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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

UV laser patterning of silicone-based soft electrode grids

Jakobsson, Maria January 2023 (has links)
Roughly 123 million people worldwide are affected by conditions such as epilepsy, dementia, and cardiovascular diseases. Wearable electrodes are currently used to monitor these conditions short-term. Long-term monitoring would allow for predicting seizures and could be used as a preventive treatment. As opposed to the currently used electrodes, wearables that are intended for long-term use must be soft and flexible in order not to cause harm or discomfort for the user. The electrodes should also have high resolution, meaning that the electrode paths should be as narrow as possible without negatively affecting the performance of the electrode. In this thesis, soft and flexible electrode grids based on silicones are developed using UV laser patterning. Two different methods are evaluated: laser curing of silicones with the addition of a photoinitiator, and laser ablation of conductive composite. The results found in this thesis are that photocuring silicones gives a too low resolution to be useful for patterning soft electrode grids. UV laser ablation on the other hand showed high resolution while the electrodes retained stretchability. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
32

An Application To Improve Music For People With Hearing Loss When Doing Sports / En applikation för att förbättra musik för personer med hörselnedsättning under sport

Josefsson, Jonathan January 2022 (has links)
It is well-known that many people like to listen to music when they are running,something that is not always available for people with hearing aids [1].The experience of music is not often taken into account when people have lostparts of their hearing, but music is in many ways important for the well-being[2]. In this project has an application been developed, to make certain audioparameters accessible for adjustments according to the users individual hearing.The parameters chosen were latency, compression, balance and loudness. Theseparameters have been chosen with the argument that they have big impact onthe experience of the music. As an example there might be latency betweenthe hearing aids between the left and the right hearing. Very often people withhearing aids have different hearing at the left and the right ear, therefore thebalance was chosen as a parameter. Compression were chosen with respect tothe fact that hearing loss often leads to less capability to hear frequencies indifferent frequencies areas. Loudness was chosen due to that it is a subjectiveparameter, that will have different impact on different individuals. The parametershave been chosen with a hypothesis that they may affect the hearingexperience for different individuals. The result show that the participants changed audio settings, each of theaudio parameters to different values and appreciated the function to changethese parameters. The participants said that the application developed in thisproject, improved their music experience and they said that they would appreciateto use an application like this, to get more value of listening to music. Theapplication was well designed and easy to use during a sport session.
33

Flödesberoende avvikelser hos distributionen av läkemedel inom neonatalvården vid användning av infusionspumpar / Flow Rate Dependent Distribution Deviation of Pharmaceuticals with Pumps in Neonatal Care

Kravchenko, Evgenija, Forsberg Trägårdh, Patrik January 2018 (has links)
Volym- och sprutpumpar används inom neonatalvården tillsammans med en specialanpassad kateter. De prematurfödda barnen är mycket känsliga för feldoseringar men det finns minimalt med dokumenterade projekt som undersöker hur väl den distribuerade dosen stämmer överens med den angivna på infusionspumpen. Målet med denna studie var att kontrollera om det fettbaserade läkemedlet Clinoleic flyter tillbaka i det gemensamma blocket, avgöra tiden det tar för läkemedel att flyta fram samt mäta mängden av läkemedel som kommer till mynningen av katetern. Antalet pumpar begränsades till startuppsättningen inom intensivvården på neonatalavdelningen, vilket är fyra pumpar. Mängden av läkemedlet för fem olika flöden undersöktes endast för läkemedlet Peyona med koffeinbas. Projektet genomfördes på Karolinska Universitetssjukhuset och i samarbete med Nya Karolinska Solna förbättrades förståelse för uppsättningens användning. Samtliga sjuksköterskor och ingenjörer vi kom i kontakt med på sjukhusen ansåg att fler studier behöver göras inom distribution av läkemedlen. Tydliga kopplingar kan ses mellan resultat som presenteras i arbetet och misstankar och förväntningar efter samtal med de som jobbar med pumpar. Möjliga framtida experiment som kan ge tydligare riktlinjer inom neonatalvården diskuteras. Det är några anmärkningsvärda resultat som redovisas i studien. De är att Clinoleic flyter bakåt i blocket och att fylla backventilen tar mellan 16 och 25 minuter för de undersökta flödena. Dessutom framgår det att distributionen av Peyona avviker minst för de högre flödena. / Volume and syringe pumps are used in neonatal care together with a customized catheter. The premature born children are extremely sensitive to incorrect dosage, but there are only a short number of documented projects that investigate how well the distributed dose corresponds to that indicated on the infusion pump. The aim of this study was to check whether the fat-based drug Clinoleic flows back into the common block, determine the time it takes for drug to flow and measure the amount of drug that comes to the orifice of the catheter. The number of pumps and drugs was limited to the initial set that is used in intensive care in the neonatal department. The setup consists of four pumps and the drugs Peyona, Clinoleic, Glucos and Sodium Chloride solution. The amount of medicine distributed for five different flows was investigated only for the caffeine-based drug Peyona. The project was implemented at Karolinska Universitetssjukhuset and with help of Nya Karolinska Solna the understanding for the used setup was improved. All nurses and engineers we came into contact with at the hospitals felt that more studies should be done in the subject of the distribution of the drugs. Obvious connections are seen between results that are presented and suspicions and expectations after consultation with those who work with pumps daily. Possible future experiments that provide clearer guidelines for neonatal care are discussed. There are some notable results reported in the study. They are that Clinoleic is flowing back into the block and filling the check valve takes between 16 and 25 minutes for the investigated flows. for the investigated flows and that that the smallest distribution deviation of Peyona is observed in higher flows.
34

