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  • 851.
    Ahl, Ing-Marie
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Protein Engineering of Extracellular Superoxide Dismutase: Characterization of Binding to Heparin and Cellular Surfaces2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Accumulating evidence indicates that oxygen free radicals are involved in many diseases and pathological conditions, such as aging, inflammation, reperfusion damage of ischemic tissue and various cardiovascular diseases. Extracellular superoxide dismutase (ECSOD) thus plays a major role in the maintenance of cells by providing protection against these toxic substances in the extracellular space. Various animal studies have shown that ECSOD has the ability to protect against many of these disorders, and interest has therefore evolved in the potential therapeutic use of the enzyme.

    However, despite strenuous efforts, large-scale production of the enzyme has not been achieved. To overcome this problem, a mimic of the enzyme, PseudoECSOD, has previously

    been constructed. This chimera is easy to produce in large amounts and has all the structural, enzymatic and heparin-binding characteristics of ECSOD, making it a potential substitute for ECSOD in therapeutic situations. However, the copper content of PseudoECSOD has been shown to be rather low, and since the copper ion is very important for the catalytic function of the enzyme, a production system that utilizes a copper chaperone for proper insertion of copper into the active site of the enzyme was constructed. The results show that the copper content of PseudoECSOD produced by this system is close to 100 %.

    In order to use PseudoECSOD therapeutically, further investigations of its binding capability and protective properties are needed. Therefore, the binding of ECSOD and PseudoECSOD to heparin was investigated using isothermal titration calorimetry. The results show that although some purely ionic interactions are important for the binding between ECSOD and heparin, there is also a substantial contribution from non-ionic interactions. The investigation also showed that the C-terminal domain is the only part of ECSOD that contributes to productive binding, and that the binding of PseudoECSOD and ECSOD to heparin is similar.

    In addition, analysis of mutant proteins strongly indicated that the amino acids R210, K211 and R214 are important for optimal binding of ECSOD to heparin, accounting for about 30 % of the total binding energy. The structural placement of these amino acids in an α-helix also confirms the hypothesis postulated by Margalit et al., that a common structural motif for heparin-binding proteins may be two positively charged amino acids at a distance of approximately 20 Å in the 3D-structure, facing opposite directions of a α-helix. The importance of these residues was also confirmed by analysis of a phage display library of the C-terminal domain of ECSOD.

    The binding of PseudoECSOD to heparan sulfate on cell surfaces of two different cell types, HepG2 and endothelial cells, was also investigated. The results clearly show that PseudoECSOD binds to these cells in a very similar manner to ECSOD. To investigate the protective properties of PseudoECSOD against ischemia-reperfusion injuries, an isolated rabbit heart model was used. The results indicate that the enzyme has a protective effect. However, more experiments using the rabbit heart and other animal models are needed to identify the optimal dose for protective purposes. The protective properties of PseudoECSOD in human tissue should also be thoroughly investigated.

    In summary, the findings in these studies, together with earlier results showing the close resemblance of PseudoECSOD to ECSOD in structural, enzymatic and heparin-binding properties, further support the proposition that PseudoECSOD may be a good substitute for ECSOD to use in therapeutic interventions.

    List of papers
    1. Thermodynamic Characterization of the Interaction between the C-Terminal Domain of Extracellular Superoxide Dismutase and Heparin by Isothermal Titration Calorimetry
    Open this publication in new window or tab >>Thermodynamic Characterization of the Interaction between the C-Terminal Domain of Extracellular Superoxide Dismutase and Heparin by Isothermal Titration Calorimetry
    2009 (English)In: BIOCHEMISTRY, ISSN 0006-2960, Vol. 48, no 41, p. 9932-9940Article in journal (Refereed) Published
    Abstract [en]

    Extracellular superoxide dismutase (ECSOD) interacts with heparin through its C-terminal domain. In this study we used isothermal titration calorimetry (ITC) to get detailed thermodynamic information about the interaction. We have shown that the interaction between ECSOD and intestinal mucosal heparin (M-w 6000-30000 Da) is exothermic and driven by enthalpy at physiological salt concentration. However, the contribution from entropy is favorable for binding or small isolated heparin fragments. By studying different size-defined heparin fragments, we also concluded that it hexasaccharide moiety is sufficient for strong binding to ECSOD. The binding involves proton transfer from the buffer to the ECSOD-heparin complex, and the results indicate that the number of ionic interactions made between ECSOD and heparin upon binding varies from three to five for heparin and an octasaccharide fragment, respectively. Surprisingly and despite the many charges found oil both the protein and the polysaccharide, our results indicate that the nonionic contribution to the binding is large. From the temperature dependence we have calculated the constant pressure heat capacity change (Delta C-p) of the interaction to -644 J K-1 mol(-1) and -306 J K-1 mol(-1) for heparin and all octasaccharide, respectively

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-51398 (URN)10.1021/bi900981k (DOI)
    Available from: 2009-10-30 Created: 2009-10-30 Last updated: 2016-05-04
    2. Analysis of Effects of Mutations in the C-Terminal Domain of Extracellular Superoxide Dismutase by Isothermal Titration Calorimetry and Phage Display
    Open this publication in new window or tab >>Analysis of Effects of Mutations in the C-Terminal Domain of Extracellular Superoxide Dismutase by Isothermal Titration Calorimetry and Phage Display
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    n/a

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-52450 (URN)
    Available from: 2009-12-21 Created: 2009-12-21 Last updated: 2016-05-04
    3. Coexpression of yeast copper chaperone (yCCS) and CuZn-superoxide dismutases in Escherichia coli yields protein with high copper contents
    Open this publication in new window or tab >>Coexpression of yeast copper chaperone (yCCS) and CuZn-superoxide dismutases in Escherichia coli yields protein with high copper contents
    2004 (English)In: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 37, no 2, p. 311-319Article in journal (Refereed) Published
    Abstract [en]

    To fully understand the function of the Cu- and Zn-containing superoxide dismutases in normal and disordered cells, it is essential to study protein variants with full metal contents. We describe the use of an Escherichia coli-based expression system for the overproduction of human intracellular wild type CuZn-superoxide dismutase (SOD), the CuZnSOD variant F50E/G51E (monomeric), two amyotrophic lateral sclerosis-related mutant CuZnSOD variants (D90A and G93A), and PseudoEC-SOD, all with high Cu contents. This system is based on coexpression of the SOD variants with the yeast copper chaperone yCCS during growth in a medium supplemented with Cu2+ and Zn2+. The recombinant SOD enzymes were all found in the cytosol and represented 30-50% of the total bacterial protein. The enzymes were purified to homogeneity and active enzymes were obtained in high yield. The resulting proteins were characterized through immunochemical reactivity and specific activity analyses, in conjunction with mass-, photo-, and atomic absorption-spectroscopy. © 2004 Elsevier Inc. All rights reserved.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-22221 (URN)10.1016/j.pep.2004.06.006 (DOI)1379 (Local ID)1379 (Archive number)1379 (OAI)
    Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
    4. Cell Association and Protective Effects of PseudoECSOD: a progress report
    Open this publication in new window or tab >>Cell Association and Protective Effects of PseudoECSOD: a progress report
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    n/a

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-52451 (URN)
    Available from: 2009-12-21 Created: 2009-12-21 Last updated: 2016-05-04
  • 852.
    Ahl, Ing-Marie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Jonsson, Bengt-Harald
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Biotechnology . Linköping University, The Institute of Technology.
    Tibell, Lena
    Linköping University, Department of Science and Technology, Visual Information Technology and Applications (VITA). Linköping University, The Institute of Technology.
    Thermodynamic Characterization of the Interaction between the C-Terminal Domain of Extracellular Superoxide Dismutase and Heparin by Isothermal Titration Calorimetry2009In: BIOCHEMISTRY, ISSN 0006-2960, Vol. 48, no 41, p. 9932-9940Article in journal (Refereed)
    Abstract [en]

    Extracellular superoxide dismutase (ECSOD) interacts with heparin through its C-terminal domain. In this study we used isothermal titration calorimetry (ITC) to get detailed thermodynamic information about the interaction. We have shown that the interaction between ECSOD and intestinal mucosal heparin (M-w 6000-30000 Da) is exothermic and driven by enthalpy at physiological salt concentration. However, the contribution from entropy is favorable for binding or small isolated heparin fragments. By studying different size-defined heparin fragments, we also concluded that it hexasaccharide moiety is sufficient for strong binding to ECSOD. The binding involves proton transfer from the buffer to the ECSOD-heparin complex, and the results indicate that the number of ionic interactions made between ECSOD and heparin upon binding varies from three to five for heparin and an octasaccharide fragment, respectively. Surprisingly and despite the many charges found oil both the protein and the polysaccharide, our results indicate that the nonionic contribution to the binding is large. From the temperature dependence we have calculated the constant pressure heat capacity change (Delta C-p) of the interaction to -644 J K-1 mol(-1) and -306 J K-1 mol(-1) for heparin and all octasaccharide, respectively

  • 853.
    Ahl, Ing-Marie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Jonsson, Bengt-Harald
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Biotechnology . Linköping University, The Institute of Technology.
    Tibell, Lena A. E.
    Linköping University, Department of Science and Technology, Visual Information Technology and Applications (VITA). Linköping University, The Institute of Technology.
    Analysis of Effects of Mutations in the C-Terminal Domain of Extracellular Superoxide Dismutase by Isothermal Titration Calorimetry and Phage DisplayManuscript (preprint) (Other academic)
    Abstract [en]

    n/a

  • 854.
    Ahl, Ing-Marie
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Division of cell biology.
    Lindberg, Mikael J
    Tibell, Lena
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Division of cell biology.
    Coexpression of yeast copper chaperone (yCCS) and CuZn-superoxide dismutases in Escherichia coli yields protein with high copper contents2004In: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 37, no 2, p. 311-319Article in journal (Refereed)
    Abstract [en]

    To fully understand the function of the Cu- and Zn-containing superoxide dismutases in normal and disordered cells, it is essential to study protein variants with full metal contents. We describe the use of an Escherichia coli-based expression system for the overproduction of human intracellular wild type CuZn-superoxide dismutase (SOD), the CuZnSOD variant F50E/G51E (monomeric), two amyotrophic lateral sclerosis-related mutant CuZnSOD variants (D90A and G93A), and PseudoEC-SOD, all with high Cu contents. This system is based on coexpression of the SOD variants with the yeast copper chaperone yCCS during growth in a medium supplemented with Cu2+ and Zn2+. The recombinant SOD enzymes were all found in the cytosol and represented 30-50% of the total bacterial protein. The enzymes were purified to homogeneity and active enzymes were obtained in high yield. The resulting proteins were characterized through immunochemical reactivity and specific activity analyses, in conjunction with mass-, photo-, and atomic absorption-spectroscopy. © 2004 Elsevier Inc. All rights reserved.

