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  • 301.
    Fahlstedt, Madelen
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Halldin, Peter
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Importance of the Bicycle Helmet Design and Material for the Outcome in Bicycle Accidents2014In: Proceedings, International Cycling Safety Conference 2014, Chalmers , 2014, p. 1-14Conference paper (Refereed)
    Abstract [en]

    In Sweden the most common traffic group that needs to be hospitalized due to injury is cyclists where head injuries are the most common severe injuries. According to current standards, the performance of a helmet is only tested against radial impact which is not commonly seen in real accidents. Some studies about helmet design have been published but those helmets have been tested for only a few loading conditions. Therefore, the purpose of this study was to use finite element models to evaluate the effect of the helmet’s design on the head in some more loading conditions.

    A detailed head model was used to evaluate three different helmet designs as well as non-helmet situations. The first helmet (Baseline Helmet) was an ordinary helmet available on the market. The two other helmet designs were a modification of the Baseline helmet with either a lower density of the EPS liner (Helmet 1) or a sliding layer between the scalp and the EPS liner (Helmet 2). Four different impact locations combined with four different impact directions were tested.

    The study showed that using a helmet can reduce the peak linear acceleration (85%), peak angular acceleration (87%), peak angular velocity (77%) and peak strain in the brain tissue (77%). The reduction of the strain level was dependent on the loading conditions. Moreover, in thirteen of the sixteen loading conditions Helmet 2 gave lowest peak strain.

    The alteration of the helmet design showed that more can be done to improve the protective effect of the helmet. This study highlighted the need of a modification of current helmet standard test which can lead to helmets with even better protective properties as well as some challenges in implementing new test standards.

  • 302.
    Fahlstedt, Madelen
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Halldin, Peter
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    S. Alvarez, Victor
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Influence of the Body and Neck on Head Kinematics and Brain Injury Risk in Bicycle Accident Situations2016In: IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury, International Research Council on the Biomechanics of Injury , 2016, p. 459-478Conference paper (Refereed)
    Abstract [en]

    Previous studies about the influence of the neck on head kinematics and brain injuries have shown different results. Today bicycle helmets are certified with only a headform in radial experiments but could be improved with oblique impacts. Then the question is how the helmet's performance will be affected by the neck and the rest of the body. Therefore, the objective of this study was to use finite element simulations to investigate the influence of the body on head kinematics and injury prediction in single bicycleaccident situations with and without a helmet. The THUMS-KTH model was used to study the difference between head only and full body. In total, a simulation matrix of 120 simulations was compared by altering initial impact posture, head protection, and muscle activation. The results show that the body in impacts against a hard surface can change the amplitudes and curve shapes of the kinematics and brain tissue strain. The study found an average ratio between head only and full body for peak brain tissue strain to be 1.04 (SD 0.11), for peak linear acceleration 1.06 (SD 0.04), for peak angular acceleration 1.08 (SD 0.09) and for peak angular velocity 1.05 (SD 0.13).

  • 303.
    Falck, Josefina
    KTH, School of Technology and Health (STH), Medical Engineering.
    Effect of side windows, stiffening plate and roof sheet on the stiffness of the bus body2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As a bus developer, Scania focus to construct a safe vehicle for the passengers, i.e. high strength of the bus structure and good comfort, which is also profitable for the operator, i.e. high passenger capacity and low fuel consumption. The trade-off when developing a bus body structure is to get both high stiffness and low weight. The bus body including exterior panels plays together with the chassis an important role for the stiffness of the bus. By gathering knowledge about how various exterior panels affects the stiffness of the bus body, the design of the panels can be optimized with respect to high stiffness and low weight. Also from a calculation point of view is it of interest to know how important different panels are for the stiffness of the bus body, in order to make conscious simplifications in the calculation model.

    The aim with this master thesis was to investigate how the stiffening plate, side windows and roof sheet influence the strength of the bus body. How the thickness of the side windows affects the stiffness of the bus body is also investigated. The investigations were made as a relative comparison between a complete bus and comparison models.

     

    The results showed that exterior panels participate in distributing load. By distributing the load, the load uptake gets more efficient since a bigger part of the bus structure is used to take up the load. The side windows affect the stiffness for all tested load cases, with increased importance for the load case where a gravity field is applied in the longitudinal direction, for the torsion load case and when a load is applied to the power train in vertical direction. The roof sheet has a high impact on the stiffness in the torsion load case, but has negligible influence on the stiffness of the bus body for the other tested load cases. The stiffening plate has little influence on the stiffness of the bus body in general and is negligible for all tested load cases except for when a lateral load is applied as either a gravity field or locally to the power train.

     

    Thinner side windows are shown to have a positive influence on the stiffness of the bus body.

  • 304. Falkmer, Torbjern
    et al.
    Dahlman, Joakim
    Dukic, Tania
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Fixation identification in centroid versus start-point modes using eye-tracking data2008In: Perceptual and Motor Skills, ISSN 0031-5125, E-ISSN 1558-688X, Vol. 106, no 3, p. 710-724Article in journal (Refereed)
    Abstract [en]

    Fixation-identification algorithms, needed for analyses of eye movements, may typically be separated into three categories, viz. (i) velocity-based algorithms, (ii) area-based algorithms, and (iii) dispersion-based algorithms. Dispersion-based algorithms are commonly used but this application introduces some difficulties, one being optimization. Basically, there are two modes to reach this goal of optimization, viz., the start-point mode and the centroid mode. The aim of the present study was to compare and evaluate these two dispersion-based algorithms. Manual inspections were made of 1,400 fixations in each mode. Odds ratios showed that by using the centroid mode for fixation detection, a valid fixation is 2.86 times more likely to be identified than by using the start-point mode. Moreover, the algorithm based on centroid mode dispersion showed a good interpretation speed, accuracy, robustness, and ease of implementation, as well as adequate parameter settings.

  • 305.
    Fan, Xuelong
    KTH, School of Technology and Health (STH), Medical Engineering.
    Kinematic analysis of traumatic brain injuries in boxing using finite element simulations2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of the thesis was to analyze and evaluate the head injuries due to a striking in a boxing match by LS-DYNA.

    A simplified arm model was built up and was equipped with three segments which were linked with two spherical joints. The strain-stress curves of the boxing glove foam and glove leather were measured in the Neuronic Lab in School of Technology and Health, KTH. The dimension and weight of the model was also set as adjustable to fulfill various requirements in different cases. Then a method was developed to facilitate the simulation. Finally, 39 video clips from the database were processed and the 13 cases were chosen to test the method and to perform the simulations. Additionally, the reliability of the model was assessed by comparing the outcome of the simulations with the results of the visual analysis from a previous study.

    The outcome showed that the model was able to restore the scenario from the videos both quantitatively and qualitatively, but it also suggest a high sensitivity of the model to the data artifacts from the video analysis. Interpretations and suggestions for the future work were also discussed.

  • 306.
    Farhan, Amani
    et al.
    KTH, School of Technology and Health (STH).
    Kardelind, Jonathan
    KTH, School of Technology and Health (STH).
    IT- och informationssäkerhet inom prehospital vård: Kommunikation mellan ambulans och sjukhus inom Stockholms Läns Landsting och Region Kronoberg2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Prehospital care is an important part of the Swedish health system, the care process is dedicated to any kind of emergency out-of-hospital acute medical care. The quality of prehospital care varies between different counties, depending on their technical equipment and work methods. This essay investigates how Region Kronoberg (RK) and Stockholm’s County Council (SLL) have dealt with IT- and information security questions concerning prehospital care.

     

    The essay is conducted by collecting laws and guidelines related to IT-security. Interviews were later on conducted with intention to collect information about RK’s and SLL’s definition of accessibility and communication of patient journals

     

    This essay shows that RK and SLL begun digitizing their prehospital care at different times, but that they are as in now able to use equally safe methods for dealing with journals. The reason behind this is that they both root their solutions in the secluded network Sjunet. It is further concluded that SLL and RK have different prerequisites for journal access. Lastly, we could conclude that the greatest security risk is not associated with the connection between hardware, but rather misplacing any hardware containing delicate information.