Principkonstruktion för kvalitetsbedömning av medicinska slangsvetsfogar / Theoretical Prototype for Quality Assessment of Medical Tube Welds

Malmsten, Chanel, Ekberg, Amanda January 2022 (has links)
Medicinska plastslangar har en väsentlig roll inom sjukvården, vilket även ställer krav på de maskiner som försluter dessa slangar. Den typ av förslutningsteknik som beskrivs i rapporten är radiofrekvenssvetsning, som sammanfogar en utvald del av den medicinska slangen till en svetsfog. Idag sker det ofta okulär inspektion av svetsfogar vilket leder till att felaktigt utförda svetsfogar kan råka hamna på laboratorium. Att tillverka en utrustning som kan testa svetsfogarna enkelt, kan därför vara gynnsamt för alla användare av slangsvetsare. För att säkerställa kvalitén på svetsfogar har målet för arbetet varit att ta fram en teoretisk principkonstruktion, vars funktion är att kvalitetssäkra svetsfogar utförda på medicinska slangar. För arbetet har det även tagits in relevant information om vad för krav en svetsfog måste klara av enligt ett urval av användare och distributörer, vilket har använts för att ta fram principkonstruktionerna. Dessa mål uppfylldes genom att via litteraturstudie insamla information och läsa om tidigare studier, sammanställa viktiga nyckelkomponenter och sedan presentera idéerna för handledarna som gav återkoppling. Denna återkoppling användes för att färdigställa den slutliga principkonstruktionen. Den teoretiska principkonstruktion som framtagits anses ha en god användarvänlighet, då människa och maskininteraktion är minimal. Vidare anses den även ha en stor nytta för användarna då principkonstruktionen är avsedd för att kunna utföra tester på alla typer av medicinska slangar och deras svetsfogar, utan att förstöra slangen eller kontaminera dess innehåll. / Medical tubes have a significant role in healthcare, which also puts a high demand on the machines that seal the tubes. The type of seal technique which is described in the report is radio-frequency welding, which joins a selected part of the medical tube into a weld. Today, ocular inspection is often used when inspecting sealed ends, which leads to incorrectly performed sealings accidentally ending up in laboratories. Manufacturing equipment that can test welds easily, can therefore be beneficial for all users of tube welds. To ensure the quality of welds, this study has aimed to develop a theoretical prototype, with the function to test the quality of welds made on medical tubes. In this study, various information has been gathered about what requirements a weld must withstand according to a selection of users and distributors, which has been used to develop the theoretic prototype. To fulfill the aim of the study a literature study and previous work were gathered. Then important key components were compiled and the ideas for the theoretical prototype were presented to the supervisors who provided feedback. This feedback was used to complete the final theoretical prototype. The theoretical prototype that has been developed is considered to have good user-friendliness, as human and machine interaction is minimal. Furthermore, it is also considered to be of great benefit to the users as the theoretical prototype is intended to perform tests on all types of medical tubing and their welds without rupturing the tube or contaminating its contents.
35