  • 855.
    Ahl, Ing-Marie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Nelson, Sally K
    Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, CO-800 45, Aurora, USA.
    Enström, Camilla
    Department of Medical Sciences, Uppsala University, SE-751 85, Uppsala, Sweden.
    Ericson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Tibell, Lena A. E.
    Linköping University, Department of Science and Technology, Visual Information Technology and Applications (VITA). Linköping University, The Institute of Technology.
    Cell Association and Protective Effects of PseudoECSOD: a progress reportManuscript (preprint) (Other academic)
    Abstract [en]

    n/a

  • 856.
    Ahl Jonsson, Christina
    et al.
    Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Stenberg, Annette
    Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Hollman Frisman, Gunilla
    Linköping University, Department of Medical and Health Sciences, Nursing Science. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Endocrinology and Gastroenterology UHL.
    The lived experience of the early postoperative period after colorectal cancer surgery2011In: European Journal of Cancer Care, ISSN 0961-5423, E-ISSN 1365-2354, Vol. 20, no 2, p. 248-256Article in journal (Refereed)
    Abstract [en]

    Colorectal cancer is one of the most common cancer diagnoses and undergoing colorectal cancer surgery is reported to be associated with physical symptoms and psychological reactions. Social support is described as important during the postoperative period. The purpose of this paper was to describe how patients experience the early postoperative period after colorectal cancer surgery.

    Interviews according a phenomenological approach were performed with 13 adult participants, within 1 week after discharge from hospital. Data were collected from August 2006 to February 2007. Analysis of the interview transcripts was conducted according to Giorgi.

    The essence of the phenomenon was to regain control over ones body in the early postoperative period after colorectal cancer surgery. Lack of control, fear of wound and anastomosis rupture, insecurity according to complications was prominent findings.

    When caring for these patients it is a challenge to be sensitive, encourage and promote patients to express their feelings and needs. One possibility to empower the patients and give support could be a follow up phone call within a week after discharge.

  • 857.
    Ahl, Linda
    Linköping University, Department of Computer and Information Science.
    Hur fungerar datorer?: En fallstudie av att utveckla pedagogisk multimedia för ett datorhistoriskt museum.2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [sv]

    Få människor vet hur datorer fungerar, vilka komponenter de är uppbyggda av och hur dessa samverkar. I detta examensarbete har en prototyp till en multimediepresentation utvecklats. Presentationen kommer att placeras på ett datorhistoriskt museum och dess syfte kommer där att vara att hjälpa människor förstå hur datorer fungerar. Prototypen är baserad på bilder och enklare animationer som förklarar samverkan och funktion hos de olika datorkomponenterna, bland annat genom att visa scenarier som många människor troligtvis känner igen från sin vardag.

    Målet med arbetet har varit att inskaffa kunskap kring hur multimedia kan användas för att illustrera tekniska processer, samt kunskap kring hur multimediepresentationer skall utveck-las. Därför har en systemutvecklingsmetod tagits fram som är anpassad till denna typ av system och som använts vid utvecklingen av prototypen.

    Systemutvecklingsmetoden är av iterativ modell, eftersom det visat sig att ett iterativt arbetssätt är att föredra framför ett linjärt vid multimedieutveckling. Detta beror på att det i denna typ av arbete där det till en början oftast är oklart vilka krav och önskemål som finns på slutprodukten är svårt att gå enkelriktat genom utvecklingsprocessen, d v s att göra ett steg helt färdigt innan nästa påbörjas.

    När det gäller multimedia är en slutsats att det med fördel kan användas för att visa och förklara tekniska förlopp och att det verkar vara ett användbart hjälpmedel inom utbildning och museiverksamhet.

  • 858.
    Ahl, Liselott
    et al.
    Linköping University, Department of Medical and Health Sciences.
    Engstrand, Pernilla
    Linköping University, Department of Medical and Health Sciences.
    Sjuksköterskans upplevelse av att bedöma en person med försämrat hälsotillstånd under jourtid inom kommunsjukvården2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Nurses working in municipal health care during on-call time

    constantly assess persons with deteriorated health condition, often under time

    pressure, with low staffing and over a wide spread geographical area.

    Aims: To describe the nurses’ experience of assessing a person’s deteriorated health

    condition during on-call time in municipal health care.

    Method: A qualitative design with inductive approach. Twenty semi-structured

    interviews with nurses working in municipal health care were conducted.

    A conventional content analysis method inspired by Hsieh & Shannon was used to

    analyse the collected data.

    Results: The data analysis resulted in one general theme; different factors affect the

    assessment. Three categories were identified: personal feelings, resources and

    communication. Six sub categories were found: positive and negative feelings,

    preconditions at work, personal preconditions, organisational preconditions and

    cooperation. The feeling of comfort in the assessment process was greater with

    experienced nurses. Inadequacies were found regarding medical record systems and

    there was sometimes lack of access to medical records. There was insufficient

    reporting from healthcare aids and a need for increased staffing.

    Conclusion: Good communication between involved parties was important.

    Competence and communication skills in health care aid workers needs

    improvement. Access to medical records and a common computerized system would

    ease the assessment process.

  • 859.
    Ahl, Roy
    Linköping University, Department of Management and Engineering, Commercial and Business Law.
    Utökat betalningsansvar för medverkande till skattebrott2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    År 1968 infördes reglerna som idag återfinns i 59 kap. SFL i syfte att förhindra juridiska personer från att förfara oriktigt vad gäller betalning av skatt. Detta personliga betalningsansvar som kan aktualiseras mot företrädare för juridiska personer har diskuterats sedan dess tillkomst. Regleringen är i allra högsta grad rättspolitiskt laddad och således ställs olika intressen mot varandra. Vågskålen innehåller således på ena sidan det all­männas intresse och på den andra näringsidkares rätt att skilja sina tillgångar från den juridiska person­ens.

    Att ingen ska få behålla vinningen av sitt brott torde alla vara rörande överens om, vilket kommer till uttryck i såväl offentliga utredningar som propositioner på området. En brist i den nuvarande regleringen är att medverkande tredje män inte kan göras ersättningsskyldiga för den ekonomiska skada som staten åsamkas genom skattebrott. Förslag till en utökad reglering som träffar även medverkande tredje män har diskuterats under senare år, även om det ännu ej har resulterat i någon lagändring.

    Genom införandet av 36 kap. 1 b § BrB, utvidgat förverkande, har rättskiparen givits ytterligare ett verktyg i kampen mot den organiserade brottsligheten. Denna regel tillkom år 2008 och kan aktualiseras vid grova skattebrott. Dock har utvidgat förverkande till följd av skattebrott varken åberopats eller prövats sedan paragrafens tillkomst. Detta synes bero på okunskap hos aktuella myndigheter och förhoppningsvis kan verktyget komma att användas i kampen mot den grova skattebrottsligheten inom den närmsta framtiden.

    Det behövs en utvid­g­ning av betalningsansvaret alternativt ett införande av en skadestånds­paragraf i 59 kap. SFL för att kunna komma åt de allmänna medlen som går förlorade genom skattebrott. Det första förslaget, att utöka kretsen betalningsansvariga, är enligt min mening det mest önskvärda, eftersom alternativet rörande en skadeståndsrättslig reglering behäftats med en rad processuella problem till skillnad mot utvidgningsförslaget. Jag anser att genom en sådan utökning av regleringen i komb­i­na­tion med ökad kunskap rörande det rättsliga verktyget utvid­gat förverk­ande, kan kampen mot skattebrottsligheten komma att effektiviseras. Med tanke på de enorma belopp detta handlar om torde det vara av yttersta intresse för sam­hället att en sådan reglering kommer till stånd snarast möjligen, även om den givetvis behöver vara väl genom­arbetad. Dess förenlighet med Europakonventionen måste även beaktas och prövas.

  • 860.
    Ahlander, Britt-Marie
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Magnetic Resonance Imaging of the Heart: Image quality, measurement accuracy and patient experience2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Non-invasive diagnostic imaging of atherosclerotic coronary artery disease (CAD) is frequently carried out with cardiovascular magnetic resonance imaging (CMR) or myocardial perfusion single photon emission computed tomography (MPS). CMR is the gold standard for the evaluation of scar after myocardial infarction and MPS the clinical gold standard for ischemia. Magnetic Resonance Imaging (MRI) is at times difficult for patients and may induce anxiety while patient experience of MPS is largely unknown.

    Aims: To evaluate image quality in CMR with respect to the sequences employed, the influence of atrial fibrillation, myocardial perfusion and the impact of patient information. Further, to study patient experience in relation to MRI with the goal of improving the care of these patients.

