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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.
1

Jack The Gripper : Fixationsplatta för typ 3-frakturer på scapula

Ekelund, Gustaf, Andersson, Sebastian January 2017 (has links)
Reverse Total Shoulder Arthroplasty (rTSA) is an increasingly common approach to treating different shoulder injuries. The rTSA results in increased force from m. deltoideus which originates from acromion. However, postoperative fractures on the scapula have occurred in some cases. These fractures are divided into 3 different types depending on where the fracture occurs. There is no recommended treatment for type 3 fractures. This project is a product development project with the purpose to find a solution to the fixation problem of type 3 fractures.To reach the project goal, the group has used well-known and proven product development methods, calculations, FEM analyzes and a model assembly analysis. The concept development was performed by interviewing orthopedics who have a lot of experience with rTSA and osteosynthesis related to these fractures. A prototype, which shows the features of the fixation plate, was made using 3D printers.The result of this project has provided a fixation plate that meets the groups requirements and has features that a modern fixation plate has today. In addition, two types of extra plates mounted on the fixation plate to the thin structure of spina scapula, was developed to counteract the axial force. The fixation plate shows excellent results on the FEM analyzes and assembly analysis performed on a scapula model. The prototype has also been given good testimonials from the orthopedics who participated in the project.
2

Modeling and Characterization of a Propagation Channel in a Body-Centric Nano-Network

Pettersson, Charlie January 2018 (has links)
Researchers have been trying to find smart health solutions that will allow people to continuously monitor their health through applications connected to the internet. One possible solution involve using nano-machines to create body-centric networks. However, the biggest challenge using nano-machines are how they would communicate with the outside world. To investigate this, I have in this thesis developed a multi-layer channel model for human skin tissues and investigated how signals at the terahertz frequency band interact with skin biomaterial. The model is built upon analytical equations describing electromagnetic propagation in a dielectric medium were the electromagnetic properties of human tissue were collected from different sources. The model were implemented in a flexible matlab program able to simulate different numbers of layers from a library with either fixed or random depths. The human skin model used to gather results were chosen to consist of 4 layers of epidermis, dermis, blood and hypodermis, and the depth of the layers were chosen to vary between typical values for the human body. This Matlab based multi-layer channel model was validated by a similar model made in CST Studio Suite, both for a single layer as well as for a 2-layer scenario. Results from the Matlab program showed that the path loss is significantly affected by frequency and material. The expected path loss could therefore vary significantly, however for a human skin model with depths of 1.23, 3.76, 0.21 and 1.38 mm respectively, the path loss was approximately between 250-350 dB for frequencies of 0.5-1.5 THz at the end distance. Finally, numerical analysis were used on 10 data sets created from the multi-layer channel model in order to develop a simple interpolation equation able to describe path loss through the human skin with varying tissue layer depths. The equation had an average mean error of 4.08 \% and a maximum mean error of 6.61\% against 90 different random data sets.
3

Evaluation of margins and plan robustness for proton therapy of unilateral tonsil cancer.

