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  • 301.
    Buendia, Rubén
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Bosaeus, I.
    Gil-Pita, R.
    Johannsson, G.
    Ellegård, L.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Robustness study of the different immittance spectra and frequency ranges in bioimpedance spectroscopy analysis for assessment of total body composition2014In: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 35, no 7, p. 1373-1395Article in journal (Refereed)
    Abstract [en]

    The estimation of body fluids is a useful and common practice for assessment of disease status and therapy outcomes. Electrical bioimpedance spectroscopy (EBIS) methods are noninvasive, inexpensive and efficient alternatives for determination of body fluids. One of the main source of errors in EBIS measurements in the estimation of body fluids is capacitive coupling. In this paper an analysis of capacitive coupling in EBIS measurements was performed and the robustness of the different immittance spectra against it tested. On simulations the conductance (G) spectrum presented the smallest overall error, among all immittance spectra, in the estimation of the impedance parameters used to estimate body fluids. Afterwards the frequency range of 10-500 kHz showed to be the most robust band of the G spectrum. The accuracy of body fluid estimations from the resulting parameters that utilized G spectrum and parameters provided by the measuring device were tested on EBIS clinical measurements from growth hormone replacement therapy patients against estimations performed with dilution methods. Regarding extracellular fluid, the correlation between each EBIS method and dilution was 0.93 with limits of agreement of 1.06 +/- 2.95 l for the device, 1.10 +/- 2.94 l for G [10-500 kHz] and 1.04 +/- 2.94 l for G [5-1000 kHz]. Regarding intracellular fluid, the correlation between dilution and the device was 0.91, same as for G [10-500 kHz] and 0.92 for G [5- 1000 kHz]. Limits of agreement were 0.12 +/- 4.46 l for the device, 0.09 +/- 4.45 for G [10- 500 kHz] and 0.04 +/- 4.58 for G [5-1000 kHz]. Such close results between the EBIS methods validate the proposed approach of using G spectrum for initial Cole characterization and posterior clinical estimation of body fluids status.

  • 302.
    Buendía López, Rubén
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Model Based Enhancement of Bioimpedance Spectroscopy Analysis: Towards Textile Enabled Applications2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Several signal processing approaches have been developed to overcome the effect of stray capacitances in Electrical Bioimpedance Spectroscopy (EBIS) measurements. EBIS measurements obtained with textile-enabled instrumentation are more vulnerable to stray capacitances. Currently, the most widespread approach for correcting the effect of stray capacitances in EBIS is the time delay (

    Td) compensation method, which also has several drawbacks. In this study, the Td method is revisited and its limitations and its lack of a scientific basis are demonstrated. To determine better ways to overcome the effect of stray capacitances, a simplified measurement model is proposed that is based on previous models of artefacts in EBIS measurements described in the literature. The model consists of a current divider with a parasitic capacitance (Cpar) in parallel with the load. Cpar creates a pathway for the measurement current to leak away from the load, provoking a capacitive leakage effect. In this thesis, three approaches with different limitations are proposed to overcome the capacitive leakage effect. The first approach estimates Cpar and subtracts it from the measurements, thus finding the load. Cpar can be estimated because the susceptance of biological tissue is null at infinite frequency. Therefore, at high frequencies, the susceptance of the tissue can be neglected, and the slope of the susceptance of the measurement is Cpar. The accuracy of Cpar depends on the maximum frequency measured and the value of Cpar. Therefore, it may not be possible to accurately estimate small values of Cpar in the typical frequency ranges used in EBIS. The second and third approaches use the Cole fitting process to estimate the Cole parameters, which form the basis for most EBIS applications. Because the conductance of the measurement is free from the effect of Cpar, performing Cole fitting on the conductance avoids the effect of Cpar in the fitting process. With a poor skin-electrode contact, this approach may not be sufficiently accurate. The third approach would be to perform the Cole fitting on the modulus with a reduced upper frequency limit because the modulus and the low-medium frequencies are very robust against the effect of artefacts. In this approach, a slight capacitive leakage effect is unavoidable. Since it is common to find tainted measurements, especially among those obtained with textile-enabled instrumentation, it is important to find viable methods to avoid their effect. The three methods studied showed that they could reduce the effect of tainted measurements.

  • 303.
    Buizza, Giulia
    KTH, School of Technology and Health (STH).
    Classifying patients' response to tumour treatment from PET/CT data: a machine learning approach2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Early assessment of tumour response has lately acquired big interest in the medical field, given the possibility to modify treatments during their delivery. Radiomics aims to quantitatively describe images in radiology by automatically extracting a large number of image features. In this context, PET/CT (Positron Emission Tomography/Computed Tomography) images are of great interest since they encode functional and anatomical information, respectively. In order to assess the patients' responses from many image features appropriate methods should be applied. Machine learning offers different procedures that can deal with this, possibly high dimensional, problem.

    The main objective of this work was to develop a method to classify lung cancer patients as responding or not to chemoradiation treatment, relying on repeated PET/CT images. Patients were divided in two groups, based on the type of chemoradiation treatment they underwent (sequential or concurrent radiation therapy with respect to chemotherapy), but image features were extracted using the same procedure. Support vector machines performed classification using features from the Radiomics field, mostly describing tumour texture, or from handcrafted features, which described image intensity changes as a function of tumour depth. Classification performance was described by the area under the curve (AUC) of ROC (Receiving Operator Characteristic) curves after leave-one-out cross-validation. For sequential patients, 0.98 was the best AUC obtained, while for concurrent patients 0.93 was the best one. Handcrafted features were comparable to those from Radiomics and from previous studies, as for classification results. Also, features from PET alone and CT alone were found to be suitable for the task, entailing a performance better than random.

  • 304.
    Burmeister, Jens
    et al.
    University of Dresden, Germany.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lundberg, Stefan
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Contention-Based Wireless Sensor Networks: A case study for ambient assisted living2010In: Active Ageing, Smart Solutions, New Markets, 2010Conference paper (Refereed)
    Abstract [en]

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

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

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

  • 305. Busenlehner, Laura S.
    et al.
    Alander, Johan
    Jegerscohld, Caroline
    Holm, Peter J.
    Bhakat, Priyaranjan
    Hebert, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Morgenstern, Ralf
    Armstrong, Richard N.
    Location of substrate binding sites within the integral membrane protein microsomal glutathione transferase-12007In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 46, no 10, p. 2812-2822Article in journal (Refereed)
    Abstract [en]

    Microsomal glutathione transferase-1 (MGST1) is a trimeric, membrane-bound enzyme with both glutathione (GSH) transferase and hydroperoxidase activities. As a member of the MAPEG superfamily, MGST1 aids in the detoxication of numerous xenobiotic substrates and in cellular protection from oxidative stress through the GSH-dependent reduction of phospholipid hydroperoxides. However, little is known about the location of the different substrate binding sites, including whether the transferase and peroxidase activities overlap structurally. Although molecular density attributed to GSH has been observed in the 3.2 A resolution electron crystallographic structure of MGST1, the electrophilic and phospholipid hydroperoxide substrate binding sites remain elusive. Amide H-D exchange kinetics and H-D ligand footprinting experiments indicate that GSH and hydrophobic substrates bind within similar, but distinct, regions of MGST1. Site-directed mutagenesis, guided by the H-D exchange results, demonstrates that specific residues within the GSH footprint effect transferase activity toward 1-chloro-2,4-dinitrobenzene. In addition, cytosolic residues surrounding the chemical stress sensor C49 but not modeled in the crystal structure appear to play an important role in the formation of the binding site for hydrophobic substrates. Although the fatty acid/phospholipid binding site structurally overlaps that for GSH, it does not appear to be localized to the same region as other hydrophobic substrates. Finally, H-D exchange mass spectrometry reveals a specific conformational transition that may mediate substrate binding and/or product release. Such structural changes in MGST1 are essential for activation of the enzyme and are important for its biological function.

  • 306.
    Bährecke, Niklas
    KTH, School of Technology and Health (STH).
    Automatic Classification and Visualisation of Gas from Infrared Video Data2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Optical gas imaging denotes the visualisation of gases by means of an infrared camera, which allows operators to quickly, easily, and safely scan a large area and therefore plays a major role in the early detection and repair of gas leaks in various environments within the petrochemical industry such as processing plants and pipelines, but also in production facilities and hospitals. Thereby they help to avert damage to the environment as well as to health and safety of workers or inhabitants of nearby residential areas. The current generation of thermal gas cameras employs a so-called high-sensitivity mode, based on frame differencing, to increase the visibility of gas plumes. However, this method often results in image degradation through loss of orientation, distortion, and additional noise. Taking the increased prevalence and sinking costs for IR gas cameras – entailing an increased number of inexperienced users – into consideration, a more intuitive and user-friendly system to visualise gas constitutes a useful feature for the next generation of IR gas cameras. A system that retains the original infrared video images and highlights the gas cloud, providing the user with a clear and distinct visualisation of gas on the camera’s display, would be one example for such a visualisation system. This thesis discusses the design of such an automatic gas detection and visualisation framework based on machine learning and computer vision methods, where moving objects in video images are detected and classified as gas or non-gas based on appearance and spatiotemporal features. The main goal was to conduct a proof-of-concept study of this method, which included gathering examples for training a classifier as well as implementing the framework and evaluating several feature descriptors – both static and dynamic ones – with regard to their classification performance in gas detection in video images. Depending on the application scenario, the methods evaluated in this study are capable of reliably detecting gas.