Towards laser fabrication of soft neural electrodes

Schill, John January 2022 (has links)
Electronic devices define our everyday lives. They are often large, rigid, and brittle. Modern medical science has come so far as to start using miniature electronic devices to monitor many types of diseases. Especially, neurological disorders pose obstacles hard to overcome when treating them but it also motivates finding methods that allow for continuous monitoring. Implementing a small electronic device inside the human body adds requirements on the device to be stretchable, biocompatible, and more. Not only is the device limited by these factors, but also, current fabrication methods are not efficient for creating nanoscale versions for these types of devices. patterninglaser ablation is a growing field for cutting out and pattern nano-materialistic devices with high precision and good repeatability. This project is focused on using a laser engraving tool from metaquip on different substrates. This project is focused on the development of methods for laser fabrication of soft neural electrodes. The requiered steps are the alignment of samples to assure good precision when engraving it with the laser engraving tool, that also will be called “laserpatterner”, finding good parameters for cutting out devices and pattern conductors for said devices. On top of that, a linear force stretching will be used to characterize samples that were cut, in the form of strips, using the laserpatterner. The stretching behavior of strips consisting of the elastomer polydimethylsiloxane, which in turn will be the insulator for silver nanowires, is examined in the stretching setup. Parameter optimization is relevant in all experiments done in this project and lay the foundations for cutting and patterning silver nanowires devices. All factors included will eventually lead to a good method for fabricating soft neural electrode devices and this project is stepping stone towards that goal. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
36

Utvärdering av en befintlig plattform för neurofeedback med hjälp av open-source EEG

Al Kouatli, Hakim, Achmawi, Mohamed January 2022 (has links)
Neurofeedback is a type of biofeedback in which subjects learn to use the activity of their own electrical brain waves to respond to a visual or auditory feedback from the activity of the brain. This is done by connecting electrodes to the body to get the brain's electrical activity in the form of encephalogram signals (EEG) which are then calculated and converted into useful feedback.The purpose of this work was to evaluate a neurofeedback platform via an OpenBCI open-source EEG technology that could lead to more accessible neurofeedback for society.This study was conducted with different methods where the focus was on testing and data analysis. The study has included a summary of theory used in neurofeedback, a comprehensive pilot study on an 8-channel open-source EEG neurofeedback platform and some of the ethical aspects behind the technology used and neurofeedback in Sweden. During the work, two different experts were interviewed: Gunilla Radu, founder and owner of Nordic Center of Neurofeedback AB and Jan Rutkowski, who is an engineer in medical engineering at the Uppsala Hospital.The tests with 8-channel EEG with an OpenBCI hardware and software show results from three subjects. The answers from a follow-up survey that subjects were allowed to answer are presented in the report. This was used as an evaluation of the tests performed. The aim of the tests was to give Biohackeri an opportunity to see the potential for a neurofeedback platform and to create a basis for further development of such a platform. The result indicates that a measurement of the brain activity at rest with the technology from OpenBCI shows a higher concentration level in the human body with open eyes compared to closed eyes. In addition, a higher level of relaxation is noticed when resting with eyes closed compared to eyes open. Answers from the survey show that what is important to the test subjects is, among other things, the convenience while testing the technology. In terms of requirements and rules that Neurofeedback therapists must meet, it turned out that in Sweden therapists do not need to have a specific background or education. There are ethical perspectives that Neurofeedback therapists may consider in implementing Neurofeedback Therapy.The conclusion of this project is that the tested 8-channel EEG equipment gives a result that agrees with the presented theory. Thus, a Neurofeedback platform could be built on the commercially available open-source technology, such as the technology from OpenBCI. / Neurofeedback är en typ av biofeedback som försökspersoner lär sig att använda sin egen elektriska hjärnvågors aktivitet för att svara på en visuell eller auditiv återkoppling från hjärnans aktivitet. Det görs huvudsakligen genom att ansluta elektroder till huvudet för att få hjärnans elektriska aktivitet i form av encefalogramsignaler (EEG) som sedan beräknas och omvandlas till användbar återkoppling.Syftet med detta arbete var att utvärdera en Neurofeedback-plattform via en OpenBCI open-source EEG-teknologi som skulle kunna leda till mer tillgänglig Neurofeedback för samhället.Denna studie genomfördes med olika metoder där huvudfokus låg på testning och dataanalys. Studien har innefattat en sammanfattning av teori som används inom Neurofeedback, en pilotstudie på en 8-kanals open-source EEG-Neurofeedback plattform och en del av de etiska aspekterna bakom den använda tekniken och Neurofeedback i Sverige. Under arbetets gång intervjuades två olika experter, Gunilla Radu, grundare och ägare av Nordic Center of Neurofeedback AB och Jan Rutkowski som är medicinteknisk ingenjör på Akademiska sjukhuset.Från testerna med 8-kanal EEG med en OpenBCI hårdvara och mjukvara visas resultat från tre försökspersoner. Svaren från en efterundersökningsenkät som försökspersoner fick svara på presenteras i rapporten. Detta användes som en utvärdering på de utförda testerna. Målet med testerna var att ge Biohackeri en möjlighet att se potentialen för en Neurofeedback-plattform samt att skapa en grund för vidareutveckling av en sådan plattform. Resultatet indikerar att en mätning på hjärnaktiviteten vid vilotillstånd med tekniken från OpenBCI kan det märkas högre koncentrationsnivån i människokroppen med öppna ögon jämfört med stängda ögon. Dessutom märks det en högre avslappningsnivå vid vilotillstånd med stängda ögon jämfört med öppna ögon. Svar från enkäten visar att det som är viktigt för testpersonerna är bland annat bekvämligheten under provning av tekniken. När det gäller krav och regler som Neurofeedback-terapeuter ska uppfylla visade det sig att i Sverige behöver terapeuter inte ha en specifik bakgrund eller utbildning. Det finns etiska perspektiv som Neurofeedback-terapeuter kan överväga att implementera vid Neurofeedbackterapi.Slutsatsen av detta projekt blir att den testade 8-kanal EEG utrustningen ger ett resultat som stämmer överens med den presenterade teorin. Därmed skulle en Neurofeedback-plattform kunna byggas på den kommersiellt tillgängliga open-source tekniken såsom tekniken från OpenBCI.
37