Grefve, Josefine January 2021 (has links)
During proton therapy both target volumes and healthy tissue, including organs at risk (OARs), receives radiation dose. Thus, radiotherapy is a trade-off between good target coverage and OAR sparing. For protons, most of the dose is deposited right before it is stopped, a phenomenon termed the Bragg peak. Beyond this point no dose will be deposited, which is an advantageous feature since it enables more OAR sparing. However, this feature also makes proton therapy sensitive to variations in patient position, uncertainties in dose calculation and geometry/anatomy changes. Geometrical margins are therefore added around the target volume to ensure proper coverage.  An evaluation of the margins and plan robustness for proton therapy of unilateral tonsil cancer was conducted in this study, where the endpoint was to further optimize the margins to account for the trade-off between target coverage and doses to OAR. Verification CTs were compared with the plan CT of seven patients using the software Elastix and MICE toolkit. Dose volume histograms (DVHs) were evaluated together with Hausdorff distances (HdD), target coverage and dose differences along the craniocaudal direction, and related to the patient vertebrae.  Tendencies for the need of larger margins caudally of the cervical vertebra C3 was concluded from the HdD and two patients were selected for replanning. Four new treatment plans were created for each patient in the treatment planning system Eclipse and the resulting proton dose distributions were evaluated in MICE toolkit. Two plans utilized a uniform uncertainty of 4 and 5 mm respectively, and two plans utilized a varying uncertainty around the CTV.  Since Eclipse only allows the user to evaluate and optimize a plan with uniform setup uncertainty, new structures for the CTV had to be created for the varying uncertainty before the optimization. Caudally of C3 added PTV margins of 2 and 3 mm were created. Thereafter these new structures were evaluated and optimized with a setup uncertainty of 3 mm.  The limited available data suggests that the treatment plans with varying margins shows favorable characteristics and may improve the treatment quality. Tendencies for improved balance between target coverage and OAR sparing could be seen for the plan with a PTV margin of 3 mm caudally of C3 and a setup uncertainty of 3 mm. However, more patients need to be included in the study before certain conclusions can be made.
4

BICOM Bioresonans : En fallstudie

Lindblom, Louise, Sörhammar, Linnea January 2021 (has links)
Aim: The primary aim of this study was to investigate BICOM Optima with the treatment concept Bicom-Prevent and explore if it can affect physical aspects and wellbeing for participants in this study.   Method:  The study had four participants aged between 25 to 35 years. The study had two test sessions that were accomplished at the University Hospital in Uppsala. First, the study began with a test session, then a treatment period of five weeks with BICOM bioresonance was conducted in the participants' home. The study was finalized with another test session. To get background data of the participants, they all completed different questionnaires about activities, stress and sleeping habits at the first test opportunity. The same form was answered again at the final test opportunity, after the treatment with BICOM Optima. BICOM is a Class 2 medical device based on bioresonance technology.    Results: All of the participants reduced their blood pressure between the two test occasions, and three participants decreased their maximal oxygen uptake capacity. One of the participants suffered an injury during the second test occasion and was not able to finish the test. A second participant was sick when the second test session was, and therefore could not perform the test. As the number of participants was low, the result is greatly affected by the injuries and diseases that existed among the participants during the study. Due to this, no clear correlation between treatment with BICOM bioresonance and an increase in maximal oxygen uptake could be seen.   The results from the stress impact of the participants at the first and the second test session are very similar. No major difference could be identified, and therefore it is difficult to determine whether BICOM had any effects according to this during the treatment period of five weeks. What could be seen was that all participants received a lower blood pressure at the final test.    Conclusion: The conclusion made during the study was that to be able to demonstrate whether BICOM bioresonance have an impact on physical aspects and well-being for the participants a longer treatment period and more comprehensive studies is required.   Key Words: Bicom Optima, Heart rate variability, sleep, stress, case study, bioresonance.
5