  • 307.
    Bälter, Olle
    et al.
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID.
    Colareti Tosti, Massimiliano
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Kann, Viggo
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Svedin, Maria
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID.
    Lärstrategier på längden och tvären2015In: 5:e Utvecklingskonferensen för Sveriges ingenjörsutbildningar, Uppsala universitet, Uppsala universitet, 2015Conference paper (Refereed)
    Abstract [sv]

    Studiestrategier påverkar vad studenter får ut av sin utbildning. Vi har genomfört enkätstudier (ASSIST och RSPQ) för att mäta strategierna hos civilingenjörsstudenter på två olika program (Datateknik respektive Medicinsk teknik) på KTH. Resultaten visar att för denna tämligen homogena studentgrupp finns det inga större skillnader mellan årskurser eller program, men studenter med ytinriktad studiestrategi kommer efter eller hoppar av i större utsträckning än andra. Eftersom det åtminstone går att normalisera studiestrategier är det viktigt att arbeta för att normen är konstruktiv, det vill säga minska inslaget av ytinriktade strategier. De bägge instrumenten korrelerar runt 0,5 med varandra och enstaka frågor går att ifrågasätta, varför tolkningar av enstaka mätningar bör göras med försiktighet. 

  • 308. Börsbo, Björn
    et al.
    Peolsson, Michael
    KTH, School of Technology and Health (STH), Centres, Centre for Technology in Medicine and Health, CTMH.
    Gerdle, Björn
    Catastrophizing, depression, and pain: Correlation with and influence on quality of life and health - A study of chronic whiplash-associated disorders2008In: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 40, no 7, p. 562-569Article in journal (Refereed)
    Abstract [en]

    Objective: The aims of this study were: (i) to classify subgroups according to the degree of pain intensity, depression, and catastrophizing, and investigate distribution in a group of patients with chronic whiplash-associated disorders; and (h) to investigate how these subgroups were distributed and inter-related multivariately with respect to consequences such as health and quality of life outcome measures. Design: Descriptive cross-sectional study. Patients: A total of 275 consecutive chronic pain patients with whiplash-associated disorders who were referred to a university hospital. Methods: The following data were obtained by means of self-report questionnaires: pain intensity in neck and shoulders, background history, Beck Depression Inventory, the catastrophizing scale of Coping Strategy Questionnaire, Life Satisfaction Checklist, the SF-36 Health Survey, and the EuroQol. Results: Principal component analysis was used to recognize subgroups according to the degree of pain intensity, depression, and catastrophizing. These subgroups have specific characteristics according to perceived health and quality of life, and the degree of depression appears to be the most important influencing factor. Conclusion: From a clinical point of view, these findings indicate that it is important to assess patients for intensity of pain, depression, and catastrophizing when planning a rehabilitation programme. Such an evaluation will help individualize therapy and intervention techniques so as to optimize the efficiency of the programme.

  • 309. Börsbo, Björn
    et al.
    Peolsson, Michael
    KTH, School of Technology and Health (STH), Centres, Centre for Technology in Medicine and Health, CTMH.
    Gerdle, Björn
    The complex interplay between pain intensity, depression, anxiety and catastrophising with respect to quality of life and disability2009In: Disability and Rehabilitation, ISSN 0963-8288, E-ISSN 1464-5165, Vol. 31, no 19, p. 1605-1613Article in journal (Refereed)
    Abstract [en]

    Purpose. To identify subgroups of patients with chronic pain based on the occurrence of depression, anxiety and catastrophising and the duration of pain and pain intensity. In addition to this, the relationship between the subgroups with respect to background variables, diagnosis, pain-related disability and perceived quality of life are investigated. Methods. This study used 433 patients with chronic pain including 47 patients with spinal cord injury-related pain, 150 with chronic whiplash associated disorders and 236 with fibromyalgia. The participants answered a postal questionnaire that provided background data, pain intensity and duration and psychological and health-related items. Results. On the basis of depression, anxiety, catastrophising, pain intensity and duration, we identified subgroups of patients with chronic pain that differed with respect to perceived quality of life, disability and diagnosis. The psychological factors, especially depression, significantly influenced perceived quality of life and disability. Pain intensity and duration play a minor role with respect to quality of life, although pain intensity is associated to perceived disability. Conclusions. The results of this study highlight the importance of not looking at patients with chronic pain as a homogenous entity. A detailed assessment, including psychological factors with emphasis on depressive symptoms, might be essential for planning and carrying through treatment and rehabilitation.

  • 310. Börösund, E
    et al.
    Ekstedt, Mirjam
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Patient-centered care challenges nurses´professional role: Experiences of using an interactive tailored patient assessment tool in clinical practice2013In: The 10th Nordic Conference on Advances in Health Care Sciences Research, 2013Conference paper (Refereed)
  • 311. Børøsund, E.
    et al.
    Cvancarova, M.
    Moore, S. M.
    Ekstedt, Mirjam
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Ruland, C. M.
    Comparing effects in regular practice of e-communication and web-based self-management support among breast cancer patients: Preliminary results from a randomized controlled trial2014In: Journal of Medical Internet Research, ISSN 1438-8871, E-ISSN 1438-8871, Vol. 16, no 12, article id e295Article in journal (Refereed)
    Abstract [en]

    Background: While Web-based interventions have been shown to assist a wide range of patients successfully in managing their illness, few studies have examined the relative contribution of different Web-based components to improve outcomes. Further efficacy trials are needed to test the effects of Web support when offered as a part of routine care. Objective: Our aim was to compare in regular care the effects of (1) an Internet-based patient provider communication service (IPPC), (2) WebChoice, a Web-based illness management system for breast cancer patients (IPPC included), and (3) usual care on symptom distress, anxiety, depression, (primary outcomes), and self-efficacy (secondary outcome). This study reports preliminary findings from 6 months' follow-up data in a 12-month trial. Methods: We recruited 167 patients recently diagnosed with breast cancer and undergoing treatment from three Norwegian hospitals. The nurse-administered IPPC allowed patients to send secure e-messages to and receive e-messages from health care personnel at the hospital where they were treated. In addition to the IPPC, WebChoice contains components for symptom monitoring, tailored information and self-management support, a diary, and communication with other patients. A total of 20 care providers (11 nurses, 6 physicians, and 3 social workers) were trained to answer questions from patients. Outcomes were measured with questionnaires at study entry and at study months 2, 4, and 6. Linear mixed models for repeated measures were fitted to compare effects on outcomes over time. Results: Patients were randomly assigned to the WebChoice group (n=64), the IPPC group (n=45), or the usual care group (n=58). Response rates to questionnaires were 73.7% (123/167) at 2 months, 65.9 (110/167) at 4 months, and 62.3% (104/167) at 6 months. Attrition was similar in all study groups. Among those with access to WebChoice, 64% (41/64) logged on more than once and 39% (25/64) sent e-messages to care providers. In the IPPC group, 40% (18/45) sent e-messages. Linear mixed models analyses revealed that the WebChoice group reported significantly lower symptom distress (mean difference 0.16, 95% CI 0.06-0.25, P=.001), anxiety (mean difference 0.79, 95% CI 0.09-1.49, P=.03), and depression (mean difference 0.79, 95% CI 0.09-1.49, P=.03) compared with the usual care group. The IPPC group reported significant lower depression scores compared with the usual care group (mean difference 0.69, 95% CI 0.05-1.32, P=.03), but no differences were observed for symptom distress or anxiety. No significant differences in self-efficacy were found among the study groups. Conclusions: In spite of practice variations and moderate use of the interventions, our results suggest that offering Web support as part of regular care can be a powerful tool to help patients manage their illness. Our finding that a nurse-administered IPPC alone can significantly reduce depression is particularly promising. However, the multicomponent intervention WebChoice had additional positive effects.

  • 312.
    Børøsund, Elin
    et al.
    Oslo University Hospital.
    Cvancarova, Milada
    Oslo University Hospital.
    Ekstedt, Mirjam
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Moore, Shirley M
    Ruland, Cornelia
    Oslo University Hospital.
    How user characteristics affect use patterns in web-based illness management support for patients with breast and prostate cancer.2013In: Journal of medical Internet research, ISSN 1438-8871, Vol. 15, no 3, p. e34-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Frequently eHealth applications are not used as intended and they have high attrition rates; therefore, a better understanding of patients' need for support is warranted. Specifically, more research is needed to identify which system components target different patient groups and under what conditions.

    OBJECTIVE: To explore user characteristics associated with the use of different system components of a Web-based illness management support system for cancer patients (WebChoice).

    METHODS: For this secondary post hoc analysis of a large randomized controlled trial (RCT), in which WebChoice was tested among 325 breast cancer and prostate cancer patients who were followed with repeated measures for 1 year, usage patterns of 162 cancer patients in the intervention arm with access to WebChoice were extracted from the user log. Logistic regression was performed to identify patterns of associations between system use and patient characteristics. Latent class analyses (LCA) were performed to identify associations among the use of different system components and levels of social support, symptom distress, depression, self-efficacy, and health-related quality of life.