    Method: Four study designs have been used. In paper I, experimental cross-over, paper (II) experimental controlled clinical trial, paper (III) psychometric crosssectional study and paper (IV) prospective intervention study. A total of 475 patients ≥ 18 years with primarily cardiac problems (I-IV) except for those referred for MRI of the spine (III) were included in the four studies.

    Result: In patients (n=20) with atrial fibrillation, a single shot steady state free precession (SS-SSFP) sequence showed significantly better image quality than the standard segmented inversion recovery fast gradient echo (IR-FGRE) sequence (I). In first-pass perfusion imaging the gradient echo-echo planar imaging sequence (GREEPI) (n=30) had lower signal-to-noise and contrast–to-noise ratios than the steady state free precession sequence (SSFP) (n=30) but displayed a higher correlation with the MPS results, evaluated both qualitatively and quantitatively (II). The MRIAnxiety Questionnaire (MRI-AQ) was validated on patients, referred for MRI of either the spine (n=193) or the heart (n=54). The final instrument had 15 items divided in two factors regarding Anxiety and Relaxation. The instrument was found to have satisfactory psychometric properties (III). Patients who prior CMR viewed an information video scored significantly (lower) better in the factor Relaxation, than those who received standard information. Patients who underwent MPS scored lower on both factors, Anxiety and Relaxation. The extra video information had no effect on CMR image quality (IV).

    Conclusion: Single shot imaging in atrial fibrillation produced images with less artefact than a segmented sequence. In first-pass perfusion imaging, the sequence GRE-EPI was superior to SSFP. A questionnaire depicting anxiety during MRI showed that video information prior to imaging helped patients relax but did not result in an improvement in image quality.

    List of papers
    1. Image quality and myocardial scar size determined with magnetic resonance imaging in patients with permanent atrial fibrillation: a comparison of two imaging protocols
    Open this publication in new window or tab >>Image quality and myocardial scar size determined with magnetic resonance imaging in patients with permanent atrial fibrillation: a comparison of two imaging protocols
    Show others...
    2010 (English)In: CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, ISSN 1475-0961, Vol. 30, no 2, p. 122-129Article in journal (Refereed) Published
    Abstract [en]

    Pandgt;Background: Magnetic resonance imaging (MRI) of the heart generally requires breath holding and a regular rhythm. Single shot 2D steady-state free precession (SS_SSFP) is a fast sequence insensitive to arrhythmia as well as breath holding. Our purpose was to determine image quality, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios and infarct size with a fast single shot and a standard segmented MRI sequence in patients with permanent atrial fibrillation and chronic myocardial infarction. Methods: Twenty patients with chronic myocardial infarction and ongoing atrial fibrillation were examined with inversion recovery SS_SSFP and segmented inversion recovery 2D fast gradient echo (IR_FGRE). Image quality was assessed in four categories: delineation of infarcted and non-infarcted myocardium, occurrence of artefacts and overall image quality. SNR and CNR were calculated. Myocardial volume (ml) and infarct size, expressed as volume (ml) and extent (%), were calculated, and the methodological error was assessed. Results: SS_SSFP had significantly better quality scores in all categories (P = 0 center dot 037, P = 0 center dot 014, P = 0 center dot 021, P = 0 center dot 03). SNRinfarct and SNRblood were significantly better for IR_FGRE than for SS_SSFP (P = 0 center dot 048, P = 0 center dot 018). No significant difference was found in SNRmyocardium and CNR. The myocardial volume was significantly larger with SS_SSFP (170 center dot 7 versus 159 center dot 2 ml, P andlt; 0 center dot 001), but no significant difference was found in infarct volume and infarct extent. Conclusion: SS_SSFP displayed significantly better image quality than IR_FGRE. The infarct size and the error in its determination were equal for both sequences, and the examination time was shorter with SS_SSFP.

    Keywords
    atrial fibrillation, magnetic resonance imaging, myocardial infarction, segmented inversion recovery 2D fast gradient echo, single shot inversion recovery 2D steady-state free precession
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-54159 (URN)10.1111/j.1475-097X.2009.00914.x (DOI)000274438800006 ()
    Available from: 2010-02-26 Created: 2010-02-26 Last updated: 2016-08-24
    2. An echo-planar imaging sequence is superior to a steady-state free precession sequence for visual as well as quantitative assessment of cardiac magnetic resonance stress perfusion
    Open this publication in new window or tab >>An echo-planar imaging sequence is superior to a steady-state free precession sequence for visual as well as quantitative assessment of cardiac magnetic resonance stress perfusion
    Show others...
    2017 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 37, no 1, p. 52-61Article in journal (Refereed) Published
    Abstract [en]

    Background To assess myocardial perfusion, steady-state free precession cardiac magnetic resonance (SSFP, CMR) was compared with gradient-echo–echo-planar imaging (GRE-EPI) using myocardial perfusion scintigraphy (MPS) as reference. Methods Cardiac magnetic resonance perfusion was recorded in 30 patients with SSFP and in another 30 patients with GRE-EPI. Timing and extent of inflow delay to the myocardium was visually assessed. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Myocardial scar was visualized with a phase-sensitive inversion recovery sequence (PSIR). All scar positive segments were considered pathologic. In MPS, stress and rest images were used as in clinical reporting. The CMR contrast wash-in slope was calculated and compared with the stress score from the MPS examination. CMR scar, CMR perfusion and MPS were assessed separately by one expert for each method who was blinded to other aspects of the study. Results Visual assessment of CMR had a sensitivity for the detection of an abnormal MPS at 78% (SSFP) versus 91% (GRE-EPI) and a specificity of 58% (SSFP) versus 84% (GRE-EPI). Kappa statistics for SSFP and MPS was 0·29, for GRE-EPI and MPS 0·72. The ANOVA of CMR perfusion slopes for all segments versus MPS score (four levels based on MPS) had correlation r = 0·64 (SSFP) and r = 0·96 (GRE-EPI). SNR was for normal segments 35·63 ± 11·80 (SSFP) and 17·98 ± 8·31 (GRE-EPI), while CNR was 28·79 ± 10·43 (SSFP) and 13·06 ± 7·61 (GRE-EPI). Conclusion GRE-EPI displayed higher agreement with the MPS results than SSFP despite significantly lower signal intensity, SNR and CNR.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2017
    Keywords
    cardiac imaging techniques, coronary heart disease, Magnetic Resonance Imaging, nuclear medicine, perfusion
    National Category
    Radiology, Nuclear Medicine and Medical Imaging Medical Laboratory and Measurements Technologies Medical Image Processing Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-130795 (URN)10.1111/cpf.12267 (DOI)000390688200008 ()26147785 (PubMedID)
    Note

    Funding agencies: Medical Research Council of Southeast Sweden [12437]; Futurum, the County council of Jonkoping [12440, 81851, 217261]; Linkoping University; County Council of Ostergotland [281281]; Swedish Heart-Lung Foundation [20120449]

    Available from: 2016-08-24 Created: 2016-08-24 Last updated: 2017-11-28Bibliographically approved
    3. Development and validation of a questionnaire evaluating patient anxiety during Magnetic Resonance Imaging: the Magnetic Resonance Imaging-Anxiety Questionnaire (MRI-AQ)
    Open this publication in new window or tab >>Development and validation of a questionnaire evaluating patient anxiety during Magnetic Resonance Imaging: the Magnetic Resonance Imaging-Anxiety Questionnaire (MRI-AQ)
    Show others...
    2016 (English)In: Journal of Advanced Nursing, ISSN 0309-2402, E-ISSN 1365-2648, Vol. 72, no 6, p. 1368-1380Article in journal (Refereed) Published
    Abstract [en]

    Aim. To develop and validate a new instrument measuring patient anxiety during Magnetic Resonance Imaging examinations, Magnetic Resonance Imaging-Anxiety Questionnaire. Background. Questionnaires measuring patients anxiety during Magnetic Resonance Imaging examinations have been the same as used in a wide range of conditions. To learn about patients experience during examination and to evaluate interventions, a specific questionnaire measuring patient anxiety during Magnetic Resonance Imaging is needed. Design. Psychometric cross-sectional study with test-retest design. Methods. A new questionnaire, Magnetic Resonance Imaging-Anxiety Questionnaire, was designed from patient expressions of anxiety in Magnetic Resonance Imaging-scanners. The sample was recruited between October 2012-October 2014. Factor structure was evaluated with exploratory factor analysis and internal consistency with Cronbachs alpha. Criterion-related validity, known-group validity and test-retest was calculated. Results. Patients referred for Magnetic Resonance Imaging of either the spine or the heart, were invited to participate. The development and validation of Magnetic Resonance Imaging-Anxiety Questionnaire resulted in 15 items consisting of two factors. Cronbachs alpha was found to be high. Magnetic Resonance Imaging-Anxiety Questionnaire correlated higher with instruments measuring anxiety than with depression scales. Known-group validity demonstrated a higher level of anxiety for patients undergoing Magnetic Resonance Imaging scan of the heart than for those examining the spine. Test-retest reliability demonstrated acceptable level for the scale. Conclusion. Magnetic Resonance Imaging-Anxiety Questionnaire bridges a gap among existing questionnaires, making it a simple and useful tool for measuring patient anxiety during Magnetic Resonance Imaging examinations.

