1.
Deyhle Jr, Richard
(author)
Cross-modal Imaging in Lung Research: From µCT dosimetry to synchrotron phase contrast microtomography biomechanical insights in preclinical lung injury models
2024
Licentiate thesis (other academic/artistic) abstract
Lung diseases continue to present a large burden to public health, especially in industrialized countries. For abetter understanding of the underlying patho-mechanisms in lung related diseases as well as for testing theefficacy of novel therapies, preclinical studies in animal models are indispensable. The significance of preclinical X-ray based micro-computed tomography (µCT) research lies in its ability to provide high-resolution, non-invasive lung imaging of small animals as the air inside the lung acts as a natural contrast and to image the lung parenchyma longitudinally to assess functional and morphological alterations and test efficacy of therapeutic interventions. This often requires requires imaging protocols that balance between sufficient image quality and clinically relevant radiation absorbed doses. A reproducible method for evaluation of absorbed radiation absorbed doses is desirable. Absorbed radiation absorbed doses were measured in a polymethyl methacrylate (PMMA) phantom using standard TLD and a novel type of OSLD made form household salt. Four imaging protocols from MILabs “xUHR-µCT” scanner were tested. A large discrepancy was observed from results compared to vendor-provided values. The results indicate a need for thorough empirical dose measurements prior to performing longitudinal studies. Four-dimensional imaging, allows for investigation of the dynamics of regional lung functional parameters simultaneously with structural deformation of the lung as a function of time. It is of significant interest to have direct visualization and quantification of interstitial lung diseases at spatial resolutions beyond the capabilities of clinical and conventional absorption-based only CT. Thus far, the high intensity of synchrotron X-ray light sources offer a tool to investigate dynamic morphological and mechanistic features, enabling dynamic in-vivo microscopy. This investigation elucidates the direct effects of interventions targeting the pathophysiology of Acute Respiratory Distress Syndrome (ARDS) and Ventilator-Induced Lung Injury (VILI) on the terminal airways and alveolar microstructure within intact lungs. In such conditions, the relationship between microscopic strain within the mechanics of the alveolar structure and the broader mechanical characteristics and viscoelastic properties of the lungs remains poorly understood. A time-resolved synchrotron phase-contrast micro-computed tomography imaging acquisition protocol based on the synchronization between the mechanical ventilation and the cardiac activity was used to resolve the lung parenchyma motion with an effective isotropic voxel size of 6 µm. Quantitative maps of microscopic local lung tissue strain within aerated lung alveolar tissue under protective mechanical ventilation in anesthetized rats were obtained. This approach was used to assess the effect of alterations in lung tissue biomechanics induced by lung injury at 7 days after single-dose, intratracheal bleomycin instillation in combination with short-term high-tidal volume (VT) mechanical ventilation. Overall, this work address the aspects of radiation exposure to in experimental imaging of small animals and lays a foundation for a more nuanced understanding of lung injury and mechanical ventilation. In the future, it may result in a more effective and less injurious respiratory support for patients with acute lung injury or chronic lung diseases.
2.
Erici, Sten
(author)
Challenging patient communication in a medical education curriculum - Perspectives on learning with simulated patients
2023
Licentiate thesis (other academic/artistic) abstract
Being able to manage challenging patient communication and the associated emotional burden is a vital skill for physicians that is regularly utilized in clinical work. Therefore, it is reasonable that medical students get the opportunity to acquire and develop the relevant knowledge and skills related to challenging patient communication during their education. Simulated patient scenarios are useful learning activities known to improve the managing of challenging patient communication. Understanding student and teacher perceptions of vital communicative strategies and how to effectively organize learning activities, including simulated patients, within the curriculum, can enhance students' communicative progression.The aim of this thesis is to explore perceptions of learning in a simulated patient scenario from three different perspectives: students, simulated patients, and teachers. Additionally, we aim to examine the communicative approaches perceived as vital to manage challenging patient communication and how they are learned from a programme perspective. Furthermore, we seek to explore the relationship between patient simulation and adjacent learning activities.A qualitative approach was applied. Individual interviews and a narrative survey were conducted with students, teachers, and a simulated patient as part of two separate studies during the 9th semester of a medical programme. Curriculum documents served as a framework.Our findings indicate that simulated patients in learning how to manage challenging patient communication is perceived beneficial for developing professional identity and self-knowledge. It is crucial that the learning activity enables student centred learning, supported by flexible simulated patients. Self-knowledge and the ability to convey empathy is perceived as essential in handling challenging patient communication. The organization of learning activities is perceived to be enhanced by interweaving activities related to learning medical knowledge and patient communication, including simulated patients.
3.
