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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Identifiering av tecken på kommande hypotension i samband med operation / Recognition of Signs of a Near Onset of Hypotension during Surgery

Lagerqvist, Filip, Jefford-Baker, Benjamin January 2020 (has links)
Hypotension är vanligt förekommande vid anestesi och i den postoperativa fasen. Om blodtrycket sjunker till för låga nivåer eller pågår under för lång tid kan vitala organ som hjärta och njurar ta allvarlig skada. De flesta fall av hypotension behandlas idag retroaktivt. Med möjlighet att kunna upptäcka hypotension innan det uppstår skulle behandling kunna ske i ett förebyggande syfte och på så sätt minska tiden i hypotension för patienten. Med hjälp av maskininlärning går det att analysera blodtryckskurvor och kunna hitta vilka attribut i dem som kan förutse hypotension. Detta projekt har gått ut på att definiera och beräkna attribut för att i framtida arbeten kunna låta en maskininlärningsalgoritm analysera dem. Utöver detta har arbetet med signalbehandling skett för att kunna upptäcka bristande kvalitet på den analyserade signalen och kunna förbättra den vid behov. Målet att definiera och beräkna attribut har lyckats. Målet att kunna avgöra kvaliteten på signalen har lyckats delvis.
32

Fluorescence Guided Resection of Brain Tumors : Evaluation of a Hand-held Spectroscopic Probe

Richter, Johan January 2017 (has links)
Malignant gliomas grow infiltrative in the brain and can therefore not be completely removed by neurosurgical means. However, for an optimized oncological treatment it has proven useful to resect as much as possible of tumor. The identification of the tumor in the marginal zone is difficult but crucial. Studies have shown that visualization of the specific enhancement of 5-aminolevulinic acid(5-ALA) in the tumor can help to maximize the resection. The Department of Biomedical Engineering, Linköping University, has developed an optical hand-held probe (HHP) to identify tumor tissue with a high sensitivity by means of fluorescence spectroscopy. The technical design and the optical properties of the probe were gradually developed in a standard neurosurgical setting during resection of malignant gliomas. The device could easily be implemented in the operating room, meeting all requirements in terms of sterile handling and without interference of any kind with other equipment. The integration of the device in a navigation system and its use in combination with a blue light surgical microscope were simple. Measurements in 27 operations during resection of malignant gliomas were compared to results from biopsies from the same tumor locations. The equipment was tested as a stand-alone device (n = 180), integrated in a navigation system or in combination with the blue light microscope (n = 190). A ratiocal culated from the measurements enabled objective and comparable values for different tissue types, in correspondence with the findings from the histopathological examinations and in accordance with the navigation system as well as with the surgical microscope.The marginal zone was explored and tumor fluorescence could be identified beyond the fluorescence as seen through the microscope. A higher sensitivity of the HHP was confirmed; the specificity was lower. The combined use of the HHP with a navigation system and with asurgical microscope was beneficial. / Maligna hjärntumörer växer infiltrerande i hjärnan och kan därförinte helt avlägsnas genom kirurgiska operationer. För en optimerad behandling har det emellertid visat sig vara av värde att avlägsna såmycket som möjligt av tumörvävnaden. Identifiering av tumören i gränszonen är mycket svårt, men avgörande. Studier har visat att visualisering av den specifika laddningen av 5-aminolevulinsyra (5-ALA) i tumören kan bidra till att maximera resektionen. Institutionen för Medicinsk Teknik (IMT) på Linköpings universitet,har utvecklat en liten handhållen optisk prob (HHP) för att identifiera tumörvävnad med hög känslighet med hjälp avfluorescens-spektroskopi. Den tekniska konstruktionen och de optiska egenskaperna hos proben utvecklades stegvis genom testning i flera neurokirurgiska operationer för resektion av maligna gliom. Utrustningen uppfyllde alla krav när det gällde steril hantering i operationssalen och kunde användas utan störningar av något slag med annan operationsutrustning. Integreringen i ett navigerings-system och användningen i kombination med ett kirurgiskt mikroskop för fluorescens-styrd kirurgi var oproblematiska. Mätningar under 27 operationer vid resektion av maligna gliom jämfördes med resultat från biopsier från samma tumörtagningsställen. Utrustningen testades såväl som en fristående enhet (n = 180) och som integrerad i ett navigationssystem eller i kombination med mikroskopet (n =190). En särskild kvot beräknad ur mätningarna möjliggjorde objektiva och jämförbara värden för olika vävnader, i överensstämmelse med resultaten från de vävnadspatologiska undersökningarna och i överensstämmelse med navigationssystemet såväl som med det kirurgiska mikroskopet. Tumörernas gränszon undersöktes och tumörfluorescens kunde identifieras bortom fluorescensen som mikroskopet visade. En högre känslighet hos HHP bekräftades; specificiteten var lägre. Den kombinerade användningen av HHP med ett navigationssystem och med ett kirurgiskt mikroskop visade sig vara fördelaktig.
33