  • 307.
    Favero, Federico
    KTH, School of Technology and Health (STH), Ergonomics (Closed 20130701).
    Natural light lighting qualities for the design of future spaces development of a methodology2011In: 27TH SESSION OF THE CIE, VOL. 1, PTS 1 AND 2, C I E CENTRAL BUREAU , 2011, p. 482-487Conference paper (Refereed)
    Abstract [en]

    This paper wants to contribute to the development of a novel methodology in which daylight and artificial light are combined in the definition of the user's experience of architectural space. This experience is based upon the three systems that are triggered by light, visual, biological and perceptual/psychological. Natural Light is an attempt to deal with the issue of quality in spaces under a human perspective. This paper resumes the theoretical question that is leading a PhD research work, the result of a workshop developed in the city of Stockholm and the practical and methodological applications that will follow.

  • 308.
    Ferreira Gonzalez, Javier
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Textile-enabled Bioimpedance Instrumentation for Personalised Health Monitoring Applications2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    A growing number of factors, including the costs, technological advancements, an ageing population, and medical errors are leading industrialised countries to invest in research on alternative solutions to improving their health care systems and increasing patients’ life quality. Personal Health System (PHS) solutions envision the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centred healthcare delivery model toward a preventive and person-centred approach. PHS offers the means to follow patient health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive bio-data acquisition, allowing remote access to patient status and treatment monitoring.

    Electrical Bioimpedance (EBI) technology is a non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. EBI technology combined with state-of-the-art advances in sensor and textile technology are fostering the implementation of wearable bioimpedance monitors that use functional garments for the implementation of personalised healthcare applications.

    This research studies the development of a portable EBI spectrometer that can use dry textile electrodes for the assessment of body composition for the purposes of clinical uses. The portable bioimpedance monitor has been developed using the latest advances in system-on-chip technology for bioimpedance spectroscopy instrumentation. The obtained portable spectrometer has been validated against commercial spectrometer that performs total body composition assessment using functional textrode garments.

    The development of a portable Bioimpedance spectrometer using functional garments and dry textile electrodes for body composition assessment has been shown to be a feasible option. The availability of such measurement systems bring closer the real implementation of personalised healthcare systems.

  • 309. Ferreira, J.
    et al.
    Seoane, Fernando
    School of Engineering, University of Borås, Borås 501 90, Sweden .
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Portable bioimpedance monitor evaluation for continuous impedance measurements: Towards wearable plethysmography applications2013In: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, 2013, p. 559-562Conference paper (Refereed)
    Abstract [en]

    Personalised Health Systems (PHS) that could benefit the life quality of the patients as well as decreasing the health care costs for society among other factors are arisen. The purpose of this paper is to study the capabilities of the System-on-Chip Impedance Network Analyser AD5933 performing high speed single frequency continuous bioimpedance measurements. From a theoretical analysis, the minimum continuous impedance estimation time was determined, and the AD5933 with a custom 4-Electrode Analog Front-End (AFE) was used to experimentally determine the maximum continuous impedance estimation frequency as well as the system impedance estimation error when measuring a 2R1C electrical circuit model. Transthoracic Electrical Bioimpedance (TEB) measurements in a healthy subject were obtained using 3M gel electrodes in a tetrapolar lateral spot electrode configuration. The obtained TEB raw signal was filtered in MATLAB to obtain the respiration and cardiogenic signals, and from the cardiogenic signal the impedance derivative signal (dZ/dt) was also calculated. The results have shown that the maximum continuous impedance estimation rate was approximately 550 measurements per second with a magnitude estimation error below 1% on 2R1C-parallel bridge measurements. The displayed respiration and cardiac signals exhibited good performance, and they could be used to obtain valuable information in some plethysmography monitoring applications. The obtained results suggest that the AD5933-based monitor could be used for the implementation of a portable and wearable Bioimpedance plethysmograph that could be used in applications such as Impedance Cardiography. These results combined with the research done in functional garments and textile electrodes might enable the implementation of PHS applications in a relatively short time from now.

  • 310.
    Ferreira, Javier
    KTH, School of Technology and Health (STH), Medical Engineering. Högskolan i Borås.
    Modular textile-enabled bioimpedance system for personalized health monitoring applications2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A growing number of factors, including costs, technological advancements, ageing populations, and medical errors, are leading industrialized countries to invest in research on alternative solutions to improve their health-care systems and increase patients’ quality of life. Personal health systems (PHS) examplify the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centered healthcare delivery model toward a preventive and person-centered approach. PHS offer the means to monitor a patient’s health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive biodata

    acquisition, allowing remote monitoring of treatment and access to the patient’s status. Electrical bioimpedance (EBI) technology is non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. When combined with state-of-the-art advances in sensors and textiles, EBI technologies are fostering the implementation of wearable bioimpedance monitors that use functional garments for personalized healthcare applications. This research work is

    focused on the development of wearable EBI-based monitoring systems for ubiquitous health monitoring applications. The monitoring systems are built upon portable monitoring instrumentation and custom-made textile electrode garments.

    Portable EBI-based monitors have been developed using the latest material technology and advances in system-on-chip technology. For instance, a portable EBI spectrometer has been validated against a commercial spectrometer for total body composition assessment using functional textile electrode garments. The development of wearable EBI-based monitoring units using functional garments and dry textile electrodes for body composition assessment and respiratory monitoring has been shown to be a feasible approach. The availability of these measurement systems indicates progress toward the real implementation of personalized healthcare systems.

  • 311.
    Ferreira, Javier
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering. Högskolan i Borås.
    Pau de la Cruz, Ivan
    Technical University of Madrid.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    A handheld and textile-enabled bioimpedance system for ubiquitous body composition analysis.: An initial functional validation2016In: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208Article in journal (Refereed)
    Abstract [en]

    In recent years, many efforts have been made to promote a healthcare paradigm shift from the traditional reactive hospital-centered healthcare approach towards a proactive, patient-oriented and self-managed approach that could improve service quality and help reduce costs while contributing to sustainability. Managing and caring for patients with chronic diseases accounts over 75% of healthcare costs in developed countries. One of the most resource demanding diseases is chronic kidney disease (CKD), which often leads to a gradual and irreparable loss of renal function, with up to 12% of the population showing signs of different stages of this disease. Peritoneal dialysis and home haemodialysis are life-saving home-based renal replacement treatments that, compared to conventional in-center hemodialysis, provide similar long-term patient survival, less restrictions of life-style, such as a more flexible diet, and better flexibility in terms of treatment options and locations. Bioimpedance has been largely used clinically for decades in nutrition for assessing body fluid distributions. Moreover, bioimpedance methods are used to assess the overhydratation state of CKD patients, allowing clinicians to estimate the amount of fluid that should be removed by ultrafiltration. In this work, the initial validation of a handheld bioimpedance system for the assessment of body fluid status that could be used to assist the patient in home-based CKD treatments is presented. The body fluid monitoring system comprises a custom-made handheld tetrapolar bioimpedance spectrometer and a textile-based electrode garment for total body fluid assessment. The system performance was evaluated against the same measurements acquired using a commercial bioimpedance spectrometer for medical use on several voluntary subjects. The analysis of the measurement results and the comparison of the fluid estimations indicated that both devices are equivalent from a measurement performance perspective, allowing for its use on ubiquitous e-healthcare dialysis solutions.