Holmboe, Michael
(author)
The bentonite barrier : microstructural aspects on colloid filtration and radiation effects on bentonite colloid stability
2009
Licentiate thesis (other academic/artistic) abstract
In many countries a multi-barrier concept in a deep geological repository is planned for final disposal of nuclear waste. Many of these different concepts, for example the Swedish KBS-3 model, include an engineered barrier consisting of compacted bentonite. The compacted bentonite barrier will be positioned around copper canisters holding the nuclear waste and act as a transport barrier for various radioactive species. This is due to the compact microstructure as well as the large sorption capacity of compacted water saturated bentonite. During its required lifetime (> 100000 years) a deep geological repository and the bentonite barrier itself will be subjected to changing groundwater composition and flow, geochemistry, temperature, and large doses of ionizing irradiation. The long lifetime and significance of a deep geologic repository mean that it must be regarded as a thermodynamically open system and be assessed in terms of worst case scenarios. In case of water bearing fractures, formed by future movements in the granitic host bedrock, low ionic strength groundwater can endanger the stability of the bentonite barrier. Prolonged erosion of the bentonite barrier might cause significant loss of buffer material and jeopardize its overall functionality. This thesis deals with the microstructure of the water saturated compacted bentonite as a function of compaction, as well as effects of γ-radiation on bentonite dispersions. The microstructure was investigated both indirectly through colloid filtration experiments, as well as using low-angle XRD. Effects of γ-irradiation were investigated in terms of colloid stability and sediment behavior of bentonite (and Na-montmorillonite) dispersions. The colloid filtration experiments, using small gold colloids of different sizes as tracers, shows that the microstructural constraints of bentonite effectively filter even extremely small inorganic colloids. Colloid transport was only observed at very low compactions (i.e. dry density g/cm3) where the average interlayer distances of montmorillonite exceeded the colloid size, indicating interlayer rather than interparticle transport. From the low-angle XRD experiments the free porosity of water saturated compacted bentonite was determined by comparing its basal spacings (interlayer distances + 1 nm) with the hypothetical basal spacings assuming no free porosity. Irrespective of compaction, the maximum free porosity proved to be very low, in line with the colloid filtration experiments. The results showed that existing microstructural models sometimes exaggerate the importance of interparticle voids. The γ-irradiation experiments showed a radiation induced increase in colloid stability. This radiation induced effect also changed the sedimentation behavior of irradiated bentonite dispersions compared to unirradiated samples. The effect is attributed to an increase in surface potential of the bentonite colloids, due to reactions with the short-lived radicals formed upon water radiolysis.
4.
Leledakis, Alexandros, 1991
(author)
Pre-Crash and In-Crash Car Occupant Safety Assessment
2021
Licentiate thesis (other academic/artistic) abstract
Tens of millions are annually injured in Road Traffic Accidents (RTAs) worldwide, while the estimated number of RTA fatalities amounted to 1.35 million in 2016. In Europe, car occupants hold the largest share (48%) of fatalities among all road users. The high fatality and injury numbers motivate the work of enhancing road traffic safety. A holistic safety assessment approach, considering both the pre- and the in-crash phase of a crash, has the potential to enhance real-world occupant protection evaluation, as well as facilitate the development of effective countermeasures. In standardized car occupant safety assessments, occupant surrogates of standardized anthropometries are employed in standardized postures, with the seat adjusted to a single predefined position. The vehicle is then subjected to predefined crash configurations with meticulously described impact points and angles. In contrast, real-world traffic crashes involve occupants of different shapes and sizes, who adjust the position of the seat and their posture on the seat differently, and the vehicles are subjected to diverse crash configurations (multiple impact locations, impact directions, and speed combinations). The overall aim of this thesis is to develop and apply methods, spanning from the pre-crash to the in-crash phase, capable of evaluating and enhancing the real-world occupant protection of future vehicles. The introduction of crash-avoidance systems has the potential to alter the crash configurations that future vehicles will be exposed to. A method for predicting crash configurations has been developed in this thesis and applied to highway driving, and urban intersection crashes. Performing counterfactual simulations of digitized real-world crashes, with and without the addition of a conceptual Automatic Emergency Braking system, provides a prediction of the remaining crashes. The use of a novel crash configuration definition, along with a purpose-designed clustering method, facilitates the reduction of the number of predicted crash configurations without sacrificing coverage of the diverse real-world situations. Three predicted crash configurations, representative of urban intersection crashes, were further analyzed during the in-crash phase. A Human Body Model was positioned in a wide range of occupant postures identified from the literature. The findings suggest that the lower extremity postures had the largest overall influence on the lower extremities, pelvis, and whole-body responses for all crash configurations. In the evaluated side-impacts, leaning the torso in the coronal plane affected the torso and head kinematics by changing the interaction with the vehicle’s interior. Additionally, in far-side impacts supporting the occupant’s arm on the center console resulted in increased torso excursions. Moreover, the upper extremity responses were consistently sensitive to posture variations of all body regions.
5.
6.
Peolsson, Michael
(author)
Att beskriva kronisk smärta : en lärprocess
2000
Licentiate thesis (other academic/artistic) abstract
Sammanfattningsvis syftar denna uppsats till att studera hur patienter beskriver sin smärta samt på vilka sätt de beskriver hur de utforskar sin smärta i vardagen. Jag vill med dessa beskrivningar som bakgrund lyfta fram patienters egen lärprocess om sin smärta. Avhandlingen syftar vidare till att diskutera hur vårdgivare kan lära sig av patienters smärtbeskrivningar. I detta sammanhang vill jag lyfta fram några begrepp som kan belysa hur patienterna i mina studier delger vad jag tolkar som smärtupplevelser.
