Global ETD Search

11	Bioconjugation of RGD peptides on injectable PEGDMA for enhancing biocompatibility Thorendal, Victor January 2019 (has links) A cerebral aneurysm is a weakened area of an artery in the brain, creating an abnormal expansion. Recent research for treatment is utilizing a photopolymerizable hydrogel as a possible operation for injection in situ. This paper aimed to achieve bioconjugation of peptides on a PEGDMA polymer network (using the photoinitiator PEG-BAPO) to form a biocompatible photopolymerizable hydrogel, without compromise to any of its mechanical attributes. Achieving cell adhesion to the hydrogel surface is a critical requirement as that could drive the growth of endothelium between aneurysm and artery, to considerably enhance its sustainability and decrease the risk of inflammation. The hydrogel was synthesized by functionalizing RGD with a PEG-spacer and co-polymerize it with PEGDMA using UV-radiation to create an intertwined cross-linking network. Samples of various peptide concentrations were studied in cell culture to analyze cell adhesion, followed by mechanical tests to identify possible deviations. A subsequent study was established to create a dynamic prototype as a quantifiable replication of a hydrogel inside an aneurysm in vivo. The model was designed in SolidWorks and connected with an Ibidi sticky-Slide to roughly replicate a cerebral aneurysm connected to an artery with space to introduce a hydrogel sample. Biocompatibility Bioconjugation RGD Photopolymerization Surface cell adhesion Injectable Dynamic cell culture system Polymer Technologies Polymerteknologi Medical Materials Medicinska material och protesteknik
12	PCL-Calcium Phosphate 3D Printed Scaffolds For Bone Tissue Regeneration Garcia Perez Delabat, Javier January 2020 (has links) The design and selection of a biomaterial will depend on its specific application and the required properties for that application, both mechanical physicochemical properties. Biomaterials can be extremely helpful in order to treat and help the human body to heal and repair faster any kind of fracture produced in bones. Calcium phosphate scaffolds produced by sol-gel procedures have been used for this purpose with a great success regarding mechanical properties and biocompatibility. This is the reason why new techniques needs to be developed to be able to produce scaffolds in a faster way and to reach a personalized treatment to each patient. By using 3D printing techniques, a new and promising scope is open for bone tissue engineering due to the possibility of printing scaffolds with any shape and complexity through CAD design and modelling. In this project 3D printed scaffolds with a matrix combination of polymers and calcium phosphate will be produced and studied for bone tissue regeneration. Self-setting alpha tricalcium phosphate (α-TCP) based cement inks combined with polycaprolactone (PCL) were optimized, and 3D printed structure scaffolds were successfully generated by direct ink writing. Afterwards, the scaffolds were subjected to different hardening processes in order to obtain different hydroxyapatite microstructure morphologies and were characterised by different methodologies. It was demonstrated the important effect of obtaining a complete transformation from the α-TCP into hydroxyapatite in the mechanical properties. An improvement in the mechanical properties at compression was achieved with the addition of PCL within the scaffold ́s structure and a different fracture mode of the scaffolds was observed. scaffold bone regeneration tissue biomaterials calcium phosphates 3D printing medical device polycaprolactone Biomaterials Science Biomaterialvetenskap Materials Engineering Materialteknik Medical Materials Medicinska material och protesteknik Ceramics Keramteknik
13	EEG Signal Analysis in the Frequency Domain : An Examination of Abnormalities During the Gait Cycle / EEG-signalanalys i frekvensdomänen : En undersökning av avvikelser under gångcykeln Gripentoft, Lou, Isik, Zilan January 2022 (has links) Many people experience discomfort during movement when using a knee prosthesis. As a result, a study is being conducted to see if biomedical models can be used to produce an optimal prosthetic socket to reduce discomfort. This has previously been accomplished using pressure sensors embedded in the sleeve to measure leg pressure at various stages of the gait cycle. To gather more information, an EEG should be performed to find where discomfort occurs throughout a gait cycle. The purpose of the EEG is to perform measurements for a certain time during walking to then be able to analyze the signals that occur from the brain's motor cortex. The signal analysis is performed by applying the Fast Fourier transform to convert EEG data from the time domain to the frequency domain. By examining frequency differences, it is demonstrated that additional measurements with more individuals are required to ensure that the results reflect discomfort, and that the EEG is useful in the applied field of use. / Vid användning av knäproteser upplever ett stort antal personer obehag vid rörelse. På grund av detta utförs det en studie där man genom biomedicinska modeller kan producera den optimala proteshylsan för att minska obehag. Detta har tidigare