Navmark - ett nytt sätt att rädda liv

Stjärnborg, Ida, Torkelsson, Lina January 2023 (has links)
Cancer is a tough disease and in some cases is difficult to treat, which leads to too many people dying. Of the cancer diagnoses made each year, 3.2 million of these are primary and secondary liver cancer. The world needs to be able to reduce these tragic outcomes and to be able to remove a liver tumor in a more patient-centered way. Today, resection of the liver is performed through an open operation, which entails a long and more painful recovery process for the patient compared to a keyhole surgery. The reason keyhole surgery is not used in these operations today is because the surgeon lacks sufficient visualization, which makes it difficult to navigate and remove the tumor with high precision.  Navari Surgical AB is therefore developing a solution that makes it possible to apply keyhole operations for liver cancer by increasing the visualization with Augmented Reality. For the technology to work, a single-use device must be attached to the liver surface and it then acts as a navigation marker in their overall solution. The mission has been to examine and develop a fastener for the single-use device that attaches to the liver and can be removed without damaging the surface. The fastener must also be able to maintain the same position throughout the operation, withstand the moist environment inside the abdomen and comply with the Medical Device Regulations. After research and several tests, the project was able to result in a working fastener, which is a specific hydrogel. Due to the fact that the hydrogel does not adhere to plastic, it will be attached to the single-use device with medical epoxy and a layer of carbon fiber film. Together, these components make up a complete and functioning product, called Navmark. Applying keyhole surgery for liver cancer with Navmark and Navari's technology has several advantages. First, together they increase the surgeon's visualization and localization of the tumor, which in turn increases the precision of the operation. Undergoing keyhole surgery, instead of open surgery, also results in fewer complications and shorter recovery time for the patient. By applying Navmark and Navari's technology, it will in the future be possible to carry out keyhole surgery for liver cancer in a minimally invasive and more patient-centered way, which in turn will be able to save lives.
6

Alarms in hospitals: The fatigue problems and the improvisations in sociotechnical perspective / Larm på sjukhus: Trötthetsproblem och improvisationer i sociotekniska perspektiv

Singh, Suthesh Kumar Balbir January 2020 (has links)
Introduction Alarms have always been an agent of notification, but it can also be distressing and annoying. As much as the sounds of alarm effects the patient’s care and their well-being, it also impacts on the well-being of the healthcare workers which often goes unnoticed as the priority is on the patient-care. Purpose The purpose of the thesis was to investigate the problems of the alarms fatigue and how the improvisations can be done technically and in the point of management and technical organization. Methods The study was conducted through interviews to healthcare staffs and the management of the departments. Four participants from two different hospitals participated in the interview session. Result and Analysis The results obtained from the interviews are analysed with the literature reviews that have been studied and the outcome from the interview tallies on the findings from the literature studies. Additional measures have been implemented based on observation and feedback among the healthcare workers. Conclusion The interview feedback supports the studies of the literature reviews and the measures that have been practiced and implemented to improve the workflow and fatigue issues based on the feedback of the hospital interviews have shown improvements in some departments. The outcome can be presented as a suggestion on future improvements, with better access to newer technology on making working efficiency better. / Introduktion Alarm används i varnande syfte, men kan upplevas som irriterande och störande. Så mycket som det kan upplevas som störande för patienterna, så är det personalens välbefinnande som avgör hur alarmen hanteras eller om de passeras obemärkt. Syfte Syftet med detta projekt är att undersöka problematiken med alarmutmattning och hur detta hanteras tekniskt utifrån personal- och ledningsnivå. Metod Studien genomfördes genom intervjuer med vårdpersonal och förvaltningen av avdelningarna. Fyra deltagare från två olika sjukhus deltog i intervjusessionen. Resultat och Analys  Resultaten som erhållits från intervjuerna analyseras med litteraturöversikter som har studerats och resultatet från intervjun berättar om resultaten från litteraturstudierna. Ytterligare åtgärder har genomförts baserat på observationer och feedback hos sjukvårdsarbetarna. Slutsats Intervjuåterkopplingen stöder studierna av litteraturgranskningarna och de åtgärder som har praktiserats och genomförts för att förbättra arbetsflödet och trötthetsfrågorna baserade på feedback från sjukhusintervjuerna har visat förbättringar i vissa avdelningar. Resultatet kan presenteras som ett förslag på framtida förbättringar, med bättre tillgång till nyare teknik för att göra arbetseffektiviteten bättre.
7

Verification measurements on MRI-linac with PTW BEAMSCAN MR / Verifikationsmätningar på MR-linac med skanningsfantomet PTW BEAMSCAN MR