Hur upplever personer med hjärtsvikt eHälsa som stöd för egenvård?

Möllerstedt, Carl, Ingrid, Winblad January 2021 (has links)
Bakgrund: Hjärtsvikt är en av Sveriges vanligaste folksjukdomar och orsakar ett stort lidande hos drabbade personer. Egenvården vid hjärtsvikt är av stor vikt för att främja hälsa och välmående där individen själv utför dessa åtgärder. Brist i egenvården då individen saknar motivation eller har en otillräcklig sjukdomsinsikt kan leda till en försämring av tillståndet. eHälsa kan vara en möjlighet att underlätta egenvården. eHälsa kan också förbättra kommunikationen mellan individ och vårdgivare. Syfte: Syftet med litteraturöversikten var att beskriva hur personer med hjärtsjukdom upplever eHälsa som stöd för egenvård. Metod: En allmän litteraturöversikt enligt Friberg (2017). Litteraturöversikten baserades på nio vetenskapliga artiklar med kvalitativ ansats. Analysen utfördes med Fribergs (2017) analysmetod. Resultat: Resultatet visade att personerna med hjärtsvikt upplevde eHälsa som ett stöd i egenvården. Resultatet visade även att det fanns vissa tekniska hinder vid användandet av eHälsa. Resultatet baserades på tre teman upplevelse av att vara delaktighet i sin egen vård, upplevelse av tekniken och upplevelse av vårdrelationen med följande subtemankunskap/medvetenhet, motivation, autonomi, hanteringen av tekniken, teknikrädsla och kommunikation till och från vårdgivare. Slutsats: Det framkom i studien att eHälsa är ett stort stöd i individernas egenvård även vid en begränsad kunskap om tekniken. eHälsa bidrog till en ökad motivation och en förbättrad kunskap för individerna för bibehålla en god hälsa. De brister som resultatet visade berodde på tekniska problem och det är därför viktigt att anpassa eHälsan utifrån varje individs behov.
34