gjorts med trycksensorer placerade i hylsan, för att kunna mäta tryck från benet vid olika faser av en gångcykel. EEG ska användas för att få mer information var det uppstår obehag under en gångcykel. Syftet med EEG är att genomföra mätningar under en viss tid vid gång, för att sedan kunna analysera signalerna från hjärnans motoriska cortex. Signalanalysen sker genom att transformera EEG-data från tidsdomänen till frekvensdomänen med hjälp av Snabb Fourier transform. Genom att undersöka frekvensskillnader påvisas att ytterligare mätningar med fler individer krävs för att säkerställa att resultaten återspeglar obehag och att EEG är användbart inom det tillämpade användningsområdet. / This work was supported by the research project SocketSense (https://www.socketsense.eu/), funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 825429 EEG Frequency Domain Signal Analysis Fast Fourier transform EEG Frekvensdomän Signalanalys Snabb Fourier transform. Medical Materials Medicinska material och protesteknik Medicinsk laboratorie- och mätteknik
14	Investigation of nanocellulose-based hydrogels as scaffolds for cell-delivery to chonic wounds Eriksson, Jenny January 2022 (has links) No description available. Hydrogel nanocellulose chronic wound wound dressing rheology Hydrogel nanocellulosa kroniska sår sårläkning Nano Technology Nanoteknik Medical Materials Medicinska material och protesteknik Bio Materials Biomaterial Polymer Technologies Polymerteknologi
15	Can Bone Void Fillers Carry Load? : Behaviour of Calcium Phosphate Cements Under Different Loading Scenarios Ajaxon, Ingrid January 2017 (has links) Calcium phosphate cements (CPCs) are used as bone void fillers and as complements to hardware in fracture fixation. The aim of this thesis was to investigate the possibilities and limitations of the CPCs’ mechanical properties, and find out if these ceramic bone cements can carry application-specific loads, alone or as part of a construct. Recently developed experimental brushite and apatite cements were found to have a significantly higher strength in compression, tension and flexion compared to the commercially available CPCs chronOS™ Inject and Norian® SRS®. By using a high-resolution measurement technique the elastic moduli of the CPCs were determined and found to be at least twice as high compared to earlier measurements, and closer to cortical bone than trabecular bone. Using the same method, Poisson's ratio for pure CPCs was determined for the first time. A non-destructive porosity measurement method for wet brushite cements was developed, and subsequently used to study the porosity increase during in vitro degradation. The compressive strength of the experimental brushite cement was still higher than that of trabecular bone after 25 weeks of degradation, showing that the cement can carry high loads over a time span sufficiently long for a fracture to heal. This thesis also presents the first ever fatigue results for acidic CPCs, and confirms the importance of testing the materials under cyclic loading as the cements may fail at stress levels much lower than the material’s quasi-static compressive strength. A decrease in fatigue life was found for brushite cements containing higher amounts of monetite. Increasing porosity and testing in a physiological buffer solution (PBS), rather than air, also decreased the fatigue life. However, the experimental brushite cement had a high probability of surviving loads found in the spine when tested in PBS, which has previously never been accomplished for acidic CPCs. In conclusion, available brushite cements may be able to carry the load alone in scenarios where the cortical shell is intact, the loading is mainly compressive, and the expected maximum stress is below 10 MPa. Under such circumstances this CPC may be the preferred choice over less biocompatible and non-degradable materials. Calcium phosphate bone cement brushite apatite monetite porosity solvent exchange degradation compressive strength diametral tensile strength flexural strength elastic modulus Poisson’s ratio fatigue Ceramics Keramteknik Medical Materials Medicinska material och protesteknik Biomaterials Science Biomaterialvetenskap
16	An alignment tool for prosthetic components : A conceptual development Johansson, Robin January 2022 (has links) Prosthetic alignment is the principle of the position and orientation and of the components in a lower limb prosthesis to achieve desirable biomechanical characteristics. Poor alignment of lower limb prostheses is related to decreased balance, knee and hip arthritis, and higher energy expenditure for the user. Clinicians, the prosthetists, have declared they need better tools and increased knowledge in how to perform lower limb prosthetic alignments. Therefore, the aim was to develop a tool concept for clinicians to use in the prosthetic alignment process. This thesis mapped out most of the variables a clinician must consider in the alignment process, identified the clinicians needs of an alignment tool, and screened the market for existing solutions. A systematic approach was applied to develop a conceptual tool from the gathered information. The needs of the customer were based on interviews with clinicians and competing products were benchmarked. Two different conceptual