  • 312.
    Ferreira, Javier
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    AD5933-based electrical bioimpedance spectrometer: Towards textile-enabled applications2011In: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, 2011, Vol. 2011, p. 3282-3285Conference paper (Refereed)
    Abstract [en]

    Advances on System-On-Chip and Textile technology allows the development of Textile-enabled measurement instrumentation. Textile Electrodes (Textrodes) have been proven reliable for performing Electrical Bioimpedance Spectroscopy (EBIS) measurements, and the availability of a integrated circuit impedance spectrometer, the AD5933, has allowed the implementation of small size EBIS spectrometers. In this work an AD5933-based spectrometer has been implemented, and its performance on 2R1C circuits and for tetrapolar total right side EBIS measurements has been compared against the commercially available spectrometer SFB7. The study has been focused on the working upper frequency range and the estimation of the Cole parameters required for assessment of body fluid distribution: R(0) and R(∞). The results indicate that AD5933-based spectrometer implemented in this work can perform accurate impedance measurements well above the upper limits recommended in the datasheet. The AD5933-EBIS presents a good performance compared with the SFB7 on the 2R1C circuit and the total right side measurements, showing a smaller error in the resistance spectrum and small deviation error in the reactance when measuring over 270 kHz. The comparison on the Cole parameters estimation obtained with the SFB7 and the AD5933-based spectrometer exhibit a difference below 1% for the estimation of R(0) and R(∞). Consequently the overall measurement performance shown by the implemented AD5933-based spectrometer suggests its feasible use for EBIS measurements using dry Textrodes. This is of special relevance for the proliferation of EBI-based personalized health monitoring systems for patients that require to monitor the distribution of body fluids, like in dialysis.

  • 313.
    Ferreira, Javier
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Álvarez, L.
    Buendía, R.
    Ayllón, D.
    Llerena, C.
    Gil-Pita, R.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Bioimpedance-based wearable measurement instrumentation for studying the autonomic nerve system response to stressful working conditions2013In: XV International Conference on Electrical Bio-Impedance (ICEBI) & XIV Conference on Electrical Impedance Tomography (EIT), 2013, Vol. 434, no 1, p. 012015-Conference paper (Refereed)
    Abstract [en]

    The assessment of mental stress on workers under hard and stressful conditions is critical to identify which workers are not ready to undertake a mission that might put in risk their own life and the life of others. The ATREC project aims to enable Real Time Assessment of Mental Stress of the Spanish Armed Forces during military activities. Integrating sensors with garments and using wearable measurement devices, the following physiological measurements were recorded: heart and respiration rate, skin galvanic response as well as peripheral temperature. The measuring garments are the following: a sensorized glove, an upper-arm strap and a repositionable textrode chest strap system with 6 textrodes. The implemented textile-enabled instrumentation contains: one skin galvanometer, two temperature sensors, for skin and environmental, and an Impedance Cardiographer/Pneumographer containing a 1 channel ECG amplifier to record cardiogenic biopotentials. The implemented wearable systems operated accordingly to the specifications and are ready to be used for the mental stress experiments that will be executed in the coming phases of the project in healthy volunteers.

  • 314. Flink, M.
    et al.
    Lindblad, Marlene
    KTH, School of Technology and Health (STH).
    Frykholm, O.
    Kneck, A.
    Nilsen, P.
    Årestedt, K.
    Ekstedt, Mirjam
    KTH, School of Technology and Health (STH). Department of Learning, Informatics, Management, and Ethics, Karolinska Institutet, Stockholm, School of Health and Caring Sciences, Faculty of Health and Life Sciences Linnaeus University, Kalmar, .
    The Supporting Patient Activation in Transition to Home (sPATH) intervention: A study protocol of a randomised controlled trial using motivational interviewing to decrease re-hospitalisation for patients with COPD or heart failure2017In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 7, no 7, article id e014178Article in journal (Refereed)
    Abstract [en]

    Introduction Deficient hospital discharging and patients struggling to handle postdischarge self-management have been identified as potential causes of re-hospitalisation rates. Despite an increased interest in interventions aiming to reduce re-hospitalisation rates, there is yet no best evidence on how to support patients in being active participants in their self-management postdischarge. The aim of this paper is to describe the study protocol for an upcoming randomised controlled trial (RCT) of the Supporting Patient in Activation to Home (sPATH) intervention. Methods/analysis The described study is a randomised, controlled, analysis-blinded, two-site trial, with primary outcome re-hospitalisation within 90 days. In total, 290 participants aged 18 years or older with chronic obstructive pulmonary disease or congestive heart failure who are admitted to hospital and who are living in an own home will be eligible for inclusion into an intervention (n=145) or control group (n=145). Patients who need an interpreter to communicate in Swedish, or who have a diagnosis of dementia or cognitive impairment, will be excluded from inclusion. The sPATH intervention, developed with a theoretical base in the self-determination theory, consists of five postdischarge motivational interviewing sessions (face to face or by phone). The intervention covers the self-management areas medication management, follow-up/care plan, symptoms/signs of worsening condition and relations/contacts with healthcare providers. This RCT will add to the literature on evidence to support patient activation in postdischarge self-management. Ethics and dissemination The study is approved by the Regional Research Ethics Committee (No. 2014/1498-31/2) in Stockholm, Sweden. The results of the study will be published in peer-reviewed journals and presented at international and national scientific conferences. Trial registration number NCT02823795; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved.

  • 315.
    Fogelberg, Jonathan
    et al.
    KTH, School of Technology and Health (STH).
    Nordbrøden, Mats
    KTH, School of Technology and Health (STH).
    Infusionspumpar - en studie vid Astrid Lindgrens Barnsjukhus2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bakgrunden till detta arbete är att det saknas riktlinjer från den tekniska avdelningen när vårdavdelningar på Astrid Lindgrens barnsjukhus skall köpa in infusionspumpar.

    Syftet med arbetet är att rekommendera ett antal pumpar vilka möter de krav och önskemål som ställs på dessa. Krav och önskemål kommer framförallt ifrån sjuksköterskorna men även ifrån rapportskrivarna.

    I resultatet presenteras sammanfattningar från de intervjuer som hållits med sjuksköterskor.

    I diskussionen kommenterar vi sjuksköterskornas önskemål och lyfter fram våra egna. Vi spekulerar även om infusionspumpens framtid.

    I slutsatsen anges vilka pumpmodeller som bäst möter de krav och önskemål som ställts på pumparna och varför vi rekommenderar Brauns pumpar före CareFusions. 

  • 316.
    Fornstedt, Cecilia
    KTH, School of Technology and Health (STH), Health Systems Engineering, Human Communication Science. Välj.
    Medical Technology and eHealth for Prevention against LifestyleRelated Diseases: A survey of attitudes among health center personnel and patients prescribed with physical activity on prescription (PAP)2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With an aging population that suffers from comorbidity, healthcare is facing grand challenges. In order to meet the demand, digitalization is thought to be an opportunity. Digitalization of curative care, such as diagnostics and treatment, have been initiated and is today used and appreciated. Preventative care, on the other hand, has not been included in the digital adaptions to the same extent and there are few scientific studies within the area. Nonetheless, a further proactive care that meets patients and healthcare personnel are of interest to several actors. The Swedish Government has a vision that Sweden, in 2025, will be world leading within eHealth. For that to be possible, digital preventative care have to support and complete the preventative work that is performed today.

    The present study has investigated the attitude towards Connected Medical Devices for Prevention (CMDfP) within the primary care. By a mixed-methodology including questionnaires, the opinions of 24 health center personnel and 17 patients prescribed with Physical Activity on Prescription (PAP) were collected and analyzed. The results show that health center personnel are willing to prescribe connected eHealth devices for prevention and patients are willing to use the devices prescribed. Additionally, among the respondents there is a belief that CMDfP could facilitate in order to increase the adherence to PAP without any major impact on the personnel's workload.