Evaluation of performance of MSI detection tools using targeted sequencing data

Kolluri, Satya Krishna Prasanna January 2021 (has links)
In recent years, digitalization and computer-based technologies have greatly revolutionized the field of bioinformatics. Advance research and development of computer-based programs have enhanced various DNA sequencing technologies. This advancement has significantly broadened our understanding of genomic evolution and has widely contributed to the application of clinical genomics. Cancer has been one of the major causes of death across the world. Cancer is mainly caused due to the damage or changes in DNA that affect the function of genes which contain a set of instructions that control various functions of cells. This damage in genes that maintain DNA repair mechanism may lead towards genome instability allowing rapid growth of cancer.   Microsatellite instability (MSI) is one such condition characterized due to genomic alteration leading towards the failure of DNA repair mechanism in cancerous cells. MSI is found in various types of cancer but is most often found in colorectal cancer, gastric cancer, and endometrial cancer. Hence, detection of this MSI can greatly contribute towards cancer therapies and enable to plan for the best treatment. This study mainly focuses on evaluating the performance of MSI calling algorithms using targeted sequencing methods.   The literature provides a detailed outline of various topics related to MSI detection. Moreover, different computational methods like MSIsensor, MSIsensor-ct, MSIsensor-pro, MSings, MiMSI, and MSIsensor2 were used in this study for the detection of MSI in selected samples are thoroughly discussed in the methodology section. Finally, the findings of this study conclude that the MSI calling algorithms mentioned above provide accurate detection of MSI in the chosen samples. Also, these algorithms enable us to determine the MSI status of the chosen samples more precisely
35

Optomyography - Detection ofmuscle surface displacement using reflective photo resistor.

Raghavendra, Jammalamadaka January 2014 (has links)
A human body can carry out many physiological complex processes which can be mechanical, electrical or bio-chemical. Each mechanical activity generates a signal that describes the characteristics of the particular action in the form of pressure or temperature. Any irregularity in the process changes the usual functioning thus affecting the performance of the system. Several techniques were introduced to evaluate these muscular signals in order to get a deeper understanding of the medical abnormalities. Displacement sensors, laser optics, electrodes, accelerometers and microphones are some of the widely used devices in measuring the electrical and mechanical activities produced in the muscles. The aim of this thesis project was to find and implement a simple non-contact optical method to measure and monitor the displacements caused on the surface of the skin due to muscular movements. In this study, a device was developed using photo electric sensors that can record surface changes caused on the skin due to the movements forearm muscles.
36

Mathematical modeling of fatty acid metabolism during consecutive meals and fasting : New insights into fatty acid regulation based on arterio-venous data / Matematisk modellering av fettsyremetabolism vid konsekutiva måltider och fasta : Nya insikter om fettsyrereglering baserade på arteriovenösa data

Tunedal, Kajsa January 2021 (has links)
Obesity, type 2 diabetes, and cardiovascular diseases are major problems in today's society, causing millions of deaths every year. One of the main risk factors for these diseases is a dysregulation of the fatty acid metabolism, where the balance between release and uptake of fatty acids is disturbed. Thus, understanding how fatty acid metabolism works is of great importance in the battle against these diseases. The human fatty acid release and uptake can be unraveled by measuring the difference in metabolite concentrations between an artery before the adipose tissue and a vein draining the tissue. Such measurements are called arterio-venous. However, due to the complexity of the fatty acid mechanisms, the resulting measurements alone are not enough to understand all of the involved reactions governing the metabolism. One analytical tool to decipher such complex mechanisms is mathematical modeling. A few mathematical models have previously used arterio-venous data of the fatty acid metabolism, but none of the previous models describe a full day including several meals and nightly fast. In this project, I combine mathematical modeling and arterio-venous data to investigate the mechanisms of fatty acid metabolism during three consecutive meals and fasting. The resulting mathematical model can explain arterio-venous data of free fatty acids, triglycerides, and glycerol. The model predictions show that re-esterification of monacylglycerides, a mechanism that has not been considered before when analyzing arterio-venous data, is of importance to be able to accurately describe the fatty acid metabolism. Additionally, the model predicts that there is a hormonal regulation during the night. Finally, it is shown that many of the previous simple calculations used to approximate metabolic reactions do not capture the desired reactions but instead calculate more complex properties, while the use of the model allows for a more detailed analysis separating all of the different reaction rates. These results give new insights into the complex mechanisms of fatty acid metabolism and provide a new tool to analyze arterio-venous data more comprehensively. In the future, this can lead to a better understanding of metabolic diseases such as obesity, type 2 diabetes, and cardiovascular diseases.
37

Monte Carlo simulations of Linear Energy Transfer distributions in radiation therapy