    Place, publisher, year, edition, pages
    WILEY-BLACKWELL, 2016
    Keywords
    anxiety; instrument development; magnetic resonance imaging; nurse; nursing; reliability; validity
    National Category
    Other Medical Sciences not elsewhere specified
    Identifiers
    urn:nbn:se:liu:diva-129145 (URN)10.1111/jan.12917 (DOI)000376007400014 ()26893007 (PubMedID)
    Note

    Funding Agencies|Swedish Heart and Lung Foundation; Futurum County Council of Jonkoping

    Available from: 2016-06-13 Created: 2016-06-13 Last updated: 2017-11-28
  • 861.
    Ahlander, Britt-Marie
    et al.
    Department of Radiology, Ryhov County Hospital, SE-55185, Jönköping, Sweden..
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Maret, Eva
    Department of Clinical Physiology, Karolinska Institutet, Karolinska University Hospital, SE-14186, Stockholm, Sweden..
    Ericsson, Elisabeth
    Faculty of Medicine and Health, School of Health Science, Örebro University, SE-701 82, Örebro, Sweden..
    Positive effect on patient experience of video-information given prior to cardiovascular magnetic resonance imaging, a clinical trial2018In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 27, no 5-6, p. 1250-1261Article in journal (Refereed)
    Abstract [en]

    Aims: To evaluate the effect of video information given before cardiovascular magnetic resonance imaging on patient anxiety and to compare patient experiences of cardiovascular magnetic resonance imaging versus myocardial perfusion scintigraphy. To evaluate if additional information has an impact on motion artefacts. Background: Cardiovascular magnetic resonance imaging and myocardial perfusion scintigraphy are technically advanced methods for the evaluation of heart diseases. Although cardiovascular magnetic resonance imaging is considered to be painless, patients may experience anxiety due to the closed environment. Design: A prospective randomized intervention study, not registered. Methods: The sample (n=148) consisted of 97 patients referred for cardiovascular magnetic resonance imaging, randomized to receive either video information in addition to standard text-information (CMR-video/n=49) or standard text-information alone (CMR-standard/n=48). A third group undergoing myocardial perfusion scintigraphy (n=51) was compared with the cardiovascular magnetic resonance imaging-standard group. Anxiety was evaluated before, immediately after the procedure and one week later. Five questionnaires were used: Cardiac Anxiety Questionnaire, State-Trait-Anxiety Inventory, Hospital-Anxiety and Depression-scale, MRI-Fear-Survey-Schedule and the MRI-Anxiety-Questionnaire. Motion artefacts were evaluated by three observers, blinded to the information given. Data were collected between April 2015 and April 2016. The study followed the CONSORT guidelines RESULT: The CMR-video group scored lower (better) than the cardiovascular magnetic resonance imaging-standard group in the factor Relaxation (p=0.039) but not in the factor Anxiety. Anxiety levels were lower during scintigraphic examinations compared to the CMR-standard group (p<0.001). No difference was found regarding motion artefacts between CMR-video and CMR-standard. Conclusion: Patient ability to relax during cardiovascular magnetic resonance imaging increased by adding video information prior the exam, which is important in relation to perceived quality in nursing. No effect was seen on motion artefacts. Relevance To Clinical Practice: Video information prior to examinations can be an easy and time effective method to help patients cooperate in imaging procedures.

  • 862.
    Ahlander, Britt-Marie
    et al.
    Department of Radiology, Ryhov County Hospital, Jönköping.
    Maret, Eva
    Department of Radiology, Ryhov County Hospital, Jönköping / Department of Clinical Physiology, Karolinska University Hospital, Stockholm.
    Brudin, Lars
    Department of Clinical Physiology, Kalmar County Hospital, Kalmar.
    Starck, Sven-Åke
    Department of Natural Science and Biomedicine, School of Health Sciences, Jönköping University / Department of Oncology, Hospital Physics, Ryhov County Hospital, Jönköping.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    An echo-planar imaging sequence is superior to a steady-state free precession sequence for visual as well as quantitative assessment of cardiac magnetic resonance stress perfusion2017In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 37, no 1, p. 52-61Article in journal (Refereed)
    Abstract [en]

    Background To assess myocardial perfusion, steady-state free precession cardiac magnetic resonance (SSFP, CMR) was compared with gradient-echo–echo-planar imaging (GRE-EPI) using myocardial perfusion scintigraphy (MPS) as reference. Methods Cardiac magnetic resonance perfusion was recorded in 30 patients with SSFP and in another 30 patients with GRE-EPI. Timing and extent of inflow delay to the myocardium was visually assessed. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Myocardial scar was visualized with a phase-sensitive inversion recovery sequence (PSIR). All scar positive segments were considered pathologic. In MPS, stress and rest images were used as in clinical reporting. The CMR contrast wash-in slope was calculated and compared with the stress score from the MPS examination. CMR scar, CMR perfusion and MPS were assessed separately by one expert for each method who was blinded to other aspects of the study. Results Visual assessment of CMR had a sensitivity for the detection of an abnormal MPS at 78% (SSFP) versus 91% (GRE-EPI) and a specificity of 58% (SSFP) versus 84% (GRE-EPI). Kappa statistics for SSFP and MPS was 0·29, for GRE-EPI and MPS 0·72. The ANOVA of CMR perfusion slopes for all segments versus MPS score (four levels based on MPS) had correlation r = 0·64 (SSFP) and r = 0·96 (GRE-EPI). SNR was for normal segments 35·63 ± 11·80 (SSFP) and 17·98 ± 8·31 (GRE-EPI), while CNR was 28·79 ± 10·43 (SSFP) and 13·06 ± 7·61 (GRE-EPI). Conclusion GRE-EPI displayed higher agreement with the MPS results than SSFP despite significantly lower signal intensity, SNR and CNR.

  • 863.
    Ahlander, Britt-Marie
    et al.
    Ryhov County Hospital, Sweden.
    Årestedt, Kristofer
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences. Linnaeus University, Sweden.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Maret, Eva
    Karolinska University Hospital, Sweden; Karolinska Institute, Sweden.
    Ericsson, Elisabeth
    University of Örebro, Sweden.
    Development and validation of a questionnaire evaluating patient anxiety during Magnetic Resonance Imaging: the Magnetic Resonance Imaging-Anxiety Questionnaire (MRI-AQ)2016In: Journal of Advanced Nursing, ISSN 0309-2402, E-ISSN 1365-2648, Vol. 72, no 6, p. 1368-1380Article in journal (Refereed)
    Abstract [en]

    Aim. To develop and validate a new instrument measuring patient anxiety during Magnetic Resonance Imaging examinations, Magnetic Resonance Imaging-Anxiety Questionnaire. Background. Questionnaires measuring patients anxiety during Magnetic Resonance Imaging examinations have been the same as used in a wide range of conditions. To learn about patients experience during examination and to evaluate interventions, a specific questionnaire measuring patient anxiety during Magnetic Resonance Imaging is needed. Design. Psychometric cross-sectional study with test-retest design. Methods. A new questionnaire, Magnetic Resonance Imaging-Anxiety Questionnaire, was designed from patient expressions of anxiety in Magnetic Resonance Imaging-scanners. The sample was recruited between October 2012-October 2014. Factor structure was evaluated with exploratory factor analysis and internal consistency with Cronbachs alpha. Criterion-related validity, known-group validity and test-retest was calculated. Results. Patients referred for Magnetic Resonance Imaging of either the spine or the heart, were invited to participate. The development and validation of Magnetic Resonance Imaging-Anxiety Questionnaire resulted in 15 items consisting of two factors. Cronbachs alpha was found to be high. Magnetic Resonance Imaging-Anxiety Questionnaire correlated higher with instruments measuring anxiety than with depression scales. Known-group validity demonstrated a higher level of anxiety for patients undergoing Magnetic Resonance Imaging scan of the heart than for those examining the spine. Test-retest reliability demonstrated acceptable level for the scale. Conclusion. Magnetic Resonance Imaging-Anxiety Questionnaire bridges a gap among existing questionnaires, making it a simple and useful tool for measuring patient anxiety during Magnetic Resonance Imaging examinations.

  • 864.
    Ahlbeck, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Allergy Center.
    Astma lathund: Astma hos vuxna2018Other (Other academic)
    Abstract [sv]

    Åtta till tio procent av den vuxna befolkningen har astma. Av dessa har65 procent lindrig, 25 procent medelsvår och 10 procent svår astma.Astma är en heterogen sjukdom, där en kronisk luftvägsinflammationoftast föreligger.

    Sjukdomen kännetecknas av återkommande luftvägssymtom såsom pipi bröstet, andnöd, trånghetskänsla i bröstet och hosta som varierar övertiden tillsammans med en variabel luftvägsobstruktion.

  • 865.
    Ahlbeck, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Division of Inflammation Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Allergy Center.
    Astmainhalator med återkopplingssystem gav bättre vård och sänkta kostnader [Asthma inhaler with feedback system provided better care and lower costs].2014In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 111, no 5, p. 160-160Article in journal (Other academic)
  • 866.
    Ahlbeck, Lars
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Allergy Center.
    Ahlberg, Emelie
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Nyström Kronander, Ulla
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Allergy Center.
    Björkander, Janne
    Futurum, Academy of Health and Care, Jönköping, Sweden.
    Jenmalm, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Intralymphatic allergen immunotherapy against pollen allergy. A 3-year open follow-up study of 10 patients2018In: Annals of Allergy, Asthma & Immunology, ISSN 1081-1206, E-ISSN 1534-4436, Vol. 121, no 5, p. 626-627Article in journal (Refereed)
    Abstract [en]

    To date, allergen immunotherapy (AIT) is the only treatment that affects the long-term development of allergic rhinoconjunctivitis and induces clinical tolerance primarily by stimulating regulatory T (Treg) cells, attenuating T helper 2 (Th2) responses and synthesis of blocking antibodies1. Conventional AIT with subcutaneous injections, sublingual tablets or drops is effective, but consumes time and resources 2.