    RESULTS: Approximately two-thirds (103/162, 63.6%) of the patients logged on to WebChoice more than once, and were defined as users. A high level of computer experience (odds ratio [OR] 3.77, 95% CI 1.20-11.91) and not having other illnesses in addition to cancer (OR 2.10, 95% CI 1.02-4.34) increased the overall probability of using WebChoice. LCA showed that both men with prostate cancer and women with breast cancer who had low scores on social support accompanied with high levels of symptom distress and high levels of depression were more likely to use the e-message component. For men with prostate cancer, these variables were also associated with high use of the self-management advice component. We found important differences between men with prostate cancer and women with breast cancer when associations between WebChoice use and each user characteristic were analyzed separately. High use of all components was associated with low levels of social support among women with breast cancer, but not among men with prostate cancer. High use of e-messages, advice, and the discussion forum were associated with high levels of depression among women with breast cancer, but not among men with prostate cancer. For men with prostate cancer (but not women with breast cancer), high use of symptom assessments, advice, and the discussion forum were associated with high levels of symptom distress. However, it is unclear whether these findings can be attributed to differences related to diagnosis, gender, or both.

    CONCLUSIONS: This study provides evidence that different user characteristics are associated with different use patterns. Such information is crucial to target Web-based support systems to different patient groups. LCA is a useful technique to identify subgroups of users. In our study, e-messages and self-management advice were highly used components for patients who had low levels of social support and high illness burden, suggesting that patients with these characteristics may find such tools particularly useful.

  • 313. Børøsund, Elin
    et al.
    Ruland, Cornelia M
    Moore, Shirley
    Ekstedt, Mirjam
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Nurses' experiences of using an interactive tailored patient assessment tool one year past implementation2013In: International Journal of Medical Informatics, ISSN 1386-5056, E-ISSN 1872-8243, Vol. 83, no 7, p. E23-E34Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Despite evidence of benefits, integration of patient-centered communication in clinical practice is challenging. Interactive tailored patient assessment (ITPA) tools can contribute to a more patient-centered care approach. However, little research has examined the impact of such tools on nursing care once they have been implemented.

    OBJECTIVE: To explore nurses' experiences of the benefits of and barriers to using an ITPA called Choice, in cancer care one year after its implementation.

    METHODS: This investigation is a part of a larger study examining the use of Choice in cancer care. Four focus group interviews were conducted with 20 nurses experienced in using the Choice application. The data were analyzed using qualitative content analysis.

    RESULTS: Three themes and nine sub-themes emerged: (1) "Choice as facilitator for shared understanding and engagement in patients' own care," with three sub-themes: preparing both patient and nurse for communication, shared engagement in care planning, and giving the patients a voice; (2) "enhancing the patients' strengths," with two sub-themes: releasing patient's internal strengths and confirming "normalcy" for the patient; and (3) "new challenges for the nurse," with four sub-themes: organizational challenges, interactions with technology, a need for training in communication skills, and new ethical challenges.

    CONCLUSIONS: Findings suggest that, from nurses' perspectives, integration of ITPAs such as Choice in clinical practice offers many benefits that can contribute to patient-centered care. However, to reap these benefits, use of such tools must receive equal priority as other routines, and require sufficient time, space and competence. Choice also challenged nurses' professional roles and created dilemmas such as nurses' ambivalence regarding patients' levels of disclosure of sensitive issues and the nurses' ability to respond to them. Although patient-centered care is advocated as model for good clinical practice, this is not always internalized. Tools such as Choice may help to make such a shift happen.

  • 314. Caceres, L.
    et al.
    Lepailleur, A.
    Sorlin, O.
    Stanoiu, M.
    Sohler, D.
    Dombradi, Zs.
    Bogner, S. K.
    Brown, B. A.
    Hergert, H.
    Holt, J. D.
    Schwenk, A.
    Azaiez, F.
    Bastin, B.
    Borcea, C.
    Borcea, R.
    Bourgeois, C.
    Elekes, Z.
    Fueloep, Zs.
    Grevy, S.
    Gaudefroy, L.
    Grinyer, G. F.
    Guillemaud-Mueller, D.
    Ibrahim, F.
    Kerek, Andras
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine.
    Krasznahorkay, A.
    Lewitowicz, M.
    Lukyanov, S. M.
    Mrazek, J.
    Negoita, F.
    de Oliveira, F.
    Penionzhkevich, Yu. -E.
    Podolyak, Zs.
    Porquet, M. G.
    Rotaru, F.
    Roussel-Chomaz, P.
    Saint-Laurent, M. G.
    Savajols, H.
    Sletten, G.
    Thomas, J. C.
    Timar, J.
    Timis, C.
    Vajta, Zs.
    Nuclear structure studies of F-242015In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 92, no 1, article id 014327Article in journal (Refereed)
    Abstract [en]

    The structure of the F-24 nucleus has been studied at GANIL using the beta decay of O-24 and the in-beam.-ray spectroscopy from the fragmentation of Na-27,Na-28, Ne-25,Ne-26, and Mg-29,Mg-30 nuclei. Combining these complementary experimental techniques, the level scheme of F-24 has been constructed up to 3.6 MeV by means of particle-gamma and particle-gamma gamma coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces. Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned.

  • 315.
    Callerström, Emma
    KTH, School of Technology and Health (STH).
    Clinicians' demands on monitoring support in an Intensive Care Unit: A pilot study, at Capio S:t Görans Hospital2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Patients treated at intensive care units (ICUs) are failing in one or several organs and requireappropriate monitoring and treatment in order to maintain a meaningful life. Today clinicians inintensive care units (ICUs) manage a large amount of data generated from monitoring devices.The monitoring parameters can either be noted down manually on a monitoring sheet or, for some parameters, transferred automatically to storage. In both cases the information is stored withthe aim to support clinicians throughout the intensive care and be easily accessible. Patient datamanagement systems (PDMSs) facilitate ICUs to retrieve and integrate data. Before managinga new configuration of patient data system, it is required that the ICU makes careful analysis ofwhat data desired to be registered. This pilot study provides knowledge of how the monitoringis performed in an Intensive Care Unit in an emergency hospital in Stockholm.The aim of this thesis project was to collect data about what the clinicians require and whatequipment they use today for monitoring. Requirement elicitation is a technique to collectrequirements. Methods used to collect data were active observations and qualitative interviews.Patterns have been found about what the assistant nurses, nurses and physicians’ require of systems supporting the clinician’s with monitoring parameters. Assistant nurses would like tobe released from tasks of taking notes manually. They also question the need for atomized datacollection since they are present observing the patient bed-side. Nurses describe a demanding burden of care and no more activities increasing that burden of care is required. Physicians require support in order to see how an intervention leads to a certain result for individual patients.The results also show that there is information about decision support but no easy way to applythem, better than the ones used today. Clinicians state that there is a need to be able to evaluatethe clinical work with the help of monitoring parameters. The results provide knowledge about which areas the clinicians needs are not supported enough by the exciting tools.To conclude results show that depending on what profession and experience the clinicians have the demands on monitoring support di↵ers. Monitoring at the ICU is performed while observing individual patients, parameters from medical devices, results from medical tests and physical examinations. Information from all these sources is considered by the clinicians and is desired to be supported accordingly before clinicians commit to action resulting in certain treatment,diagnosis and/or care.

  • 316.
    Callert Jakobsson, Helene
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Rätt från början: Att verka för användbara och tillgängliga lokaler inom hälso- och sjukvård2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Occupational injuries are a problem in healthcare in Sweden. Both occupational accidents and most of all occupational diseases caused by great physical workloads constitute a large proportion of work related musculoskeletal disorders (MSD) of healthcare professionals. The aim of the study was to explore and describe the work process in the design teams of the building design process. The main focus was the building design process of health care buildings and the design teams where ergonomists and safety engineers are asked to participate. The purpose was to create a knowledge base consisting of this study and an appendix with methods and relevant literature. Eight people with different professions were interview. All of them had a good hold on the building design processes and on hospital architecture issues. Among them there were two ergonomists and two safety engineers. The result indicates that ergonomists and safety engineers were those who possessed the knowledge of working environment factors such as ergonomics in the building design processes. The methodology was to follow the agreed plan for the building design process established by the project Manager. Moreover the role of the ergonomists and safety engineers in the design team was to coach and supervise particularly the healthcare professionals. The main approach was to create a good dialogue and conversation and to keep a solution-oriented approach in the design team. Furthermore the most important method was to visualize drawings of Architects which made it possible for the healthcare workers to be able to audit the drawings correctly. This procedure gave the healthcare professionals a decision-making support which helped them to make well-reasoned decisions about their future work environment. The conclusion indicates that ergonomists and safety engineers are important because of their unique knowledge of working environment, especially ergonomics. Ergonomists and safety engineers need to be involved in the early phases of the building design process in order to be able to influence the design of new workspaces. The participation of these two professions in the design team may also benefit the healthcare workers with a future work environment which is largely designed according to their requirements and needs and will probably help to prevent MSDs. In the future there is a need for a specific education just for the ergonomists and the safety engineers participating in the building design process of healthcare buildings. There are great opportunities for them to develop their role towards a more prominent one in the building design process.

    Keywords: Ergonomists, safety engineers, building design process, health care architecture, methods, procedures

  • 317.
    Camling, Johan
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lönnegren, Fredrik
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Karttillämpningar för rikstäckande accessnät2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the process of analyzing and evaluating geographic services, and the development of map applications for nationwide networks. The project was performed at DGC, a datacommunications-, telephony- and networks operator which distributes customer access across Sweden where consumers are connected to the backbone network. In whole, the task consisted of an analysis regarding the possibilities of address-to-coordinate lookup for established customer sites, displaying the access network in a map interface and developing one or more tools, aimed at supporting order processes. Architecture patterns, use-cases construed from user requests and analysis of external provider services for geocoding determined the design of the solution. Software was partially integrated in existing systems, and partially distributed as stand-alone applications. The product was finalized with a release. Read further to get a description of the monitoring tool, network mapping with KML, dealing with geographic data, and also the process of fetching coordinates for addresses.