    By digitalizing preventative care, it is possible that people will be able to live healthier and therefore not require care to the same extent as today. Reasons to the possible results are that digital tools within curative care have been shown to generate positive outcomes to chronically ill patients that utilize home care. Additionally, studies of preventative care have generated positive outcomes to the health of the population in several countries. It is therefore likely that the combination, digital preventative care, would be rapidly relished. These thoughts align with the positive results on attitudes of this study.

    Before CMDfP could be prescribed to patients, pilot studies have to be performed and new work routines including reimbursement models, have to be established within healthcare. These are all areas of future work within medical engineering.

  • 317.
    Fornstedt, Cecilia
    et al.
    KTH, School of Technology and Health (STH).
    Fendukly, Mattias
    KTH, School of Technology and Health (STH).
    The Feasibility of the Speech Intelligibility Index in the Clinical Hearing Care2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Hearing-impaired individuals that use hearing aids often experience problems

    when exposed to daily situations in life. The dierent environments include for

    example classrooms, oces and public areas. For the hearing impaired, the correct

    adjustments of the hearing aids are of great importance. For these settings to be

    proper, a measurement called the Speech Intelligibility Index (SII), is questioned

    to be implemented in the clinical hearing care. To answer this question of issue

    whether feasibility lay in the implementation of SII in the clinical hearing care

    with the interface of hearing aids, a literature study ordered by the Hearing- &

    Balance Clinic (H&B) at Karolinska University Hospital situated at Rosenlund

    Hospital, was initiated. The focus of the study was primarily held in concern of

    SII as a hearing aid validation measurement and later extended to SII as a room

    acoustic measurement disregarding the eect of hearing aids. The result of the

    study showed that the use of SII in the clinical hearing care is troubled and further

    that the implementation as a room acoustic measurement is probable but has to

    be additionally investigated.

  • 318.
    Fornstedt, Cecilia
    et al.
    KTH, School of Technology and Health (STH).
    Fendukly, Mattias
    KTH, School of Technology and Health (STH).
    The Feasibility of the Speech Intelligibility Index in the Clinical Hearing Care2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Hearing-impaired individuals that use hearing aids often experience problemswhen exposed to daily situations in life. The di↵erent environments include forexample classrooms, offices and public areas. For the hearing impaired, the correctadjustments of the hearing aids are of great importance. For these settings to beproper, a measurement called the Speech Intelligibility Index (SII), is questionedto be implemented in the clinical hearing care. To answer this question of issuewhether feasibility lay in the implementation of SII in the clinical hearing carewith the interface of hearing aids, a literature study ordered by the Hearing- &Balance Clinic (H&B) at Karolinska University Hospital situated at RosenlundHospital, was initiated. The focus of the study was primarily held in concern ofSII as a hearing aid validation measurement and later extended to SII as a roomacoustic measurement disregarding the e↵ect of hearing aids. The result of thestudy showed that the use of SII in the clinical hearing care is troubled and furtherthat the implementation as a room acoustic measurement is probable but has tobe additionally investigated.

  • 319.
    Forsman, Mikael
    et al.
    Institute of Environmental Medicine, Karolinska Institutet, Stockholm, SWEDEN.
    Yang, Liyun
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Lind, Carl
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Practical objective measurements for sedentary time and body postures using Excel and iOS2016In: Preventing work-related musculoskeletal disorders in a global economy: Book of Abstracts, 2016, p. 61-61Conference paper (Refereed)
  • 320.
    Frank A, Flachskampf
    et al.
    Uppsala Universitet, Institutionen för Medicinska Vetenskaper, Akademiska sjukhuset.
    Mattias, Mårtensson
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    How should tissue Doppler tracings be measured?2014In: European Heart Journal Cardiovascular Imaging, ISSN 2047-2404, E-ISSN 2047-2412, Vol. 15, no 7, p. 828-829Article in journal (Refereed)
  • 321.
    Fredrik, Nilsson
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Bodin, Arvid
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Ombyggnad av en statisk webbsida till en responsiv2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today ́s society people are working more and more while travelling, which makes them use smartphones and tablets instead of laptops. These screens are usually smaller than a laptop screen. That is why a more dynamic web design has been re- quested in order to fit the screen on the device being used. The static webpage’s width was 1000 pixels and the goal was to fit all the tables and information in the respon- sive version with a width of 320 pixels. Important information also had to be moved to a different page in order to make it more visible. A new CSS-template was imple- mented and several new Java Scripts followed by finer adjustments to the HTML code. Since some information had to be more visible to the user, a new tab was cre- ated in order to fulfill this demand. The new tab contained information about “Net- work Status” only related to the signed in user. After simulating the webpage in Chrome the responsiveness of the page was confirmed on all screen sizes. Sending the webpage asynchronously made the slow pages respond instantly but the total loading time was still slow. To fix this, back-end programming would have been re- quired. The project’s webpage fulfilled all the requirements. 

  • 322. Frennert, Susanne
    et al.
    Eftring, Håkan
    Östlund, Britt
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Case report: Implications of Doing Research on Socially Assistive Robots in real Homes2017In: International Journal of Social Robotics, ISSN 1875-4791, E-ISSN 1875-4805Article in journal (Refereed)
    Abstract [en]

    The current paper addresses the implications of doing research on socially assistive robots in real homes. In contrast to laboratory studies, studies of robots in their intended natural environments can provide insights into people’s experiences of robots, and if and how a robot becomes embedded and used in people’s everyday life. However, moving robots out of the lab and into real life environments poses several challenges. Laboratory methods mainly focus on cause-and-effect relations between independent and dependent variables, while researchers who are conducting studies in real homes have much less control. In home trials, researchers need to decide what kind of data is obtainable and available. In real homes, researchers face unique challenges that require unique and pragmatic approaches. Any single study conducted in a real home is likely to have methodological limitations. Therefore, several different studies using different robots and methods are needed before the results can be converged in order to reach conclusions that are convincingly supported. This paper is an effort to provide such a report on a specific empirical case and converging findings from other studies. The goal is to provide an account of the research challenges and opportunities encountered when introducing a robot into its intended practice: the homes of older people. The aim is to give enough details for other researchers to critically examine and systematically build on the insights and findings presented.

  • 323.
    Friberg, Daniel
    et al.
    KTH, School of Technology and Health (STH).
    Johansson, Martin
    KTH, School of Technology and Health (STH).
    En jämförelse mellan elektroniska journalsystem för öppenvården2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 324.
    Friedrich, Anja
    KTH, School of Technology and Health (STH).
    A new seeding and conditioning reactor for vascular tissue engineering2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 325. Frykberg, Gunilla E.
    et al.
    Thierfelder, Tomas
    Aberg, Anna Cristina
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Borg, Jorgen
    Hirschfeld, Helga
    Impact of stroke on anterior-posterior force generation prior to seat-off during sit-to-walk2012In: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 35, no 1, p. 56-60Article in journal (Refereed)
    Abstract [en]

    Force generation during sit-to-walk (STW) post-stroke is a poorly studied area, although STW is a common daily transfer giving rise to a risk of falling in persons with disability. The purpose of this study was to describe and compare strategies for anterior-posterior (AP) force generation prior to seat-off during the STW transfer in both subjects with stroke and in matched controls. During STW at self-selected speed, AP force data were collected by 4 force plates, beneath the buttocks and feet from eight subjects with stroke '(>6 months after onset) and 8 matched controls. Subjects with post-stroke hemiparesis and matched controls generated a similar magnitude of total AP force impulses (F-1.71 = 0.67; p = 0.42) beneath buttocks and feet prior to seat-off during STW. However, there were significant group differences in AP force impulse generation beneath the stance buttock (i.e. the non-paretic buttock in the stroke group), with longer duration (F-1.71 = 8.78; p <0.005), larger net AP impulse (F-1.71 = 6.76; p < 0.05) and larger braking impulse (F-1.71 = 7.24; p <0.05) in the stroke group. The total braking impulse beneath buttocks and feet was about 4.5 times larger in the stroke group than in the control group (F-1.71 = 8.84; p < 0.005). An intra-and inter-limb dys-coordination with substantial use of braking impulses was demonstrated in the stroke group. This motor strategy differed markedly from the smooth force interaction in the control group. These results might be important in the development of treatment models related to locomotion post-stroke.

