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  • 201.
    Chowdhury, Manish
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Rota Bulò, S.
    Moreno, Rodrigo
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Kundu, M.K.
    Smedby, Örjan
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    An Efficient Radiographic Image Retrieval System Using Convolutional Neural Network2016In: 2016 23rd International Conference on Pattern Recognition (ICPR), Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 3134-3139, article id 7900116Conference paper (Refereed)
    Abstract [en]

    Content-Based Medical Image Retrieval (CBMIR) is an important research field in the context of medical data management. In this paper we propose a novel CBMIR system for the automatic retrieval of radiographic images. Our approach employs a Convolutional Neural Network (CNN) to obtain high- level image representations that enable a coarse retrieval of images that are in correspondence to a query image. The retrieved set of images is refined via a non-parametric estimation of putative classes for the query image, which are used to filter out potential outliers in favour of more relevant images belonging to those classes. The refined set of images is finally re-ranked using Edge Histogram Descriptor, i.e. a low-level edge-based image descriptor that allows to capture finer similarities between the retrieved set of images and the query image. To improve the computational efficiency of the system, we employ dimensionality reduction via Principal Component Analysis (PCA). Experiments were carried out to evaluate the effectiveness of the proposed system on medical data from the “Image Retrieval in Medical Applications” (IRMA) benchmark database. The obtained results show the effectiveness of the proposed CBMIR system in the field of medical image retrieval.

  • 202.
    Christakopoulos, Fotios
    KTH, School of Technology and Health (STH).
    Modeling of beta-cell Metabolic Activity and Islet Function: a Systems Approach to Type II Diabetes2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Diabetes has gained growing attendance as one of the key non communicable diseases (NCD) with the World Health Organization identifying it as the focus of the World Health Day 2016. It is reported that more than 420 million people suffer from diabetes, a number predicted to rise in the coming years. This report forms part of a broader, long term focus project that aims to establish a systems approach to type 2 diabetes (T2D), the variant that accounts for more than 90% of reported diabetes cases. The broader project objectives are to identify possible biomarkers for the onset and the progression of T2D as a precursor to enable potential future approaches to delay onset, or even reverse disease states, via active bio-compounds and/or establishment of beneficial nutritional patterns.

    The 6-month master’s work reported here is sub-project that focused specifically on cell level vesicle trafficking processes. These processes are believed to be crucial in understanding the formation amyloid plaques, which compromise or kill the insulin secreting beta cells. Up until now, there has been a lack of appropriate experimental techniques to directly observe this process in live cells.  Hence we have developed 2 new techniques:

    (i)               a method of imaging the actin and tubulin network reorganization during exocytosis of the insulin containing granules while exploring novel ways of characterizing the network.

    (ii)             a method of imaging the granules themselves and using particle tracking microrheology to analyze their movement patterns during stimulation with glucose.

    These new techniques open the door to follow up experiments which would allow development of a cell scale mathematical model or simulation correlating short term glucose dynamics to risk of amyloid plaque formation and T2D. 

  • 203.
    Christiansson, Samuel
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Potentialen för spillvärmeuppvärmda växthus i Sverige: ur ett hållbarhetsperspektiv2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

    Denna studie är en delstudie i ett större växthusprojekt som drivs av KTH Centrum för Hälsa och Byggande i Haninge utanför Stockholm. Projektet inbegriper ett integrerat spillvärme- och växthussystem med besöks- och forskningsändamål, placerat i anslutning till en reningsanläggning och ett naturbruksgymnasium. Studiens primära syften är att undersöka spillvärmepotentialen och potentialen för uppvärmning av växthus med spillvärme i Sverige. De sekundära syftena är att undersöka vilka hållbarhetsaspekter som kan identifieras som viktiga för spillvärme-växthus-system och att göra en idé- och informationssammanställning för dem som vill bygga spillvärme-växthus-system, med bland annat tips om hur produktpriser kan beräknas, vilka nyckeltal som kan användas för energikalkyler och vilka användningsområden som finns med ett växthus. Rapporten får ett visst fokus på livsmedels- och tomatodling, eftersom både tidigare studier och den fallstudie som ingår i rapporten handlade om detta. Studiens avsikt är dock att förespråka för en bredare syn på växthusanvändning.

    Studien visar att det finns stora spillvärmepotentialer bland särskilt högtempererade spillvärmekällor på västkusten och medeltempererade spillvärmekällor i Stockholmsområdet, eftersom dessa områden har både god spillvärmepotential och stor befolkning. Växthus kan byggas nära spillvärmekällan och kräver inte lika höga ingångstemperaturer som exempelvis fjärrvärmenäten, vilket gör spillvärme-växthus-system mer flexibla än spillvärme-fjärrvärme-system. Studien visar på viktiga fysiska, ekonomiska och organisatoriska förutsättningar för att bygga spillvärme-växthus-system, att det finns biologiska, sociala och kulturella potentialer med växthusen och vidare att det finns flera intressanta hållbarhetsaspekter med spillvärme-växthus-system, särskilt om de byggs rätt från början.

    Så gjordes i Habo, där studiens fallstudie gjordes. I Habo drivs ekologisk växthusodling med hjälp av spillvärme från en närliggande och elproducerande biogasanläggning, där de organiska resurserna består av gödsel och godisrester från en lokal godisindustri. Hela spillvärme-växthus-systemet är småskaligt och i stort sett kretsloppsanpassat. Modellen rekommenderas starkt både för projektet i Haninge och var helst man funderar på att bygga spillvärme-växthus-system, eftersom det överallt finns och alltid kommer att finnas tillgång på organiskt avfall. Energistudier visar att det finns stor potential i det organiska avfallet, särskilt från jordbruk

  • 204. Cinti, M. N.
    et al.
    Scafe, R.
    Bennati, Paolo
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lo Meo, S.
    Frantellizzi, V.
    Pellegrini, R.
    De Vincentis, G.
    Sacco, D.
    Fabbri, A.
    Pani, R.
    Innovative LuYAP:Ce array for PET imaging2017In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, no 3, article id C03069Article in journal (Refereed)
    Abstract [en]

    We present an imaging characterization of a 10 x 10 LuYAP array (2 x 2 x 10 mm3 pixels) with an innovative dielectric coating insulation (0.015 mm thick), in view of its possible use in a gamma camera for imaging positron emission tomography (PET) or in similar applications, e.g. as γ-prompt detector in hadron therapy. The particular assembly of this array was realized in order to obtain a packing fraction of 98%, improving detection efficiency and light collection. For imaging purpose, the array has been coupled with a selected Hamamatsu H10966-100 Multi Anode Photomultiplier read out by a customized 64 independent channels electronics. This tube presents a superbialkali photocathode with 38% of quantum efficiency, permitting to enhance energy resolution and consequently image quality. A pixel identification of about 0.5 mm at 662 keV was obtained, highlighting the potentiality of this detector in PET applications.

  • 205. Cippitelli, E.
    et al.
    Gasparrini, S.
    Gambi, E.
    Spinsante, S.
    Wåhslén, Jonas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Time synchronization and data fusion for RGB-Depth cameras and inertial sensors in AAL applications2015In: 2015 IEEE International Conference on Communication Workshop, ICCW 2015, IEEE conference proceedings, 2015, p. 265-270Conference paper (Refereed)
    Abstract [en]

    Ambient Assisted Living applications often need to integrate data from multiple sensors, to provide consistent information on the observed phenomena. Data fusion based on samples from several sensors requires accurate time synchronization with sufficient resolution, depending on the sensor sampling frequency. This work presents a technical platform for the efficient and accurate synchronization of the data captured from RGB-Depth cameras and wearable inertial sensors, that can be integrated in AAL solutions. A case study of sensor data fusion for Timed Up and Go test is also presented and discussed.

  • 206.
    Cloots, Rudy J.H.
    et al.
    Eindhoven University of Technology, Department of Mechanical Engineering.
    van Dommelen, J.A.W.
    Eindhoven University of Technology, Department of Mechanical Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Geers, Marc
    Eindhoven University of Technology, Department of Mechanical Engineering.
    Multi-scale mechanics of traumatic brain injury: predicting axonal strains from head loads2013In: Biomechanics and Modeling in Mechanobiology, ISSN 1617-7959, E-ISSN 1617-7940, Vol. 12, no 1, p. 137-150Article in journal (Refereed)
    Abstract [en]

    The length scales involved in the development of diffuse axonal injury typically range from the head level (i.e., mechanical loading) to the cellular level. The parts of the brain that are vulnerable to this type of injury are mainly the brainstem and the corpus callosum, which are regions with highly anisotropically oriented axons. Within these parts, discrete axonal injuries occur mainly where the axons have to deviate from their main course due to the presence of an inclusion. The aim of this study is to predict axonal strains as a result of a mechanical load at the macroscopic head level. For this, a multi-scale finite element approach is adopted, in which a macro-level head model and a micro-level critical volume element are coupled. The results show that the axonal strains cannot be trivially correlated to the tissue strain without taking into account the axonal orientations, which indicates that the heterogeneities at the cellular level play an important role in brain injury and reliable predictions thereof. In addition to the multi-scale approach, it is shown that a novel anisotropic equivalent strain measure can be used to assess these micro-scale effects from head-level simulations only.