  • 318. Campo, A. B.
    et al.
    Dirckx, J. J.
    Widman, Erik
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Waz, A. T.
    Dudzik, G.
    Abramski, K. M.
    Application of a new four-channel vibrometer for determination of atherosclerosis: Further advances towards a handheld device2016In: 2016 IEEE International Symposium on Medical Measurements and Applications, MeMeA 2016 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2016Conference paper (Refereed)
    Abstract [en]

    Cardiovascular diseases (CD) are the leading cause of death worldwide and their prevalence is expected to rise. Important in the etiology of CD is the stiffening of the large arteries (arteriosclerosis) and plaque formation (atherosclerosis) in the common carotid artery (CCA). Increasing evidence shows that both arteriosclerosis and atherosclerosis can be detected by assessing pulse wave velocity (PWV) in the CCA, and several techniques focus on the detection of PWV in this structure. In previous studies, laser Doppler vibrometry (LDV) was proposed as an approach to detect arterial stiffness. In the present work, a compact four-channel LDV system is introduced for PWV detection. Four phantom arteries were assessed mimicking real life cardiovascular pathologies. Due to the high sensitivity and the increased spatial and temporal resolution of the LDV system, PWV could be assessed, and even local changes in phantom architecture could be detected. The system could potentially be used to detect arteriosclerosis and arterial plaque during cardiovascular screening.

  • 319. Capece, Sabrina
    et al.
    Chiessi, Ester
    Cavalli, Roberta
    Giustetto, Pierangela
    Grishenkov, Dmitry
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Paradossi, Gaio
    A general strategy for obtaining biodegradable polymer shelled microbubbles as theranostic devices2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 51, p. 5763-5765Article in journal (Refereed)
    Abstract [en]

    Fabrication of multifunctional ultrasound contrast agents (UCAs) has been recently addressed by several research groups. A versatile strategy for the synthesis of UCA precursors in the form of biodegradable vesicles with a biocompatible crosslinked polymer shell is described. Upon ultrasound irradiation, acoustic droplet vaporization transforms such particles into microbubbles behaving as UCAs. This proof of concept entails the features of a potential theranostic microdevice.

  • 320. Capese, Sabrina
    et al.
    Chiessi, E.
    Cavalli, R.
    Giustetto, P.
    Grishenkov, Dmitry
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Paradossi, Gaio
    Diapartimento di Chimica, Università di Roma Tor Vergata.
    A general strategy for the obtainment of biodegradable polymer shelled microbubbles as theranostic device2013Conference paper (Refereed)
    Abstract [en]

    Introduction

    Fabrication of multifunctional ultrasound contrast agents (UCAs) has been addressed by many research groups.1,2 Recently a poly(vinyl alcohol) shelled microbubble 3 has shown a remarkable chemical and physical stability and versatility for the surface functionalization, leading to a platform for multimodality imaging (ultrasounds, magnetic resonance, single photon emission computer tomography) and targeting inflammation and tumours4. In this contribution we present a new strategy for the synthesis of UCAs precursors in the form of vesicles with a biodegradable crosslinked polymer shell.

    Methods

    Deposition of methacryloyl-derivative of hydrophilic and biodegradable polymers as dextran (DexMA50) or hyaluronic acid (HAMA30) on a lipid vesicle with a liquid perfluoropentane core, 5,6 followed by a photopolymerization of the methacrylate moiety allows the obtainment of polymer shelled vesicles.

    Results

    Lipid shelled vesicles with a perfluorocarbon (PFC) core (Figure 1a) undergo an acoustic droplet vaporization (ADV),7 upon ultrasounds (US) irradiation, transforming such particles into ultrasound effective microbubbles (Fig 1b). The process is reversible as the US are switched off (Fig 1c). In the “microbubble” state, i.e. during US irradiation, the system is echogenic at low mechanical index, allowing their use as UCAs. In this contribution we show that additional functions can be implemented into the microbubbles. For example, we demonstrated the possibility to obtain shells with a thermoreversible behaviour.

    Conclusions

    This new class of polymer shelled vesicles/microbubbles entails features desired in a potential theranostic microdevice.

  • 321.
    Carlid, Olle
    et al.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB. KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Hjelm, Mats
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Arbetsmetodik för att minska vattenfotavtrycket: Exemplet Ornö, Haninge2010Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    In today's society is a large shipment of virtual water between countries in the world. Virtual water refers to all the water consumed to produce a product. From this standpoint, Sweden is importing virtual water from Brazil when we import coffee. Hoekstra and Chapagain have calculated that one cup of coffee contains 140 liters of virtual water. This water is all the freshwater that is consumed in Brazil to grow, package and carry the goods to Sweden. Fresh water is something that exists in limited quantities. In Sweden we have plenty of fresh water, but many of the countries we are importing virtual water from there is a shortages of fresh water. As an example, Sweden is importing large quantities of virtual water from countries like Germany, Spain and India, which today consumes between 40-50% of their renewable water resources. With an increased population and as the temperature increases, this consumption is going to be problematic.

    In order to analyze how much fresh water is actually needed in a country, territory, region or similar Arjen Y. Hoekstra introduced the water footprint concept in year 2002. Water footprint is defined as the volume of water that goes in to producing the products and services consumed in that area. The water footprint is divided into two parts, internal and external water footprint. With the internal water footprint means the total volume of water used by the domestic water in the national economy, minus the virtual water exported to other areas. The external water footprint is defined as the annual volume of water used in other countries to produce the goods consumed in the area and is the part that this degree thesis will be focused on.

    Sweden's total water footprint is estimated to 2150 m

    3/inhabitants/year, this can be taken in relation to the global average, which is 1564 m3

    /inhab/year. Daily the average Swede consumes an average of 5890 liters of water/person/day. 4240 liters of this (72 %) is related to agricultural products, 1320 liters (22.4 %) for industrial products and only 330 liters (5.6 %) water used in the household.

    The purpose of this degree thesis is to develop a methodology for identifying the products that cause a large external water footprint for a local community, how this society affects global water consumption in the form of virtual water and how it can be reduced. The methodology is a step-by-step approach and is divided into four phases. Phase 1. Delimit the study area, Phase 2. Identify the water footprint, Phase 3. Planning measures to reduce external water footprint, Phase 4. Analyze the results. The methodology describes what to think about, what is missing and how to calculate when you want to calculate a local society's external water footprint. The degree thesis is using Ornö as an example to apply the presented methodology on.

    Our example, Ornö, is an island in the Stockholm archipelago. The island which is located in Haninge municipality is sparsely populated, 5.7 inhabitants per square kilometer, compared to iv

    Sweden as a country, which has 22.8 inv/km

    2

    . This means that there is much access to fresh water and good farming opportunities on the island.

    The degree thesis identifies 17 agricultural products that accounts for 60 % of Sweden's external water footprint. Of these 17 products coffee is the individual crop, which accounts for the bulk of Sweden's external water footprint, 16.3 %. In addition to coffee, meat products accounts for about 16 % of the footprint. All of these 17 products are not products that can be replaced with local production. Because of the Swedish climate not all crops are fit to grow there, such as coffee. However, the study shows that 35% of the external water footprint can be replaced with local production.

    To make a study, at a local community, it is above all statistics and data on consumption in the current society that is missing. To overcome this, we see two main solutions. The first is through a detailed survey that produces what people in the society consume in detail. A second solution could be that the Statistiska centralbyrån (SCB), or a similar organization, did a survey on what people in the country with different incomes, ages or other groupings are consuming. In order to transfer it back to the residents in the local community

  • 322.
    Carlquist, Olle
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Boström Leijon, Santos
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Implikat: A System for Categorizing Products using Implicit Feedback on a Website2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Implicit feedback is a form a relevance feedback that is inferred from how users interact with an information retrieval system such as an online search engine. This degree project report describes a method of using implicit feedback to establish relevance judgments and rank products based on their relevance to a specified attribute. The report contains an overview of the benefits and limitations of implicit feedback, as well as a description on how those limitations can be mitigated.

    A prototype that interpreted user actions as relevance votes and calculat-ed a fair relevance score based on these votes with the help of an algo-rithm was developed. This system was then tested on a website with real users during a limited period of time. The results from the test period were evaluated and the system was concluded to be far from perfect, but that improvements could be made by making adjustments to the algo-rithm. The system performed better when looking at the algorithm’s pre-cision rather than its sensitivity.

  • 323. Carlsson, Lars
    et al.
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Laaksonen, Marko S.
    Berglund, Bo
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Holmberg, Hans-Christer
    Enhanced systolic myocardial function in elite endurance athletes during combined arm-and-leg exercise2011In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 111, no 6, p. 905-913Article in journal (Refereed)
    Abstract [en]

    The aim here was to employ color tissue velocity imaging (TVI), to test the hypothesis that highly trained endurance athletes exhibit enhanced systolic function of the left ventricular (LV) myocardium both at rest and during combined arm-and-leg exercise in comparison with untrained subjects. For each of the ten elite male (EG) and ten matched control participants (CG), LV dimensions and systolic function were assessed at rest using echocardiography. Subsequently, these subjects exercised continuously on a combined arm-and-leg cycle ergometer for 3 min each at 50, 60, 70, 80, 90 and 100% of VO2max. Oxygen uptake, heart rate, systolic blood pressure (SBP) and peak contraction systolic velocities of the LV myocardium (PSV) were recorded in the end of each level. At rest, the trained and untrained groups differed with respect to LV dimensions, but not systolic function. At 60-100% VO2max, the EG group demonstrated both higher PSV and SBP. The observation that the EG athletes had higher PSV than CG during exercise at 60-100% VO2max, but not at rest or at 50% of VO2max, suggested an enhanced systolic capacity. This improvement is likely to be due to an enhanced inotropic contractility, which only becomes apparent during exercise.