  • 326.
    Frånberg, Oskar
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Oxygen content in semi-closed rebreathing apparatuses for underwater use: Measurements and modeling2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The present series of unmanned hyperbaric tests were conducted in order to investigate the oxygen fraction variability in semi-closed underwater rebreathing apparatuses. The tested rebreathers were RB80 (Halcyon dive systems, High springs, FL, USA), IS-Mix (Interspiro AB, Stockholm, Sweden), CRABE (Aqua Lung, Carros Cedex, France), and Viper+ (Cobham plc, Davenport, IA, USA). The tests were conducted using a catalytically based propene combusting metabolic simulator. The metabolic simulator connected to a breathing simulator, both placed inside a hyperbaric pressure chamber, was first tested to demonstrate its usefulness to simulate human respiration in a hyperbaric situation. Following this the metabolic simulator was shown to be a useful tool in accident investigations as well as to assess the impact of different engineering designs and physiological variables on the oxygen content in the gas delivered to the diver by the rebreathing apparatuses. A multi-compartment model of the oxygen fractions was developed and compared to the previously published single-compartment models. The root mean squared error (RMSE) of the multi-compartment model was smaller than the RMSE for the single-compartment model, showing its usefulness to estimate the impact of different designs and physiological variables on the inspired oxygen fraction.

  • 327.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Modeling a demand constant volume ratio exhaust and a self-mixing constant oxygen injection semi-closed rebreatherManuscript (preprint) (Other academic)
    Abstract [en]

    Unmanned tests of two types of gas dosage techniques for semi-closed underwater rebreathing apparatuses were carried out with a metabolic simulator in a water filled pressure chamber. Tests were conducted over a wide range of tidal volumes (0.5-3 L), respiratory frequencies (5-25 min-1), and oxygen consumptions (0.5-4 L/min), as well as with changing chamber pressures from 100 kPa to 920 kPa. Two models were set up, one single compartment model and one model assuming multiple serial compartments. Both models seem to have about the same level of accuracy at predicting the inspired oxygen levels at pressure, but the surface tests seem to favor the serial compartments model.

  • 328.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Loncar, Mario
    Larsson, Ake
    Örnhagen, Hans
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    A Metabolic Simulator for Unmanned Testing of Breathing Apparatuses in Hyperbaric Conditions2014In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 85, no 11, p. 1139-1144Article in journal (Refereed)
    Abstract [en]

    Background: A major part of testing of rebreather apparatuses for underwater diving focuses on the oxygen dosage system. Methods: A metabolic simulator for testing breathing apparatuses was built and evaluated. Oxygen consumption was achieved through catalytic combustion of propene. With an admixture of carbon dioxide in the propene fuel, the system allowed the respiratory exchange ratio to be set freely within human variability and also made it possible to increase test pressures above the condensation pressure of propene. The system was tested by breathing ambient air in a pressure chamber with oxygen uptake (VO2) ranging from 1-4 L.min(-1), tidal volume (V-T) from 1-3 L, breathing frequency (f) of 20 and 25 breaths/min, and chamber pressures from 100 to 670 kPa. Results: The measured end-tidal oxygen concentration (FO2) was compared to calculated end-tidal FO2. The largest average difference in end-tidal FO2 during atmospheric pressure conditions was 0.63%-points with a 0.28%-point average difference during the whole test. During hyperbaric conditions with pressures ranging from 100 to 670 kPa, the largest average difference in FO2 was 1.68%-points seen during compression from 100 kPa to 400 kPa and the average difference in FO2 during the whole test was 0.29%-points. Conclusion: In combination with a breathing simulator simulating tidal breathing, the system can be used for dynamic continuous testing of breathing equipment with changes in V-T, f, VO2, and pressure.

  • 329. Fröberg, Asa
    et al.
    Mårtensson, Mattias
    KTH, School of Technology and Health (STH), Medical Engineering.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Janerot-Sjöberg, Birgitta
    KTH, School of Technology and Health (STH), Medical Engineering.
    D'Hooge, Jan
    Arndt, Anton
    High variability in strain estimation errors when using a commercial ultrasound speckle tracking algorithm on tendon tissue2016In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 10, p. 1223-1229Article in journal (Refereed)
    Abstract [en]

    Background: Ultrasound speckle tracking offers a non-invasive way of studying strain in the free Achilles tendon where no anatomical landmarks are available for tracking. This provides new possibilities for studying injury mechanisms during sport activity and the effects of shoes, orthotic devices, and rehabilitation protocols on tendon biomechanics. Purpose: To investigate the feasibility of using a commercial ultrasound speckle tracking algorithm for assessing strain in tendon tissue. Material and Methods: A polyvinyl alcohol (PVA) phantom, three porcine tendons, and a human Achilles tendon were mounted in a materials testing machine and loaded to 4% peak strain. Ultrasound long-axis cine-loops of the samples were recorded. Speckle tracking analysis of axial strain was performed using a commercial speckle tracking software. Estimated strain was then compared to reference strain known from the materials testing machine. Two frame rates and two region of interest (ROI) sizes were evaluated. Results: Best agreement between estimated strain and reference strain was found in the PVA phantom (absolute error in peak strain: 0.21 +/- 0.08%). The absolute error in peak strain varied between 0.72 +/- 0.65% and 10.64 +/- 3.40% in the different tendon samples. Strain determined with a frame rate of 39.4Hz had lower errors than 78.6Hz as was the case with a 22mm compared to an 11mm ROI. Conclusion: Errors in peak strain estimation showed high variability between tendon samples and were large in relation to strain levels previously described in the Achilles tendon.

  • 330.
    Gabrail, Philip
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Samuelsson, Sam
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Analys av fältfördelning i kabelavslut av linjära och icke linjära material: Analysis of the field distribution in cable termination by linear and nonlinear material2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays XLPE high voltage cables are used in transmission and distribution of electrical power and has an important role in the electrical system. Power transmission that occurs over long distances is diverted from one point to another and is done with the help of cable terminations. These cable terminations have some vulnerabilities that affect the entire power system.

    The theoretical part of the report was carried out with the help of FEM software Comsol Multiphysics. Results showed that the highest field concentration occurs at the insulation of the cable and caused malfunction and vulnerabilities. In the linear case for the electrical part resulted a high permittivity that the potential and the electric field was reduced, which showed the same result for low conductivity. For the nonlinear material the conductivity changes with the electric field and time.

    The temperature of the linear case showed that at high temperatures the material became more conductive. In the nonlinear case the conductive material was reduced. This could be controlled with different threshold value (Eb) which cannot in the linear case.

    The practical part was done in E.ON:s laboratory for different type of cable terminations that were tested with 33kV. Some of the tested cable terminations were used for testing purposes and was picked out of operation because of a malfunction in the cable. An attempt to control field concentration was carried out in the laboratory and resulted to a reduced field  istribution in the cable termination. The result of the practical part showed how the field concentration was distributed in the cable termination and that the field distribution led to the collapse of the cable.

  • 331.
    Gao, Bo
    KTH, School of Technology and Health (STH).
    Multigrid reconstruction of micro-CT data2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The group of Medical Imaging at School of Health and Technology is developing a micro-CT scanner for small animal imaging. Micro-CT refers to reconstructing CT image with resolution in scale of micrometer, and this goal is achieved by acquiring projection data with high resolution. Nevertheless, high resolution projection data and high resolution recon- struction image have introduced the problem of memory insufficiency, as more points need to be processed during micro-CT reconstruction.