tools were developed, tested with clinicians with promising results, and presented in this thesis. Due to confidentiality agreements with the cooperating company, the designs and functions of the final concepts cannot be shown in the report and are therefore covered in the publication. / Protesuppställning är principen av att orientera och positionera komponenterna i en benprotes för att uppnå önskvärda biomekaniska egenskaper. Undermålig protesuppställning är relaterat till försämrad balans, knä- och höftartros, samt högre energiförbrukning hos användaren. Ortopedingenjörer har uttalat att de behöver bättre verktyg och ökad kunskap kring hur man bäst utför uppställning för benproteser. Uppsatsen ämnade därför att utveckla ett verktygskoncept för ortopedingenjören att använda i protesuppställningen. Den här uppsatsen har kartlagt de flesta variabler som en ortopedingenjör behöver överväga i uppställningsprocessen, identifierat ortopedingenjörers behov i ett uppställningsverktyg, samt undersökt marknaden för existerande lösningar. Ett systematiskt tillvägagångsätt användes för att utveckla ett konceptuellt verktyg baserat på den insamlade informationen. Kundens behov identifierades genom intervjuer med ortopedingenjörer och konkurrerande lösningar sammanställdes i en konkurrensanalys. Två olika konceptuella verktyg utvecklades, testades tillsammans med ortopedingenjörer med lovande resultat, samt har presenterats i denna uppsats. På grund av sekretessavtal med företaget som ingått i samarbetet kunde designen och funktioner, som ingår i de slutliga koncepten och resultatet, inte visas i denna rapport och är därmed övertäckta vid publicering. Prosthetics alignment malalignment misalignment artificial limb design product development. Protes uppställning inställning felställning konstgjord kroppsdel design produktutveckling Medical Materials Medicinska material och protesteknik Övrig annan medicin och hälsovetenskap
17	A 3D-printed Fat-IBC-enabled prosthetic arm : Communication protocol and data representation Engstrand, Johan January 2020 (has links) The aim of this thesis is to optimize the design of the Fat-IBC-based communication of a novel neuroprosthetic system in which a brain-machine interface is used to control a prosthetic arm. Fat-based intra-body communication (Fat-IBC) uses the fat tissue inside the body of the bearer as a transmission medium for low-power microwaves. Future projects will use the communication system and investigate ways to control the prosthetic arm directly from the brain. The finished system was able to individually control all movable joints of multiple prosthesis prototypes using information that was received wirelessly through Fat-IBC. Simultaneous transmission in the other direction was possible, with the control data then being replaced by sensor readings from the prosthesis. All data packets were encoded with the COBS/R algorithm and the wireless communication was handled by Digi Xbee 3 radio modules using the IEEE 802.15.4 protocol at a frequency of 2.45 GHz. The Fat-IBC communication was evaluated with the help of so-called "phantoms" which emulated the conditions of the human body fat channel. During said testing, packet loss measurements were performed for various combinations of packet sizes and time intervals between packets. The packet loss measurements showed that the typical amount of transmitted data could be handled well by the fat channel test setup. Although the transmission system was found to be well-functioning in its current state, increasing the packet size to achieve a higher granularity of the movement was perceived to be viable considering the findings from the packet loss measurements. prosthetic arm bionic arm 3D-printing intra-body communication ibc fat tissue fat-ibc arduino xbee 802.15.4 cobs cobs/r packet loss serial transmission armprotes 3D-utskrift intrakroppslig kommunikation fettvävnad paketförlust seriell överföring Communication Systems Kommunikationssystem Embedded Systems Inbäddad systemteknik Medical Materials Medicinska material och protesteknik
18	U-Med : A Mobile Application and a Reverse Vending Machine for Individuals to Reduce Unused Medication Waste Bacaksizlar, Ecenur January 2022 (has links) Medication waste, both packaging and actual drug waste, has been having a tremendous impact on the environment and healthcare budget. However, this is even more concerning after Covid-19 affects the drug purchasing behaviours and causes potentially more unused medications while many people are not able to access healthcare. Some of the main challenges of lack of contribution to the life after the purchase of unused medicine are the patient’s lack of knowledge of how to dispose of them, the medication distribution, the legislation and not having an encouraging sustainable system to reduce medication waste on a bigger scale. This project focused on understanding medicine usage behaviours in Turkish society and developing a circular model called U-Med (Unused Medications). The model has a mobile application and reverse vending machines which are linked with e-Nabız (e-Heartbeat, an application that Turkish citizens and health professionals access to health data collected from health institutions) to reduce medication waste by providing individuals to dispose