  • 207.
    Cloots, Rudy J.H.
    et al.
    Eindhoven University of Technology, Department of Mechanical Engineering.
    van Dommelen, JAW
    Eindhoven University of Technology, Department of Mechanical Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Geers, Marc
    Eindhoven University of Technology, Department of Mechanical Engineering.
    Traumatic Brain Injury at Multiple Length Scales: Relating Diffuse Axonal Injury to Discrete Axonal Impairment2010In: 2010 INTERNATIONAL IRCOBI CONFERENCE ON THE BIOMECHANICS OF INJURY PROCEEDINGS, 2010, p. 119-130Conference paper (Refereed)
  • 208.
    Commowick, Olivier
    et al.
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France..
    Istace, Audrey
    Hosp Civils Lyon, Lyon Sud Hosp, Dept Radiol, Lyon, France..
    Kain, Michael
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France..
    Laurent, Baptiste
    Univ Brest, IBSAM, INSERM, LaTIM,UMR 1101, Brest, France..
    Leray, Florent
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France..
    Simon, Mathieu
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France..
    Pop, Sorina Camarasu
    Univ Claude Bernard Lyon 1, Univ Lyon,INSA Lyon, UJM St Etienne,CNRS,Inserm, CREATIS,UMR 5220,U1206, F-69621 Lyon, France..
    Girard, Pascal
    Univ Claude Bernard Lyon 1, Univ Lyon,INSA Lyon, UJM St Etienne,CNRS,Inserm, CREATIS,UMR 5220,U1206, F-69621 Lyon, France..
    Ameli, Roxana
    Hosp Civils Lyon, Lyon Sud Hosp, Dept Radiol, Lyon, France..
    Ferre, Jean-Christophe
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France.;CHU Rennes, Dept Neuroradiol, F-35033 Rennes, France..
    Kerbrat, Anne
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France.;CHU Rennes, Dept Neurol, F-35033 Rennes, France..
    Tourdias, Thomas
    CHU Bordeaux, Serv Neuroimagerie, Bordeaux, France..
    Cervenansky, Frederic
    Univ Claude Bernard Lyon 1, Univ Lyon,INSA Lyon, UJM St Etienne,CNRS,Inserm, CREATIS,UMR 5220,U1206, F-69621 Lyon, France..
    Glatard, Tristan
    Concordia Univ, Dept Comp Sci & Software Engn, Montreal, PQ, Canada..
    Beaumont, Jeremy
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France..
    Doyle, Senan
    Pixyl Med, Grenoble, France..
    Forbes, Florence
    Pixyl Med, Grenoble, France.;Inria Grenoble Rhone Alpes, Grenoble, France..
    Knight, Jesse
    Univ Guelph, Sch Engn, Image Anal Med Lab, Guelph, ON, Canada..
    Khademi, April
    Ryerson Univ, Image Anal Med Lab IAMLAB, Toronto, ON, Canada..
    Mahbod, Amirreza
    KTH, School of Technology and Health (STH).
    Wang, Chunliang
    KTH, School of Technology and Health (STH).
    McKinley, Richard
    Univ Bern, Dept Diagnost & Intervent Neuroradiol, Inselspital, Bern, Switzerland..
    Wagner, Franca
    Univ Bern, Dept Diagnost & Intervent Neuroradiol, Inselspital, Bern, Switzerland..
    Muschelli, John
    Johns Hopkins Bloomberg Sch Publ Hlth, Baltimore, MD USA..
    Sweeney, Elizabeth
    Johns Hopkins Bloomberg Sch Publ Hlth, Baltimore, MD USA..
    Roura, Eloy
    Univ Girona, Res Inst Comp Vis & Robot VICOROB, Girona, Spain..
    Llado, Xavier
    Univ Girona, Res Inst Comp Vis & Robot VICOROB, Girona, Spain..
    Santos, Michel M.
    Univ Fed Pernambuco, Ctr Informat, Recife, Brazil..
    Santos, Wellington P.
    Univ Fed Pernambuco, Dept Engn Biomed, Recife, Brazil..
    Silva-Filho, Abel G.
    Univ Fed Pernambuco, Ctr Informat, Recife, Brazil..
    Tomas-Fernandez, Xavier
    Childrens Hosp, Dept Radiol, Computat Radiol Lab, 300 Longwood Ave, Boston, MA 02115 USA..
    Urien, Helene
    Univ Paris Saclay, LTCI, Telecom ParisTech, Paris, France..
    Bloch, Isabelle
    Univ Paris Saclay, LTCI, Telecom ParisTech, Paris, France..
    Valverde, Sergi
    Univ Girona, Res Inst Comp Vis & Robot VICOROB, Girona, Spain..
    Cabezas, Mariano
    Univ Girona, Res Inst Comp Vis & Robot VICOROB, Girona, Spain..
    Javier Vera-Olmos, Francisco
    Univ Rey Juan Carlos, Med Image Anal Lab, Madrid, Spain..
    Malpica, Norberto
    Univ Rey Juan Carlos, Med Image Anal Lab, Madrid, Spain..
    Guttmann, Charles
    Brigham & Womens Hosp, Dept Radiol, Ctr Neurol Imaging, 75 Francis St, Boston, MA 02115 USA..
    Vukusic, Sandra
    Hosp Civils Lyon, Lyon Sud Hosp, Dept Radiol, Lyon, France..
    Edan, Gilles
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France.;CHU Rennes, Dept Neurol, F-35033 Rennes, France..
    Dojat, Michel
    Univ Grenoble Alpes, CHU Grenoble, GIN, Inserm,U1216, Grenoble, France..
    Styner, Martin
    Univ N Carolina, Dept Comp Sci, Chapel Hill, NC 27515 USA..
    Warfield, Simon K.
    Childrens Hosp, Dept Radiol, Computat Radiol Lab, 300 Longwood Ave, Boston, MA 02115 USA..
    Cotton, Francois
    Hosp Civils Lyon, Lyon Sud Hosp, Dept Radiol, Lyon, France..
    Barillot, Christian
    Univ Rennes 1, CNRS, INSERM, VISAGES,U1228,UMR6074, Rennes, France..
    Objective Evaluation of Multiple Sclerosis Lesion Segmentation using a Data Management and Processing Infrastructure2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 13650Article in journal (Refereed)
    Abstract [en]

    We present a study of multiple sclerosis segmentation algorithms conducted at the international MICCAI 2016 challenge. This challenge was operated using a new open-science computing infrastructure. This allowed for the automatic and independent evaluation of a large range of algorithms in a fair and completely automatic manner. This computing infrastructure was used to evaluate thirteen methods of MS lesions segmentation, exploring a broad range of state-of-theart algorithms, against a high-quality database of 53 MS cases coming from four centers following a common definition of the acquisition protocol. Each case was annotated manually by an unprecedented number of seven different experts. Results of the challenge highlighted that automatic algorithms, including the recent machine learning methods (random forests, deep learning,.), are still trailing human expertise on both detection and delineation criteria. In addition, we demonstrate that computing a statistically robust consensus of the algorithms performs closer to human expertise on one score (segmentation) although still trailing on detection scores.

  • 209.
    Corné, Josefine
    et al.
    KTH, School of Technology and Health (STH).
    Ullvin, Amanda
    KTH, School of Technology and Health (STH).
    Prediktiv analys i vården: Hur kan maskininlärningstekniker användas för att prognostisera vårdflöden?2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project was performed in cooperation with Siemens Healthineers. The project aimed to investigate possibilities to forecast healthcare processes by investigating how big data and machine learning can be used for predictive analytics. The project consisted of two separate case studies. Based on data from previous MRI examinations the aim was to investigate if it is possible to predict duration of MRI examinations and identify potential no show patients. The case studies were performed with the programming language R and three machine learning methods were used to develop predictive models for each case study. The results from the case studies indicate that with a greater amount of data of better quality it would be possible to predict duration of MRI examinations and potential no show patients. The conclusion is that these types of predictive models can be used to forecast healthcare processes. This could contribute to increased effectivity and reduced waiting time in healthcare.

