace rehabilitation/supportive conditions at work and work ability and RTW over time, among women on long-term sick leave. Methods Questionnaire data were collected (baseline, 6 and 12 months) from a cohort of women (n = 324). Linear mixed models were used for longitudinal analysis of the repeated measurements of work ability index (WAI), work ability score and working degree. These analyses were performed with different models; the explanatory variables for each model were workplace rehabilitation, supportive conditions at work and time. Results The individuals provided with workplace rehabilitation and supportive conditions (e.g. influence at work, possibilities for development, degree of freedom at work, meaning of work, quality of leadership, social support, sense of community and work satisfaction) had significantly increased WAI and work ability score over time. These individuals scored higher work ability compared to those individuals having workplace rehabilitation without supportive conditions, or neither. Additionally, among the individuals provided with workplace rehabilitation and supportive conditions, working degree increased significantly more over time compared to those individuals with no workplace rehabilitation and no supportive conditions. Conclusion The results highlight the importance of integrating workplace rehabilitation with supportive conditions at work in order to increase work ability and improve the RTW process for women on long-term sick leave.

  • 7.
    Ahlstrom, Linda
    et al.
    Högskolan Borås.
    Larsson Fallman, Sara
    Högskolan Borås.
    Dellve, Lotta
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics. Public Health and Community Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Return to work from long-term sick leave: a five-year prospective study of the importance of adjustment latitudes at work and home2014Conference paper (Other academic)
    Abstract [en]

    Background

    Adjustment latitude among employees, i.e. adjusting work to individual’s health capacity, has been associated with successful return to work (RTW) in cross-sectional studies. The aim is to investigate the long-term importance of adjustment latitude at the workplace and at home, as well as attitudes (own and colleagues) for increased work ability (WA), working degree (WD) and health-related quality of life (HRQoL) among female human service workers (HSW) on long-term sick leave in Sweden.

    Methods

    A cohort of female HSW (n=324) on long-term sick leave (>60 day) received a questionnaire at four times (0, 6, 12, 60 months). Prevalence ratios (PR) were used to examine possible relationships between explanatory factors and outcomes. Linear mixed models were used for longitudinal analysis of the repeated measurements of WA Score (0-10), WD (0-100%) and HRQoL (0-100). Analyses were performed with different models; the explanatory variables for each model were adjustment latitude, attitudes towards breaks at work, shared or single household and amount of household work.

    Result

    Having more adjustment latitude at work was associated with both increased WA and RTW compared to having few adjustment latitude opportunities. Adjustments related to working-pace were strongly associated with increased WD (PR 3.29(95%CI=1.71-6.26)), as were adjustments to working-place. Having opportunities to take short breaks at work, and a general acceptance at work to take short breaks was associated with increased WA. At home, a higher responsibility for household work (PR 1.98(95%CI=1.33-2.95)) was related to increased WA and RTW. Individuals with possibilities for adjustment latitude, especially pace and place, at work, and an acceptance to take breaks at work, increased in WA score significantly more over time and had higher WA score compared with individuals not having such opportunities at work. These prospective results were similar for the outcome WD and HRQoL.

    Conclusions

    The results highlight the importance of possibilities for adjustment latitude at work and at home, as well as accepting attitudes to take short breaks to increase WA and RTW among female human service workers previously on long-term sick leave.

  • 8. Ahmed, Mona
    et al.
    Cerroni, Barbara
    Razuvaev, Anton
    Härmark, Johan
    KTH, School of Technology and Health (STH).
    Paradossi, Gaio
    Caidahl, Kenneth
    Gustafsson, Bjorn
    Cellular Uptake of Plain and SPION-Modified Microbubbles for Potential Use in Molecular Imaging2017In: Cellular and Molecular Bioengineering, ISSN 1865-5025, E-ISSN 1865-5033, Vol. 10, no 6, p. 537-548Article in journal (Refereed)
    Abstract [en]

    Both diagnostic ultrasound (US) and magnetic resonance imaging (MRI) accuracy can be improved by using contrast enhancement. For US gas-filled microbubbles (MBs) or silica nanoparticles (SiNPs), and for MRI superparamagnetic or paramagnetic agents, contribute to this. However, interactions of MBs with the vascular wall and cells are not fully known for all contrast media. We studied the in vitro interactions between three types of non-targeted air-filled MBs with a polyvinyl-alcohol shell and murine macrophages or endothelial cells. The three MB types were plain MBs and two types that were labelled (internally and externally) with superparamagnetic iron oxide nanoparticles (SPIONs) for US/MRI bimodality. Cells were incubated with MBs and imaged by microscopy to evaluate uptake and adhesion. Interactions were quantified and the MB internalization was confirmed by fluorescence quenching of non-internalized MBs. Macrophages internalized each MB type within different time frames: plain MBs 6 h, externally labelled MBs 25 min and internally labelled MBs 2 h. An average of 0.14 externally labelled MBs per cell were internalized after 30 min and 1.34 after 2 h; which was 113% more MBs than the number of internalized internally labelled MBs. The macrophages engulfed these three differently modified new MBs at various rate, whereas endothelial cells did not engulf MBs. Polyvinyl-alcohol MBs are not taken up by endothelial cells. The MB uptake by macrophages is promoted by SPION labelling, in particular external such, which may be important for macrophage targeting.