  • 324.
    Carlsson, Tor
    KTH, School of Technology and Health (STH).
    Individualized Motion Monitoring by Wearable Sensor: Pre-impact fall detection using SVM and sensor fusion2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Among the elderly, falling represents a major threat to the individual health, and is considered as a major source of morbidity and mortality. In Sweden alone, three elderly are lost each day in accidents related to falling. The elderly who survive the fall are likely to be suffering from decreased quality of life. As the percentage of elderly increase in the population worldwide, the need for preventive methods and tools will grow drastically in order to deal with the increasing health-care costs. This report is the result of a conceptual study where an algorithm for individualized motion monitoring and pre-impact fall detection is developed. The algorithm learns the normal state of the wearer in order to detect anomalous events such as a fall. Furthermore, this report presents the requirements and issues related to the implementation of such a system. The result of the study is presented as a comparison between the individualized system and a more generalized fall detection system. The conclusion is that the presented type of algorithm is capable of learning the user behaviour and is able to detect a fall before the user impacts the ground, with a mean lead time of 301ms.

  • 325.
    Carlsson-Kanyama, Annika
    et al.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Thunqvist, Eva-Lotta
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB. KTH, School of Technology and Health (STH), Health Systems Engineering.
    Larsson, Tore J
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Odla under tak i eller nära bostaden2014Report (Other academic)
    Abstract [en]

    Within a project called “The sustainable greenhouse as a complement to buildings” financed by the Delegation of sustainable cities in Sweden, researchers, consultants and students have during 2013 developed, tested and evaluated various solutions for cultivating under roofs in or close to dwellings. We included solutions such as cultivating a plot in a rooftop greenhouse, a circular cultivation balcony or to cultivate in one’s kitchen or living room using a fish and vegetable furniture, a green wall, a green lamp or a green frame attached to the wall. The practical trials were preceded by a literature survey that described good examples of cultivation under roofs in various cities around the world.The results show that here are many inspiring examples of cultivating under roofs in cities and that such cultivation has gained some momentum. Our practical trials show among others that urban agriculture seems challenging and appealing for many but that the solutions that we have tested seem to be too expensive and partly also too time-consuming. Those who like to cultivate do so because it is fun and they can get products of good quality. To lessen the environmental impacts are also a reason but here our results that productivity in urban farming has to be higher than in our trials in order for the products to be considered as “climate-friendly”. Growing fish at home showed to be rather unpopular and many thought that slaughtering the fish by themselves would be nasty. Others results from the project are a water cooled LED lamp built in four copies and successfully installed in a fish and vegetable production unit as well as drawings and costs estimates for a cultivation bench.Proposals for further studies include analysis of flight and nutrient requirements for cultivation under roofs in cities as well as measurements of productivity. More low cost solutions for cultivating under glass should also be developed. To expand and maintain interest and knowledge for cultivation under roofs in cities is not only important for increasing social sustainability and eventually the environmental one as well but also because of the need to enhance preparedness.

  • 326.
    Carlström, Malin
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Design for Human Behaviour and Automation: Development and Evaluation of a Holistic Warning Approach2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A human-centered approach when developing new support systems in vehicles has the potential to enable the driver to make safe decisions in the transition between manual and automatic control. However, careful considerations have to be taken. Not only would the design of the systems, in terms of interface be important, but also what kind of activities the systems support. The aim of this study was to identify an appropriate activity to support the cognitive processes for truck drivers, develop an interface for this activity, and evaluate it in driving situations. This was executed in three sub-studies: the Pre-study, the Design-study, and the Evaluation study.

    In the Pre-study, the aim was to investigate for what kind of driver-related activity distribution and long haulage truck drivers need a driver support and interface. This was investigated via contribution from truck drivers, HMI/Ergonomics experts, as well as engineers. The activity chosen to support was detecting objects around the vehicle. However, reconsiderations were made due to constrains in the simulator. Suggested by Scania’s Vehicle Ergonomics group a holistic system was chosen; an interface approach enabling for more technologies to be included within the same interface, reducing the amount of modalities a driver can be exposed to.

    The Design-study addressed the aim of designing an interface for the Holistic system with truck drivers’ cognitive workload in focus. A LED-prototype was built running along the window edges inside the cab of Shania’s Vehicle Ergonomics groups’ simulator, to create warning signal concepts. Literature findings, the LED-prototype, and the simulator were used in an iterative process to design and improve warning signal concepts, until two final concepts were created. The holistic system informs of hazards around and near the vehicle by lighting the area risky objects occurs to guide drivers’ attention and this was done either with 1) the informative display or, 2) the directional display. The Informative display conveys information of a hazard location and type, and the Directional display exclusively conveys information of the hazard location.

    The Evaluation study explored how drivers were affected by, and how they perceived, the holistic interface design regarding mental workload and hazard detection. A user simulator test was designed to collect data within the areas of ‘Event detection’, ‘Workload’, ‘Driving performance’ and ‘Subjective opinion’. Fourteen professional truck drivers assessed three conditions: 1) Baseline (driving without a system), 2) the Informative display, and, 3) the Directional display, while being exposed to potential hazards. To further increase workload, a secondary task was performed at the end of each condition.

    The results showed that the Informative display did not only result in more ‘Detection hits’, instances when a driver responded to a present hazard, but also significantly decreased reaction time to detect a hazard. However, in terms of acceptance, the two concepts were considered equally preferred. As the Informative display showed to be more efficient in terms of hazard detection, this should be investigated further. A holistic interface enables for more systems to be included within the same interface, reducing the amount of alarms and modalities drivers are exposed to if designed skillfully. Thus, more support systems can be included in future vehicles, without causing unnecessary distraction when applying a holistic interface approach.

  • 327.
    Carnevale Lon, Sergio Christian
    KTH, School of Technology and Health (STH).
    A new helmet testing method to assess potential damages in the Brain and the head due to rotational energy2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Preservation and protection of the head segment is of upmost importance due to the criticality of the functions entailed in this section of the body by the brain and the nervous system. Numerous events in daily life situations such as transportation and sports pose threats of injuries that may end or change a person’s life.

    In the European Union, statistics report that almost 4.2 million of road users are injured non-fatally, out of which 18% is represented by motorcyclist and 40% by cyclists, being head injuries 34% for bicyclists, and 24% for two-wheeled motor vehicles. Not only vehicles, are a source of injuries for the human head according to the injury report, 6,1 million people are admitted in hospitals for sports related injuries, where sports such as hockey, swimming, cycling presented head injuries up to 28%, 25% and 16% respectively (European Association for Injury Prevention and Safety Promotion, 2013). 

    According to records the vast majority of head crashes result in an oblique impact (Thibault & Gennarelli, 1985). These types of impacts are characterized for involving a rotation of the head segment which is correlated with serious head injuries. Even though there is plenty of evidence suggesting the involvement of rotational forces current helmet development standards and regulations fail to recognize their importance and account only for translational impact tests.

    This thesis contains an evaluation for a different developed method for testing oblique impacts. In consequence a new test rig was constructed with basis on a guided free fall of a helmeted dummy head striking an oblique (angled) anvil which will induce rotation.

    The results obtained are intended to be subjected to a comparison with another oblique test rig that performs experiments utilizing a movable sliding plate which when impacted induces the rotation of a dropped helmeted dummy head. The outcome will solidify the presence of rotational forces at head-anvil impact and offer an alternative testing method.

    After setting up the new test rig; experiments were conducted utilizing bicycle helmets varying the velocities before impact from 5m/s to 6m/s crashing an angled anvil of 45°. Results showed higher peak resultant values for rotational accelerations and rotational velocities in the new test rig compared to the movable plate impact test, indicating that depending on the impact situation the “Normal Force” has a direct effect on the rotational components. On the other hand a performed finite element analysis predicted that the best correlation between both methods is when the new angled anvil impact test is submitted to crashes with a velocity before impact of 6 m/s at 45° and the movable sliding impact test to a resultant velocity vector of 7,6m/s with an angle of 30° .

    In conclusion the new test method is meant to provide a comparison between two different test rigs that will undoubtedly have a part in the analysis for helmet and head safety improvements.

  • 328.
    Carniello, Vera
    KTH, School of Technology and Health (STH).
    Tailoring interactions betweendegradable polymers and proteins,exploiting nanodiamond particlesand Quartz Crystal Microbalance2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Quartz Crystal Microbalance (QCM) is a sensitive and effective technique to analyze mass changes at the interface between a solid material and a liquid environment. In this Master thesis, QCM was employed for evaluating the interactions between selected degradable polymers and nanodiamond particles (nDP), fibronectin and the growth factor BMP-2.

     

    Many parameters must be adapted to allow QCM measurements involving degradable polymers. These parameters were then tailored to allow QCM measurements with PLA, poly(LLA-co-CL), poly(TMC-D-LA) and PS.