  • 210.
    Courteille, Olivier
    et al.
    Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Fahlstedt, Madelen
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Ho, Johnson
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Hedman, Leif
    Department of Psychology, Umeå University, Umeå, Sweden.
    Fors, Uno
    Department of Computer and Systems Sciences, Stockholm University, Stockholm, Sweden.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Felländer-Tsai, Li
    Department of Clinical Science, Intervention and Technology, Division of Orthopaedics and Biotechnology, Karolin-ska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    Möller, Hans
    Department of Clinical Science, Intervention and Technology, Division of Orthopaedics and Biotechnology, Karolin-ska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    Learning through a virtual patient vs. recorded lecture: a comparison of knowledge retention in a trauma case2018In: International Journal of Medical Education, ISSN 2042-6372, E-ISSN 2042-6372, Vol. 9, p. 86-92Article in journal (Refereed)
    Abstract [en]

    Objectives: To compare medical students' and residents' knowledge retention of assessment, diagnosis and treatment procedures, as well as a learning experience, of patients with spinal trauma after training with either a Virtual Patient case or a video-recorded traditional lecture. Methods: A total of 170 volunteers (85 medical students and 85 residents in orthopedic surgery) were randomly allocated (stratified for student/resident and gender) to either a video-recorded standard lecture or a Virtual Patient-based training session where they interactively assessed a clinical case portraying a motorcycle accident. The knowledge retention was assessed by a test immediately following the educational intervention and repeated after a minimum of 2 months. Participants' learning experiences were evaluated with exit questionnaires. A repeated-measures analysis of variance was applied on knowledge scores. A total of 81% (n = 138) of the participants completed both tests. Results: There was a small but significant decline in first and second test results for both groups (F-(1,F-135) = 18.154, p = 0.00). However, no significant differences in short-term and long-term knowledge retention were observed between the two teaching methods. The Virtual Patient group reported higher learning experience levels in engagement, stimulation, general perception, and expectations. Conclusions: Participants' levels engagement were reported in favor of the VP format. Similar knowledge retention was achieved through either a Virtual Patient or a recorded lecture.

  • 211.
    Cronebäck, Alexandra
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Input interface requirements on board mounted DC/DC converters2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out on behalf of the department of Power Modules at Ericsson.

    In a telecom system interface A is a physical point between the power supply system and the telecommunication equipment described in a European standard called ETSI EN 300 132-2. This interface is also described in the American standard ATIS-0600315.2007. For board-mounted products, such as DC/DC converters, a well-defined input interface description is lacking.

    The goal of this thesis was to evaluate if the requirements in the standards ETSI EN 300 132-2 and ATIS-0600315.2007 are viable for the input interface of DC/DC converters. A part of this goal was also to investigate and analyze how the systems, in which the DC/DC converters operate, works.

    To be able to determine if any of the two standards, ETSI and ATIS, are viable for use for the input interface, both were reviewed and described with focus on voltage levels and transients.

    In the information gathering phase it became clear that an extended limitation was needed. Therefore, in order to investigate what happens from interface A to the input interface of DC/DC converters, the system used in this thesis is the EBS LOD (Ericsson Blade System – Low Ohmic Distribution). EBS is one of the systems in Core sites.

    The report describes the construction of EBS where in the PFM (Power Fan Module), backplanes and various boards are important parts. Furthermore some key principles within Core sites, such as HOD (High Ohmic Distribution), LOD, Two-wire system and Three-wire system, are also described in order to explain how the EBS system works.

    EBS (including PIM (Power Interface Module)) was modeled in OrCad PSpice, with both one board and 26 boards, and was simulated with different transients at an input to the system. The simulation results show that the high voltages never reach the DC/DC converter and that they therefore are well protected from transients in an EBS LOD system.

    In order to determine whether the standards ETSI and ATIS are viable for the input interface of DC/DC converters, it is concluded that more investigations, tests and simulations are needed.

  • 212.
    Cruz Nunez, Paulo
    et al.
    KTH, School of Technology and Health (STH).
    Sorcini, Emil
    Utvekling av ett nytt roterande fantom: Vid extrakorporeal strålbehandling av lokalt avancerat sarkom i skelett2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Extrakorporeal strålbehandling av skelettsarkom är en variant av strålbehandling där en del av en patients skelett opereras ut från kroppen. Skelettsegmentet transporteras sedan vidare till ett annat behandlingsrum där den bestrålas inuti ett fantom m.h.a. en linjäraccelerator. Detta sker medan patienten är nedsövd. Efter bestrålningen kan skelettsegmentet opereras tillbaka in till patienten. På Karolinska Universitetssjukhuset i Solna görs denna strålbehandling med en metod som kräver relativt lång bestrålningstid. Detta beror på fantomets kubiska form. Ju närmare ett fantom är strålkällan desto mindre stråltid behövs. Vid det kubiska fantomet används två strålfält, ett framför och ett bakom fantomet. Det här betyder att ifall fantomets position förs närmare strålkällan, så måste den föras tillbaka lika mycket åt andra hållet efter första strålfältet. Detta gör att det blir opraktiskt samt att man inte vinner någon tid. Målet med detta projekt var att skapa ett fantom som kan förflyttas så nära strålkällan som möjligt för att minska så mycket stråltid som möjligt. Detta kommer i sin tur minska den totala behandlingstiden. Genom att skapa ett roterande cylinderformat fantom som inte är riktningsberoende, så kunde fantomet förflyttas 25 cm närmare (från 95 cm till 70 cm), jämfört med det kubiska fantomets avstånd till strålkällan. Cylinderfantomet var gjord av akrylplast och en rotationsanordning konstruerades för att rotera fantomet. Vinkelhastigheten på rotationsanordningen sattes till 15 varv/minut. Det kubiska och cylindriska fantomet jämfördes genom simuleringar. Det visade sig att bägges stråldosfördelning var likvärdiga. Bestrålningstiden kunde förkortas ner från 640 sekunder till 340 sekunder utan att negativt påverka dosfördelningen jämfört med tidigare metod.

  • 213.
    Cuba-Gyllensten, Illapha
    et al.
    KTH, School of Technology and Health (STH). Philips Research Europe, High Tech. Campus 34, 5656AE, Eindhoven, Netherlands; ACTLab., Signal Processing Systems, TU Eindhoven, 5600MB Eindhoven, Netherlands.
    Abtahi, Farhad
    Philips Research Europe, High Tech. Campus 34, 5656AE, Eindhoven, Netherlands.
    Bonomi, Alberto G.
    KTH, School of Technology and Health (STH).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. University of Borås, Sweden.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Karolinska Institute, Sweden.
    Amft, O.
    ACTLab., Signal Processing Systems, TU Eindhoven, 5600MB Eindhoven, Netherlands.
    Removing respiratory artefacts from transthoracic bioimpedance spectroscopy measurements2013In: XV International Conference on Electrical Bio-Impedance (ICEBI) & XIV Conference on Electrical Impedance Tomography (EIT), Institute of Physics Publishing (IOPP), 2013, Vol. 434, no 1Conference paper (Refereed)
    Abstract [en]

    Transthoracic impedance spectroscopy (TIS) measurements from wearable textile electrodes provide a tool to remotely and non-invasively monitor patient health. However, breathing and cardiac processes inevitably affect TIS measurements, since they are sensitive to changes in geometry and air or fluid volumes in the thorax. This study aimed at investigating the effect of respiration on Cole parameters extracted from TIS measurements and developing a method to suppress artifacts. TIS data were collected from 10 participants at 16 frequencies (range: 10 kHz - 1 MHz) using a textile electrode system (Philips Technologie Gmbh). Simultaneously, breathing volumes and frequency were logged using an electronic spirometer augmented with data from a breathing belt. The effect of respiration on TIS measurements was studied at paced (10 and 16 bpm) deep and shallow breathing. These measurements were repeated for each subject in three different postures (lying down, reclining and sitting). Cole parameter estimation was improved by assessing the tidal expiration point thus removing breathing artifacts. This leads to lower intra-subject variability between sessions and a need for less measurements points to accurately assess the spectra. Future work should explore algorithmic artifacts compensation models using breathing and posture or patient contextual information to improve ambulatory transthoracic impedance measurements.

  • 214. Cui, Zhao Ying
    et al.
    Famaey, Nele
    Depreitere, Bart
    Ivens, Jan
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Vander Sloten, Jos
    On the assessment of bridging vein rupture associated acute subdural hematoma through finite element analysis2017In: Computer Methods in Biomechanics and Biomedical Engineering, ISSN 1025-5842, E-ISSN 1476-8259, Vol. 20, no 5, p. 530-539Article in journal (Refereed)
    Abstract [en]

    Acute subdural hematoma (ASDH) is a type of intracranial haemorrhage following head impact, with high mortality rates. Bridging vein (BV) rupture is a major cause of ASDH, which is why a biofidelic representation of BVs in finite element (FE) head models is essential for the successful prediction of ASDH. We investigated the mechanical behavior of BVs in the KTH FE head model. First, a sensitivity study quantified the effect of loading conditions and mechanical properties on BV strain. It was found that the peak rotational velocity and acceleration and pulse duration have a pronounced effect on the BV strains. Both Young's modulus and diameter are also negatively correlated with the BV strains. A normalized multiple linear regression model using Young's modulus, outer diameter and peak rotational velocity to predict the BV strain yields an adjusted -value of 0.81. Secondly, cadaver head impact experiments were simulated with varying sets of mechanical properties, upon which the amount of successful BV rupture predictions was evaluated. The success rate fluctuated between 67 and 75%. To further increase the predictive capability of FE head models w.r.t. BV rupture, future work should be directed towards improvement of the BV representation, both geometrically and mechanically.