Dahlgren, David January 2021 (has links)
In radiotherapy, a quantity asked for by clinics when calculating a treatment plan, along withdose, is linear energy transfer. Linear energy transfer is defined as the absorbed energy intissue per particle track length and has been shown to increase with relative biologicaleffectiveness untill the overkilling effect. In this master thesis the dose averaged linear energytransfer from proton and carbon ion beams was simulated using the FLUKA multi purposeMonte Carlo code. The simulated distributions have been compared to algorithms fromRaySearch Laboratories AB in order to investigate the agreement between the computationmethods. For the proton computation algorithm improvements to the current scoring algorithmwere also implemented. A first version of the linear energy transfer validation code was alsoconstructed. Scoring of linear energy transfer in the RaySearch algorithm was done with theproton Monte Carlo dose engine and the carbon pencil beam dose engine. The results indicatedthat the dose averaged linear energy transfer from RaySearch Laboratories agreed well for lowenergies for both proton and carbon beams. For higher energies shape differences were notedwhen using both a small and large field size. The protons, the RaySearch algorithm initiallyoverestimates the linear energy transfer which could result from fluence differences in FLUKAcompared to the RaySearch algorithm. For carbon ions, the difference could stem from someloss of information in the tables used to calculate the linear energy transfer in the RaySearchalgorithm. From validation γ-tests the proton linear energy transfer passed for (3%/3mm) and(1%/1mm) with no voxels out of tolerance. γ-tests for the carbon linear energy transfer passedwith no voxels out of tolerance for (5%/5mm) and a fail rate of 2.92% for (3%/3mm).
38

Testbed Development for Non-invasive Intracranial Pressure Monitoring with a Microwave based Electromagnetic Skin Patch Sensor

Palm, Sandra, Saado, Hassan January 2021 (has links)
Traumatic brain injuries (TBIs) are a major public health problem worldwide where the symptoms can be anything from mild concussion to severe swelling of the brain tissue. As a result of TBI the intracranial pressure (ICP) can elevate to pathological levels with severe consequences such as hypoxia, ischemia and brain hemorrhage. TBI and the subsequent ICP increase could hence lead to disability or in worst cases death. Therefore to understand the severity of a head injury and the path regarding further treatments, monitoring of a patient's ICP is crucial in the intensive care units (ICU) environment. Invasive methods of ICP monitoring are at this present date the standard in ICU because of the accuracy when compared to non-invasive methods. All invasive ICP monitoring methods come with a risk to the patient and require the presence of a neurosurgeon. The thesis's objective was to develop a gradually increasing ICP testbed for a new non-invasive microwave based skin patch sensor. The aim with this project was to verify if a dependence in the resonance characteristic of the NASA SansEC microwave sensor with respect to ICP exists as suggested by previous works in a novel testbed and to provide a correlation model based on the testbed experiment. The developed testbed simulate increasing ICP by increasing volume of an artificial cerebro-spinal fluid (aCSF) liquid, a liquid emulating the CSF. The microwave sensor's resonance frequency is due to the permittivity changes caused by the change (increasing) in the fluid volume, which for this setup is directly correlated to the pressure change as well. Trials with different aCSF samples were made to ensure that the used aCSF in the testbed had the same dielectric properties as human CSF. The developed testbed had a simple structure made with several plastic containers of rectangular shape which were found to be well suited for the purpose of the experiment. For the microwave sensor trials an Fieldfox microwave analyzer was used and the sensor was evaluated around 1 - 4 GHz. The testbed pressure was increasing from 0 - 47 mmHg covering most useful ICP ranges. Larger pressures were also possible but limited by the height of the work room and the increase of complexity in the testbed design. The results from the trials showed a total resonance frequency shift of 76 MHz from 4 - 30 mmHg with an linear correlation of R2 = 0,91. The sensor measurements above 30 mmHg showed a saturation where the first principal frequencies were stable at 1,368 GHz. The linear relationship obtained for 4-30 mmHg is a reassurance that the Nasa SansEC sensor should be studied further. Future work should include new trials with modifications to the testbed setup and sensor design.
39