  • 867.
    Ahlbeck, Lars
    et al.
    Östergötlands Läns Landsting, Local Health Care Services in West Östergötland, Research & Development Unit in Local Health Care.
    Faresjö, Tomas
    Linköping University, Department of Department of Health and Society, General Practice. Linköping University, Faculty of Health Sciences.
    Åkerlind, Ingemar
    Östergötlands Läns Landsting, Local Health Care Services in West Östergötland, Research & Development Unit in Local Health Care.
    Differences in patient perception of appropriate level of care1996In: European Journal of General Practice, Vol. 2, no 3, p. 109-112Article in journal (Refereed)
    Abstract [en]

    Objectives: The principle of achieving the most cost-effective level of care in relation to needs is an essential aim for all health care systems. However, it is not certain that the corresponding knowledge and attitudes with respect to the appropriate level of care for different symptoms can be found in the general population. There may be age-related differences in illness behaviour that manifest in ‘overutilisation’ of the system. We studied illness behaviour with regard to attitudes and inclination to seek care for different symptoms at various levels in the health care system.Methods: The study group consisted of a random selection of 296 persons, born in the 1940s, ′50s and ′60s, and living in a defined region in Sweden. In a questionnaire they had to choose between different levels of care for twelve symptom descriptions with varying degrees of severity. The answers were scored according to the level of care, adequacy and overutilisation.Results: The vast majority of participants chose an adequate level of care. However, overutilisation was found, particularly among women born in the 1960s and to some extent among men born in the 1940s. These two groups together constituted about 70% of all the individuals who tended to overutilise the health care in their expressed preferences.Conclusions: These individuals do not receive cost-effective care, or the most adequate care with regard to their needs. The results indicate, however, that the problem was more a question of attitude rather than a lack of knowledge and information.

  • 868.
    Ahlberg, Anders
    Linköping University, Department of Behavioural Sciences and Learning, Education and Sociology.
    Körkortsutbildning efter GDE-matrisen: Hur trafiklärare uppfattar sin pedagogiska roll2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna kandidatuppsats undersöker hur trafiklärare uppfattar målen med Transportstyrelsens nya kursplan (2006) och hur de undervisar för att eleven ska nå målen i kursplanen.

    Studien är av explorativ karaktär och därför valdes en kvalitativ ansats med empiri i form av intervjudata. Sex trafiklärare intervjuades och materialet analyserades med meningskoncentrering och kategorisering.

    Den teoretiska referensramen bygger på Mezirows ”transformativa vuxenundervisning”, samt forskning inom kognitiv neuropsykologi.

    Resultatet visar att trafiklärarna i studien övervägande är positiva till den nya kursplanen och att de försöker undervisa på ett sätt så att eleven ska nå målen och uppfylla kraven. Till exempel rapporterar samtliga lärare att de jobbar mera med självvärdering, men även med insiktshöjande pedagogiska metoder.

    Av resultatet framgår att trafiklärarna är mycket negativa till förarprovet som de uppfattar som en begränsande faktor i utbildningssystemet. Av den anledningen är de också pessimistiska till hur nyblivna körkortsinnehavare kommer klara sig i framtiden.

  • 869.
    Ahlberg, Beth Maina
    et al.
    Uppsala University, Sweden.
    Carr, Claudette
    University of Westminster, UK.
    Diakite, Madubuko
    El-Tayeb, Fatima
    University of California, San Diego, USA.
    Hübinette, Tobias
    Södertörns University, Sweden.
    Jallow, Momodou
    Kawesa, Victoria
    Linköping University, The Tema Institute, The Department of Gender Studies. Linköping University, Faculty of Arts and Sciences.
    McEachrane, Michael
    McKnight, Utz
    University of Alabama, USA.
    Neergaard, Anders
    Linköping University, REMESO - Institute for Research on Migration, Ethnicity and Society. Linköping University, Department of Social and Welfare Studies. Linköping University, Faculty of Arts and Sciences.
    Patel, Shailja
    Sabuni, Kitimbwa
    Afrosvenskarnas riksförbund, Stockholm, Sweden.
    Salami, Minna
    MsAfropolitan.
    Racism Is No Joke: A Swedish Minister and a Hottentot Venus Cake-An Email Conversation2014In: Afro-Nordic landscapes: equality and race in Northern Europe / [ed] Michael McEachrane, New York: Routledge, 2014Chapter in book (Other academic)
  • 870.
    Ahlberg, Eva-Lena
    et al.
    Region Östergötland, Center for Business support and Development.
    Elfström, Johan
    Region Östergötland, Center for Business support and Development.
    Borgstedt Risberg, Madeleine
    Region Östergötland, Center for Business support and Development.
    Öhrn, Annica
    Region Östergötland, Regional Board.
    Andersson, Christer
    Region Östergötland, Regional Board.
    Sjödahl, Rune
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Regional Board. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Nilsen, Per
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Learning From Incident Reporting?: Analysis of Incidents Resulting in Patient Injuries in a Web-Based System in Swedish Health Care2017In: Journal of patient safety, ISSN 1549-8417, E-ISSN 1549-8425Article in journal (Refereed)
    Abstract [en]

    Objectives Incident reporting (IR) systems have the potential to improve patient safety if they enable learningfrom the reported risks and incidents. The aim of this study was to investigate incidents registered in an IR system in a Swedish county council.

    Methods The study was conducted in the County Council of Östergötland, Sweden. Data were retrieved from the IR system, which included 4755 incidents occurring in somatic care that resulted in patient injuries from 2004 to 2012. One hundred correctly classified patient injuries were randomly sampled from 3 injury severity levels: injuries leading to deaths, permanent harm, and temporary harm. Three aspects were analyzed: handling of the incident, causes of the incident, and actions taken to prevent its recurrence.

    Results Of the 300 injuries, 79% were handled in the departments where they occurred. The department head decided what actions should be taken to prevent recurrence in response to 95% of the injuries. A total of 448 causes were identified for the injuries; problems associated with procedures, routines, and guidelines were most common. Decisions taken for 80% of the injuries could be classified using the IR system documentation and root cause analysis. The most commonly pursued type of action was change of work routine or guideline.

    Conclusions The handling, causes, and actions taken to prevent recurrence were similar for injuries of different severity levels. Various forms of feedback (information, education, and dialogue) were an integral aspect of the IR system. However, this feedback was primarily intradepartmental and did not yield much organizational learning.

  • 871.
    Ahlberg, Fredrik
    et al.
    Linköping University, Department of Behavioural Sciences and Learning.
    Siggelsten, Marcel
    Linköping University, Department of Behavioural Sciences and Learning.
    Arbetsbaserade Formella Utbildningar: En Fallstudie2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna fallstudie är av kvalitativ metod och syftar till att undersöka och öka förståelsen för hur formella arbetsbaserade utbildningar används i praktiken och vilken roll de spelar för utbildningssatsande företag inom detaljhandeln. Studien behandlar både ledare och medarbetares syn på de tillhandahållna utbildningarna.

    Resultaten tyder på att formella arbetsbaserade utbildningar kan fungera som en grund för informellt lärande på arbetsplatsen. Medarbetarna tryckte på vikten av att inkludera diskussionsmoment i utbildningarna för ge de möjlighet att öppna upp sig för alternativa tolkningar. Vidare tyder resultaten på att ökat reflekterande lärande sannolikt leder till att de anställda bättre kan anpassa sina metoder efter olika kontexter. Våra resultat visade även på att motivationen till att gå på utbildningarna minskas i det fall den är repetition. Således bör utbildningarna i högre individanpassas.

  • 872.
    Ahlberg, Gustav
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    Generating web applications containing XSS and CSRF vulnerabilities2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Most of the people in the industrial world are using several web applications every day. Many of those web applications contain vulnerabilities that can allow attackers to steal sensitive data from the web application's users. One way to detect these vulnerabilities is to have a penetration tester examine the web application. A common way to train penetration testers to find vulnerabilities is to challenge them with realistic web applications that contain vulnerabilities. The penetration tester's assignment is to try to locate and exploit the vulnerabilities in the web application. Training on the same web application twice will not provide any new challenges to the penetration tester, because the penetration tester already knows how to exploit all the vulnerabilities in the web application. Therefore, a vast number of web applications and variants of web applications are needed to train on.

    This thesis describes a tool designed and developed to automatically generate vulnerable web applications. First a web application is prepared, so that the tool can generate a vulnerable version of the web application. The tool injects Cross Site Scripting (XSS) and Cross Site Request Forgery (CSRF) vulnerabilities in prepared web applications. Different variations of the same vulnerability can also be injected, so that different methods are needed to exploit the vulnerability depending on the variation. A purpose of the tool is that it should generate web applications which shall be used to train penetration testers, and some of the vulnerabilities the tool can inject, cannot be detected by current free web application vulnerability scanners, and would thus need to be detected by a penetration tester.

    To inject the vulnerabilities, the tool uses abstract syntax trees and taint analysis to detect where vulnerabilities can be injected in the prepared web applications.

    Tests confirm that web application vulnerability scanners cannot find all the vulnerabilities on the web applications which have been generated by the tool.

  • 873.
    Ahlberg, Jesper
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Blomquist, Esbjörn
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Online Identification of Running Resistance and Available Adhesion of Trains2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Two important physical aspects that determine the performance of a running train are the total running resistance that acts on the whole train moving forward, and the available adhesion (utilizable wheel-rail-friction) for propulsion and breaking. Using the measured and available signals, online identification of the current running resistance and available adhesion and also prediction of future values for a distance ahead of the train, is desired. With the aim to enhance the precision of those calculations, this thesis investigates the potential of online identification and prediction utilizing the Extended Kalman Filter.

    The conclusions are that problems with observability and sensitivity arise, which result in a need for sophisticated methods to numerically derive the acceleration from the velocity signal. The smoothing spline approximation is shown to provide the best results for this numerical differentiation. Sensitivity and its need for high accuracy, especially in the acceleration signal, results in a demand of higher sample frequency. A desire for other profound ways of collecting further information, or to enhance the models, arises with possibilities of future work in the field.