  • 9. Aili, K.
    et al.
    Nyman, Teresia
    KTH, School of Technology and Health (STH).
    Hillert, L.
    Svartengren, M.
    Sleep disturbances predict future sickness absence among individuals with lower back or neck-shoulder pain: A 5-year prospective study2015In: Scandinavian Journal of Public Health, ISSN 1403-4948, E-ISSN 1651-1905, Vol. 43, no 3, p. 315-323Article in journal (Refereed)
    Abstract [en]

    Background: Musculoskeletal pain is one of the most common causes of sickness absence. Sleep disturbances are often co-occurring with pain, but the relationship between sleep and pain is complex. Little is known about the importance of self-reported sleep, when predicting sickness absence among persons with musculoskeletal pain. This study aims to study the association between self-reported sleep quality and sickness absence 5 years later, among individuals stratified by presence of lower back pain (LBP) and neck and shoulder pain (NSP). Methods: The cohort (n = 2286) in this 5-year prospective study (using data from the MUSIC-Norrtälje study) was stratified by self-reported pain into three groups: no LBP or NSP, solely LBP or NSP, and oncurrent LBP and NSP. Odds ratios (ORs) for the effect of self-reported sleep disturbances at baseline on sickness absence (> 14 consecutive days), 5 years later, were calculated. Results: Within all three pain strata, individuals reporting the most sleep problems showed a significantly higher OR for all-cause sickness absence, 5 years later. The group with the most pronounced sleep problems within the concurrent LBP and NSP stratum had a significantly higher OR (OR 2.00; CI 1.09-3.67) also for long-term sickness absence (> 90days) 5 years later, compared to the group with the best sleep. Conclusions: Sleep disturbances predict sickness absence among individuals regardless of co-existing features of LBP and/or NSP. The clinical evaluation of patients should take possible sleep disturbances into account in the planning of treatments.

  • 10.
    Akay, Altug
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Dragomir, Andrei
    Erlandsson, Björn-Erik
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    A Novel-Data Mining Platform to Monitor the Outcomes of Erlontinib (Tarceva) using Social Media2014In: XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013, Springer, 2014, p. 1394-1397Conference paper (Refereed)
    Abstract [en]

    A novel data-mining method was developed to gauge the experiences of the oncology drug Tarceva. Self-organizing maps were used to analyze forum posts numerically to infer user opinion of drug Tarceva. The result is a word list compilation correlating positive and negative word cluster groups and a web of influential users on Tarceva. The implica-tions could open new research avenues into rapid data collec-tion, feedback, and analysis that would enable improved solu-tions for public health.

  • 11.
    Akay, Altug
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Dragomir, Andrei
    Erlandsson, Björn-Erik
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Assessing Antidepressants Using Intelligent Data Monitoring and Mining of Online Fora2016In: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208, Vol. 20, no 4, p. 977-986Article in journal (Refereed)
    Abstract [en]

    Depression is a global health concern. Social networks allow the affected population to share their experiences. These experiences, when mined, extracted, and analyzed, can be converted into either warnings to recall drugs (dangerous side effects), or service improvement (interventions, treatment options) based on observations derived from user behavior in depression-related social networks. Our aim was to develop a weighted network model to represent user activity on social health networks. This enabled us to accurately represent user interactions by relying on the data's semantic content. Our three-step method uses the weighted network model to represent user's activity, and network clustering and module analysis to characterize user interactions and extract further knowledge from user's posts. The network's topological properties reflect user activity such as posts' general topic as well as timing, while weighted edges reflect the posts semantic content and similarities among posts. The result, a synthesis from word data frequency, statistical analysis of module content, and the modeled health network's properties, has allowed us to gain insight into consumer sentiment of antidepressants. This approach will allow all parties to participate in improving future health solutions of patients suffering from depression.

  • 12.
    Akay, Altug
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Dragomir, Andrei
    University of Houston, Biomedical Engineering.
    Erlandsson, Björn-Erik
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Mining Social Media Big Data for Health2015In: IEEE PulseArticle, review/survey (Refereed)
    Abstract [en]

    Advances in information technology (IT) and big data are affecting nearly every facet of the public and private sectors. Social media platforms are one example of such advances: its nature allows users to connect, collaborate, and debate on any topic with comparative ease. The result is a hefty volume of user-generated content that, if properly mined and analyzed, could help the public and private health care sectors improve the quality of their products and services while reducing costs. The users of these platforms are the key to these improvements, as their valuable feedback will help improve health solutions.

  • 13.
    Alaei, Zohreh
    KTH, School of Technology and Health (STH).
    Molecular Dynamics Simulations of Axonal Membrane in Traumatic Brain Injury2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The following project presents in silico investigation of axonal damage in Diffuse Axonal Injury (DAI). When axons face a shear force, orientation of the lipids in the axonal membrane gets disrupted. Depending on the value of the force, a tensile strain causes the axons to get partially or fully deformed and in some cases a pore forms in the membrane. Using Molecular Dynamic (MD) simulation and a coarse grain model, a series of bilayers with various bilayer structure (single bilayer, parallel bilayer and cylindrical bilayer) and similar composition to biological axonal membrane were simulated. This was initially done to investigate the strain rate dependency of the bilayers, and their viscoelastic ability on returning to their original shape from their deformed forms. To achieve this, various deformation velocities were applied to the bilayers reaching 20% strain and relaxing the bilayer after. Additionally, the bilayers were deformed further until they reached a pore. It was found that the bilayers can almost recover from their deformed forms to their original length when they were deformed at 20% strain level. In conjunction, no correlation between the deformation velocity and lipid deformation was observed. Further, it was found that bilayers with different lipid percentage to axonal bilayer has different strain values for water penetration and for pore formation. The strain value for cylindrical bilayer was found very high compared to the strain values found in vitro. The strain for pore formation of parallel and single bilayer was found to be around 80% to 90% and for water penetration was found to be 70% for single bilayer and 50% for parallel bilayer. A slight difference in strain for pore formation between single and parallel bilayer was found which showed the bilayer structure can play a role in simulation results. The effect of the length in the simulations results was also observed where shorter bilayers showed lower strain for pore formation compared to longer bilayers. 