7.
Schmöker, Annika
(author)
Parents’ needs and perceptions on emotional support in neonatal care and patterns of stress in parents of preterm infants during the first year after birth
2023
Licentiate thesis (other academic/artistic) abstract
Many parents experience preterm birth as traumatic and develop high levels of emotional stress, anxiety, and depressive symptoms. This can have a negative impact on the bonding process and the development of their parental identity. The emotional support provided by the staff varies between Swedish neonatal intensive care units (NICUs), and little is known about parents´ needs and preferences for emotional support. Further, there are knowledge gaps regarding parental stress in fathers and their needs for emotional support, differences in stress between mothers and fathers, change of parental stress over time and potential predictors for parental stress.The aim of this thesis was to explore the needs and preferences for emotional support in parents of preterm infants during their infant’s hospitalisation in a NICU, and to describe parental stress in mothers and fathers up until the infant’s age of 12 months and predictors for parental stress. Study I was a qualitative study using semi-structured interviews with 51 parents of preterm infants, which were analysed using qualitative content analysis. The results showed that parents need a sense of coherence during their infant’s stay in a neonatal intensive care unit, and they want to be offered emotional support according to their preferences. Many parents preferred to attend professionally led parental groups as other NICU parents could really understand their situation and feelings. Parents also emphasised the value of combining parental groups with other means of support.Study II was a longitudinal cohort study in which data on self-reported parental stress during the first year were obtained from 493 mothers and 329 fathers of preterm infants and analysed using descriptive statistics, Student’s independent t-tests, linear regression, and linear mixed-effects modelling. The results showed that mothers perceived more role restriction than fathers, and that fathers experienced more social isolation than mothers. Further, parental stress decreased during the first year for mothers but increased for fathers, especially between 6 months and 12 months postpartum. For both mothers and fathers, having twins and a lower perceived general health were associated to higher levels of parental stress. In addition, mothers with infants of lower gestational age experienced significantly higher levels of parental stress. In conclusion, individualised emotional support is important for parents of preterm infants for them to manage their situation both during their infant’s hospitalisation and during the first year postpartum. Apart from professional support, peer-support in the form of professionally led parental groups are perceived to be potentially valuable emotional support by parents. This peer-support could, preferably, be combined with other means of support during hospitalisation as ‘one size does not fit all’. In a next step, support interventions need to be designed, tested, and evaluated. Antonovsky’s theory of Sense of Coherence can be used to identify emotional needs in NICU parents and how to provide emotional support consistent with the parents’ preferences. After discharge from the NICU, vulnerable groups of parents, including parents of very preterm infants and twins need additional support. Moreover, there is a need in fathers for additional emotional support programmes offered during the first year of infants’ lives.
8.
Terner, Annika, 1960-
(author)
Predefined Headings in a Multi-professional Electronic Health Record : Professionals’ Application, Aspects of Health and Health Care and Correspondence to Legal Requirements
2014
Licentiate thesis (other academic/artistic) abstract
The overall aim of this thesis was to investigate predefined headings in a Swedish county council multi-professional EHR system in terms of their shared application, what aspects of health and health care they reflected, and their correspondence to legal requirements. An analysis of 3 596 predefined headings, applied to 20 398 104 occasions by eight professional groups, was conducted. Less than 2% of the predefined headings were applied by all eight professional groups, whereas 60% were not shared at all between the professional groups. A classification of the predefined headings revealed that 13% were “Specialist terms”, which were the least ambiguous predefined headings, 46% were “Terms for specific purposes”, which are less ambiguous than the “Common words” (28%), which were the most ambiguous predefined headings according to the sociolinguistic method employed. The remaining predefined headings (13%) were sorted into “Unclassified headings”. A qualitative content analysis of the predefined headings yielded 23 subcategories grouped into five categories: Description of the patient, Health care process, Resources employed, Administrative documentation, and Development and research. A comparison of the 23 subcategories to the Patient Data Act showed, first, that 15 of 23 subcategories corresponded to four legal requirements, second, that there were legal requirements with a focus on patient rights that were not being met, and third, that there were eight subcategories of predefined headings that could not be attributed to the legal provisions of the Patient Data Act. In conclusion, the proportion of shared predefined headings in the EHRs was limited. The predefined headings in the multi-professional EHRs did not constitute a joint language for specific purposes. A meaningful structure comprising categories and subcategories of different aspects of health and health care as reflected in the applied predefined headings was identified. The structure reflected a wide range of health and health care. No subcategory corresponded to the three legal requirements concerning patient rights. Future research should include professionals’ and patients’ understanding of predefined headings, the correspondence of documented notes to predefined headings and how the documentation in the EHR has had an impact on patient safety.