Mathematical Modelling of Insulin Resistance Development Caused by Chronic Inflammation / Matematisk Modellering av Insulinresistensutveckling orsakad av kronisk inflammation

Wu, Simon January 2019 (has links)
Obesity has in recent times become a more serious health issue and was estimated to affect over 650 million people world-wide in 2016. Furthermore, the list of obesity-associated diseases is countless, many of which have severe consequences. Type 2 diabetes (T2D) is such a disease, and it was estimated to be over 1.5 million new cases in America alone in 2015. It is thought that insulin resistance development which causes T2D is associated with a low-level chronic inflammation in the adipose tissue. The inflammatory state is caused by the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) which is secreted by macrophages. To further understand the complexity of the underlying mechanisms of both the adipocytes as well as the macrophages, mathematical models are being developed in the fields of systems biology. However, as of now, no mathematical model has been developed which can explain the association between chronic inflammation and the development of insulin resistance. Because of this, a first model will be presented which is able to describe the mechanisms of insulin resistance development caused by chronic inflammation. The model was fitted to data from intraperitoneal glucose tolerance test in mice and yielded a cost below the threshold of chi-square test, which suggests that the model cannot be rejected. Furthermore, the model was expanded, introducing more complexity in the intracellular cascade reaction of an activated macrophage. Once again, the model was fitted to the same data and yielded a cost below the threshold of chi-square test. Uncertainty tests were made to further validate the models and showed a low uncertainty for both models. These results increase the understanding regarding the association between adipocytes and macrophages, in the role of insulin resistance caused by chronic inflammation. This increased knowledge can help, for instance, in the development of new drugs which are able to prevent the development of insulin resistance and T2D.
40

En skrivbordsapplikation för inventering och produktionsplanering : En digital lösning för hantering av analysmaterial inom klinisk mikrobiologi på Karolinska Universitetssjukhuset / A Desktop Application for Inventory and Production Planning : A Digital Solution for Handling Analysis Material within Clinical Microbiology at Karolinska University Hospital

Larsson, Andreas, Shafiei, Armin January 2023 (has links)
På substratenheten på Karolinska Universitetssjukhuset inventerades och produktionsplanerades allt för hand på papper 3 gånger i veckan. Syftet med projektet har varit att hitta en digital lösning för att effektivisera arbetet kopplat till inventeringen och produktionsplaneringen. Målet har därför varit att utveckla en skrivbordsapplikation för att uppnå detta syfte genom avläsning av QR-koder. Projektet genomfördes genom programmering i språket Java och utnyttjade JavaFX för alla grafiska komponenter. Databaskopplingen som krävdes använde mySQL för att sammankoppla program med databas. För utvecklandet av applikationen så har designmönstret Model-View-Controller använts. Vi som författare anser att applikationen bör bearbetas vidare, detta då en del funktionalitet skulle behöva optimeras och även utvecklas vidare för att uppnå önskad användarvänlighet. Dock är vår slutsats att alla de uppsatta målen uppfylldes. / At the substrate unit at Karolinska University Hospital they previously did their inventory and production planning by hand three times a week. The purpose of the project has been to find a digital solution to streamline this unit’s workload connected to inventory and production planning. Therefore, the aim of the project was to develop a desktop application to fulfill the purpose of the project by scanning QR-codes. The project has been performed through programming in the language Java and used the JavaFX library for all graphical components. The database connection used mySQL to connect the program to the database. For the development of the application the design-pattern Model-View-Controller were used. As authors of the report, we consider that the application should be further optimized, and additional functions should be introduced in order to achieve greater usability. However, our conclusion is that the application fulfills the aims set at the beginning of the project.

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