of or share their unused medicines with the healthcare system or the other industries that can reuse. The concept also aims to show a sustainable approach which can influence decision-making in legislation on medication distribution. This project includes face-to-face, semi-structured interviews in a neighbourhood in Sarıyer, Istanbul Turkey with 5 patients, 3 doctors, 3 nurses and 5 pharmacists along with the health director in the municipality of Sarıyer. Additionally, remote interviews were organised with a non-profit organisation in Greece called GIVMED which has similar concerns. Apart from these, a Turkish survey among 88 Turkish citizens about medication usage behaviour was conducted. Medication waste circular economy participatory design sustainability medicine sharing unused medication reverse vending machine smart bins interaction design Human Computer Interaction Interaction Technologies Interaktionsteknik Design Design Medical Materials Medicinska material och protesteknik Environmental Management Miljöledning
19	Preventing fatal effects of overworking : Product design solution Adawi, Rahim January 2018 (has links) “Overworking to death” is a phenomenon that has been noticeable in developing countries. The cause of death is mainly through ischemic strokes. While the victims’ occupations differed, they all shared a common characteristic, being positioned in a sedentary work, ranging from IT workers to doctors. This project’s aim was to develop a product that prevented or decreased the strokes that derived from sedentary overwork. This was mainly tackled by preventing one of the three causes of developing blood props, slowed blood flow. In order to gather rich data of the phenomenon, a qualitative study was conducted in China, during two months. By doing an extensive structured sampling, information rich data could be gathered during a short period of time. Data were derived from observations, questionnaires and an interview, which then was interpreted to customer needs and the final product specification. The final product became a trouser with an in built dynamic compression mechanic, that can compress the veins mostly during sitting activities, in order to prevent blood stasis. The compression mechanic works like the Chinese finger trap; compressing the calves while sitting and stretching the legs forward. It is made only out of polysaccharides fibres; cotton and corn. / "Guolaosi" eller död från överarbete är ett fenomen som i regel uppkommer bland utvecklingsländer. Dödsorsaken är huvudsakligen genom stroke. Offrens yrken varierar allt från professorer, IT-arbetare till läkare. De delar dock en sak gemensamt; att arbeta under långa perioder stillasittande. Projektets mål var att utveckla en produkt som minskar dödliga följderna av sedentära överarbete, genom att förebygga en av de tre orsakerna för att utveckla blodproppar; saktad blodström. Målgruppen var då kineser av de yrken som hade tidigare drabbats av fenomenet. För att samla informationsrika data om fenomenet genomfördes en kvalitativ studie i Kina under två månader. Genom att göra en omfattande strukturerad provtagning kunde informationsrika data samlas under en kort tidsperiod. Fältstudien bestod av observationer, frågeformulär och en intervju, som då tolkades till kundbehov och eventuellt produktspecifikationen. Den slutliga produkten kom att bli ett par byxor med en inbyggd dynamisk komprimeringsmekanism, som kan komprimera venerna under sittande aktiviteter, för att förhindra saktad blodström. Kompressionsmekanismen fungerar som den kinesiska fingerfällan. Den komprimerar blodkärlen medan personen sitter och sträcker benen framåt. Produkten är konstruerad på så sätt att den kan tillverkas endast av polysackariders tråd, från bomull och majs. Vilket är lämpligt för Kinas lokala resurser. stroke DVT overworking karoshi guolaosi prolonged inactivity sedentary death product design China Sweden Sida MFS field study trouser pants sampling observation questionnaire interview blood circulation stasis cardiovascular disease cotton corn agenda 2030 Chinese finger trap textile fibre yarn soil erosion muscle pump mechanism gradual compression stockings GECS PECS pressure distribution blood clot veins therapy stool chair PE PTS economy class syndrome methodology plastic sample concept sketch stroke DVT överarbete karoshi guolaosi förlängd inaktivitet stillasittande död produkt design Kina Sverige Sida MFS fältstudie byxa byxor provtagning observation frågeformulär intervju blodcirkulation stasis kardiovaskulär sjukdom bomull majs agenda 2030 kinesisk fingerfälla textil fiber garn jord erosion muskel pump mekanism gradvis komprimering strumpor stödstrumpa tryck kraft GECS PECS tryckfördelning blod blodproppar vener terapi pall stol PE PTS ekonomi klass syndrom metodik plast prov koncept skiss Design Design Pharmacology and Toxicology Farmakologi och toxikologi Occupational Therapy Arbetsterapi Cardiac and Cardiovascular Systems Kardiologi Environmental Sciences Miljövetenskap Medical Ergonomics Medicinsk ergonomi Textile, Rubber and Polymeric Materials Textil-, gummi- och polymermaterial Composite Science and Engineering Kompositmaterial och -teknik Medical Materials Medicinska material och protesteknik

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