  • 215. Cunico, F. J.
    et al.
    Marquez, Juan Carlos
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Hilke, H.
    Skrifvars, M.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Studying the performance of conductive polymer films as textile electrodes for electrical bioimpedance measurements2013In: XV International Conference on Electrical Bio-Impedance (ICEBI) & XIV Conference on Electrical Impedance Tomography (EIT), 2013, Vol. 434, no 1, p. 012027-Conference paper (Refereed)
    Abstract [en]

    With the goal of finding novel biocompatible materials suitable to replace silver in the manufacturing of textile electrodes for medical applications of electrical bioimpedance spectroscopy, three different polymeric materials have been investigated. Films have been prepared from different polymeric materials and custom bracelets have been confectioned with them. Tetrapolar total right side electrical bioimpedance spectroscopy (EBIS) measurements have been performed with polymer and with standard gel electrodes. The performance of the polymer films was compared against the performance of the gel electrodes. The results indicated that only the polypropylene 1380 could produce EBIS measurements but remarkably tainted with high frequency artefacts. The influence of the electrode mismatch, stray capacitances and large electrode polarization impedance are unclear and they need to be clarified with further studies. If sensorized garments could be made with such biocompatible polymeric materials the burden of considering textrodes class III devices could be avoided.

  • 216.
    da Silva, Cristina
    et al.
    KTH, School of Technology and Health (STH). Karolinska Inst, Sweden.
    Sahlen, Anders
    Winter, Reidar
    KTH, School of Technology and Health (STH), Medical Engineering. Karolinska Univ Hosp, Sweden.
    Back, Magnus
    Ruck, Andreas
    Settergren, Magnus
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH), Medical Engineering. Karolinska Univ Hosp, Sweden.
    Shahgaldi, Kambiz
    KTH, School of Technology and Health (STH), Medical Engineering. Sunderby Hosp, Sweden.
    Prosthesis-patient mismatch after transcatheter aortic valve implantation: impact of 2D-transthoracic echocardiography versus 3D-transesophageal echocardiography2014In: International Journal of Cardiac Imaging, ISSN 1569-5794, E-ISSN 1875-8312, Vol. 30, no 8, p. 1549-1557Article in journal (Refereed)
    Abstract [en]

    To investigate the role of 2D-transthoracic echocardiography (2D-TTE) and 3D-transesophageal echocardiography (3D-TEE) in the determination of aortic annulus size prior transcatheter aortic valve implantation (TAVI) and its' impact on the prevalence of patient prosthesis mismatch (PPM). Echocardiography plays an important role in measuring aortic annulus dimension in patients undergoing TAVI. This has great importance since it determines both eligibility for TAVI and selection of prosthesis type and size, and can be potentially important in preventing an inadequate ratio between the prosthetic valvular orifice and the patient's body surface area, concept known as prosthesis-patient mismatch (PPM). A total of 45 patients were studied pre-TAVI: 20 underwent 3D-TEE (men/women 12/8, age 84.8 +/- A 5.6) and 25 2D-TTE (men/women 9/16, age 84.4 +/- A 5.4) in order to measure aortic annulus diameter. The presence of PPM was assessed before hospital discharge and after a mean period of 3 months. Moderate PPM was defined as indexed aortic valve area (AVAi) a parts per thousand currency sign 0.85 cm(2)/m(2) and severe PPM as AVAi < 0.65 cm(2)/m(2). Immediately post-TAVI, moderate PPM was present in 25 and 28 % of patients worked up using 3D-TEE and 2D-TTE respectively p value = n.s) and severe PPM occurred in 10 % of the patients who underwent 3D-TEE and in 20 % in those with 2D-TTE (p value = n.s). The echocardiographic evaluation 3 months post-TAVI showed 25 % moderate PPM in the 3D-TEE group compared with 24 % in the 2D-TTE group (p value = n.s) and no cases of severe PPM in the 3DTEE group comparing to 20 % in the 2D-TTE group (p = 0.032). Our results indicate a higher incidence of severe PPM in patients who performed 2DTTE compared to those performing 3DTEE prior TAVI. This suggests that the 3D technique should replace the 2DTTE analysis when investigating the aortic annulus diameter in patients undergoing TAVI.

  • 217.
    da Silva, Cristina
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging. Karolinska Institute, Stockholm, Sweden .
    Sahlén, Anders
    Winter, Reidar
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging. Karolinska University Hospital, Sweden.
    Bäck, Magnus
    Ruck, Andreas
    Settergren, Magnus
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging. Department of Cardiology, Karolinska University Hospital, Huddinge, Sweden .
    Shahgaldi, Kambiz
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging. Department of Cardiology, Karolinska University Hospital, Huddinge, Sweden .
    Hemodynamic outcomes of transcatheter aortic valve implantation with the CoreValve system: an early assessment2015In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 35, no 3, p. 216-222Article in journal (Refereed)
    Abstract [en]

    Background and Aims: Transcatheter aortic valve implantation (TAVI) is an established method for the treatment of high-risk patients with aortic stenosis (AS). The beneficial effects of TAVI in cardiac hemodynamics have been described in recent studies, but those investigations were mostly performed after an interval of more than 6 months following aortic valve implantation. The aim of this study is to investigate the acute and short-term alterations in hemodynamic conditions using the echocardiography outcomes in patients undergoing TAVI. Methods and Results: A total of 60 patients (26 males, 34 females; age 84·7 ± 5·8) who underwent TAVI with CoreValve system were included in the study. Echocardiography was performed before hospital discharge and at 3 months follow-up. As expected, TAVI was associated with an immediate significant improvement in aortic valve area (AVA) (from 0·64 ± 0·16 cm2 to 1·67 ± 0·41 cm2, P-value<0·001) and mean gradient (from 51·9 ± 15·4 mmHg to 8·8 ± 3·8 mmHg, P-value<0·001). At 3-month follow-up, systolic LV function was augmented (EF: 50 ± 14% to 54 ± 11%, P-value = 0·024). Left ventricle (LV) mass and left atrium (LA) volume were significantly reduced (LV mass index from 126·5 ± 30·5 g m-2 to 102·4 ± 32·4 g m-2; LA index from 42·9 ± 17·3 ml m-2 to 33·6 ± 10·6 ml m-2; P-value<0·001 for both). Furthermore, a decrement in systolic pulmonary artery pressure (SPAP) from 47·5 ± 13·5 mmHg to 42·5 ± 11·2 mmHg, P-value = 0·02 was also observed. Despite the high incidence of paravalvular regurgitation (PVR) (80%), most of the patients presented mild or trace PVR and no significant progress of the regurgitation grade was seen after 3 months. Conclusion: This study demonstrates that the beneficial effects of TAVI in cardiac function and hemodynamics occur already after a short period following aortic valve implantation.

  • 218.
    Dahl, Maria
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Ekholm, Cecilia
    KTH, School of Technology and Health (STH), Ergonomics.
    Konsekvenser av ny teknik på en sjukhusmottagning2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 219.
    Dahlberg, Axel
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Francén, Jonas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    IPv6-adresshantering och prefixdelegering i MPLS VPN-nät2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Full migration to IPv6 brings the need to adjust datacommunication services for the new generationof IP protocols with maintained or expanded functionality. This thesis’ goals is to submitone or more solutions that meets requirements and the technical conditions that enables thecompany DGC:s to expand the service IP-VPN for IPv6. This includes address assignmenttechniques like prefix delegation and automatic address configuration in existing network infrastructure.Solutions are presented in six scenarios that have been investigated considering tests, analysis andexperienced problems. The investigation formed the criteria scalability, configuration complexity,compatibility, support by RFC:s and requirements stated by DGC that adds to the evaluationof the most suitable solution.The evaluation has resulted in a recommended scenario that is implementable according to givengoals.Techniques that may influence the choice of most suitable solution, but that is not yet available,are discussed and presented to point out what may needed to be considered in the future.

  • 220.
    Dahlgren, Sofia
    KTH, School of Technology and Health (STH).
    Evaluation of a Flooring System to Help Reduce Fall-Related Injuries among Elderly: A Compilation of Requirements together with Hip Impact Simulations, using a Computational Human Body Model2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Fall-related incidents are the most common cause of injury among elderly, and may result in hip fractures. Svein Kleiven and Hans von Holst, professors at the Royal Institute of Technology, have developed a technology for a compliant flooring system with the intention of reducing the peak force acting on the proximal femur during a fall. A project is underway to make the floor commercially available, where this thesis was a part of the first phase of the project.