  • 14. Albrecht, Stefano V.
    et al.
    Beck, J. Christopher
    Buckeridge, David L.
    Botea, Adi
    Caragea, Cornelia
    Chi, Chi-hung
    Damoulas, Theodoros
    Dilkina, Bistra
    Eaton, Eric
    Fazli, Pooyan
    Ganzfried, Sam
    Giles, C. Lee
    Guillet, Sebastien
    Holte, Robert
    Hutter, Frank
    Koch, Thorsten
    Leonetti, Matteo
    Lindauer, Marius
    Machado, Marlos C.
    Malitsky, Yuri
    Marcus, Gary
    Meijer, Sebastiaan
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Rossi, Francesca
    Shaban-Nejad, Arash
    Thiebaux, Sylvie
    Veloso, Manuela
    Walsh, Toby
    Wang, Can
    Zhang, Jie
    Zheng, Yu
    Reports on the 2015 AAAI Workshop Series2015In: The AI Magazine, ISSN 0738-4602, Vol. 36, no 2, p. 90-101Article in journal (Refereed)
    Abstract [en]

    AAAI's 2015 Workshop Program was held Sunday and Monday, January 25-26, 2015, at the Hyatt Regency Austin Hotel in Austin, Texas, USA. The AAAI-15 workshop program included 16 workshops covering a wide range of topics in artificial intelligence. Most workshops were held on a single day. The titles of the workshops included Algorithm Configuration; Artificial Intelligence and Ethics; Artificial Intelligence Applied to Assistive Technologies and Smart Environments; Artificial Intelligence for Cities; Artificial Intelligence for Transportation: Advice, Inter-activity, and Actor Modeling; Beyond the Turing Test; Computational Sustainability; Computer Poker and Imperfect Information; Incentive and Trust in E-Communities; Knowledge, Skill, and Behavior Transfer in Autonomous Robots; Learning for General Competency in Video Games; Multiagent Interaction without Prior Coordination; Planning, Search, and Optimization; Scholarly Big Data: AI Perspectives, Challenges, and Ideas; Trajectory-Based Behaviour Analytics; and World Wide Web and Public Health Intelligence.

  • 15. Alkner, B.
    et al.
    Norrbrand, Lena
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Tesch, P.
    Neuromuscular adaptations following 90 days bed rest with or without resistance exercise.2016In: Aerospace Medicine and Human Performance, ISSN 2375-6322, Vol. 87, no 7, p. 610-617Article in journal (Refereed)
  • 16.
    Alvarez, Victor
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Fahlstedt, Madelen
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Halldin, Peter
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Importance of neck muscle tonus in head kinematics during pedestrian accidents2013In: 2013 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury, 2013, p. 747-761Conference paper (Refereed)
    Abstract [en]

    Unprotected pedestrians are an exposed group in the rural traffic and the most vulnerable human body region is the head which is the source of many fatal injuries. This study was performed to gain a better understanding of the influence that the neck muscle tonus has on head kinematics during pedestrian accidents. This was done using a detailed whole body FE model and a detailed FE vehicle model. To determine the influence of the muscle tonus a series of simulations were performed where the vehicle speed, pedestrian posture and muscle tonus were varied. Since the human reaction time for muscle activation is in the order of the collision time, the pedestrian was assumed to be prepared for the oncoming vehicle in order to augment the possible influence of muscle tonus. From the simulations performed, kinematic data such as head rotations, trajectory and velocities were extracted for the whole collision event, as well as velocity and accelerations at head impact. These results show that muscle tonus can influence the head rotation during a vehicle collision and therefore alter the head impact orientation. The level of influence on head rotation was in general lower than when altering the struck leg forward and backward, but in the same order of magnitude for some cases. The influence on head accelerations was higher due to muscle tonus than posture in all cases.

  • 17. Amon, M
    et al.
    Keramidas, Michail E.
    Kounalakis, S
    Kölegård, Roger
    KTH, School of Technology and Health (STH), Environmental Physiology (Closed 20130701).
    Simpson, L
    MacDonald, I
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology (Closed 20130701).
    Mekjavic, IB
    Effect of hypoxia on postprandial blood glucose and insulin response2011Conference paper (Refereed)
  • 18. Andersson, Thord
    et al.
    Romu, Thobias
    Karlsson, Anette
    Norén, Bengt
    Forsgren, Mikael F
    Smedby, Örjan
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization. Linköping University.
    Kechagias, Stergios
    Almer, Sven
    Lundberg, Peter
    Borga, Magnus
    Leinhard, Olof Dahlqvist
    Consistent intensity inhomogeneity correction in water-fat MRI2015In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 42, no 2Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To quantitatively and qualitatively evaluate the water-signal performance of the consistent intensity inhomogeneity correction (CIIC) method to correct for intensity inhomogeneities

    METHODS: Water-fat volumes were acquired using 1.5 Tesla (T) and 3.0T symmetrically sampled 2-point Dixon three-dimensional MRI. Two datasets: (i) 10 muscle tissue regions of interest (ROIs) from 10 subjects acquired with both 1.5T and 3.0T whole-body MRI. (ii) Seven liver tissue ROIs from 36 patients imaged using 1.5T MRI at six time points after Gd-EOB-DTPA injection. The performance of CIIC was evaluated quantitatively by analyzing its impact on the dispersion and bias of the water image ROI intensities, and qualitatively using side-by-side image comparisons.

    RESULTS: CIIC significantly ( P1.5T≤2.3×10-4,P3.0T≤1.0×10-6) decreased the nonphysiological intensity variance while preserving the average intensity levels. The side-by-side comparisons showed improved intensity consistency ( Pint⁡≤10-6) while not introducing artifacts ( Part=0.024) nor changed appearances ( Papp≤10-6).

    CONCLUSION: CIIC improves the spatiotemporal intensity consistency in regions of a homogenous tissue type.