Kvarnlöf, Olivia January 2022 (has links)
In radiotherapy the main goal is to kill cancer cells, prevent them from growing and reproducing, while healthy tissue is spared. One technique to treat cancer is to use external radiotherapy where a linear accelerator (linac) is used to generate a high energy radiation photon beam. An MRI-linac is a combined magnetic resonance imaging (MRI) and linac and is used to perform adaptive radiotherapy. However, in order to perform treatments on the MRI-linac commissioning measurements must be performed to acquire all radiation beam data, verify its accuracy, and enter all these data into a com- puterized treatment planning system (TPS). To acquire the radiation beam data absorbed dose, output factors, percentage depth dose (PDD) curves and cross- and inplane profiles are measured. This was done together with a gamma analysis by Elekta in connection with the installation of the Elekta Unity MRI-linac at the Uppsala University Hospital in the year 2019. In this project these commissioning measurements and gamma analysis have been recreated and compared with the expected dose distributions calculated in the TPS Monaco. In addition to this a comparison with the result from Elekta has been done. With a water phantom, PTW BEAMSCAN MR, and three different detectors, PTW Semiflex 3D, PTW microDiamond and Farmer chamber PTW30013, PDDs and profiles have been acquired at different field sizes at gantry angles 0° and 270°. The absorbed dose was measured under reference conditions, depth 10 cm and field size 10x10 cm2, to be 0.8656 cGy/MU and 1.1666 cGy/MU at gantry angle 0° and 270°, respectively. This yielded a difference between Elekta’s result of 0.02% and -0.24% for 0° and 270°, respectively. The output factors were measured at 0° and 270° and differed with Elekta’s result in a range from -2.45% to 0.04%. From these values the PDDs and profiles were created and compared with the calculated result from Monaco.
8

Using Fetal Myocardial Velocity Recordings to Evaluate an AI Platform to Predict High-risk Deliveries / Utvärdering av en AI-plattform med hastighetsmönster från fosterhjärtan för att förutspå svåra förlossningar

Baban, Hanna, Grauning, Olivia January 2019 (has links)
Diagnosing abnormal fetal cardiac function using ultrasound is a complicated procedure which makes it difficult to obtain high quality results from ultrasound examinations that are performed shortly before delivery. Color tissue Doppler imaging (cTDI) is the echocardiographic technique that has been used to obtain the data for this project. Subtle changes in the fetal cardiac function caused by a variety of complications can possibly be detected using cTDI. Fetuses suffering from these complications are often involved in high-risk deliveries. Combining the data obtained from cTDI with Artificial Intelligence (AI) may improve precision and accuracy when it comes to diagnosing pathological conditions involving fetal cardiac function before delivery. AI uses machines to perform and execute tasks that are characteristic of human intelligence. AI can be achieved by using deep learning. Deep learning uses algorithms called artificial neural networks that are inspired by the biological structure and function of the human brain. The neural networks classify information in a similar manner to the human brain. A platform that uses deep learning can make statements or predictions based on the data fed to it. The AI platform Peltarion uses deep learning to perform tasks. The aim of this project was to use Peltarion to evaluate the possibility of predicting high-risk deliveries with abnormal perinatal outcome by using data obtained by cTDI velocity recordings of the fetal heart. The data included myocardial velocity recordings from 107 pregnancies, out of the 107 pregnancies 82 of the babies were born healthy while 25 babies had an adverse perinatal outcome. The data was uploaded in the platform and three models were built and trained in order to evaluate the performance of the platform using the data. The parameters that have been used to determine the results are loss, accuracy and precision. The results showed that the accuracy parameter was measured to be 0.8 in all cases which means that the model correctly predicts if a fetal heart is healthy or likely to have an adverse outcome 80% of the time. The precision parameter was measured to be around 0.4 which means out of all the times the model predicted a fetal heart to have an adverse outcome, only 40% truly had an adverse outcome. It was concluded that a substantially larger amount of evenly distributed data is required to appropriately evaluate the possibility of using fetal myocardial velocity recordings as data for the AI platform Peltarion to predict high-risk deliveries.
9

Implementation and Evaluation of Uncertainty Estimation for Advanced Pharmacokinetic Models in DCE-MRI