    The goal with this thesis was to modify a computational human body model (HBM) to predict hip fractures when falling, using different material and geometry regarding the flooring system. It was also to compile a set of requirements that the final product would need to fulfill.

    The human body model was validated and modified using a study where cadavers had been tested. With the Finite Element Method (FEM), impacts were performed with the human body model and a flooring system. Requirements regarding the flooring system were compiled using literature studies, a study visit in a geriatric care facility and dialogues with well-informed people.

    Modifications involving contacts, material and the proximal femur were made on the model. A total of 18 simulations were performed using different flooring systems. When compared to rigid floor condition, all configurations showed a reduction in peak force on the proximal femur. The maximal attenuation was calculated to 33.04%, provided by pins with a diameter of 3 mm and with a distance of 5 mm between their midpoints.

  • 221.
    Dahlgren, Sofia
    et al.
    KTH, School of Technology and Health (STH).
    Melander, lovisa
    KTH, School of Technology and Health (STH).
    Wemmert, Ellinor
    KTH, School of Technology and Health (STH).
    Förbättrad patientsäkerhet på neonatalavdelningen vid Karolinska Universitetssjukhuset i Solna: en undersökning av arbetssituationen i nutritionsrummet2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 222.
    Damberg, Emmy
    KTH, School of Technology and Health (STH).
    Data Mining for Description and Prediction of Antibiotic Treated Healthcare-Associated Infections2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Healthcare-associated infections is the most common healthcare related injury and affect almost every tenth patient. With the purpose of reducing these infections Infektionsverktyget, The Anti-Infection Tool, was developed for registration and feedback of infection data. The tool is now used in all Swedish county councils resulting in a wealth of data. The purpose of this thesis was thus to investigate how data mining can be applied to describe patterns in this data and predict patient outcomes regarding healthcare-associated infections that need to be treated with antibiotics.

    Data mining was performed with Microsoft SQL Server 2008 in which models based on six different data mining algorithms with different parameter settings were developed. They used the attributes gender, age and previous diagnoses and medical actions as inputs and antibiotic treated healthcare-associated infection outcome as output. The predictive performance of the models was evaluated using 5-fold cross validation and macro averaged measures of recall, precision and F-measure. Patterns generated by selected models were extracted.

    Models based on the Naive Bayes algorithm showed the highest predictive capabilities with respect to recall and models based on the Decision Trees algorithm with low pruning had the highest precision. Although, none were considered to perform sufficiently well and several areas of improvement were identified. The most important factor in the inadequate performance is believed to be the relatively rare occurrences of infections in the dataset. Extracted patterns based on the Association Rules algorithm were considered the easiest to interpret. Patterns included clinically valid and invalid as well as trivial relationships.

    Future studies should be focused on further model improvements and gathering of more patient data. The idea is that data mining in Infektionsverktyget in the future could be used both to provide ideas for further medical research and to identify risk patients and prevent healthcare-associated infections in daily clinical work.

  • 223.
    Danell Lindström, Emma
    et al.
    KTH, School of Technology and Health (STH).
    El-Ghorayeb, Graziella
    KTH, School of Technology and Health (STH).
    Evaluation of Impact Loading Rates Dependency on Prescale Pressure Film2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Migraine is the third most common medical condition in the world. Xiaogai Li have a hypothesis that implies that a hit to the head when first sensing the aura symptoms will stop the migraine attack. An investigation was made to ensure that the blow does not cause a head injury. The prescale pressure film from Fujifilm is a sensor that measures pressure and the pressure distribution. It is supplied with charts to determine the pressure when purchased. The pressure film was used to measure the reached loading impact from the blow. The new chart for the pressure film would in that case be used to create simulations to study the potential brain damage a hit to the head can result in.

    This paper examines whether loading rates has an influence on a prescale pressure film from Fujifilm, in order to create new pressure charts if such dependency is found. The testing was made with the help of a loading machine where the desired force could be set. The results showed a lower color density in the test results when comparing with the provided charts. The reason for this is unknown, although it could be a consequence of the environmental conditions that the pressure film was held in. The conclusion made by studying the results was that no loading rate dependency exists.

  • 224.
    Danielsson, Christina
    KTH, School of Technology and Health (STH), Design, Work Environment, Safety and Health, DASH.
    Office Design: Applying Lynch’s Theory on Office Environments2005In: Nordisk arkitekturforskning, ISSN 1102-5824, no 4, p. 69-79Article in journal (Refereed)
  • 225.
    Danielsson, Christina
    KTH, School of Technology and Health (STH), Design, Work Environment, Safety and Health, DASH.
    Office Environment and Employee Satisfaction: The Impact of Office-type.Manuscript (Other academic)
  • 226.
    Danielsson, Christina
    KTH, School of Technology and Health (STH).
    Office environment, health and job satisfaction: an explorative study of office design's influence2005Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The present thesis investigates environmental factors impact on office employees. More specifically, it investigates: 1) perception and experience of office environments, 2) satisfaction with office environments, and 3) health status and job satisfaction in connection to office environment. It is based on an empirical study with 491 office employees from twenty-six companies and divisions in larger companies. Each one respectively represents one of seven identified office-types in office design: cell-office, sharedroom office, small open plan office, medium open plan office, large open plan office, flex-office and combi-office. This study takes its basis in architecture, although an interdisciplinary approach from organizational and management theory, environmental psychology, and social and stress medicine has been used. Qualitative and quantitative methods were used.

    In Article I a review of the different research fields that investigate environmental influences are presented with a focus on office environments. Different perspectives on the environmental impact on office employees are investigated.

    In Article II an analysis of office environment based on the employee’s perception and experience of the architecture is done based on in-depth interviews using a method originally developed by Kevin Lynch (1960). The method measures the "imagebility" of a space, rated by the users with following elements: landmark, node, path, edge and district. The result showed that the method, based on employees’ perception and use of space, is a possible tool in the design process to get a better understanding of where the elements that reinforce "imageability" most likely will appear in an office environment. The method thus gives a better idea of the future "imageability" of a space and could be useful as guidance in the design process of how the architectural design will be received by the users in the end.

    In Article III employees’ satisfaction with the office environment in different office-types is investigated. The article focuses on three domains: 1) Ambient factors, 2) Noise and Privacy and 3) Designrelated factors. The statistical analysis was done using a logistic regression model with multivariate analysis. Adjustment was done for: age, gender, job rank, job satisfaction and market division. The results show differences in satisfaction with the office environment between employees in different office-types, many of which were statistically significant. When differences persist in the multivariate analysis they can possibly be ascribed to the office-type. Results show that employees in cell-offices are prominently most satisfied followed by those in flex-offices. Cell-offices rate only low on social aspects of Design-related factors. A major finding is internal differences between different office-types where employees share workspace and facilities. The medium and large open plan offices could be described as high-risk officetypes.

    In Article IV differences between employees in different office-types with regard to health, wellbeing and job satisfaction are analyzed. A multivariate analysis of the data was done with adjustment for the confounders: age, gender, job rank and market division. The results show that there are risks of ill health and poor well-being in medium and small open plan offices. Employees in these office-types show significantly higher risks compared with those in other office-types. In medium open plan and combioffices the employees show the highest prevalence of low job satisfaction. The best chance for good health status and job satisfaction is among employees in cell-offices and flex-offices; there are, however, internal differences in distribution on different outcome variables for job satisfaction. The major finding of these studies is that there are significant differences with regard to satisfaction with office environments as well as health status and job satisfaction between employees in different office-types; differences that can possibly can be ascribed to the office-types as they persist after adjustment for important confounders.

  • 227.
    Danielsson, Christina
    KTH, School of Technology and Health (STH).
    Three Approaches to Office Design; A Review of Environmental InfluencesManuscript (Other academic)
  • 228.
    Danielsson, Åsa
    KTH, School of Technology and Health (STH).
    Karaktärisering och vidareutveckling av teknik för provsamling av utandade partiklar2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Analysis of drug particles in exhaled air is a new research area with great potential for medical diagnoses. A major advantage is that sampling can be performed much easier and that the procedure may be perceived as less intrusive than, for example, blood or urine samples.

    The overall aim of this thesis work was to investigate some of the properties of a sampler named SensAbues, which is designed to collect particles in exhaled air. Another part of the purpose was to examine the variation in the results of previous research related to drugs through expiration. The work was based on literature studies and six separate experiments. Experiments I-III was related to SensAbues properties. The properties examined were the sampler's flow resistance (experiment I), how the particles are distributed over the sampler (experiment II) and particle statistics regarding exhaled particles and the sampler's collection effectiveness (experiment III). In experiments IV-VI previous research results variety was examined based on primarily three hypotheses: 1) Increased resistance would stimulate the amount of exhaled particles and thereby increase the concentration (experiment IV). 2) That a special breathing maneuver would stimulate the amount of exhaled particles and thereby increase the concentration (experiment V). 3) That particles from the oral cavity, such as saliva, would contaminate the filter and explain the variation in previous research results (experiment VI).