  • 19. Andrade, Pedro Amarante
    et al.
    Wistbacka, Greta
    Larsson, Hans
    Sodersten, Maria
    Hammarberg, Britta
    Simberg, Susanna
    Svec, Jan G.
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine. Karolinska Institutet, Sweden.
    The Flow and Pressure Relationships in Different Tubes Commonly Used for Semi-occluded Vocal Tract Exercises2016In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 30, no 1, p. 36-41Article in journal (Refereed)
    Abstract [en]

    This experimental study investigated the back pressure (Pback) versus flow (U) relationship for 10 different tubes commonly used for semi-occluded vocal tract exercises, that is, eight straws of different lengths and diameters, a resonance tube, and a silicone tube similar to a Lax Vox tube. All tubes were assessed with the free end in air. The resonance tube and silicone tube were further assessed with the free end under water at the depths from 1 to 7 cm in steps of 1 cm. The results showed that relative changes in the diameter of straws affect Pback considerably more compared with the same amount of relative change in length. Additionally, once tubes are submerged into water, Pback needs to overcome the pressure generated by the water depth before flow can start. Under this condition, only a small increase in Pback was observed as the flow was increased. Therefore, the wider tubes submerged into water produced an almost constant Pback determined by the water depth, whereas the thinner straws in air produced relatively large changes to Pback as flow was changed. These differences may be taken advantage of when customizing exercises for different users and diagnoses and optimizing the therapy outcome.

  • 20.
    Andreasson, Jörgen
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Ahlstrom, Linda
    Eriksson, Andrea
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Dellve, Lotta
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    The importance of healthcare managers’ organizational preconditions and support resources for their appraisal of planned change and its outcomes2017In: Journal of Hospital Administration, ISSN 1927-6990, E-ISSN 1927-7008, Vol. 6, no 1Article in journal (Refereed)
    Abstract [en]

    Background: Healthcare managers are expected to lead and manage planned organizational change intended to improve healthcare process quality. However, their complex working conditions offer limited decision control, and healthcare managers often feel ill prepared and inadequately supported to perform their duties. Healthcare managers have previously described their need for organizational support, but we lack knowledge of the preconditions and resources that help managers implement planned change.Methods: This prospective cohort study examined healthcare managers at three Swedish hospitals implementing lean production and two Swedish hospitals implementing their own improvement model. Questionnaire data from 2012, 2103, and 2014 were used in following up. We used t-tests and a linear mixed model design in analysing the data.Results: Healthcare managers who perceived strong support from managers, employees, colleagues, and the organization and managers with the longest managerial experience had the least negative appraisal of change. Managers who perceived strong support from employees, management, and the organizational structure perceived higher levels of healthcare process quality.Conclusions: Long managerial experience and strong support from managers, employees, and the organization are important formanagers’ appraisal of, work on, and successful implementation of planned change. Top management must therefore ensure that the healthcare managers have sufficient managerial experience and support before they delegate to them the responsibility to implement planned change.

  • 21.
    Andreasson, Jörgen
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Eriksson, Andrea
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Dellve, Lotta
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Health care managers' views on and approaches to implementing models for improving care processes2016In: Journal of Nursing Management, ISSN 0966-0429, E-ISSN 1365-2834, Vol. 24, no 2Article in journal (Refereed)
    Abstract [en]

    Aim: To develop a deeper understanding of health-care managers' views on and approaches to the implementation of models for improving care processes. Background: In health care, there are difficulties in implementing models for improving care processes that have been decided on by upper management. Leadership approaches to this implementation can affect the outcome. Method: In-depth interviews with first- and second-line managers in Swedish hospitals were conducted and analysed using grounded theory. Results: 'Coaching for participation' emerged as a central theme for managers in handling top-down initiated process development. The vertical approach in this coaching addresses how managers attempt to sustain unit integrity through adapting and translating orders from top management. The horizontal approach in the coaching refers to managers' strategies for motivating and engaging their employees in implementation work. Conclusion and implications for nursing management: Implementation models for improving care processes require a coaching leadership built on close manager-employee interaction, mindfulness regarding the pace of change at the unit level, managers with the competence to share responsibility with their teams and engaged employees with the competence to share responsibility for improving the care processes, and organisational structures that support process-oriented work. Implications for nursing management are the importance of giving nurse managers knowledge of change management.

  • 22.
    Anthikat-Albert, Benedict D.
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Yiallourou, Theresia I.
    Haba-Rubio, Jose
    Heinzer, Raphael
    Fonari, Eleonora
    Chevrey, Nicolas
    Santini, Francesco
    Stergiopulos, Nikolaos
    Martin, Bryn A.
    Continuous positive airway pressure impacts cerebral blood flow and cerebrospinal fluid motion: A phase contrast mri study2012In: Proceedings Of The ASME 2012 Summer Bioengineering Conference, Parts A and B, ASME Press, 2012, p. 569-570Conference paper (Refereed)
    Abstract [en]

    The physiological impacts of continuous positive airway pressure (CPAP) are not yet fully understood. In this study we developed an MRI protocol to assess the impact of CPAP on cerebral hemodynamics and cerebrospinal fluid (CSF) hydrodynamics in the upper cervical spine. MRI measurements were obtained on 14 healthy male subjects. The preliminary results indicated that the CSF pulsation decreased and venous outflow was altered with CPAP usage in comparison to the baseline values. Cerebral arterial flow was not impacted by CPAP usage. These findings support the hypothesis that the CSF system can act to dampen cerebral blood flow (CBF) pulsations.