    For this reason, this paper has investigated how to alleviate the burden on computers memory through applying multi-grid reconstruction algo- rithms, which means to reconstruct region of interest (ROI) with high resolution while reconstructing background with lower resolution. By do- ing that, pixels being considered in the reconstruction space has been decreased and normal computers will be capable to handle reconstruction of micro-CT image.

    Through testing on numerical data (Shepp Logan Phantom), it can be concluded that multi-grid reconstruction algorithm could reconstruct high fidelity ROI with much faster speed comparing to full resolution reconstruction. Moreover, this proposed technique can also give decent reconstruction to data acquired from micro-CT scanner. 

  • 332.
    Gardmo, Madeleine
    KTH, School of Technology and Health (STH).
    En attraktiv arbetsplats för undersköterskor: - Samband mellan arbetstillfredsställelse och intention att sluta ur ett systemperspektiv2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Personalomsättningen bland undersköterskor är hög. Få tidigare gjorda studier har fokuserat på undersköterskans arbetsmiljö i sjukvården och hur arbetsplatsfaktorer kan kopplas till arbetstillfredsställelse och intention att sluta. Syftet med föreliggande studie var att undersöka om det fanns ett samband mellan arbetstillfredsställelse och intention att sluta sitt arbete som undersköterska och identifiera arbetsplatsfaktorer med koppling till arbetstillfredsställelse, intention att sluta och attraktivt arbete ur ett systemperspektiv. Studien bestod av två delar, en tvärsnittsstudie (studie 1) med enkäter baserade på redan insamlat material med 238 undersköterskors svar från COPSOQ II gällande arbetstillfredsställelse och intention att sluta samt en semistrukturerad intervjustudie (studie 2) med fem undersköterskor från akut verksamhet från två olika sjukhus i Stockholms län. Studie 1 visade en signifikant positiv samvariation mellan arbetstillfredsställelse och intention att sluta (Pearsons r = 0,490, p= 0,00). De enskilda arbetsplatsfaktorer som visade signifikant samvariation var arbete som helhet (Pearsons r= 0,487) samt arbetsmiljö (Pearson r= 0,398, p= 0,064) med tendens till signifikans. R Square visade att 28% av variationen i intentionen att sluta kunde förklaras utifrån de ingående variablerna i arbetstillfredsställelse. I studie 2 lyftes 6 olika teman; Socialt klimat, Kontroll över hur arbetet planeras och organiseras, Interaktion mellan fysisk arbetsmiljö, Teknik och arbetsuppgift, Möjlighet till lärande och utveckling, Organisation och ledarskap, Produktionstänk kontra meningsfullhet och etik som faktorer kopplade till arbetstillfredsställelse, intention att sluta och attraktivt arbete för undersköterskor. Ett sammanfattande systemperspektiv av resultatet identifierade de arbetsplatsfaktorer som kopplats till arbetstillfredsställelse, intention att sluta och attraktivt arbete genom en kartläggande analys. En del av resultaten är samstämmiga med tidigare gjorda studier kring sjuksköterskors arbetsmiljö (Aiken et al.., 2011, Björn, 2016., Chan et al., 2013., Hayes, et al., 2012., Carter & Tourangeau, 2012., Lu et al., 2015 mfl). Fler studier behövs dock för att identifiera och verifiera de arbetsplatsfaktorer som bidrar till attraktiva arbetsplatser för undersköterskor.

  • 333. Gasparrini, S.
    et al.
    Cippitelli, E.
    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.
    Proposal and experimental evaluation of fall detection solution based on wearable and depth data fusion2016In: ICT Innovations 2015: Emerging Technologies For Better Living, Springer, 2016, Vol. 399, p. 99-108Conference paper (Refereed)
    Abstract [en]

    Fall injury issues represent a serious problem for elderly in our society. These people want to live in their home as long as possible and technology can improve their security and independence. In this work we study the joint use of a camera based system and wearable devices, in the so called data fusion approach, to design a fall detection solution. The synchronization issues between the heterogeneous data provided by the devices are properly treated, and three different fall detection algorithms are implemented. Experimental results are also provided, to compare the proposed solutions.

  • 334.
    Gatu, Andreas
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Svensson, Alexander
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Justerbar modell av transmissionsledning för elkraftsöverföring2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This diploma work has been carried out on behalf of Terco. TercosPST 2220 Transmission Line and Distribution Module works as a physicalmodel of a real transmission and distribution grid where five different typesof networks based on length, voltage and apparent effect are available. Thereis today a need of a model where the user self can adjust these parameters sothat the model more precisely can reflect the characteristics that the specificgrid has. Here it’s investigated how the length and its impact on a line canbe varied in a model.A presentation of how the transmission and distribution grid works andare described theoretically provides the basics for the different models thatcan describe a whole network and its properties.Since the R, L and C components needs to be able to be varied to be ableto physically realize this theoretical model, the different methods that thiscan be realized through are investigated. Two approaches are investigated,the cascaded pi-model and variable active-passive reactance (VAPAR).A number of aspects like space, cost and variability makes the variableactive-passive reactance the most suited solution. Its function as a variablevoltage source, made out of an four switches, operated with control techno-logy and pulse width modulation, makes it possible to imitate R, L and Csproperties and effect on a transmission line. The result is that the necessaryR,L,C components are made adjustable in order to be incorporated in aadjustable transmission lin model.The result and the goal are verified with simulations where variableactive-passive reactance is proved able for further development and practicaltests to model transmission and distribution lines with different length.

    Keywords. Variability, Inverter, Impedance, DC-AC, Pulse width modula-tion, Harmonics, H-bridge, Transmission line, Voltage drop, Reactive effect.

  • 335.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Jurd, Karen M.
    Blogg, S. Lesley
    Pre-Dive Exercise and Post-Dive Evolution of Venous Gas Emboli2012In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 83, no 1, p. 30-34Article in journal (Refereed)
    Abstract [en]

    Background: Recent studies have indicated that exercise before diving significantly reduces the number of circulating bubbles and the risk of decompression sickness. However, the most effective time delay between exercise and dive is not clear; the present aim was to resolve this. Methods: In a hyperbaric chamber, 10 men were compressed to 18 m for 100 min, then decompressed as per Royal Navy Table 11. Each subject performed three dives: a control dive and two after exercise performed either 24 h or 2 h before diving. Exercise consisted of 40 min submaximal work on a cycle ergometer. Venous gas emboli (VGE) were evaluated using precordial Doppler ultrasound immediately on surfacing, with measurements made at 5-min intervals for 30 min, and at 15-min intervals for at least 2.5 h total using the Kisman Masurel (KM) scale. Results: Exercise either 24 or 2 h prior to a dive did not reduce the median number of circulating VGE (median maximum KM grade: control, 2+; for both exercise dives, 3). Bubbles disappeared from the circulation faster after the control dive than the exercise dives. Time to median KM Doppler scores of zero were: control:120 min; 2-h group: 225 min; 24-h group: 165 min. Conclusion: Cycling exercise prior to diving did not reduce the number of circulating VGE in comparison to control, in contrast to recent studies. A number of factors may be responsible for these findings, including type of exercise performed, wet diving experience, and disparity in Doppler measurement techniques.

  • 336.
    Gerkens, Rick
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Berg, David
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Elkvalitéproblem vid varvtalsstyrd motordrift i industrimiljö2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Harmonics caused by variable speed drives create problems in industrial systems. The purpose of this study is to identify these problems and give recommendations to avoid them. The study was conducted as a bachelor thesis at the Royal Technical University in Stockholm, Sweden for the consultant company Ramboll Energy. A literature review was combined with electrical power quality measurements on variable speed motor operations conducted at Sandvik Mining in Sandviken, Sweden.

    Electrical quality problems caused by variable speed drives origin mainly from frequency inverter control that gives a non-linear current usage which, if the grid is not strong enough, affects voltage quality. Examples of problems are production downtime, disruption and malfunction of equipment and increased wear of equipment.