  • 874.
    Ahlberg, Johan
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, Department of Management and Engineering, Economic Information Systems.
    Araskog, Amanda
    Linköping University, Department of Management and Engineering. Linköping University, Department of Management and Engineering, Economic Information Systems.
    Projektmodell för införande av affärssystem: Ett konsultbolags implementeringsprocess i tjänsteföretag2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Companies acquiring ERP systems are often dissatisfied with the project and therefore consultancy firms wish to make use of project models in order to achieve success in implementations. Since research on ERP implementations in service companies is limited, there is a need for mapping of critical activities in implementation projects in this line of business. Under these premises, the purpose of our master thesis is to develop a model for implementation of ERP systems, specified in activities, which can be used by mid-sized consultancy firms with mid-sized qualified service companies as customers.

    A literature study including project models, modern models and methodologies for ERP implementation, commonly existent activities, success factors and system development methods was carried out. Starting out with this, a theoretical model for ERP implementation was generated. In excess of this, a case study was conducted, where the implementation of the ERP system Microsoft Dynamics AX at the service company Eurostep, performed by the consultancy firm Medius, was studied. A comparative analysis was performed, where the theoretically deduced model of ERP implementation was complemented and revised.

    The result of the master thesis is a consultancy model with four phases, with related activities, for ERP implementation in service companies. In order to fulfill the needs identified in the study, the model includes the following:

    - Clear responsibility distribution

    - Milestones as ending criteria

    - Suitable ways of work within the phases

    During the study the need for an anchoring and commitment process, and the need to consider the customer’s features, emerged. This can contribute to consultancy firms getting enough involvement in the project from their customers, which is important in order to achieve desired quality and to finish the project within the given time frame.

  • 875.
    Ahlberg, John
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Cruz Wolter Håkansson, Christoffer
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Identification, mapping and control of non-structure-bound materials2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    I Saab Aerostructures tillverkning av flygplansdelar, används icke strukturbundet material, det vill säga material som inte har en angiven kvantifierad förbrukning per tillverkad enhet eller material vars angivna kvantifierade förbrukning per tillverkad enhet inte stämmer överens med verklig förbrukning. Personal på inköpsavdelningen vet i vissa fall inte var ett specifikt icke strukturbundet material förbrukas, alltså vilka tillverkningsavdelningar eller flygplansdelar som förbrukar materialet. Likaså saknas övergripande och gemensamma rutiner för hur material som klassas som icke strukturbundet material planeras och lagerstyrs. För att identifiera problemområden i materialförsörjningen genomfördes en flödeskartläggning för att identifiera vilka olika typer av icke strukturbundet material som används i Saab Aerostructures produktion samt hur dessa lagerstyrs mellan lager och buffertlager i produktion. Under flödeskartläggningen definierades sex olika materialgrupper tillhörande icke strukturbundet material. För att lagerstyra de identifierade materialgrupperna av icke strukturbundet material används idag åtta stycken lagerstyrningsmetoder. Saab Aerostructures har anlitat tredjepartslogistiker för att sköta merparten av dagens lagerstyrning. Lagerstyrningsmetoderna skiljer sig åt beroende på tredjepartslogistiker och materialgrupp av icke strukturbundet material. Resultatet från genomförd kartläggning och analys påvisar att det finns förbättringspotential i flera utav dessa lagerstyrningsmetoder, samt att det är möjligt att reducera antalet lagerstyrningsmetoder genom att använda samma lagerstyrningsmetod för snarlika materialgrupper av icke strukturbundet material. Genomförd analys påvisar även behovet av ett förbättrat informationsflöde mellan beredning, inköp och produktion, när det gäller hanteringen av icke strukturbundet material. Konkreta åtgärder i form av rekommendationer, för att förbättra lagerstyrningen av icke strukturbundet material, presenteras i slutet av denna rapport.  

  • 876.
    Ahlberg, Jörgen
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, The Institute of Technology.
    Active Contours in Three Dimensions1996Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To find a shape in an image, a technique called snakes or active contours can be used. An active contour is a curve that moves towards the sought-for shape in a way controlled by internal forces - such as rigidity and elasticity - and an image force. The image force should attract the contour to certain features, such as edges, in the image. This is done by creating an attractor image, which defines how strongly each point in the image should attract the contour.

    In this thesis the extension to contours (surfaces) in three dimensional images is studied. Methods of representation of the contour and computation of the internal forces are treated.

    Also, a new way of creating the attractor image, using the orientation tensor to detect planar structure in 3D images, is studied. The new method is not generally superior to those already existing, but still has its uses in specific applications.

    During the project, it turned out that the main problem of active contours in 3D images was instability due to strong internal forces overriding the influence of the attractor image. The problem was solved satisfactory by projecting the elasticity force on the contour’s tangent plane, which was approximated efficiently using sphere-fitting.

  • 877.
    Ahlberg, Jörgen
    Linköping University, Department of Electrical Engineering, Image Coding. Linköping University, The Institute of Technology.
    An active model for facial feature tracking2002In: EURASTP journal an applied signal processing, ISSN 1110-8657, E-ISSN 1687-0433, Vol. 2002, no 6, p. 566-571Article in journal (Refereed)
    Abstract [en]

    We present a system for finding and tracking a face and extract global and local animation parameters from a video sequence. The system uses an initial colour processing step for finding a rough estimate of the position, size, and inplane rotation of the face, followed by a refinement step drived by an active model. The latter step refines the previous estimate, and also extracts local animation parameters. The system is able to track the face and some facial features in near real-time, and can compress the result to a bitstream compliant to MPEG-4 face and body animation.

  • 878.
    Ahlberg, Jörgen
    Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Estimating atmosphere parameters in hyperspectral data2010In: Proc. SPIE 7695, Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XVI / [ed] Sylvia S. Shen, Paul E. Lewis, SPIE - International Society for Optical Engineering, 2010, p. Art.nr. 7695-82-Conference paper (Refereed)
    Abstract [en]

    We address the problem of estimating atmosphere parameters (temperature, water vapour content) from data captured by an airborne thermal hyperspectral imager, and propose a method based on direct optimization. The method also involves the estimation of object parameters (temperature and emissivity) under the restriction that the emissivity is constant for all wavelengths. Certain sensor parameters can be estimated as well in the same process. The method is analyzed with respect to sensitivity to noise and number of spectral bands. Simulations with synthetic signatures are performed to validate the analysis, showing that estimation can be performed with as few as 10-20 spectral bands at moderate noise levels. More than 20 bands does not improvethe estimates. The proposedmethod is alsoextended to incorporateadditionalknowledge,for examplemeasurements ofatmospheric parameters and sensor noise.

  • 879.
    Ahlberg, Jörgen
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology. Univ.,.
    Model-based coding: extraction, coding, and evaluation of face model parameters2002Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis deals with model-based coding of human faces for low bitrate communication. The basicidea of model-based coding is that the appearance and motion of a human face are analysed. By thisanalysis, compact parameters allowing realistic visualization of a synthetic face are extracted. The parameterscan be transmitted at very low bitrates, potentially allowing video face-to-face communicationover narrow channels like GSM or PSTN. Recently, numerous web-based applications for animatedfaces have emerged as well.Although the idea is two decades old by now, there are still several technical problems to be solved,and some of them are treated in this thesis. With the advent of the MPEG-4 standard for face animationwhich provides a standardized way for storing and transmitting animation parameters, model-basedcoding and face animation have been increasingly popular research topics.The first topic treated here is th ecompression of face model parameters. We propose a new compressionscheme, showing that such parameters can be transmitted with reasonable quality at bitrates lowerthan 1 kbit/s.Then, techniques for analysis of images and image sequences containing a human face are treated. Forstatic face images, a method for the extraction of facial features is proposed. For image sequences, amethod for face tracking using the active appearance model search algorithmis proposed and foundto be useful in practical experiments. Methods for achieving real-time performance have been developed,and the robustness and accuracy are analysed.To set the analysis in the context of possible applications, different ways of video synthesis using theextracted parameters are discussed as well.Finally, we take a look at the synthesized face models. Comparing them to real video sequences, wetry to evaluate how well the synthetic face models can convey emotions. Standard data sets and performancemeasures are suggested.

  • 880.
    Ahlberg, Jörgen
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering. FOI, SE-58111 Linkoping, Sweden.
    Optimizing Object, Atmosphere, and Sensor Parameters in Thermal Hyperspectral Imagery2017In: IEEE Transactions on Geoscience and Remote Sensing, ISSN 0196-2892, E-ISSN 1558-0644, Vol. 55, no 2, p. 658-670Article in journal (Refereed)
    Abstract [en]

    We address the problem of estimating atmosphere parameters (temperature and water vapor content) from data captured by an airborne thermal hyperspectral imager and propose a method based on linear and nonlinear optimization. The method is used for the estimation of the parameters (temperature and emissivity) of the observed object as well as sensor gain under certain restrictions. The method is analyzed with respect to sensitivity to noise and the number of spectral bands. Simulations with synthetic signatures are performed to validate the analysis, showing that the estimation can be performed with as few as 10-20 spectral bands at moderate noise levels. The proposed method is also extended to exploit additional knowledge, for example, measurements of atmospheric parameters and sensor noise. Additionally, we show how to extend the method in order to improve spectral calibration.

  • 881.
    Ahlberg, Jörgen
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, Faculty of Science & Engineering.
    Visualization Techniques for Surveillance: Visualizing What Cannot Be Seen and Hiding What Should Not Be Seen2015In: Konsthistorisk Tidskrift, ISSN 0023-3609, E-ISSN 1651-2294, Vol. 84, no 2, p. 123-138Article in journal (Refereed)
    Abstract [en]

    This paper gives an introduction to some of the problems of modern camera surveillance, and how these problems are, or can be, addressed using visualization techniques. The paper is written from an engineering point of view, attempting to communicate visualization techniques invented in recent years to the non-engineer reader. Most of these techniques have the purpose of facilitating for the surveillance operator to recognize or detect relevant events (such as violence), while, in contrast, some have the purpose of hiding information in order to be less privacy-intrusive. Furthermore, there are also cameras and sensors that produce data that have no natural visible form, and methods for visualizing such data are discussed as well. Finally, in a concluding discussion an attempt is made to predict how the discussed methods and techniques will be used in the future. 