  • 23.
    Antonsson, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Ergonomics (Closed 20130701).
    Christensson, Bengt
    KTH. IVL Svenska Miljöinstitutet.
    Berge, Johan
    Rättsmedicinalverket.
    Sjögren, Bengt
    Karolinska Institutet.
    Fatal Carbon Monoxide Intoxication After AcetyleneGas Welding of Pipes2013In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 57, no 5, p. 662-666Article in journal (Refereed)
    Abstract [en]

    Acetylene gas welding of district heating pipes can result in exposure to high concentrations of carbon monoxide. A fatal case due to intoxication is described. Measurements of carbon monoxide revealed high levels when gas welding a pipe with closed ends. This fatality and these measurements highlight a new hazard, which must be promptly prevented.

  • 24.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    A systems analysis of a target group of enterprises: A new way forward for the dissemination of research results and sustainable technologies2006Conference paper (Other academic)
  • 25.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    An interactive Internet tool supporting risk management in SMEs: The Chemical Guide (KemiGuiden)2005Conference paper (Other academic)
  • 26.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics. IVL Svenska Miljöinstitutet AB.
    Företagshälsovård2014In: Människan i arbetslivet: Teori och praktik / [ed] Eva Holmström, Kerstina Olsson, Lund: Studentlitteratur AB , 2014, 2:1, p. 199-223Chapter in book (Refereed)
  • 27.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Improving work environment in small enterprises: The need for a holistic perspective and adaptation to small enterprise reality2007Conference paper (Other academic)
  • 28.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Interviews with employees reporting work-related injuries as the basis for intervention2011Conference paper (Refereed)
  • 29.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Kapitel 1.: Varför företagshälsovård?2011In: Framgångsrik företagshälsovård: Möjligheter och metoder, Stockholm: Norstedts Juridik AB, 2011Chapter in book (Other (popular science, discussion, etc.))
    Abstract [en]

    Företagshälsovård, fhv, är en viktig aktör i välfärdssamhället. Den ska bidra både till att förebygga ohälsa och främja hälsa samt till att ska pagoda och säkra arbetsplatser där de anställda inte riskerar att skadas eller bli sjuka. Omvärldens förväntningar är höga. För att uppfylla dem krävs att fhv har en bred kompetens och att arbetet bygger på samarbete både mellan olika kompetenser inom den egna verksamheten och med de företag och organisationer som fhv arbetar för.

  • 30.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Kapitel 4: Att förstå kunden2011In: Framgångsrik företagshälsovård: Möjligheter och metoder, Stockholm: Norstedts Juridik AB, 2011Chapter in book (Other (popular science, discussion, etc.))
    Abstract [en]

    Verksamhet, ekonomiska förutsättningar, drivkrafter och värderingar varierar för FHV:s kunder. För att lyckas i arbetet med att stödja kunden, behöver FHV förstå hur dessa faktorer påverkar arbetsmiljöarbetet och hur insatser bäst anpassas till varje kund.

  • 31.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Kapitel 9: Företagshälsovård och småföretag2011In: Framgångsrik företagshälsovård: Möjligheter och metoder, Stockholm: Norstedts Juridik AB, 2011Chapter in book (Other (popular science, discussion, etc.))
    Abstract [en]

    Många företag med mindre än 50 anställda har någon form av avtal med FHV och de flesta är nöjda. Deras anställda står dock bara för en liten andel av alla arbetstagare som har tillgång till fhv. En stor del av småföretagen utnyttjar inte FHV:s breda kompetens utan anlitar dem främst för hälsoundersökningar. Det betyder att det finns en stor utvecklingspotential om man kan få de mindre företagen att efterfråga fler tjänster.

  • 32.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Procurement demands: a management strategy for sustainability2011Conference paper (Refereed)
  • 33.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Risk assessment tools for small enterprises: evaluation of uptake and effect2009In: USE 2009: Programme and abstract book, 2009, p. 118-118Conference paper (Other academic)
    Abstract [en]

    Background: Risk assessment is a core component in the management of the working environment. Risk assessment helps identify and prioritize risks and reduce risks through implementation of control measures. Aim: To evaluate how tools for risk assessment are used by small enterprises and what the result is from using the tools. Method: Randomly selected small enterprises in printing and electroplating industry were contacted and asked to participate in an evaluation of tools for chemical risk assessment developed to suit small enterprises. An initial interview was made with the enterprises accepting to participate in the testing, aiming at surveying how they use to assess chemical risks. The enterprises were provided with one out of six tools. Ten enterprises in each sector were asked to test each tool, adding up to 20 enterprises testing each tool. After three and six months the enterprise was contacted. If they had tested the tool, a new interview was made, exploring their opinion on the tool and their experiences from using it. Enterprises not having tested the tools were also interviewed about the reasons why they did not use the tool they were provided. In enterprises having used the tools, an expert risk assessment was made and compared to the risk assessment of the enterprise in order to evaluate the quality of the risk assessment tool and the enterprise's use of it. Result: More than 60 % of the enterprises accepted to test the tools, reflecting an interest and concern for chemical risks in their work environment. The follow-up interviews are currently conducted and will be finished during April 2009. The results show how risk assessment works in practice in small enterprises. The study has revealed several problems with different tools and some unexpected results. One example is that several enterprises have concluded that they are content with their old method for risk assessment, which was using safety data sheets, reflecting a profound lack of understanding of what risk assessment is about. Results from the evaluation will be presented, showing how small enterprises perceive the different kinds of tools tested and what the outcomes in terms of quality are of the tested tools. The results will be discussed in relation to the enterprises and their previous experience of and knowledge about risk assessment.