    This study shows that when making changes in systems containing harmonics, future harmonic levels can be approximated in some cases. Measurements before the change provide input data to model the system, describing the load as a harmonic current generator. With some assumptions on the grid impedance, calculating an approximation on harmonic after the change is possible.

    This study has used a simplified model for the prediction of harmonic levels after a change in the system. The purpose is to propose a cost effective way to approximate so that information on how to prevent problems …in the decision making. Electrical power quality problems could be prevented more often and not doing that is a waste of economical, environmental and social resources.

  • 337.
    Gibert, Guillaume
    KTH, School of Technology and Health (STH).
    Quantification of the Cerebral Perfusion with the Arterial Spin Labelling 3D-MRI method. Quantification of the Cerebral Perfusion with the Arterial Spin Labelling 3D-MRI method2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Arterial Spin Labelling (ASL) method is a Magnetic Resonance technique used toquantify the cerebral perfusion. It has the big advantage to be non-invasive so doesn’tneed the injection of any contrast agent. But due to a relatively low Signal-to-NoiseRatio (SNR) of the signal acquired (only approximately 1% of the image intensity), ithas been hampered to be widely used in a clinical setting so far.The primary objective of this project is to make the method more robust by improvingthe quality of the images, the SNR, and by reducing the acquisition time. DifferentASL protocols with different sets of parameters have been investigated. The modificationsperformed on the protocol have been investigated by analyzing images acquired onhealthy volunteers. An optimized protocol leading to a good trade-off between the differentaspects of the method, has been suggested. It is characterized by a 3:43:44:0mm3with a two-segment acquisition.A more advanced ASL method implies the acquisition of images at different inversiontimes (TI), which is called the mutli-TI method. The influence of the range of TI used inthe method has been explored. An optimized TI range (from 410ms to 3860ms, sampledevery 150ms) has been suggested to make the ASL method as performant as possible.A numerical model and a fitting algorithm have been used to extract the informationon the perfusion from the images acquired. Different models have been investigated aswell as their influence on the reliability of the results.Finally, a criterion has been implemented to evaluate the reliability of the results sothat the clinician or the user of the method can figure out how much he can count onthe results provided by the method.

  • 338.
    Gidlöf Örnerfors, Linus
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Testautomatisering av linjärmotorer2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This diploma work has been carried out on behalf of Stegia AB. Stegia manufacturesand sells linear motors that are tested in a test bench before shipped to thecustomer. Today there is a need for a test bench that collects test results from theperformed tests. The company would like to lower the risk of falsely made tests,and to make the test bench easier for the production staff to use. At this moment,the test of the linear motors is made up of several manual tasks before the test iscompleted. This increases the risk of wrong results because of incorrectly madetests, with no traceability of the results. The goal with this diploma work is to lowerthe risk of incorrect test result by automating the testing process for the productionstaff. The result is presented as a prototype, that should increase the reliability ofthe test result of the motors. The result is then validated and analyzed in this report.

  • 339.
    Giordano, Chiara
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Development of an Anisotropic Finite Element Head Model for Traumatic Brain Injury Prediction2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Traumatic brain injury (TBI) is a worldwide health care problem with very high associatedmorbidity and mortality rates. In particular, the diagnosis of TBI is challenging: symptomsoverlap with other pathologies and the injury is typically not visible with conventionalneuroimaging techniques.Finite element (FE) head models can provide valuable insight into uncovering themechanism underlying brain damage. These models enable the calculation of tissue loadsand deformation patterns, which are thought to be associated with the injury. Measuresbased on tissue strain or invariants of the strain tensor are used as injury predictors and riskinjury curves can be inferred to establish the tolerance of the human head to external loads.However, while in-vitro research shows that the vulnerability to injury is due to highlyorganized structure in white matter tracts, the majority of the current FE models model thebrain as isotropic and homogenous. The deformation of white matter tracts is not calculated.The aim of this doctoral thesis was to incorporate the effects of inhomogeneity andanisotropy of brain tissue into injury analysis. Based on in-vitro experimental evidence, thestrain in the direction of the axons (axonal strain) was proposed as a new, more anatomicallyrelevant, injury predictor. The initial hypothesis to investigate was that an FE anisotropichead model is a better tool to represent TBI because it is more biofidelic in describing thelocal mechanism of axonal impairment.The studies reported in this thesis describe a method for implementing the orientation of thewhite matter tracts in an anisotropic constitutive law for FE modeling. Results from thestudies suggested that the anisotropy of the brain significantly affected the injury predictionsof an FE head model. For an injury dataset from the American National Football League, thepeak of axonal strain - MAS - was found to be a better predictor of injury than isotropic localor global predictors. Finally, based on 27 cases of intracranial pressure, relative skull-brainmotion and brain deformation, the introduction of the brain anisotropy in the FE modelpartially enhanced the biofidelity of the simulations. However, given that the enhancementin biofidelity was not major, it was concluded that further research is necessary forunderstanding the relationship between tissue-level loading and axonal injury.

  • 340.
    Giordano, Chiara
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Connecting Fractional Anisotropy from Medical Images with Mechanical Anisotropy of a Hyperviscoelastic Fibre-reinforced Constitutive Model for Brain Tissue2014In: Journal of the Royal Society Interface, ISSN 1742-5689, E-ISSN 1742-5662, Vol. 11, no 91, p. 20130914-Article in journal (Refereed)
    Abstract [en]

    Brain tissue modelling has been an active area of research for years. Brain matter does not follow the constitutive relations for common materials and loads applied to the brain turn into stresses and strains depending on tissue local morphology. In this work, a hyperviscoelastic fibre-reinforced anisotropic law is used for computational brain injury prediction. Thanks to a fibrere-inforcement dispersion parameter, this formulation accounts for anisotropic features and heterogeneities of the tissue owing to different axon alignment. The novelty of the work is the correlation of the material mechanical anisotropy with fractional anisotropy (FA) from diffusion tensor images. Finite-element (FE) models are used to investigate the influence of the fibre distribution for different loading conditions. In the case of tensile-compressive loads, the comparison between experiments and simulations highlights the validity of the proposed FA-k correlation. Axon alignment affects the deformation predicted by FE models and, when the strain in the axonal direction is large with respect to the maximum principal strain, decreased maximum deformations are detected. It is concluded that the introduction of fibre dispersion information into the constitutive law of brain tissue affects the biofidelity of the simulations.

  • 341.
    Giordano, Chiara
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Development of a 3-year-old child FE head model, continuously scalable from 1.5-to 6-year-old2016In: 2016 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury, International Research Council on the Biomechanics of Injury , 2016, p. 288-302Conference paper (Refereed)
    Abstract [en]

    This study summarised efforts in developing a 3-year-old FE head model, continuously scalable in the range 1.5-to 6-year-old. The FE models were transformed into one another using nonlinear scaling driven by control points corresponding to anthropometric dimensions. Procedures to mimic age-specific structural changes occurring during the paediatric development were implemented by means of transition of elements. The performances of the head models were verified on drop and compressive tests available from the literature. A stable and experimentally well-correlated family of FE models in the range 1.5-to 6-year-old was created.