     

    Moreover, QCM provides quantitative measurements of protein adsorption on degradable polymers. The behavior of PLA and poly(LLA-co-CL) was further evaluated and compared with respect to protein adsorption. This behavior was demonstrated to be different for the two polymers considered and to be dependent on protein concentration in solution.

     

    Eventually, exploiting QCM it was also possible to assess the relationship between nDP and the adsorption of fibronectin and BMP-2 onto PLA and poly(LLA-co-CL).

  • 329. Cecilie, V
    et al.
    Ekstedt, Mirjam
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Challenges related to the Implementation of an Informatics Intervention into Regular Clinical Practice: A leadership Perspective2012In: 33rd Annual Meeting, Society of Behavioral Medicine, 2012, 2012Conference paper (Refereed)
  • 330.
    Cederlöf, Henrik
    KTH, School of Technology and Health (STH).
    Jag ska bara...: Om attityder, beteenden och värderingar gällande personlig skyddsutrustning i byggbranschen2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna magisteruppsats undersöker vilka attityder, värderingar och beteenden som arbetsgivare och yrkesarbetare i den svenska byggbranschen har då det gäller användningen av personlig skyddsutrustning.

  • 331.
    Chang, Yongjun
    et al.
    KTH, School of Technology and Health (STH).
    Smedby, Örjan
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Effects of preprocessing in slice-level classification of interstitial lung disease based on deep convolutional networks2018In: VipIMAGE 2017: Proceedings of the VI ECCOMAS Thematic Conference on Computational Vision and Medical Image Processing Porto, Portugal, October 18-20, 2017, Springer Netherlands, 2018, Vol. 27, p. 624-629Conference paper (Refereed)
    Abstract [en]

    Several preprocessing methods are applied to the automatic classification of interstitial lung disease (ILD). The proposed methods are used for the inputs to an established convolutional neural network in order to investigate the effect of those preprocessing techniques to slice-level classification accuracy. Experimental results demonstrate that the proposed preprocessing methods and a deep learning approach outperformed the case of the original images input to deep learning without preprocessing.

  • 332.
    Charalampidis, Vasileios
    KTH, School of Technology and Health (STH).
    Real-Time Monitoring System of Sedentary Behavior with Android Wear and Cloud Computing: An office case study2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays, prolonged sitting among office workers is a widespread problem, which is highly related to several health problems. Many proposals have been reported and evaluated to address this issue. However, motivating and engaging workers to change health behavior to a healthier working life is still a challenge.

    In this project, a specific application has been deployed for real-time monitoring and alerting office workers for prolonged sitting. The proposed system consists of three distinct parts: The first one is an android smartwatch, which was used to collect sensor data e.g., accelerometer and gyro data, with a custom android wear app. The second one is an android application, which was developed to act as a gateway for receiving the smartwatch’s data and sending them to IBM Bluemix cloud with MQTT protocol. The final part is a Node-Red cloud application, which was deployed for storing, analyzing and processing of the sensor data for activity detection i.e., sitting or walking/standing. The main purpose of the last one was to return relevant feedback to the user, while combining elements from gaming contexts (gamification methods), for motivating and engaging office workers to a healthier behavior.

    The system was firstly tested for defining appropriate accelerometer thresholds to five participants (control group), and then evaluated with five different participants (treatment group), in order to analyze its reliability for prolonged sitting detection. The results showed a good precession for the detection. No confusing between sitting and walking/standing was noticed. Communication, storage and analysis of the data was successfully done, while the push notifications to the participants, for alerting or rewarding them, were always accurate and delivered on time. Every useful information was presented to the user to a web-based dashboard accessed through a smartphone, tablet or a PC.    

    The proposed system can easily be implemented at a real-life scenario with office workers. Certainly, there is a lot space for improvement, considering mostly the type of data registered at the system, the method for sitting detection, and the user interface for presenting relevant information.

  • 333.
    Chavez Alcarraz, Erick
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Moraga, Manuel
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Linked data performance in different databases: Comparison between SQL and NoSQL databases2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Meepo AB was investigating the possibility of developing a social rating and recommendation service. In a recommendation service, the user ratings are collected in a database, this data is then used in recommendation algorithms to create individual user recommendations.

    The purpose of this study was to find out which  demands are put on a DBMS, database management system, powering a recommendation service, what impact the NoSQL databases have on the performance of recommendation services compared to traditional relational databases, and which DBMS is most suited for storing the data needed to host a recommendation service.

    Five distinct NoSQL and Relational DBMS were examined, from these three candidates were chosen for a closer comparison.

    Following a study of recommendation algorithms and services, a test suite was created to compare DBMS performance in different areas using a data set of 100 million ratings.

    The results show that MongoDB had the best performance in most use cases, while Neo4j and MySQL struggled with queries spanning the whole data set.

    This paper however never compared performance for real production code. To get a better comparison, more research is needed. We recommend new performance tests for MongoDB and Neo4j using implementations of recommendation algorithms, a larger data set, and more powerful hardware.

  • 334.
    Chen, F.
    et al.
    KTH, School of Technology and Health (STH).
    Chen, P.
    Chromium-laced medical capsules detection based on hyperspectral imaging technology2016In: International Agricultural Engineering Journal, ISSN 0858-2114, Vol. 25, no 4, p. 293-302Article in journal (Refereed)
    Abstract [en]

    Medicinal gelatin hollow hard capsule has been widely used in people's daily life, but the toxic capsule event has drew public concern on its safety issue in 2012, since the casings were made with an industrial gelatin with high amounts of metal chromium. In this paper, the traditional method, atomic absorption spectrophotometer, was used for detecting medicinal gelation hollow hard capsule as a control group; then hyperspectral image was used for detecting 347 normal capsule samples and 701 toxic capsule samples, which were analyzed and discussed from different image bands and regions of interest (ROIs). At the beginning, hyperspectral processing was used for dimension reduction by Principal Component Analysis (PCA) method, and then two kinds of capsules spectral data were obtained to do qualitative analysis according to ROIs. Partial Least Squares Discriminant Analysis(PLS-DA) and Principal Component Analysis- Artificial Neural Network(PCA-ANN) were used to identify Chromium-laced capsule based on spectral data processing, of which 60% sample are used for modeling, the remaining 40% are used for predicting. In the end, we can draw a conclusion that if chosen 4 Latent Variables (LVs) as input features in the PLSDA model, high classification accuracy would be achieved, with the accuracy of 100%. The correlation coefficient of cross validation and sample prediction are 0.923 and 0.972 respectively; sensitivity and specificity are 100% as well. The result prove that it is feasible to use hyperspectral data for chromium-laced capsule qualitative analysis, the method greatly reduces the complexity of the traditional detection and try to provide a new thought in chromium detection of capsule. © 2016, Asian Association for Agricultural Engineering. All rights reserved.

  • 335.
    Chen, Feng-Nong
    et al.
    KTH, School of Technology and Health (STH). Hangzhou Dianzi Univ, Coll Life Informat Sci & Instrument Engn, Hangzhou, Zhejiang, Peoples R China..
    Chen, Pu-Lan
    Xinjiang Med Univ, Dept Econ Management, Canc Affiliated Hosp, Urumqi, Peoples R China..
    Fan, Kai
    Hangzhou Dianzi Univ, Coll Life Informat Sci & Instrument Engn, Hangzhou, Zhejiang, Peoples R China..
    Cheng, Fang
    Zhejiang Univ, Coll Biosyst Engn & Food Sci, Hangzhou, Zhejiang, Peoples R China..
    Hyperspectral Reflectance Imaging for Detecting Typical Defects of Durum Kernel Surface2018In: Intelligent Automation and Soft Computing, ISSN 1079-8587, E-ISSN 2326-005X, Vol. 24, no 2, p. 351-357Article in journal (Refereed)
    Abstract [en]

    In recent years, foodstuff quality has triggered tremendous interest and attention in our society as a series of food safety problems. The hyperspectral imaging techniques have been widely applied for foodstuff quality. In this study, we were undertaken to explore the possibility of unsound kernel detecting (Triticum durum Desf), which were defined as black germ kernels, moldy kernels and broken kernels, by selecting the best band in hyperspectral imaging system. The system possessed a wavelength in the range of 400 to 1,000 nm with neighboring bands 2.73 nm apart, acquiring images of bulk wheat samples from different wheat varieties. A series of technologies of hyperspectral imaging processing and spectral analysis were used to separate unsound kernels from sound kernels, including the Principal Component Analysis (PCA), the band ratio, the band difference and the best band. According to the selected bands, the best accuracy was 95.6, 96.7 and 98.5% for 710 black germ kernels, 627 break kernels and 1,169 healthy kernels, respectively. The result shows that the method based on the band selection was feasible.