  • 34.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Risk management in small enterprises: A system analysis of what works and what doesn´t2006Conference paper (Other academic)
  • 35.
    Antonsson Lundberg, Ann-Beth
    KTH, School of Technology and Health (STH), Ergonomics.
    Studiehandledning2011In: Framgångsrik företagshälsovård: Möjligheter och metoder, Stockholm: Norstedts Juridik AB, 2011Chapter in book (Other (popular science, discussion, etc.))
  • 36.
    Antonsson Lundberg, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics. IVL Svenska Miljöinstitutet AB.
    Hasle, Peter
    Aalborg Universitet.
    How can the context affect what strategies are effective in improving the working environment in small companies?2015Conference paper (Other academic)
  • 37.
    Antonsson Lundberg, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics. IVL Svenska Miljöinstitutet AB.
    Hasle, Peter
    Aalborg Universitet.
    What kind of knowledge do small companies need to improve their working environment?2015Conference paper (Other academic)
  • 38.
    Antonsson Lundberg, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Holmefalk, C
    Hägg, GM
    Kumar, R
    Scmidt, L
    Hur förbättra städares arbetsförhållanden?2007In: NES2007 / [ed] Cecilia Berlin, Lars-Ola Bligård, 2007Conference paper (Other academic)
  • 39.
    Antonsson Lundberg, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Nyman, Teresia
    KI, Institutionen för folkhälsovetenskap.
    Education for Occupational health service professionals in different countries2011Conference paper (Other academic)
  • 40.
    Antonsson Lundberg, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Schmidt, L
    Swedish Occupational Health Services and Small Enterprises: How does it work?2005In: OHS2005 Conference Proceedings: SJWEH Supplements 2005; no 1, 2005Conference paper (Other academic)
  • 41.
    Antonsson Lundberg, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Verschoor, Atie H
    Ild care foundation, Maastricht.
    General Purpose of WE-LCA2004In: Working Environment in Life-Cycle Assessment / [ed] Poulsen, Jensen, Antonsson, Bengtsson, Karling, Schmidt, Brekke, Becker, Verschoor, Society of Environmental Toxicology and Chemistry (SETAC), 2004Chapter in book (Other (popular science, discussion, etc.))
  • 42. Arman, Rebecka
    et al.
    Wikström, Ewa
    Tengelin, Ellinor
    Dellve, Lotta
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Work activities and stress among managers in health care2012In: The Work of Managers: Towards a Practice Theory of Management / [ed] Tengblad, Sten, Oxford: Oxford University Press, 2012, 1Chapter in book (Other academic)
    Abstract [en]

    This chapter reports on the work activities, time-use patterns, and stress patterns of ten health care managers in Sweden. The qualitative and quantitative evidence reveals the fragmentation in their nine-hour working days where each activity, on average, lasts only ten minutes. The time-use patterns vary individually though some patterns are related to position and unit type. Activities deal with the coexisting and competing logics of employeeship, administration, and strategy and risk handling. None of the managers’ approaches for handling the multiple legitimation processes and delimiting their workload boundaries really challenges the complexity of the coexistence of the multiple logics or the boundlessness of their working hours. Using biophysical measures, the research finds that stress reported by the managers is caused by (a) interruptions during challenging tasks and (b) personal situations such as private dilemmas and conflict-loaded or ineffective meetings. It is important to acknowledge managers’ fragmented working situation and to recognize that management should be seen as collective process, or as part of an administrative system.

  • 43.
    Aronsson, K
    et al.
    Karolinska Institutet.
    Teär Fahnehjelm, K
    Karolinska Institutet.
    Nylén, P
    KTH, School of Technology and Health (STH), Ergonomics.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Synergonomi och ögonbesvär hos personal på ögonsjukhus.2012Conference paper (Other academic)
    Abstract [sv]

    Ögonläkare, ögonsjuksköterskor, optiker och annan personal på ögonsjukhus arbetar ofta med synkrävande arbetsuppgifter i dämpad belysning eller helt utan allmänbelysning. Inför den planerade byggnationen av ett nytt ögonsjukhus i Stockholm ca år 2018 gjordes en enkätstudie för att kartlägga ögonbesvär och trötthet hos personalen på S:t Eriks Ögonsjukhus. Studien som är ett multidisciplinärt samarbetsprojekt mellan S:t Erik, Karolinska Institutet och Kungliga Tekniska Högskolan, syftar till att optimera belysning, dagsljusinsläpp och ljusmiljö vid det nya ögonsjukhuset.

    Totalt 265 anställda på S:t Eriks Ögonsjukhus samt 60 röntgenläkare och 45 barnläkare, varav de senare två  utgjorde jämförelsegrupper, inviterades till  studien.  Enkäten som distribuerades baserades på synergonomienkäter av Knave och Hemphälä och bestod av 31 validerade frågor om subjektiva ögonbesvär, nuvarande belysning, tillgång till dagsljus och välbefinnande. Ögonbesvären räknades om till ett gruppmedelvärde (ögonbesvärsindex) med avseende på svårighetsgrad och frekvens. Studien är godkänd av Etikprövningsnämnden. 

    Nittiosex av 265 (33%) anställda på S:t Eriks Ögonsjukhus hade t o m juni 2012 besvarat enkäten tillsammans med 23 röntgenläkare (38%) och 14 barnläkare (31%). Ögonbesvär som torrhets- och gruskänsla var vanligt förekommande hos alla yrkesgrupper på ögonsjukhuset och generellt vanligare hos kvinnor. Då samtliga grupper jämfördes med avseende på ögonbesvärsindex var skillnaden mellan män och kvinnor statistiskt säkerställd (p<0,05). Röntgenläkarna rapporterade högst ögonbesvärsindex och barnläkarna lägst, skillnaden mellan dessa yrkesgrupper var signifikant (p<0,05). Ögonpersonal och röntgenläkare som rapporterade att de ofta arbetade i mörker, associerade detta med  ökad trötthet i högre grad än  med barnläkarna (p<0,05).