    The results from experiment I show that most of the flow resistance is located in the sampler's nozzle. In experiment II it shows that there is a great distribution of methadone particles over the sampler's different parts. Only a small part, about 3% of methadone particles exhaled trapped in the filter, which is the part that is analyzed in the laboratory. In experiment II, it is not possible to draw any conclusions about the sampler's efficiency, this examined in experiment III. In experiment III the sampler's effectiveness is examined and the results show that the sampler captures approximately 99% of exhaled particles (all exhaled particles, not drug particles). Results in experiment IV showed that the increased flow resistance does not seem to have any bearing on the particle concentration (generally exhaled particles, not drug particles). The results of experiment V did not show that the particular breathing maneuver contributes to increased concentration of exhaled drug particles compared with normal breathing. The most likely reasons for the variation in previous research are that particles from the mouth contaminate the filter, as shown in the results of experiment VI. Experiments I-VI leads to recommendations for further development of the sampler.

  • 229.
    Danielsson, Åsa
    et al.
    KTH, School of Technology and Health (STH).
    Kniberg, Anette
    KTH, School of Technology and Health (STH).
    Nokto, David
    KTH, School of Technology and Health (STH).
    Kvalitet hos orsakskategorier för inställda operationer2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 230.
    Darvish, Darvish
    et al.
    KTH, School of Technology and Health (STH).
    Öçba, F.Nadideh
    KTH, School of Technology and Health (STH).
    Presentation and evaluation of gated-SPECT myocardial perfusion images: Radial Slices - data reduction without  loss  of  information2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

     

    Single photon emission tomography (SPECT) data from myocardial perfusion imaging (MPI) are normally displayed as a set of three slices orthogonal to the left ventricular (LV) long axis for both ECG-gated (GSPECT) and non-gated SPECT studies. The total number of slices presented for assessment depends on the size of the heart, but is typically in excess of 30. 

    A requirement for data presentation is that images should be orientated about the LV axis; therefore, a set of radial slice would fulfill this need. Radial slices are parallel to the LV long axis and arranged diametrically. They could provide a suitable alternative to standard orthogonal slices, with the advantage of requiring far fewer slices to adequately represent the data.

    In this study a semi-automatic method was developed for displaying MPI SPECT data as a set of radial slices orientated about the LV axis, with the aim of reducing the number of slices viewed, without loss of information and independent on the size of the heart. Input volume data consisted of standard short axis slices orientated perpendicular to the LV axis chosen at the time of reconstruction.

     The true LV axis was determined by first determining the boundary on a central long axis slice, the axis being in the direction of the y-axis in the matrix. The skeleton of the myocardium were found and the true LV axis determined for that slice. The angle of this axis with respect to the y-axis was calculated. The process was repeated for an orthogonal long axis slice. The input volume was then rotated by the angles calculated.

    Radial slices generated for presentation were integrated over a sector equivalent to the imaging resolution (1.2 cm); assuming the diameter of the heart is about 8cm then non-gated data could be represented by 20 radial slices integrated over an 18 degree section. Gated information could be represented with four slices spaced at 45 intervals, integrated over a 30 degree sector.

  • 231. Daudi, M.
    et al.
    Hauge, Jannicke B.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Thoben, K. -D
    Behavioral factors influencing partner trust in logistics collaboration: a review2016In: Logistics Research, ISSN 1865-035X, Vol. 9, no 1, article id 19Article in journal (Refereed)
    Abstract [en]

    Logistics collaboration has emerged a prevalent strategy to mitigate challenge individuals and organizations encounter. A successful collaboration, however, depends on certain trustworthy behaviors partner exhibit. To that end, understanding aspects constituting behavioral uncertainty and mechanisms by which such aspects affect partner trust is a necessary. This necessity counts on emergent behavioral trust uncertainties, constituted by partner’s actions and interactions occurring during collaboration. While this is a necessary requirement, most of the studies in the literature lack to take into account the influence of behavioral uncertainty on collaboration and partner trust. To that effect, this paper uncovers outlined limitation by establishing behavioral factors influencing partner trust in operational stage of logistics collaboration. To accomplish this objective, a systematic literature review (SLR) is deployed to consolidate research domains of logistics, supply chain, collaboration, and trust. SLR proceeds by defining a review protocol, followed by a search process conducted in 5 databases using 20 search terms on articles published between 2001 and 2015 inclusively. Among findings this SLR has revealed are four behavioral factors and thirteen criteria proposed to affect partner trust. Additionally, these factors constitute success and measurable criteria needed for empirical investigation which may employ experimental and/or case-study methods. Moreover, synthesized factors extend further an understanding of behavioral trust in ad hoc collaborative networks, a large part of which being supported by networks of humans and computers.

  • 232. Daudi, M.
    et al.
    Hauge, Jannicke
    KTH, School of Technology and Health (STH). University of Bremen, Germany.
    Thoben, K. -D
    Effects of decision synchronization on trust in collaborative networks2016In: 17th IFIP WG 5.5 Working Conference on Virtual Enterprises, PRO-VE 2016, Springer-Verlag New York, 2016, p. 215-227Conference paper (Refereed)
    Abstract [en]

    In collaborative networks, individual and organizational entities encounter many disagreements over many decisions rights. These disagreements procreate conflicting preferences, which in turn, affect trustworthy amongst partners. To that end, it becomes necessary that partners assume a degree of fairness on decision rights by calibrating positions which they initially consider a final. This calibration involves synchronizing partners’ conflicting preferences to a compromise. The objective of this paper, therefore, is to analyze and evaluate the effect of both, compromised and uncompromised preferences on trust. To achieve this, a corresponding behavioral trust model is proposed and evaluated empirically using a logistics collaboration scenario. This evaluation applies a multi-agent systems simulation method. The simulation involves 360 observations with three preferences set as predictor variables. Results show that irrespective of a degree to which conflicting preferences are synchronized, a magnitude of the generated effect on trust, depends as well on other factors like transport cost and extent to which vehicles are loaded. Additionally, if other factors are kept constant, compromised preferences affects trust more positively than uncompromised ones.

  • 233. Daudi, M.
    et al.
    Thoben, K. -D
    Baalsrud Hauge, Jannicke
    KTH, School of Technology and Health (STH). Bremer Institut für Produktion und Logistik at the University of Bremen, Bremen, Germany.
    An Approach for Surfacing Hidden Intentions and Trustworthiness in Logistics Resource Sharing Networks2018In: 19th IFIP WG 5.5 Working Conference on Virtual Enterprises, PRO-VE 2018, Springer-Verlag New York, 2018, Vol. 534, p. 524-536Conference paper (Refereed)
    Abstract [en]

    Collaboration on sharing logistics resources aims to balance supply and demand of the idle, inefficiently, and underutilized resources. Although sharing is beneficial, many issues such as privacy, security, time, regulations, safety, biased reviews, and ratings hinder the sharing. Such problems procreate many uncertainties, which as a consequence, lead to low trust in sharing resources. Meanwhile, existing solutions such as trust and reputation mechanism, and online reviews and ratings incorporate the least consideration to monitor hidden intentions and behaviors of partners. Therefore, this paper proposes an approach to surface hidden intentions and trustworthiness of partners involved in sharing resources. The approach stands on cognitive principles to explore intentions and trustworthiness of suppliers and consumers of logistics resources. Application of the proposed approach is illustrated using industrial case extracted from ridesharing platform.

  • 234. Daudi, Morice
    et al.
    Baalsrud Hauge, Jannicke
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Thoben, Klaus-Dieter
    A Trust Framework for Agents' Interactions in Collaborative Logistics2017In: DYNAMICS IN LOGISTICS, LDIC 2016, Springer, 2017, p. 53-63Conference paper (Refereed)
    Abstract [en]

    Trust is an essential factor for successful resource sharing in logistics. To build and sustain trust among collaborating partners in logistics requires, amongst others, conceptualizing on various aspects constituting underlying mistrusts. The conception is achieved by setting up a framework describing trust-based collaborative interactions of these partnering entities, referred to as agents. This research establishes a trust framework addressing agents' trustworthy interactions and thus aims at overcoming a knowledge gap identified in the literature. The framework depicts trust-based interactions concentrating to sharing of vehicle capacities. The trust framework is conceived on a foundation of theoretical body of knowledge in the literature. It engages knowledge on collaborative networks, logistics and transportation, agent behavior as well as trust. This research contributes by identifying key agents together with their roles, characteristics, tasks, information exchange as well as perceptions; all of which linked to agent trust. The framework is reusable in many ways, including formal conception of models aspiring to empirically investigate trust amongst agents sharing logistics resources. It also provides more understanding to practitioners, especially on issues relating to compromising differences resulting from agent's perspectives.