  • 342.
    Giordano, Chiara
    et al.
    KTH, School of Technology and Health (STH).
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Development of an Unbiased Validation Protocol to Assess the Biofidelity of Finite Element Head Models used in Prediction of Traumatic Brain Injury2016In: Stapp Car Crash Journal, ISSN 1532-8546, Vol. 60, p. 363-471Article in journal (Refereed)
    Abstract [en]

    This study describes a method to identify laboratory test procedures and impact response requirements suitablefor assessing the biofidelity of finite element head models used in prediction of traumatic brain injury. The selection of theexperimental data and the response requirements were result of a critical evaluation based on the accuracy, reproducibility andrelevance of the available experimental data. A weighted averaging procedure was chosen in order to consider differentcontributions from the various test conditions and target measurements based on experimental error. According to the qualitycriteria, 40 experimental cases were selected to be a representative dataset for validation. Based on the evaluation of responsecurves from four head finite element models, CORA was chosen as a quantitative method to compare the predicted time historyresponse to the measured data. Optimization of the CORA global settings led to the recommendation of performing curvecomparison on a fixed time interval of 0-30 ms for intracranial pressure and at least 0-40 ms for brain motion and deformation.The allowable maximum time shift was adjusted depending on the shape of the experimental curves (􀜦􀯆􀮺􀯑􀀃􀀃= 0.12 forintracranial pressure, 􀜦􀯆􀮺􀯑 = 0.40 for brain motion and 􀜦􀯆􀮺􀯑 = 0.25 for brain deformation). Finally, bigger penalization ofratings was assigned to curves with fundamentally incorrect shape compared to those having inaccuracies in amplitude or timeshift (cubic vs linear). This rigorous approach is necessary to ensure confidence in the model results and progress in the usage offinite element head models for traumatic brain injury prediction.

  • 343.
    Giordano, Chiara
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Evaluation of Axonal Strain as a Predictor for Mild Traumatic Brain Injuries Using Finite Element Modeling2014In: Stapp Car Crash Journal, ISSN 1532-8546, Vol. 58Article in journal (Refereed)
    Abstract [en]

    Finite element (FE) models are often used to study the biomechanical effects of traumatic brain injury (TBI). Measures based on mechanical responses, such as principal strain or invariants of the strain tensor, are used as a metric to predict the risk of injury. However, the reliability of inferences drawn from these models depends on the correspondence between the mechanical measures and injury data, as well as the establishment of accurate thresholds of tissue injury. In the current study, a validated anisotropic FE model of the human head is used to evaluate the hypothesis that strain in the direction of fibers (axonal strain) is a better predictor of TBI than maximum principal strain (MPS), anisotropic equivalent strain (AESM) and cumulative strain damage measure (CSDM). An analysis of head kinematics-based metrics, such as head injury criterion (HIC) and brain injury criterion (BrIC), is also provided. Logistic regression analysis is employed to compare binary injury data (concussion/no concussion) with continuous strain/kinematics data. The threshold corresponding to 50% of injury probability is determined for each parameter. The predictive power (area under the ROC curve, AUC) is calculated from receiver operating characteristic (ROC) curve analysis. The measure with the highest AUC is considered to be the best predictor of mTBI.Logistic regression shows a statistical correlation between all the mechanical predictors and injury data for different regions of the brain. Peaks of axonal strain have the highest AUC and determine a strain threshold of 0.07 for corpus callosum and 0.15 for the brainstem, in agreement with previously experimentally derived injury thresholds for reversible axonal injury. For a data set of mild TBI from the national football league, the strain in the axonal direction is found to be a better injury predictor than MPS, AESM, CSDM, BrIC and HIC.

  • 344.
    Giordano, Chiara
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Zappalà, Stefano
    KTH, School of Technology and Health (STH).
    Kleiven, Svein
    KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.
    Anisotropic finite element models for brain injury prediction: the sensitivity of axonal strain to white matter tract inter-subjectvariability2017In: Biomechanics and Modeling in Mechanobiology, ISSN 1617-7959, E-ISSN 1617-7940Article in journal (Refereed)
    Abstract [en]

    Computational models incorporating anisotropic features of brain tissue have become a valuable tool for studying the occurrence of traumatic brain injury. The tissue deformation in the direction of white matter tracts (axonal strain) was repeatedly shown to be an appropriate mechanical parameter to predict injury. However, when assessing the reliability of axonal strain to predict injury in a population, it is important to consider the predictor sensitivity to the biological inter-subject variability of the human brain. The present study investigated the axonal strain response of 485 white matter subject-specific anisotropic finite element models of the head subjected to the same loading conditions. It was observed that the biological variability affected the orientation of the preferential directions (coefficient of variation of 39.41% for the elevation angle—coefficient of variation of 29.31% for the azimuth angle) and the determination of the mechanical fiber alignment parameter in the model (gray matter volume 55.55–70.75%). The magnitude of the maximum axonal strain showed coefficients of variation of 11.91%. On the contrary, the localization of the maximum axonal strain was consistent: the peak of strain was typically located in a 2 cm3 volume of the brain. For a sport concussive event, the predictor was capable of discerning between non-injurious and concussed populations in several areas of the brain. It was concluded that, despite its sensitivity to biological variability, axonal strain is an appropriate mechanical parameter to predict traumatic brain injury.

  • 345.
    Glimskär, Bo
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Developments for a future health care at home step by step2010In: Safety Science Monitor, ISSN 1443-8844, Vol. 14, no 1Article in journal (Other academic)
  • 346.
    Glimskär, Bo
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Rullatorn blir robot2012In: Forskning och framsteg, ISSN 0015-7937, no 8, p. 66-67Article in journal (Other (popular science, discussion, etc.))
  • 347.
    Glimskär, Bo
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    The Adoption of Ergonomic Innovations for Injury Prevention: Examples from the building construction and health care industries2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A good work environment is important for the individual, for industry and for society. The work environment research has, predominantly, targeted identification of problems and the measurement of the size of these problems.

    Innovations to reduce the incidence of musculoskeletal disorder, MSD, have been introduced in different branches of industry, but with limited success.

    Few of the ergonomic innovations developed for the building and construction industry have reached a sufficient level of adoption. Ergonomic innovations in the health care sector are of an incremental character and seem to have similar problems of adoption as the ones in the building and construction industry.

    Three examples of ergonomic innovation are examined in the thesis:

    • a glue spreader for floor layers

    • a four-wheel walker with a lifting device

    • a sonographer’s scanning support device

    The studies show that an ergonomic innovation is not adopted for prevention of occupational injury unless the innovation also has other relative advantages apart from the ergonomic ones. For the group who already has sustained an injury, it is enough that the ergonomic problems are solved, while the other, symptom-free group, requires other advantages in order to adopt the innovation; increased production economy seems to be the most prominent potential advantage.

  • 348.
    Glimskär, Bo
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    The Adoption of Ergonomic Innovations for Injury Prevention: Sonographer's scanning support deviceManuscript (preprint) (Other academic)
    Abstract [en]

    Studies of how people relate to the risk of occupational injury indicate that there is a tendency to underestimate the risk at work compared to other risks in society. Ultrasound examinations of the heart involve a static and very uncomfortable working posture for the sonographer. As a result many sonographers experience shoulder and neck pains which can result in long term sickness leaves.

    The purpose of the study was to evaluate how a more radical ergonomic innovation, a remote controlled ultrasound robot for cardiac examinations, Medirob, has been adopted. The study was conducted by interviews with department heads and heads of clinics, responsible for the procurement of the equipment.

    The results of this study have shown that it is not maybe enough to solve an ergonomic problem with an innovation to get it accepted and used. To prevent injuries the intervention must also have other qualities, for example improved productivity.

  • 349.
    Glimskär, Bo
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Utvecklad projektering och planering: Fallrapport (Åkerbyparken)1995Book (Other academic)
    Abstract [sv]

    1990 initierades Åkerbyparken av Täby kommun för seniorbostäder. Projektet genomfördes av Besqab i samarbete med SIAB och berörde samtliga verksamma på arbetsplatsen och i projekteringen. Projektets målsättning har varit att genom en utvecklad projektering och planering förebygga att arbetssituationer som kan leda till förslitningsskador uppkommer. Genom att särskilt beakta dessa frågor i alla skeden av ett byggobjekts genomförande kan man skapa förutsättningar för minskade förslitningsskador i branschen samt även skapa en bättre produktionsekonomi.

  • 350.
    Glimskär, Bo
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Utveckling av armeringsbollen: Etapp 11995Report (Other academic)
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