    Ögonbesvär var vanliga hos ögonpersonalen inkluderade i studien. Den grupp som arbetade mest i mörker hade mer ögonbesvär än den grupp som arbetade minst i mörker. Kvinnor hade mer ögonbesvär än män. Arbete i mörker ökade den subjektiva känslan av trötthet . Optimala ljusförhållanden och bra synergonomi bör ges hög prioritet vid planering av ett nytt ögonsjukhus.

  • 44.
    Aronsson, K
    et al.
    Karolinska Institutet.
    Teär Fahnhjelm, K
    Karolinska Institutet.
    Nylén, P
    KTH, School of Technology and Health (STH), Ergonomics.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Visual ergonomics and eye strain in eye careprofessionals2012In: NES2012 Proceedings: Ergonomics for sustainability and growth / [ed] Ann-Beth Antonsson, Göran M Hägg, 2012Conference paper (Other academic)
    Abstract [en]

    Eye care professionals spend many hours a day in darkness performing visually demanding tasks. A new eye hospital will be built in Stockholm 2018. The current lighting, logistics, and working conditions are analysed in a multidisciplinary project aiming to optimise settings in the new hospital. The main purpose of the present project was to study visual ergonomics and current eye strain in employees at an eye hospital. Ninety-six employees answered a validated questionnaire regarding their experiences of light, visual ergonomics and eye strain problems. Twenty-three radiologists and 14 paediatricians at a university hospital were used as comparison groups. Eye strain was common in all departments at the hospital but was significantly more common only among radiologists compared to paediatricians. Overall, women experienced significantly more eye strain than men.

  • 45. Arvedsen, SK
    et al.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology. KTH, School of Technology and Health (STH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Kölegård, Roger
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology. KTH, School of Technology and Health (STH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Petersen, L. G.
    Damgaard, M.
    Body height and arterial pressure in seated and supine young males during +2 G centrifugation2015In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology, ISSN 0363-6119, E-ISSN 1522-1490, Vol. 309, no 9Article in journal (Refereed)
    Abstract [en]

    It is known that arterial pressure correlates positively with body height in males and it has been suggested that this is due to the increasing vertical hydrostatic gradient from the heart to the carotid baroreceptors. Therefore we tested the hypothesis that a higher gravitoinertial stress induced by the use of a human centrifuge would increase mean arterial pressure (MAP) more in tall than in short males in the seated position. In short (162-171cm, n=8) and tall (194-203cm, n=10) healthy males (18-41y), brachial arterial pressure, heart rate (HR) and cardiac output were measured during +2G centrifugation, while they were seated upright with the legs kept horizontal (+2Gz). In a separate experiment, the same measurements were done with the subjects supine (+2Gx). During +2Gz MAP increased in the short (22±2 mmHg, p<0.0001) and tall (23±2 mmHg, p<0.0001) males, with no significant difference between the groups. HR increased more (p<0.05) in the tall than in the short group (14±2 versus 7±2 bpm). Stroke volume (SV) decreased in the short group (26±4 mL, p=0.001) and more so in the tall group (39±5 mL, p<0.0001; short vs tall p=0.047). During +2GX, systolic arterial pressure increased (p<0.001) and SV (p=0.012) decreased in the tall group only. In conclusion, during +2Gz MAP increased in both short and tall males with no difference between the groups. However, in the tall group HR increased more during +2Gz which could be caused by a larger hydrostatic pressure gradient from heart to head leading to greater inhibition of the carotid baroreceptors.

  • 46.
    Asplund, Maria
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Conjugated Polymers for Neural Interfaces: Prospects, possibilities and future challenges2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Within the field of neuroprosthetics the possibility to use implanted electrodes for communication with the nervous system is explored. Much effort is put into the material aspects of the electrode implant to increase charge injection capacity, suppress foreign body response and build micro sized electrode arrays allowing close contact with neurons. Conducting polymers, in particular poly(3,4-ethylene dioxythiophene) (PEDOT), have been suggested as materials highly interesting for such neural communication electrodes. The possibility to tailor the material both mechanically and biochemically to suit specific applications, is a substantial benefit with polymers when compared to metals. PEDOT also have hybrid charge transfer properties, including both electronic and ionic conduction, which allow for highly efficient charge injection.

     

    Part of this thesis describes a method of tailoring PEDOT through exchanging the counter ion used in electropolymerisation process. Commonly used surfactants can thereby be excluded and instead, different biomolecules can be incorporated into the polymer. The electrochemical characteristics of the polymer film depend on the ion. PEDOT electropolymerised with heparin was here determined to have the most advantageous properties. In vitro methods were applied to confirm non-cytotoxicity of the formed PEDOT:biomolecular composites. In addition, biocompatibility was affirmed for PEDOT:heparin by evaluation of inflammatory response and neuron density when implanted in rodent cortex.

     

    One advantage with PEDOT often stated, is its high stability compared to other conducting polymers. A battery of tests simulating the biological environment was therefore applied to investigate this stability, and especially the influence of the incorporated heparin. These tests showed that there was a decline in the electroactivity of PEDOT over time. This also applied in phosphate buffered saline at body temperature and in the absence of other stressors. The time course of degradation also differed depending on whether the counter ion was the surfactant polystyrene sulphonate or heparin, with a slightly better stability for the former.

     

    One possibility with PEDOT, often overlooked for biological applications, is the use of its semi conducting properties in order to include logic functions in the implant. This thesis presents the concept of using PEDOT electrochemical transistors to construct textile electrode arrays with in-built multiplexing. Using the electrolyte mediated interaction between adjacent PEDOT coated fibres to switch the polymer coat between conducting and non conducting states, then transistor function can be included in the conducting textile. Analogue circuit simulations based on experimentally found transistor characteristics proved the feasibility of these textile arrays. Developments of better polymer coatings, electrolytes and encapsulation techniques for this technology, were also identified to be essential steps in order to make these devices truly useful.