  • 882.
    Ahlberg, Jörgen
    et al.
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering.
    Arsic, Dejan
    Munich University of Technology, Germany.
    Ganchev, Todor
    University of Patras, Greece.
    Linderhed, Anna
    FOI Swedish Defence Research Agency.
    Menezes, Paolo
    University of Coimbra, Portugal.
    Ntalampiras, Stavros
    University of Patras, Greece.
    Olma, Tadeusz
    MARAC S.A., Greece.
    Potamitis, Ilyas
    Technological Educational Institute of Crete, Greece.
    Ros, Julien
    Probayes SAS, France.
    Prometheus: Prediction and interpretation of human behaviour based on probabilistic structures and heterogeneous sensors2008Conference paper (Refereed)
    Abstract [en]

    The on-going EU funded project Prometheus (FP7-214901) aims at establishing a general framework which links fundamental sensing tasks to automated cognition processes enabling interpretation and short-term prediction of individual and collective human behaviours in unrestricted environments as well as complex human interactions. To achieve the aforementioned goals, the Prometheus consortium works on the following core scientific and technological objectives:

    1. sensor modeling and information fusion from multiple, heterogeneous perceptual modalities;

    2. modeling, localization, and tracking of multiple people;

    3. modeling, recognition, and short-term prediction of continuous complex human behavior.

  • 883.
    Ahlberg, Jörgen
    et al.
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering. Termisk Systemteknik AB, Linköping, Sweden.
    Berg, Amanda
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering. Termisk Systemteknik AB, Linköping, Sweden.
    Evaluating Template Rescaling in Short-Term Single-Object Tracking2015Conference paper (Refereed)
    Abstract [en]

    In recent years, short-term single-object tracking has emerged has a popular research topic, as it constitutes the core of more general tracking systems. Many such tracking methods are based on matching a part of the image with a template that is learnt online and represented by, for example, a correlation filter or a distribution field. In order for such a tracker to be able to not only find the position, but also the scale, of the tracked object in the next frame, some kind of scale estimation step is needed. This step is sometimes separate from the position estimation step, but is nevertheless jointly evaluated in de facto benchmarks. However, for practical as well as scientific reasons, the scale estimation step should be evaluated separately – for example,theremightincertainsituationsbeothermethodsmore suitable for the task. In this paper, we describe an evaluation method for scale estimation in template-based short-term single-object tracking, and evaluate two state-of-the-art tracking methods where estimation of scale and position are separable.

  • 884.
    Ahlberg, Jörgen
    et al.
    Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Dornaika, Fadi
    Linköping University, Department of Electrical Engineering, Image Coding. Linköping University, The Institute of Technology.
    Efficient active appearance model for real-time head and facial feature tracking2003In: Analysis and Modeling of Faces and Gestures, 2003. AMFG 2003. IEEE International Workshop on, IEEE conference proceedings, 2003, p. 173-180Conference paper (Refereed)
    Abstract [en]

    We address the 3D tracking of pose and animation of the human face in monocular image sequences using active appearance models. The classical appearance-based tracking suffers from two disadvantages: (i) the estimated out-of-plane motions are not very accurate, and (ii) the convergence of the optimization process to desired minima is not guaranteed. We aim at designing an efficient active appearance model, which is able to cope with the above disadvantages by retaining the strengths of feature-based and featureless tracking methodologies. For each frame, the adaptation is split into two consecutive stages. In the first stage, the 3D head pose is recovered using robust statistics and a measure of consistency with a statistical model of a face texture. In the second stage, the local motion associated with some facial features is recovered using the concept of the active appearance model search. Tracking experiments and method comparison demonstrate the robustness and out-performance of the developed framework.

  • 885.
    Ahlberg, Jörgen
    et al.
    Dept. of IR Systems, Div. of Sensor Technology, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Dornaika, Fadi
    Computer Vision Center, Universitat Autonoma de Barcelona, Bellaterra, Spain.
    Parametric Face Modeling and Tracking2005In: Handbook of Face Recognition / [ed] Stan Z. Li, Anil K. Jain, Springer-Verlag New York, 2005, p. 65-87Chapter in book (Other academic)
  • 886.
    Ahlberg, Jörgen
    et al.
    Swedish Defence Research Agency, Sweden.
    Folkesson, Martin
    Swedish Defence Research Agency, Sweden.
    Grönwall, Christina
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Horney, Tobias
    Swedish Defence Research Agency, Sweden.
    Jungert, Erland
    Swedish Defence Research Agency, Sweden.
    Klasén, Lena
    Swedish Defence Research Agency, Sweden.
    Ulvklo, Morgan
    Swedish Defence Research Agency, Sweden.
    Ground Target Recognition in a Query-Based Multi-Sensor Information System2006Report (Other academic)
    Abstract [en]

    We present a system covering the complete process for automatic ground target recognition, from sensor data to the user interface, i.e., from low level image processing to high level situation analysis. The system is based on a query language and a query processor, and includes target detection, target recognition, data fusion, presentation and situation analysis. This paper focuses on target recognition and its interaction with the query processor. The target recognitionis executed in sensor nodes, each containing a sensor and the corresponding signal/image processing algorithms. New sensors and algorithms are easily added to the system. The processing of sensor data is performed in two steps; attribute estimation and matching. First, several attributes, like orientation and dimensions, are estimated from the (unknown but detected) targets. These estimates are used to select the models of interest in a matching step, where the targetis matched with a number of target models. Several methods and sensor data types are used in both steps, and data is fused after each step. Experiments have been performed using sensor data from laser radar, thermal and visual cameras. Promising results are reported, demonstrating the capabilities of the target recognition algorithms, the advantages of the two-level data fusion and the query-based system.

  • 887.
    Ahlberg, Jörgen
    et al.
    Linköping University, Department of Electrical Engineering, Image Coding. Linköping University, The Institute of Technology. Div. of Sensor Technology, Swedish Defence Research Agency, Linköping, Sweden.
    Forchheimer, Robert
    Linköping University, Department of Electrical Engineering, Image Coding. Linköping University, The Institute of Technology.
    Face tracking for model-based coding and face animation2003In: International journal of imaging systems and technology (Print), ISSN 0899-9457, E-ISSN 1098-1098, Vol. 13, no 1, p. 8-22Article in journal (Refereed)
    Abstract [en]

    We present a face and facial feature tracking system able to extract animation parameters describing the motion and articulation of a human face in real-time on consumer hardware. The system is based on a statistical model of face appearance and a search algorithm for adapting the model to an image. Speed and robustness is discussed, and the system evaluated in terms of accuracy.

  • 888.
    Ahlberg, Jörgen
    et al.
    Div. of Sensor Technology, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Klasén, Lena
    Div. of Sensor Technology, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Surveillance Systems for Urban Crisis Management2005Conference paper (Other academic)
    Abstract [en]

    We present a concept for combing 3D models and multiple heterogeneous sensors into a surveillance system enabling superior situation awareness. The concept has many military as well as civilian applications. A key issue is the use of a 3D environment model of the area to be surveyed, typically an urban area. In addition to the 3D model, the area of interest is monitored over time using multiple heterogeneous sensors, such as optical, acoustic, and/or seismic sensors. Data and analysis results from the sensors are visualized in the 3D model, thus putting them in a common reference frame and making their spatial and temporal relations obvious. The result is highlighted by an example where data from different sensor systems is integrated in a 3D model of a Swedish urban area.

  • 889.
    Ahlberg, Jörgen
    et al.
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, The Institute of Technology.
    Li, Haibo
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, The Institute of Technology.
    Representing and Compressing MPEG-4 Facial Animation Parameters using Facial Action Basis Functions1999In: IEEE Transactions on Circuits and Systems, ISSN 0098-4094, E-ISSN 1558-1276, Vol. 9, no 3, p. 405-410Article in journal (Refereed)
    Abstract [en]

    In model-based, or semantic, coding, parameters describing the nonrigid motion of objects, e.g., the mimics of a face, are of crucial interest. The facial animation parameters (FAPs) specified in MPEG-4 compose a very rich set of such parameters, allowing a wide range of facial motion. However, the FAPs are typically correlated and also constrained in their motion due to the physiology of the human face. We seek here to utilize this spatial correlation to achieve efficient compression. As it does not introduce any interframe delay, the method is suitable for interactive applications, e.g., videophone and interactive video, where low delay is a vital issue.

  • 890.
    Ahlberg, Jörgen
    et al.
    Termisk Systemteknik AB Linköping, Sweden; Visage Technologies AB Linköping, Sweden.
    Markuš, Nenad
    Human-Oriented Technologies Laboratory, Faculty of Electrical Engineering and Computing, University of Zagreb, Croatia.
    Berg, Amanda
    Termisk Systemteknik AB, Linköping, Sweden.
    Multi-person fever screening using a thermal and a visual camera2015Conference paper (Other academic)
    Abstract [en]

    We propose a system to automatically measure the body temperature of persons as they pass. In contrast to exisitng systems, the persons do not need to stop and look into a camera one-by-one. Instead, their eye corners are automatically detected and the temperatures therein measured using a thermal camera. The system handles multiple simultaneous persons and can thus be used where a flow of people pass, such as at airport gates.

  • 891.
    Ahlberg, Jörgen
    et al.
    Division of Information Systems, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Pandzic, Igor
    Faculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, Croatia.
    Facial Action Tracking2011In: Handbook of Face Recognition / [ed] Stan Z. Li, Anil K. Jain, London: Springer London, 2011, 2, p. 461-486Chapter in book (Refereed)
    Abstract [en]

    This chapter explains the basics of parametric face models used for face and facial action tracking as well as fundamental strategies and methodologies for tracking. A few tracking algorithms serving as pedagogical examples are described in more detail.