Design and evaluation of a novel Transillumination SFDI system for quantitative assessment of tissuesections for rapid, label-free cancer margin detection

Younan, Merel January 2023 (has links)
This study investigates the potential of Spatial Frequency Domain Imaging (SFDI) as a non-invasive imaging technique for tissue analysis in the context of Mohs surgery, a standard procedure for skin cancer removal with margin control. The current practice of performing multiple histopathologic sections during the procedure is time-consuming and labor-intensive. SFDI, utilizing optical measurements, offers quantitative imaging of biological tissues, enabling the assessment of their function and structure. This makes it particularly suitable for imaging sensitive tissues like the skin and the eye. By accurately measuring the optical properties of tissues, a deeper understanding of their characteristics and the interaction of light with tissue can be achieved. In this study, a novel transillumination SFDI system was designed and utilized to obtain spectral data from examined 2 mm thick tissue-simulating phantoms. The results demonstrated the potential of the transmission-based SFDI as a valuable tool in tissue analysis,providing rapid and accurate information about tissue properties. The implementation of transmission-based SFDI system holds promise for enhancing tissue-conserving surgeries. By enabling direct analysis of tissue properties at the point of care, this system could eliminate the need for histopathologic processing. Consequently, it can provide rapid and accurate information about tissue characteristics without the need for histopathologic processing, allowing for more precise and efficient surgical procedures and better patient outcomes
38

Ray Cast/Dose Superposition algorithm for proton grid therapy

Marusic, Tibor January 2017 (has links)
Purpose: To develop a Ray Cast/Dose Superposition (RC/DS) algorithm for proton grid therapy. Its functionality needed to include automatic positioning of small proton pencil beams in a grid-pattern and superimposing thin beam Monte Carlo (MC) dose distribution data on a Computer Tomography (CT) density volume. The purpose was to calculate and store un-weighted volumetric dose distributions of individual proton energies for subsequent optimization. Materials &amp; Methods: Using the programming language Python 3.6, CT and Volume Of Interest (VOI) data of various patients and phantoms were imported. The target VOI was projected to either two or four planes, corresponding to the number of used gantry positions. Rays were then traced through the CT voxels, which were converted from Hounseld Units to density using a look up table, to calculate Water Equivalent Distance and proton energy needed to reach the proximal and distal edge of the target volume. With automated grid-pattern beam positioning, thin beam MC calculated depth dose distribution files were interpolated, scaled and superimposed on the CT volume for all beamlet positions. The algorithm reliability was tested on several CT image sets, the proton range estimation compared to a commercial TPS and the depth dose interpolation analyzed using MC simulations. Results: The RC/DS algorithm computation time was on average around 6 hours and 30 minutes for each CT set. The dose distribution output visually conformed to target locations and maintained a grid pattern for all tested CT sets. It gave unwanted dose artifacts in situations when rays outside the beamlet center passed a significant length of low/high density regions compared to the center, which yielded dose distributions of unlikely shape. Interpolating MC dose distribution values showed comparability to true MC references of same energy, yielding results with 0.5% difference in relative range and dose. Conclusions: The developed algorithm provides unweighted dose distributions specific for small beam proton grid therapy and has been shown to work for various setups and CT data. Un-optimized code caused longer computation times then intended but was presumed faster than MC simulations of the same setup. Efficiency and accuracy improvements are planed for in future work. / Proton grid therapy group
39