     

    In summary, this work shows the potential of PEDOT to improve neural interfaces in several ways. Some weaknesses of the polymer and the polymer electronics are presented and this, together with the epidemiological data, should point in the direction for future studies within this field.

  • 47.
    Asplund, Maria
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Nilsson, Mats
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Jacobsson, Anders
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Incidence of traumatic peripheral nerve injuries and amputations in Sweden between 1998 and 20062008In: Neuroepidemiology, ISSN 0251-5350, E-ISSN 1423-0208Article in journal (Refereed)
    Abstract [en]

    Background: To define the epidemiological pattern of nerve injuries and traumatic amputations in Sweden, 1998-2006, and investigate possible targets for emerging neural engineering and neuroprosthetic technologies.

    Methods: The Swedish Hospital Discharge Register was used as basis of information, including data from all public in-patient care, excluding out-patient data. ICD-10 codes were screened for nerve injuries and traumatic amputations of high incidence or in-patient care time. Selected codes, causing factors, age and gender distribution were discussed in detail, and potential targets for tailored solutions were identified.

    Results: Incidence rate was determined to 13.9 for nerve injuries and 5.21 for amputations per 100 000 person-yrs. The majority of injuries occurred at wrist and hand level although it could be concluded that these are often minor injuries requiring less than a week of hospitalization. The single most care consuming nerve injury was brachial plexus injury constituting, in average, 68 injuries and 960 hospital days annually. When minor amputations of fingers and toes were disregarded, most frequent site of amputation was between knee and ankle (24 patients / year).

    Conclusions: Based on analysis of incidence and care time, we find that brachial plexus injuries and lower leg amputations should be primary targets of these new technologies.

  • 48.
    Atefi, Seyed Reza
    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).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Electrical Bioimpedance cerebral monitoring. Preliminary results from measurements on stroke patients2012In: Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE, IEEE , 2012, p. 126-129Conference paper (Refereed)
    Abstract [en]

    Electrical Bioimpedance Spectroscopy (EBIS) is currently used in different tissue characterization applications. In this work we aim to use EBIS to study changes in electrical properties of the cerebral tissues after an incident of hemorrhage/ischemic stroke. To do so a case-control study was conducted using six controls and three stroke cases. The preliminary results of this study show that by using Cole-based analysis on EBIS measurements and analyzing the Cole parameters R0 and R∞, it is possible to detect changes on electrical properties of cerebral tissue after stroke. 

  • 49.
    B. Kumar, Ramakrishnan
    et al.
    Karolinska institutet, Sverige.
    Zhu, Lin
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Structural Biotechnology.
    Hebert, Hans
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Structural Biotechnology. Karolinska institutet, Sverige.
    Jegerschöld, Caroline
    Karolinska institutet, Sverige.
    Method to Visualize and Analyze Membrane Interacting Proteins by Transmission Electron Microscopy2017In: Journal of Visualized Experiments, ISSN 1940-087X, E-ISSN 1940-087X, no 121, article id e55148Article in journal (Refereed)
    Abstract [en]

    Monotopic proteins exert their function when attached to a membrane surface, and such interactions depend on the specific lipid composition and on the availability of enough area to perform the function. Nanodiscs are used to provide a membrane surface of controlled size and lipid content. In the absence of bound extrinsic proteins, sodium phosphotungstate-stained nanodiscs appear as stacks of coins when viewed from the side by transmission electron microscopy (TEM). This protocol is therefore designed to intentionally promote stacking; consequently, the prevention of stacking can be interpreted as the binding of the membrane-binding protein to the nanodisc. In a further step, the TEM images of the protein-nanodisc complexes can be processed with standard single-particle methods to yield low-resolution structures as a basis for higher resolution cryoEM work. Furthermore, the nanodiscs provide samples suitable for either TEM or non-denaturing gel electrophoresis. To illustrate the method, Ca2+-induced binding of 5-lipoxygenase on nanodiscs is presented.

  • 50. Bak, Zoltan
    et al.
    Sjöberg, Folke
    Hälsouniversitetet, Linköping University.
    Eriksson, Olle
    Steinvall, Ingrid
    Janerot-Sjoberg, Birgitta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Hemodynamic changes during resuscitation after burns using the Parkland formula2009In: Journal of Trauma, ISSN 0022-5282, E-ISSN 1529-8809, Vol. 66, no 2, p. 329-336Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The Parkland formula (2-4 mL/kg/burned area of total body surface area %) with urine output and mean arterial pressure (MAP) as endpoints for the fluid resuscitation in burns is recommended all over the world. There has recently been a discussion on whether central circulatory endpoints should be used instead, and also whether volumes of fluid should be larger. Despite this, there are few central hemodynamic data available in the literature about the results when the formula is used correctly.

    METHODS: Ten burned patients, admitted to our unit early, and with a burned area of >20% of total body surface area were investigated at 12, 24, and 36 hours after injury. Using transesophageal echocardiography, pulmonary artery catheterization, and transpulmonary thermodilution to monitor them, we evaluated the cardiovascular coupling when urinary output and MAP were used as endpoints.

    RESULTS: Oxygen transport variables, heart rate, MAP, and left ventricular fractional area, did not change significantly during fluid resuscitation. Left ventricular end-systolic and end-diastolic area and global end-diastolic volume index increased from subnormal values at 12 hours to normal ranges at 24 hours after the burn. Extravascular lung water: intrathoracal blood volume ratio was increased 12 hours after the burn.

    CONCLUSIONS: Preload variables, global systolic function, and oxygen transport recorded simultaneously by three separate methods showed no need to increase the total fluid volume within 36 hours of a major burn. Early (12 hours) signs of central circulatory hypovolemia, however, support more rapid infusion of fluid at the beginning of treatment.

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