  • 336.
    Chen, Fengnong
    et al.
    KTH, School of Technology and Health (STH). College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
    Chen, Pulan
    Muhammed, Hamed Hamid
    KTH, School of Technology and Health (STH).
    Zhang, Juan
    Intravoxel Incoherent Motion Diffusion for Identification of Breast Malignant and Benign Tumors Using Chemometrics2017In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, article id 3845409Article in journal (Refereed)
    Abstract [en]

    Theaim of the paper is to identify the breast malignant and benign lesions using the features of apparent diffusion coefficient (ADC), perfusion fraction f, pseudodiffusion coefficient D*, and true diffusion coefficient D from intravoxel incoherent motion (IVIM). There are 69 malignant cases (including 9 early malignant cases) and 35 benign breast cases who underwent diffusion-weighted MRI at 3.0 T with 8 b-values (0 similar to 1000 s/mm(2)). ADC and IVIM parameters were determined in lesions. The early malignant cases are used as advanced malignant and benign tumors, respectively, so as to assess the effectiveness on the result. A predictive model was constructed using Support VectorMachine Binary Classification (SVMBC, also known Support VectorMachine Discriminant Analysis (SVMDA)) and Partial Least Squares Discriminant Analysis (PLSDA) and compared the difference between them both. The.. value and ADC provide accurate identification of malignant lesions with.. = 300, if early malignant tumor was considered as advanced malignant (cancer). The classification accuracy is 93.5% for cross-validation using SVMBC with ADC and tissue diffusivity only. The sensitivity and specificity are 100% and 87.0%, respectively, r(2) (cv) = 0.8163, and root mean square error of cross-validation (RMSECV) is 0.043. ADC and IVIM provide quantitative measurement of tissue diffusivity for cellularity and are helpful with the method of SVMBC, getting comprehensive and complementary information for differentiation between benign and malignant breast lesions.

  • 337. Chen, Gefei
    et al.
    Abelein, Axel
    Nilsson, Harriet E.
    KTH, School of Technology and Health (STH), Medical Engineering, Structural Biotechnology.
    Leppert, Axel
    Andrade-Talavera, Yuniesky
    Tambaro, Simone
    Hemmingsson, Lovisa
    Roshan, Firoz
    Landreh, Michael
    Biverstal, Henrik
    Koeck, Philip J. B.
    KTH, School of Technology and Health (STH), Medical Engineering, Structural Biotechnology.
    Presto, Jenny
    Hebert, Hans
    Fisahn, Andre
    Johansson, Jan
    Bri2 BRICHOS client specificity and chaperone activity are governed by assembly state2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, article id 2081Article in journal (Refereed)
    Abstract [en]

    . Protein misfolding and aggregation is increasingly being recognized as a cause of disease. In Alzheimer's disease the amyloid-beta peptide (A beta) misfolds into neurotoxic oligomers and assembles into amyloid fibrils. The Bri2 protein associated with Familial British and Danish dementias contains a BRICHOS domain, which reduces A beta fibrillization as well as neurotoxicity in vitro and in a Drosophila model, but also rescues proteins from irreversible nonfibrillar aggregation. How these different activities are mediated is not known. Here we show that Bri2 BRICHOS monomers potently prevent neuronal network toxicity of A beta, while dimers strongly suppress A beta fibril formation. The dimers assemble into high-molecular-weight oligomers with an apparent two-fold symmetry, which are efficient inhibitors of non-fibrillar protein aggregation. These results indicate that Bri2 BRICHOS affects qualitatively different aspects of protein misfolding and toxicity via different quaternary structures, suggesting a means to generate molecular chaperone diversity.

  • 338.
    Chen, Hongjian
    KTH, School of Technology and Health (STH).
    Towards the Development of the Dual Modal Contrast Agent for Computed Tomography and Ultrasound2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays hybrid imaging modalities are new trends in medical imaging. To improve the diagnostic outcome of hybrid imaging, multimodal contrast agents need to be developed. For example, hybrid contrast agents for computer tomography and ultrasound (CACTUS) are one of those desirable hybrid contrast agents for the modern medical imaging.

    Polyvinyl alcohol (PVA) micro-bubbles (MBs) are one of the latest generations of ultrasound contrast agents (UCAs). PVA MBs are more stable and offer longer circulation and on-shelf storage time compare to other UCAs. However, the current use as contrast agent is limited only to ultrasound imaging.

    In this project, we fabricated and characterized hybrid contrast agents based on PVA MBs.

    Two methods for developing hybrid contrast agents were proposed. The first method is to combine MBs, currently used as an ultrasound contrast agent, with gold nanoparticles that are used as a preclinical contrast agent for computer tomography (CT). The second method is to determine at which concentration plain MBs suspension has both considerable negative contrast in CT and enhancement of the backscattered signal in ultrasound imaging.

    Both methods were evaluated and optimized. A scenario to achieve promising hybrid contrast agent was described in this report.

  • 339.
    Chen, Zhongze
    KTH, School of Technology and Health (STH), Medical Engineering.
    Assessment of Ultrasound Field Properties and the Potential Effects on Cells2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Ultrasound is regarded a convenient and safe tool to acquire diagnostic information that we need for clinical use. For a long time ultrasound has been counted as a harmless method, but after all, there is a heating and a me-chanical impact by ultrasound exposure. This influence can reveal both positive (e.g., cell plant growth) and negative (e.g. cell death) effects. Acoustic exposure pattern changed drastically in recent years due to the rapid, technological developments in ultrasound imaging. Ultrasound imaging has become more sophisticated and new techniques are becoming more common, bringing with them not only increased diagnostic capabilities, but also potential threats as far as safety considerations are concerned. The goal of the thesis project is to analyze the ultrasound field characteristics, based on which research would be achievable in the future about how cells are affected by ultrasound exposure with different basic parameters. These parameters include excitation pressure amplitude, number of cycles in a pulse (n), pulse repetition frequency (PRF), acoustic working frequency (f), phase of ultrasound, shape of ultrasound wave (window mode). Some pilot cell experiments are also done in this project.

    Ultrasound-induced bioeffects on cells have been studied by many scientists, and some experiments tell us that ultrasound beams may cause serious mechanical and thermal damage on e.g. cells. Two general indices, the thermal index (TI) the mechanical index (MI) reflect information on the output level of the ultrasound machine and how a change in output would affect the likelihood of inducing a biological effect. Besides these two indices, other six parameters also are valuable to help us understand the potential threat of ultrasound applications. These parameters are peak negative pressure, peak positive pressure, spatial peak temporal peak intensity (Isptp), spatial peak temporal average intensity (Ispta), spatial peak pulse average intensity (Isppa) and output power of transducer (Wo). The above mentioned eight parameters are important in analyzing the acoustic beams.

    During the first phase of the experiment (acquisition of ultrasound field parameters) a hydrophone was put at the focus point of the ultrasound beam to acquire the time domain waveform signal of the ultrasound waves. By setting up f, PRF, n, phase and window mode into the computer controlled pulser (SNAP system, Ritec Inc), dif-ferent beams were sent to the hydrophone. Different combinations of basic parameters lead to 186 sets of acoustic beams. We used the hydrophone and oscilloscope to record the waveform signal respectively. Then by self-designed MATLAB software (Mathematical Computing Software, MATLAB®, Natick, Massachusetts, United States), the desired eight characteristics of acoustic field were calculated.

    Human chronic myelogenous leukemia cell line (K562) were exposed to defined ultrasound waves in the second phase of the experiment. Both trypan blue and resazurin viability assays were used to evaluate effect on the cells immediately after the exposure and 24 hours after the exposure. Resazurin viability assay conducted immediately after the exposure showed reduction of the cell viability up to 46% when the attenuation of amplitude is 0 dB (i.e. the output is the biggest). No cell death was induced. It also showed that after 24 hours the cells viability partially recovered to about 85%. Trypan blue assay showed nearly no cell death was induced.

  • 340.
    Cheng, Kimberley
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Single-particle cryo-electron microscopy of macromolecular assemblies2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, single-particle cryo-electron microscopy (cryo-EM) was used to study the structure of three macromolecular assemblies: the two hemocyanin isoforms from Rapana thomasiana, the Pyrococcus furiosus chaperonin, and the ribosome from Escherichia coli.

    Hemocyanins are large respiratory proteins in arthropods and molluscs. Most molluscan hemocyanins exist as two distinct isoforms composed of related polypeptides. In most species the two isoforms differ in terms of their oligomeric stability, and thus we set out to investigate the two Rapana thomasiana hemocyanins (RtH) in order to explain this behaviour. Our findings showed that the two RtHio forms are identical at the experimental resolution. Furthermore, three previously unreported connections that most likely contribute to the oligomeric stability were identified.

    Chaperonins are double-ring protein complexes that assist the folding process of nascent, non-native polypeptide chains. The chaperonin from the hyperthermophilic archaea Pyrococcus furiosus belongs to Group II chaperonins, and unlike most othergroup II chaperonins it appears to be homo-oligomeric. The 3D reconstruction of the Pyrococcus furiousus chaperonin revealed a di-octameric structure in a partially closed/open state, something in between the closed folding-active state and the open substrate-accepting state.

    The ribosome is the molecular machine where protein synthesis takes place. In bacteria there is a unique RNA molecule called transfer-messenger RNA (tmRNA) that together with its helper protein SmpB rescues ribosomes trapped on defective messenger RNAs (mRNAs) through a process called trans-translation. tmRNA is about 4 times the size of a normal tRNA, and it is composed of a tRNA-like domain (TLD) that is connected to the mRNA-like domain (MLD) by several pseudoknots (PKs) and RNA helices. During trans-translation, tmRNA utilize its TLD to receive the incomplete polypeptide from the peptidyl-tRNA in the ribosomal P site of the stalledribosome. Subsequently, its MLD is used to tag the incomplete polypeptide with adegradation signal. When tmRNA enters a stalled ribosome the MLD and pseudoknots form a highly structured arc that encircles the beak of the small ribosomal subunit. Byutilizing maximum-likelihood based methods for heterogeneity analysis we could observe the Escherichia coli ribosome in a number of different tmRNA·SmpB-boundstates. The cryo-EM map of the post-accommodated state revealed that the TLD·SmpBpart of the tmRNA·SmpB complex mimics native tRNAs in the A site of stalled ribosomes. The density map also showed that the tmRNA arc remains well structuredand that it is still attached to the beak of the small ribosomal subunit. Thereconstructions of the double-translocation tmRNA-bound ribosome complex showed that the pseudoknots of tmRNA still form an arc, and that they are located at positions similar to the ones assigned for the pseudoknots in the post-accommodated state. In addition, the tmRNA arc exists in two states; one stable and highly structured and another more flexible and disorganized.