  • 235.
    Dellve, Lotta
    et al.
    KTH, School of Technology and Health (STH). Gothenburg University, Sweden.
    Strömgren, Marcus
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Williamsson, Anna
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Holden, Richard J.
    School of Informatics and Computing, Indiana University, Indianapolis, US.
    Eriksson, Andrea
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Health care clinicians' engagement in organizational redesign of care processes: Health care clinicians' engagement in organizational redesign of care processes2018In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 68, p. 249-257Article in journal (Refereed)
    Abstract [en]

    The Swedish health care system is reorienting towards horizontal organization for care processes. A main challenge is to engage health care clinicians in the process. The aim of this study was to assess engagement (i.e. attitudes and beliefs, the cognitive state and clinical engagement behaviour) among health care clinicians, and to investigate how engagement was related to work resources and demands during organizational redesign. A cohort study was conducted, using a questionnaire distributed to clinicians at five hospitals working with care process improvement approaches, two of them having implemented Lean production. The results show that kinds of engagement are interlinked and contribute to clinical engagement behaviour in quality of care and patient safety. Increased work resources have importance for engagements in organizational improvements, especially in top-down implementations. An extended work engagement model during organizational improvements in health care was supported. The model contributes to knowledge about how and when clinicians are mobilized to engage in organizational changes.

  • 236.
    Di Sopra, Lorenzo
    KTH, School of Technology and Health (STH).
    Geometric Misalignment Calibration and Detector Lag Effect Artifact Correction in a Cone-Beam Flat Panel micro-CT System for Small Animal Imaging2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The cone-beam flat panel micro-CT is a high definition imaging system. It acquires projections of an object or animal to reconstruct a 3D image of its internal structure. The device is basically composed by a radiation tube and a detector panel, which are fixed to a gantry that rotates all around the test subject. The micro-CT system is affected by several imperfections and problems, that might lead to serious artifacts that deteriorate the quality of the reconstructed image. In particular, two issues have been discussed in the present work: the source-panel geometric misalignment and the detector lag effect. The first problem concerns the consequences of systems where the different elements are not perfectly aligned to each other. The second issue regards the residual signal, left in the detector's sensor after a projection acquisition, which affects the following frames with ghost images. Both these arguments have been investigated to describe their characteristics and behaviour in a typical acquisition protocol. Then two correction methods have been presented and tested on a real micro-CT device to verify their effectiveness in the artifacts compensation. In the end, a comparison between images before and after the corrections is provided and future prospects are discussed.

  • 237.
    Dizdarevic, Sven
    et al.
    KTH, School of Technology and Health (STH).
    Thunholm, Malin
    KTH, School of Technology and Health (STH).
    Signalförändring i automatisk urinmätare: - en ingående studie om dess orsaker2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The following report discusses what substances affect the conditions for the formation of biofim in Observe Medicals digital urine measurement system Sippi, and therefore interfere with the measuring signal. Suggestions on how to possibly avoid volume measurement errors are given. The report accounts for five different solutions used during laboratory experiments: albumin mixed with water, free hemoglobin mixed with water, albumin mixed with urine, free hemoglobin mixed with urine, and lastly only urine. During the volume measurements, fluid was pumped from a container to the measurement chamber in the Sippi set. Each measurement was performed twice, with and without a silicon capsule in the chamber. The laboration results showed that albumin develop a complete biofilm after a few hours. Free hemoglobin entailed a varying degree of biofilm development in Sippi, depending on the amount of blood in the solution. The silicon capsule counteracts the effect of albumin to a higher degree than free hemoglobin. Furthermore, urine with low pH (6,0) did not give rise to biofilm to the same extent as urine with high pH (7,0). The report discusses about the fact that low value of pH in urine negatively affects the conditions for formation of biofilm, and may be used to further develop the product in the future. The report concludes that both albumin and free hemoglobin contribute to construction of biofilm in Sippi, and therefore interfere with the signal.

  • 238.
    Dizon, Lucas
    et al.
    KTH, School of Technology and Health (STH).
    Johansson, Martin
    KTH, School of Technology and Health (STH).
    Atrial Fibrillation Detection Algorithm Evaluation and Implementation in Java2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Atrial fibrillation is a common heart arrhythmia which is characterized by a missing or irregular contraction of the atria. The disease is a risk factor for other more serious diseases and the total medical costs in society are extensive. Therefore it would be beneficial to improve and optimize the prevention and detection of the disease.

     

    Pulse palpation and heart auscultation can facilitate the detection of atrial fibrillation clinically, but the diagnosis is generally confirmed by an ECG examination. Today there are several algorithms that detect atrial fibrillation by analysing an ECG. A common method is to study the heart rate variability (HRV) and by different types of statistical calculations find episodes of atrial fibrillation which deviates from normal sinus rhythm.

     

    Two algorithms for detection of atrial fibrillation have been evaluated in Matlab. One is based on the coefficient of variation and the other uses a logistic regression model. Training and testing of the algorithms were done with data from the Physionet MIT database. Several steps of signal processing were used to remove different types of noise and artefacts before the data could be used.

     

    When testing the algorithms, the CV algorithm performed with a sensitivity of 91,38%, a specificity of 93,93% and accuracy of 92,92%, and the results of the logistic regression algorithm was a sensitivity of 97,23%, specificity of 93,79% and accuracy of 95,39%. The logistic regression algorithm performed better and was chosen for implementation in Java, where it achieved a sensitivity of 97,31%, specificity of 93,47% and accuracy of 95,25%.

  • 239.
    Duvheim Bruce, Adam
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Indreeide, Ole Martn
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Beräkning av återmatad bromsenergi på Malmbanan2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy is a limited recourse and the use of energy has to be as effective as possible to avoid harmful effects on the environment and to cut spending. Reusing the energy the ore train uses to climb the mountains of northern Sweden through regenerative breaking leads to a more effective use of energy. Calculation of energy uses the trains’ stored energy and the losses during its journey along Malmbanan. This results in a total power save of 20 % for single track and between 20 % and 21 % for double track. Traffic on double track can increase but the relationship between regenerated and consumed energy will be the same. Regenerating energy on the railway reduces today’s negative impact on the environment and leads to savings in energy cost for the company.

  • 240.
    Dybäck, Matilda
    et al.
    KTH, School of Technology and Health (STH).
    Nilsson Hall, Rebecka
    KTH, School of Technology and Health (STH).
    Kartläggning av Sveriges landstings användning av telemedicin2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sweden's aging population makes the need for a viable health care urgent and telemedicine can be a solution to enable older people to receive or give themselves care in their homes. Furthermore, implementation of telemedicine has the potential to realise profits in society by increasing the accessibility of health care and minimizing travel costs. Sweden’s low population density and geographical configuration makes the advantages of telemedicine even more appealing.

     

    To illustrate the differences between the county councils’ use of telemedicine and thus increasing the possibility for coordinated care between them, the authors have on behalf of the Innovation Centre at the Karolinska University hospital mapped the amount of telemedicine technologies that are available in the Swedish county councils’ today. To collect information an electronic survey and video or telephone interviews were used. This report answers the question of how the use of telemedicine differ between Sweden's county councils in terms of techniques used, how well implemented the technologies are and to what extent the guidelines for development, implementation and use of telemedicine is available. The report also investigated whether the county councils geographic characteristics, in terms of population density and the number of hospitals and health centers, influenced the development of telemedicine.

     

    Of the 21 regional councils information has been collected from 10 counties in seven weeks and the results that were collocated indicated that there are major differences between the county councils' use of telemedicine. It is clear that the northern region and especially Västerbotten and Norrbotten County Council have come a long way in implementing telemedicine technology.

     

    When the results of the electronic survey and interviews were compared with the county councils’ geographical features no correlation could be detected between population density and the use of telemedicine. This can be a result of the low number of participating counties and that we have not examined all departments in health care. The county councils which have university hospitals use multidisciplinary rounds more so than others. In summary, the Swedish county councils are at different stages in the implementation of telemedicine due to several external and internal factors that makes it possible for counties to benefit a lot from collaboration and sharing each other's knowledge.

  • 241.
    Dybäck, Matilda
    et al.
    KTH, School of Technology and Health (STH).
    Wallgren, Johanna
    KTH, School of Technology and Health (STH).
    Pupil dilation as an indicator for auditory signal detection: Towards an objective hearing test based on eye tracking2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An early detection of hearing loss in children is important for the child's speech and language development. For children between 3-6 months, a reliable method to measure hearing and determine hearing thresholds is missing. A hearing test based on the pupillary response to auditory signal detection as measured by eye tracking is based on an automatic physiological response. This hearing test could be used instead of the objective hearing tests used today. The presence of pupillary response has been shown in response to speech, but it is unstudied in response to sinus tones. The objective of this thesis was to study whether there is a consistent pupillary response to different sinus tone frequencies commonly used in hearing tests and if yes, to determine reliably the time window of this response.