  • 892.
    Ahlberg, Jörgen
    et al.
    Department of IR Systems, Division of Sensor Technology, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Renhorn, Ingmar
    Department of IR Systems, Division of Sensor Technology, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    An information-theoretic approach to band selection2005In: Proc. SPIE 5811, Targets and Backgrounds XI: Characterization and Representation / [ed] Wendell R. Watkins; Dieter Clement; William R. Reynolds, SPIE - International Society for Optical Engineering, 2005, p. 15-23Conference paper (Refereed)
    Abstract [en]

    When we digitize data from a hyperspectral imager, we do so in three dimensions; the radiometric dimension, the spectral dimension, and the spatial dimension(s). The output can be regarded as a random variable taking values from a discrete alphabet, thus allowing simple estimation of the variable’s entropy, i.e., its information content. By modeling the target/background state as a binary random variable and the corresponding measured spectra as a function thereof, wecan compute theinformation capacity ofa certainsensoror sensor configuration. This can be used as a measure of the separability of the two classes, and also gives a bound on the sensor’s performance. Changing the parameters of the digitizing process, bascially how many bits and bands to spend, will affect the information capacity, and we can thus try to find parameters where as few bits/bands as possible gives us as good class separability as possible. The parameters to be optimized in this way (and with respect to the chosen target and background) are spatial, radiometric and spectral resolution, i.e., which spectral bands to use and how to quantize them. In this paper, we focus on the band selection problem, describe an initial approach, and show early results of target/background separation.

  • 893.
    Ahlberg, Jörgen
    et al.
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering. Glana Sensors AB, Sweden.
    Renhorn, Ingmar
    Glana Sensors AB, Sweden.
    Chevalier, Tomas
    Scienvisic AB, Sweden.
    Rydell, Joakim
    FOI, Swedish Defence Research Agency, Sweden.
    Bergström, David
    FOI, Swedish Defence Research Agency, Sweden.
    Three-dimensional hyperspectral imaging technique2017In: ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL, AND ULTRASPECTRAL IMAGERY XXIII / [ed] Miguel Velez-Reyes; David W. Messinger, SPIE - International Society for Optical Engineering, 2017, Vol. 10198, article id 1019805Conference paper (Refereed)
    Abstract [en]

    Hyperspectral remote sensing based on unmanned airborne vehicles is a field increasing in importance. The combined functionality of simultaneous hyperspectral and geometric modeling is less developed. A configuration has been developed that enables the reconstruction of the hyperspectral three-dimensional (3D) environment. The hyperspectral camera is based on a linear variable filter and a high frame rate, high resolution camera enabling point-to-point matching and 3D reconstruction. This allows the information to be combined into a single and complete 3D hyperspectral model. In this paper, we describe the camera and illustrate capabilities and difficulties through real-world experiments.

  • 894.
    Ahlberg, Jörgen
    et al.
    Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Renhorn, Ingmar G.
    Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Wadströmer, Niclas
    Swedish Defence Research Agency (FOI), Linköping, Sweden.
    An information measure of sensor performance and its relation to the ROC curve2010In: Proc. SPIE 7695, Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XVI / [ed] Sylvia S. Shen; Paul E. Lewis, SPIE - International Society for Optical Engineering, 2010, p. Art.nr. 7695-72-Conference paper (Refereed)
    Abstract [en]

    The ROC curve is the most frequently used performance measure for detection methods and the underlying sensor configuration. Common problems are that the ROC curve does not present a single number that can be compared to other systems and that no discrimination between sensor performance and algorithm performance is done. To address the first problem, a number of measures are used in practice, like detection rate at a specific false alarm rate, or area-under-curve. For the second problem, we proposed in a previous paper1 an information theoretic method for measuring sensor performance. We now relate the method to the ROC curve, show that it is equivalent to selecting a certain point on the ROC curve, and that this point is easily determined. Our scope is hyperspectral data, studying discrimination between single pixels.

  • 895.
    Ahlberg, Jörgen
    et al.
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering.
    Åstrom, Anders
    Swedish Natl Forens Ctr NFC, Linkoping, Sweden.
    Forchheimer, Robert
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, Faculty of Science & Engineering.
    Simultaneous sensing, readout, and classification on an intensity-ranking image sensor2018In: International journal of circuit theory and applications, ISSN 0098-9886, E-ISSN 1097-007X, Vol. 46, no 9, p. 1606-1619Article in journal (Refereed)
    Abstract [en]

    We combine the near-sensor image processing concept with address-event representation leading to an intensity-ranking image sensor (IRIS) and show the benefits of using this type of sensor for image classification. The functionality of IRIS is to output pixel coordinates (X and Y values) continuously as each pixel has collected a certain number of photons. Thus, the pixel outputs will be automatically intensity ranked. By keeping track of the timing of these events, it is possible to record the full dynamic range of the image. However, in many cases, this is not necessary-the intensity ranking in itself gives the needed information for the task at hand. This paper describes techniques for classification and proposes a particular variant (groves) that fits the IRIS architecture well as it can work on the intensity rankings only. Simulation results using the CIFAR-10 dataset compare the results of the proposed method with the more conventional ferns technique. It is concluded that the simultaneous sensing and classification obtainable with the IRIS sensor yields both fast (shorter than full exposure time) and processing-efficient classification.

  • 896.
    Ahlberg, K
    et al.
    Barn- och ungdomshabiliteringen, Karlstad .
    Åhsgren,
    Barn- och ungdomshabiliteringen, Sundsvall.
    Gladh Mattsson, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Mattsson, Sven
    Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping. Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Pediatrics.
    Toilet training, incontinence and learning disability2010In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 107, no 37, p. 2164-2168Article in journal (Other academic)
  • 897.
    Ahlberg, Karin
    et al.
    Karlstad.
    Åhsgren, Ingegerd
    Sundsvall.
    Glad Mattsson, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    Mattsson, Sven
    Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping. Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Toaletträning lönar sig även vid svår utvecklingsstörning: Råd och anvisningar vid inkontinens2010In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 107, no 37, p. 2164-2168Article in journal (Other academic)
    Abstract [sv]

    Råd och anvisningar för toaletträning vid utvecklingsstörning har efterlysts av föräldrar och vårdpersonal.

    Evidensbaserade riktlinjer enligt SBU:s rekommendationer för handläggning av toaletträning vid utvecklingsstörning har tagits fram efter granskning av befintlig forskning, som nästan uteslutande berör toaletträning vid måttlig, svår eller grav utvecklingsstörning.

    Barnorienterade råd för toaletträning av normalutvecklade barn kan eller ska som regel tillämpas för barn med utvecklingsstörning utan tilläggsproblematik.

    Intensiv strukturerad beteendeträning är sannolikt den bästa metoden för barn och ungdomar med svårare grad av utvecklingsstörning och för individer med neuropsy­kiatriska funktionsnedsättningar.

    Medicinsk bedömning ska alltid föregå toaletträning vid utvecklingsstörning, då neurogena och anatomiska avvikelser är vanligare hos barn och ungdomar med utvecklingsstörning.

  • 898. Ahlberg, M
    et al.
    Bäckman, C
    Jones, C
    Walther, S
    Hollman Frisman, Gunilla
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Norrköping.
    Group communication confirms feelings among partners of former intensive care patients2014Conference paper (Refereed)
  • 899.
    Ahlberg, M
    et al.
    Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Norrköping.
    Bäckman, C
    Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Norrköping.
    Jones, C
    Musculoskeletal Biologu, Institute of Ageing & Chronic Disease, University of Liverpool, Liverpool, UK.
    Walther, S
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Hollman Frisman, Gunilla
    Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center. Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences.
    Moving forward in life after being an on-looker in intensive care partner's experience of group-communication2016Conference paper (Refereed)
    Abstract [en]

    Background: Partners have a burdensome time during and after their partners’ intensive care period. They may appear to be coping well

    outwardly but inside feel vulnerable and lost. Evaluated interventions for partners on this aspect are limited.

    Aim: The aim of this study was to describe the experience of participating in group communication with other partners of former intensive

    care patients.

    Design: The study has a descriptive intervention-based design where group communication for partners of former, surviving intensive care

    unit (ICU) patients was evaluated.

    Methods: A strategic selection was made of adult partners to former adult intensive care patients (n=15), 5 men and 10 women, aged

    37–89 years. Two group communication sessions lasting 2 h were held at monthly intervals with three to five partners. The partners later wrote,

    in a notebook, about their feelings of participating in group communications. To deepen the understanding of the impact of the sessions, six of

    the partners were interviewed. Content analysis was used to analyse the notebooks and the interviews.

    Findings: Three categories were identified: (1) Emotional impact, the partners felt togetherness and experienced worries and gratitude, (2)

    Confirmation, consciousness through insight and reflection and (3) The meeting design, group constellation and recommendation to participate

    in group communication.

    Conclusion: Partners of an intensive care patient are on a journey, constantly trying to adapt to the new situation and find new strategies

    to ever-changing circumstances. Group communications contributed to togetherness and confirmation. To share experiences with others is one

    way for partners to be able to move forward in life.

    Relevance to clinical practice: Group communication with other patients’ partners eases the process of going through the burden of

    being a partner to an intensive care patient. Group communications needs to be further developed and evaluated to obtain consensus and

    evidence for the best practice.

    Key words: Communication • Content analysis • Intensive care • Nursing • Partners

  • 900. Ahlberg, M
    et al.
    Bäckman, C
    Jones, C
    walther, S
    Hollman Frisman, Gunilla
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Gastroentorology.
    Moving forward in life after being an unlocker in intensive care - partners' experience of group communication2015Conference paper (Other academic)
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