Höglund, Jonas January 2022 (has links)
The goal of this report is to develop code in Python that implements and evaluates a multivariate linear error propagation for commonly used DCE-MRI models. Two pharmoacokinetic models (PK-models) were tested; modified Kety model and two-compartment exchange model. The analysis compared a Monte carlo simulated signal and a simple analytic model for uncertainty. The purpose of comparing was to have the Monte carlo method and the linear error estimation method reasonably close in terms of estimation of the error of the PK-parameters (parameters are specific for the PK-model). The analysis included an inspection of the resulting plots of the Coefficent of Variation (CV) of the estimation of the PK-parameters, when increasing the ratio of the true value and the added error for each of the input parameters. Generally the CV increased, I.e. the precision decreased, as the noise level increased. For both PK-models, error in injection time of contrast agent were the input parameter with the least tolerance of noise. By comparing the results from both methods, the conclusion is to implement the modified Kety model as the PK-model used in MICE Toolkit (NONPI Medical AB, Umeå, Sweden) and keep the noise to signal level below 15\% in order to obtain precision of the results to less than 33\% error. We have verified the uncertainty estimation method works well for the Modified Kety model but not so well for the two-compartment exchange model. The scope of this study only included two PK-models and one signal model, therefore it would be beneficial to test the linear estimation method used here on other PK-models and signal models to find what models it works well for. / Målet med denna rapport är att utveckla kod i Python som implementerar och utvärderar multivariat linjär felpropagering för ofta använda DCE-MRI modeller. Två farmakokinetiska modeller (PK-modeller) testades; den modifierade Kety-modellen och två-utrymme utbytesmodellen. Analysen jämförde en Monte carlo-simulerad signal och en enkel analytisk modell för osäkerhet. Syftet med jämförelsen var att ha Monte carlo-metoden och den linjära feluppskattningsmetoden någorlunda nära när det gäller uppskattning av PK-parametrarnas fel (parametrarna är specifika för PK-modellen). Analysen innebar en inspektion av de resulterande kurvorna för variationskoefficienten (CV) för uppskattningen av PK-parametrarna, när förhållandet mellan det sanna värdet och det pålagda felet för var och en av ingångsparametrarna ökades. Generellt ökade CV:n, det vill säga precisionen minskade när bruset/felet ökade. För båda PK-modellerna var det fel i injektionstid för kontrastmedel den ingångsparameter som hade minst tolerans för brus. Genom att jämföra resultaten från båda metoderna är slutsatsen att använda den modifierade Kety-modellen som PK-modell i MICE Toolkit (NONPI Medical AB, Umeå, Sverige) och hålla brus-till-signal nivån under 15\% för att få precision av resultaten till mindre än 33\% fel. Vi har verifierat att metoden för osäkerhetsuppskattning fungerar bra för den modifierade Kety-modellen men inte så bra för två-utrymme utbytesmodellen. Omfattningen av denna studie inkluderade endast två PK-modeller och en signalmodell, därför skulle det vara fördelaktigt att testa den linjära uppskattningsmetoden som används här på andra PK-modeller och signalmodeller för att hitta vilka modeller den fungerar bra för.
10

The use of and attitudes to voice amplification in higher education institutions / Användning av och attityder mot röstförstärkning i högskolor