Development, Modelling and Investigation of a Robotic Exoskeleton for Astronaut Back Support

Häggman, Evert January 2021 (has links)
Musculoskeletal disorders, specifically low back pain, has been well documented andreported by astronauts throughout the space exploration era. Statistics from astronautmemoirs states that 52-68% of astronauts experience moderate to severe lower backpain after prolonged spaceflights. The main cause is atrophy in the paraspinal musclesof the lumbar region. No sufficient countermeasure exists in-flight currently and therehabilitation programs remain ineffective. This thesis presents the first attempt to designand develop a prototype robotic exoskeleton, actuated by pneumatic artificial muscles, asan active countermeasure in-flight where it will be utilised as an equipment for muscularhypertrophy and a supporting device for rehabilitation programs on Earth. It will bemanufactured by additive manufacturing methods for adaptability while remaining lowin weight.A thorough analysis of the spine and lumbar region as a biomechanical system wasmade. Appropriate assumptions was made to simplify the understanding of the complexsystem that is the human spine. The targeted muscles were: multifidus, erector spinaeiliocostalis and erector spinae longissimus. A force analysis of the human torso bendingin the sagittal plane was made, finding that the torques of the torso reaches 244 Nm.The complete exoskeleton design is presented with the parts that will be 3D-printed andthe working principle of the system. Thereafter an extensive model of the exoskeletonis established using Denavit-Hartenberg representation of manipulators as a serial linksystem. The model provides a fundamental understanding of exoskeleton and enablesthe possibility to simulate it accurately. The evaluation protocol for the validation testsis then presented. Active pressure will be tested at 0, 3 and 6 bar and loads of 5 and 11kg will be lifted.Subsequently the assembly, with all the hardware and software selected for the prototypeis demonstrated. Thereafter the results of the evaluation tests are presented followed bya discussion of the results; anomalies, faults and challenges are subjects discussed. Thediscussion concludes that the exoskeleton shows potential for both supporting the motionin a rehabilitation use and enabling muscular hypertrophy in the lumbar region for theresistive tests. Although an extensive heavy-duty evaluation needs to be performed totruly validate the exoskeleton.
40

Evaluation of biomedical microwave sensors : Microwave sensors as muscle quality discriminators in laboratory and pilot clinical trial settings

Mattsson, Viktor January 2022 (has links)
In this thesis the primary focus is on the evaluation of biomedical microwave sensor to be used in the muscle analyzer system. Lower muscle quality is one indicator that a patient can have sarcopenia. Therefore the muscle analyzer system can be a tool used in screening for sarcopenia. Sarcopenia is a progressive skeletal muscle disorder that typically affects elderly people. It is characterized by several different things, one of them is that there is an infiltration of fat into the muscle. At microwave frequencies the dielectric properties of fat are vastly different than the muscles. So, this fat infiltration creates a dielectric contrast compared to muscle without this fat infiltration that the sensors aim to detect. The muscle analyzer system is proposed to be a portable device that can be employed in clinics to assess muscle quality. The sensors are evaluated on their ability to distinguish between normal muscle tissue and muscle of lower quality. This is achieved via electromagnetic simulations, clinical trials, where the system is compared against established techniques, and phantom experiments, where artificial tissue emulating materials is used in a laboratory setting to mimick the properties of human tissues. In a initial clinical pilot study the split ring resonator sensor was used, but the results raised concerns over the penetration depth of the sensor. Therefore, three new alternative sensors were designed and evaluated via simulations. Two of the new sensors showed encouraging results, one of which has been fabricated. This sensor was used in a another clinical study.This study only had data from 4 patients, 8 measurements in total, meaning it was hard to draw any conclusions from it. The sensors used in the clinical setting as well as another were evaluated in the phantom experiments. Those experiments were exploratory because a wider frequency range was used, although some problems in the experiments were found. A secondary approach in this thesis is devoted to a data-driven approach, where a microwave sensor is simulated. The data from it is simulated and used to train a neural network to predict the dielectric properties of materials. The network predicts these properties with relatively high accuracy. However, this approach is currently limited to simulations only. Several ideas on how to improve this approach and extend it to measurements is given.

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