    Four different tests were done. The adult pupillary response in regard to sinus tone stimuli with four frequency levels (500 Hz, 1000 Hz, 2000 Hz and 4000 Hz), and four loudness levels (silence, 30 dB, 50 dB and 70 dB) was tested (N=20, 15 females, 5 males). Different brightness levels and distractions on the eye tracking screen were investigated in three substudies (N=5, 4 females, 1 male). Differences between silence and loudness levels within frequency levels were tested for statistical significance.

    A pupillary response in regard to sinus tones occurred consistently between 300 ms and 2000 ms with individual variation, i.e. earlier than for speech sounds. Differences between silence and loudness levels were only statistically significant for 4000 Hz. No statistical difference was shown between different brightness levels or if there were distractions present on the eye tracker screen.

    The conclusion is that pupillary response to pure sinus tones in adults is a possible measure of hearing threshold for at least 4000 Hz. Larger studies are needed to confirm this, and also to more thoroughly investigate the other frequencies. 

  • 242. Dénes, E.
    et al.
    Fenyvesi, A.
    Futó, E.
    Kerék, Andras
    KTH, School of Technology and Health (STH), Medical Engineering.
    Kiss, T.
    Molnár, J.
    Novák, D.
    Soós, C.
    Tölyhi, T.
    VandeVyvre, P.
    Radiation tolerance qualification tests of the final source interface unit for the ALICE experiment for the ALICE collaboration2007In: Proceedings - 12th Workshop on Electronics for LHC and Future Experiments, LECC 2006, CERN , 2007, p. 438-441Conference paper (Refereed)
    Abstract [en]

    The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Previous tests showed that a configuration loss of SRAM-based FPGA devices may happen and the frequency of undetected data errors in the FPGA user memory area is also not acceptable. Therefore, we redesigned the SIU card using another FPGA based on flash technology. In order to detect bit errors in the user memory we added parity check logic to the design. The new SIU has been extensively tested using neutron and proton irradiation to verify its radiation tolerance. In this paper we summarize the design changes, introduce the final design, and the results of the radiation tolerance measurements on the final card.

  • 243. Dénes, E.
    et al.
    Fenyvesi, A.
    Hirn, A.
    Kerék, Andras
    KTH, School of Technology and Health (STH), Medical Engineering.
    Kiss, T.
    Molnár, J.
    Novák, D.
    Soós, C.
    Tölyhi, T.
    Vyvre, P. V.
    Radiation tolerant source interface unit for the ALICE experiment2005In: Proceedings - 11th Workshop on Electronics for LHC and Future Experiments, LECC 2005, CERN , 2005, p. 291-293Conference paper (Refereed)
    Abstract [en]

    The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Tests showed that configuration loss of the Altera APEX II FPGA device used earlier on the DDL SIU card is only marginally acceptable. We developed a new version of the SIU card using Actel ProASIC+ device based on flash memory technology. The new SIU card has been extensively tested using neutron and proton irradiation. In this paper we present the SIU card and describe the results of irradiation measurements.

  • 244.
    Edlund, Fredrik
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Sarker, Saqib
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Smart Kitchen: Automatisk inventering av föremål2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Internet of Things is growing fast and is predicted to become a part of everyday life. This can be used to create products which will make everyday life easier. Automated object detection combined with an automated inventory check can make it easier to manage what is in stock, this is something that can be used in smart refrigerators as an example, to make life more convenient through Internet of Things. This Bachelor thesis studies methods regarding object detection with the purpose to build a system which automatically identifies objects and manages the inventory status. A prototype was built and tested to see what the possibilities there is with such a system. The Prototype uses a Raspberry Pi as core unit, which uses Dlib libraries to identify predefined objects. The user will identify unknown objects via the mobile phone application, which makes it possible for the system to learn how to identify new objects. The same application is used to check the inventory status for the different objects that has been identified by the system. The prototype can identify objects and learn to identify new ones, according to the goals of the project.

  • 245.
    Eghbali, Ladan
    KTH, School of Technology and Health (STH).
    The impact of defective ultrasound transducers on the evaluation results of ultrasound imaging of blood flow2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Following X-Ray, Ultrasound is now the most common of all the medical imaging technologies specifically in obstetrics and cardiology. Plus that the ultrasound hazards perceived to be insignificant compared with X-rays. Considering the fact that the study of cardiovascular diseases, blood flow patterns and the fetal development is essential for human life, the accuracy and proper functioning of ultrasonic systems is of great importance. Hence quality control of ultrasonic transducers is necessary.

    In this thesis, a system to standardize the acceptance criteria for quality control of ultrasonic transducers is described. On this ground a study on ultrasound images conducted to compare and evaluate the quality resulted from different types of transducers in different conditions, i.e. defective or functional.

    A clinical study was also carried out to evaluate our hypothesis in real cases at department of Cardiology and department of genecology. Results from this study show that the perception of quality is somewhat subjective and clinical studies are time-consuming. But quality factors such as the ability to accurately identify anatomical structure and functional capabilities are of great importance and help.

  • 246.
    Eghbali, Ladan
    KTH, School of Technology and Health (STH).
    The impact of defective ultrasound transducers on the evaluation results of ultrasound imaging of blood flow2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Following X-Ray, Ultrasound is now the most common of all the medical imaging technologies specifically in obstetrics and cardiology. Plus that the ultrasound hazards perceived to be insignificant compared with X-rays. Considering the fact that the study of cardiovascular diseases, blood flow patterns and the fetal development is essential for human life, the accuracy and proper functioning of ultrasonic systems is of great importance. Hence quality control of ultrasonic transducers is necessary.

    In this thesis, a system to standardize the acceptance criteria for quality control of ultrasonic transducers is described. On this ground a study on ultrasound images conducted to compare and evaluate the quality resulted from different types of transducers in different conditions, i.e. defective or functional.

    A clinical study was also carried out to evaluate our hypothesis in real cases at department of Cardiology and department of genecology. Results from this study show that the perception of quality is somewhat subjective and clinical studies are time-consuming. But quality factors such as the ability to accurately identify anatomical structure and functional capabilities are of great importance and help.

  • 247.
    Egnell, Liv
    KTH, School of Engineering Sciences (SCI), Applied Physics, Experimental Biomolecular Physics. KTH, School of Technology and Health (STH).
    Transient State Monitoring and Fluorescence Correlation Spectroscopy of Flavin Adenine Dinucleotide2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many human diseases including cancer have been associated with altered cellular metabolism and a changed oxygen consumption in cells. Fluorophores are sensitive to their local environment due to their long life times in transient dark states. A recent study successfully utilized this sensitivity to image differences in oxygen concentrations in cells using transient state (TRAST) microscopy together with fluorescent labels [1]. A natural continuation of this study is to investigate the possibilities of using this method with natural fluorophores already present in cells and thereby avoid articial labeling.

    Flavin adenine dinucleotide (FAD) is an auto fluorescent coenzyme that is naturally present in cells and involved in cellular metabolism. This project is an exploratory pilot study for cellular measurements with the aim to investigate if FAD can be used to probe oxygen concentrations in aqueous solution using transient state monitoring and fluorescence correlation spectroscopy (FCS). This thesis includes the results from FCS and TRAST experiments on FAD in aqueous solutions with different oxygen concentrations as well as different ascorbic acid concentrations. The performed experiments showed that FAD monitored with TRAST is sensitive to differences in oxygen concentrations for the aqueous solutions used in this study.

  • 248.
    Ekberg, K
    et al.
    Linköpings Universitet.
    Gustavsson, M
    Linköpings Universitet.
    Lundqvist, D
    Linköpings Universitet.
    Reineholm, C
    Linköpings Universitet.
    Fagerlind, A-C
    Linköpings Universitet.
    Karlsson, N
    Linköpings Universitet.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Leading and organising for health and productivity2012In: Book of Proceedings: Zürich 2012 10th Conference, European Academy of Occupational Health Psychology, 2012Conference paper (Other academic)
  • 249.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics. Helix, Linköping University.
    Arbetsplatsnära FoU från olika synvinklar2016In: Book of Abstracts, 2016Conference paper (Refereed)
  • 250.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Belysning, buller och klimat2008In: Återvinningscentralen: Sorteringsplats, arbetsplats, mötesplats / [ed] Engkvist I-L, Linköping: LiU Tryck , 2008, p. 59-67Chapter in book (Other (popular science, discussion, etc.))
2345678 201 - 250 of 1270
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