Ashok, Joshua David January 2020 (has links)
Background: Voice is still the most important tool used by teachers, but voice is varied and subject to problems. Teachers who lecture for long hours or have taught for most of their professional lives, face issues such as voice discomfort, chronic voice disorders, occupational voice disorder, stress, physiological and psychological problems. Due to issues such as poor acoustics in the classroom and absence of any installed voice amplification system, teachers might be subject to increase their vocal load to reach all the students in the classroom. Purpose: The aim of this study is to study the fundamental frequency (fo) and the strength Leq[dB(C)] of the teacher’s voice, with and without voice amplification system.  Method: Students from the preparatory year of their studies at KTH (CBH), were asked if they would like to participate in this study that researches on the voice health of teacher. Two days of teaching sessions were recorded using a microphone attached to the teacher’s mouth and three other static microphones placed in different parts of the room. The voice amplification system used in the study, was the one that was already in use at some of the classrooms at KTH. The students and the participating teacher were given questionnaires, towards the end of the teaching session to voice their opinion on the teaching voice, with and without the voice amplification system.  Results: The results from the data collected from the recordings, have shown that the SPL increased between 0.6 dB(C) and 5 dB(C) when the voice amplification system was turned on. The fundamental frequency (fo) of the teacher’s voice reduced by 1.4% with the use of the voice amplifier. The response of the students was overwhelmingly in support of the voice amplification system used during the recordings. 60-62% of female respondents and 68-79% of male respondents felt that the voice amplification system increased the audibility in the classroom. Conclusion: Leq [dB(C)] values from the mics around the classroom showed a considerable increase and thus the amplification system provides a good acoustic condition for the teacher to communicate with his students and a significant improvement in student’s comprehension of the teacher’s voice and learning conditions. There was a decrease in the fo of the teacher’s voice with the amplification, which is good for the teacher’s vocal health and reduces voice disorders while improving the quality and audibility of teacher’s voice. Majority of the students felt that the amplification system was beneficial during the teaching sessions and would like to see more amplifiers installed in more classrooms. / Bakgrund: Rösten är fortfarande det viktigaste verktyget som en lärare har, men rösten är varierad och utsatt för en del problem. Lärare som har undervisat i hela sina professionella liv, står inför problem som obehag med sin röst, kroniska röstförluster, yrkesskador, stress, fysiologiska och psykiska problem. På grund av dålig akustik i klassrummet och frånvaron av ett installerat röstförstärkningssystem, kan lärare bli tvungna att öka sin röstvolym för att nå alla elever i klassrummet. Syfte: Syftet med denna studie är att studera den grundläggande frekvensen (fo) och styrkan Leq[dB (C)] i lärarens röst, med och utan röstförstärkningssystem. Metod: För studenter från basår på KTH (CBH) blev frågan om det skulle vilja delta i denna studie som undersöker lärarens rösthälsa. Två dagars undervisningsspel registrerades med hjälp av en mikrofon kopplad till lärarens mun och tre andra stationera mikrofoner med stativ placerades i olika delar av rummet. Det röstförstärkningssystem som användes i studien var det som redan var i bruk vid några av klassrummen på KTH. Eleverna och den deltagande läraren fick frågeformulär mot slutet av undervisningssessionen, för att svara på frågor om lärarens röst, med och utan röstförstärkningssystem. Resultat: Resultatet som samlats in från inspelningar visade att SPL ökade mellan 0,6 dB (C) och 5 dB (C) med röstförstärkningssystemet. Den grundläggande frekvens (fo) av lärarens röst minskade med 1,4% med röstförstärkaren. Svaren från eleverna var ett överväldigande stöd för röstförstärkningssystemet som användes under inspelningarna. 60-62% av det kvinnliga respondenterna och 68-79% av det manliga ansåg att röstförstärkningssystemet ökade hörbarheten i klassrummet. Slutsats: Leq [dB (C)] -värdena från mikrofonerna på olika ställen i klassrummet visade på en avsevärd ökning av hörbarheten och gav därmed förstärkningssystemet en bra akustisk möjlighet för läraren att kommunicera med sina elever och en signifikant förbättring när det gäller studentens förståelse av det som läraren ville förmedla. fo värdena minskade genom förstärkningen, vilket var bra för lärarens vokalhälsa och minskade ohälsan samtidigt som lärarens röst och kvalitet förbättrades. Flertalet studenter kände att förstärkningssystemet var fördelaktigt för undervisningen och skulle vilja se förstärkare installerade i flera klassrum.

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