  • 341.
    Cheng, Kimberley
    et al.
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Ivanova, Natalia
    Biomedicinskt centrum, Uppsala.
    Scheres, S.H.W
    Pavlov, Michael
    Biomedicinskt centrum.
    Carazo, J.M.
    Herbert, Heinz
    Ehrenberg, Måns
    Lindahl, Martin
    KTH, School of Technology and Health (STH).
    Structural analysis of double translocated tmRNA on the 70S ribosome indicates flexibility of the tmRNA structure.Manuscript (preprint) (Other academic)
  • 342.
    Cheng, Kimberley
    et al.
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Ivanova, Natalia
    Biomedicinskt centrum, Uppsala.
    Scheres, Sjores
    CSIC, Natl Biotechnol Ctr, Biocomp Unit, E-28049 Madrid, Spain .
    Pavlov, Michael Y
    Biomedicinskt centrum, Uppsala.
    Maria Carazo, Jose
    Lund Univ, Mol Biophys KILU.
    Hebert, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Ehrenberg, Måns
    Biomedicinskt centrum, Uppsala.
    Lindahl, Martin
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    tmRNA-SmpB complex mimics native aminoacyl-tRNAs in the A site of stalled ribosomes2010In: Journal of Structural Biology, ISSN 1047-8477, E-ISSN 1095-8657, Vol. 169, no 3, p. 342-348Article in journal (Refereed)
    Abstract [en]

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

  • 343.
    Cheng, Kimberley
    et al.
    KTH, School of Technology and Health (STH), Structural Biotechnology (Closed 20130701).
    Karlström, M
    Purhonen, P
    Ladenstein, R.
    Herbert, Hans
    Koeck, Philip J.B.
    Low resolution structure and apparent melting temperature of the chaperonin from Pyrococcus furiosusManuscript (preprint) (Other academic)
  • 344.
    Cheng, Kimberley
    et al.
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Koeck, Philip J. B.
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Elmlund, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Idakieva, Krassimira
    Parvanova, Katja
    Schwarz, Heinz
    Ternström, Tomas
    Hebert, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Comparison of the two Rapana thomasiana Hemocyanin isoforms: RtH1 and RtH22006In: Proc 16. International Microscopy Conference, 2006Conference paper (Refereed)
  • 345.
    Cheng, Kimberley
    et al.
    Department of Biosciences at NOVUM, Karolinska Institutet and School of Technology and Health, Royal Institute of Technology, S-141 57 Huddinge, Sweden.
    Koeck, Philip J. B.
    Department of Biosciences at NOVUM, Karolinska Institutet and School of Technology and Health, Royal Institute of Technology, S-141 57 Huddinge, Sweden.
    Elmund, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Hebert, Hans
    KTH, School of Technology and Health (STH), Structural Biotechnology.
    Ternström, Tomas
    Schwarz, Heinz
    Idakieva, Krassimira
    Parvanova, Katja
    Rapana thomasiana hemocyanin (RtH): Comparison of the two isoforms, RtH1 and RtH2, at 19 Å and 16 Å resolution2006In: Micron, ISSN 0968-4328, E-ISSN 1878-4291, Vol. 37, no 6, p. 566-576Article in journal (Refereed)
    Abstract [en]

    Three-dimensional (3D) reconstructions of the two 8.4 MDa Rapana thomasiana hemocyanin isoforms, RtH1 and RtH2, have been obtained by cryoelectron microscopy of molecules embedded in vitreous ice and single particle image processing. The final 3D structures of the RtH1 and RtH2 didecamers at 19 angstrom and 16 angstrom resolution, respectively, are very similar to earlier reconstructions of gastropodan hemocyanins, revealing structural features such as the obliquely oriented subunits, the five- and two-fold symmetrical axes. Three new interactions are defined; two of them connecting the arch and the wall while the third is formed between the collar and the wall. The collar-wall connection and one of the arch-wall connections are positioned between two individual subunit dimers, while the second arch-wall connection is located between two subunits within the subunit dimer. All three interactions establish connections to the first tier of the wall. Furthermore, for each interaction we have allocated two first tier functional units most likely involved in forming the connections.

  • 346. Chowdhury, Helena H
    et al.
    Velebit, Jelena
    Mekjavic, Igor B
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology. KTH, School of Technology and Health (STH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Kreft, Marko
    Zorec, Robert
    Systemic Hypoxia Increases the Expression of DPP4 in Preadipocytes of Healthy Human Participants2017In: Experimental and clinical endocrinology & diabetes, ISSN 0947-7349, E-ISSN 1439-3646Article in journal (Refereed)
    Abstract [en]

    Dipeptidyl peptidase 4 (DPP4) is a transmembrane glycoprotein involved in protein degradation. Due to its action on incretins, which increase insulin secretion, DPP4 is considered a therapeutic target for type 2 diabetes. Here we have studied the role of single and combined effects of hypoxia and inactivity on the expression of DPP4 in human adipose tissue of 12 adult normal-weight males. Fat biopsies were obtained at baseline and after each of three experimental campaigns. The results revealed that in isolated human preadipocytes the expression of DPP4 was significantly increased by exposure of participants to hypoxia. Physical inactivity per se had no apparent effect on the DPP4 expression. It is concluded that DPP4 may be a marker to monitor indirectly tissue hypoxia, as occurs in obese subjects.

  • 347.
    Chowdhury, Manish
    et al.
    KTH, School of Technology and Health (STH).
    Jörgens, Daniel
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Wang, Chunliang
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization. KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Smedby, Örjan
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Moreno, Rodrigo
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Segmentation of Cortical Bone using Fast Level Sets2017In: MEDICAL IMAGING 2017: IMAGE PROCESSING / [ed] Styner, MA Angelini, ED, SPIE - International Society for Optical Engineering, 2017, article id UNSP 1013327Conference paper (Refereed)
    Abstract [en]

    Cortical bone plays a big role in the mechanical competence of bone. The analysis of cortical bone requires accurate segmentation methods. Level set methods are usually in the state-of-the-art for segmenting medical images. However, traditional implementations of this method are computationally expensive. This drawback was recently tackled through the so-called coherent propagation extension of the classical algorithm which has decreased computation times dramatically. In this study, we assess the potential of this technique for segmenting cortical bone in interactive time in 3D images acquired through High Resolution peripheral Quantitative Computed Tomography (HR-pQCT). The obtained segmentations are used to estimate cortical thickness and cortical porosity of the investigated images. Cortical thickness and Cortical porosity is computed using sphere fitting and mathematical morphological operations respectively. Qualitative comparison between the segmentations of our proposed algorithm and a previously published approach on six images volumes reveals superior smoothness properties of the level set approach. While the proposed method yields similar results to previous approaches in regions where the boundary between trabecular and cortical bone is well defined, it yields more stable segmentations in challenging regions. This results in more stable estimation of parameters of cortical bone. The proposed technique takes few seconds to compute, which makes it suitable for clinical settings.

  • 348.
    Chowdhury, Manish
    et al.
    KTH, School of Technology and Health (STH).
    Klintström, Benjamin
    KTH, School of Technology and Health (STH). Linköping University, Sweden.
    Klintström, E.
    Smedby, Örjan
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization. Linköping University, Sweden.
    Moreno, Rodrigo
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Image Processing and Visualization.
    Granulometry-based trabecular bone segmentation2017In: 20th Scandinavian Conference on Image Analysis, SCIA 2017, Springer, 2017, Vol. 10270, p. 100-108Conference paper (Refereed)
    Abstract [en]

    The accuracy of the analyses for studying the three dimensional trabecular bone microstructure rely on the quality of the segmentation between trabecular bone and bone marrow. Such segmentation is challenging for images from computed tomography modalities that can be used in vivo due to their low contrast and resolution. For this purpose, we propose in this paper a granulometry-based segmentation method. In a first step, the trabecular thickness is estimated by using the granulometry in gray scale, which is generated by applying the opening morphological operation with ball-shaped structuring elements of different diameters. This process mimics the traditional sphere-fitting method used for estimating trabecular thickness in segmented images. The residual obtained after computing the granulometry is compared to the original gray scale value in order to obtain a measurement of how likely a voxel belongs to trabecular bone. A threshold is applied to obtain the final segmentation. Six histomorphometric parameters were computed on 14 segmented bone specimens imaged with cone-beam computed tomography (CBCT), considering micro-computed tomography (micro-CT) as the ground truth. Otsu’s thresholding and Automated Region Growing (ARG) segmentation methods were used for comparison. For three parameters (Tb.N, Tb.Th and BV/TV), the proposed segmentation algorithm yielded the highest correlations with micro-CT, while for the remaining three (Tb.Nd, Tb.Tm and Tb.Sp), its performance was comparable to ARG. The method also yielded the strongest average correlation (0.89). When Tb.Th was computed directly from the gray scale images, the correlation was superior to the binary-based methods. The results suggest that the proposed algorithm can be used for studying trabecular bone in vivo through CBCT.

  • 349.
    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.

  • 350.
    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. 

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