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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.
71

Ultrasound Transducers. Function and Quality Control in Hospitals

Hassoun, Abdallah January 2012 (has links)
Nowadays, most of the medical technology manufacturers try to meet the high demands of quality and design of ultrasound equipment, including transducers: easy to use, flexible image handling, multi frequencies operation use of various applications, good resolution and penetration. It is known that this kind of medical devices is extremely sensitive and should be maintained in compliance with the necessary physical and functional requirements, via regular tests (Moore, 2006). This master thesis has two purposes. The major one is to examine the physical and functional status of every single transducer in Gävleborg hospitals. It allows defining a possible problem before it has influenced formation image and diagnosis. The second purpose is to find out the advantages and disadvantages of using the ultrasound evaluation test FirstCall aPerio Testing Accreditation Program, manufactured by Sonora Medical System in Longmont, USA (www.4sonora.com).The scientific method of this evaluation test is based on three steps which are as follows: testing of ultrasound transducers, classified data collection and analysis. The evaluation test used in this report is a highly qualified system which has been designed to avoid and minimize diagnostic risks, and at the same time, maximize patient’s safety. It allows distinguishing any hidden manufacturing defects with new devices or those appearing during the operation period. For this evaluation test, 73 transducers were controlled, belonging to clinics of four different hospitals within the Gävleborg area. Tested transducers were manufactured by Siemens, GE Healthcare and Aloka. A total of 61 of transducers passed the test and 12 did not pass it.  Finally it was observed, that the reason for not passing the evaluation test was mostly due to dead elements in a row in the centre of the transducers. Thanks to the software program of FirstCall aPerio, the results of the evaluation test are immediately visible, through the report. It is useful in early discovering the source of error in transducer and minimizing of wrong diagnosis. The testing system gives a possibility to test the transducer without US equipment and to collect the database information. Keywords: ultrasound, FirstCall aPerio Testing Accreditation Program, ultrasound transducers, evaluation test, wrong diagnosis.
72

Skin cancer Detection byTemperature VariationAnalysis

Moustafa, Ahmed January 2012 (has links)
In the medical field new technologies are incorporated for the sole purpose to enhance the quality of life for patients and even for the normal persons. Infrared technology is one of the technologies that has some applications in both the medical and biological fields. In this work, the thermal infrared (IR) measurement is used to investigate its potential in skin cancer detection. IR enjoys a non-invasive and non-contact advantages as well as favorable cost, apparently. It is also very well developed regarding the technological and methodological aspects. IR radiation, per se, is an electromagnetic radiation that all objects emit when their temperature is above the absolute zero. Human body is not different. The IR range extends, ideally, to cover wavelengths from 800 nanometer to few hundreds micrometer. Cancer, in modern life, has grown tangibly due to many factors apparently such life expectancies increase, personal habits, and ultraviolet radiation (UV) exposures among others. Moreover, the significant enhancement of technologies has helped identifying more types of cancers than before. The purpose of this work is to investigate further another method and application of IR technology not yet matured in detection of skin cancer to enhance detection ability that is accompanied with higher level of safety. An extensive research project was designed to use two laboratory animals injected with cancer cells subcutaneously and two IR radiation sensors able to detect wavelengths in the range 8 – 14 μm which proved to be a favorable range to measure the temperature of the skin. Data collection performed using two lab animals as subjects that formed a double blind investigation process. An analysis of the observations was conducted both in qualitative as well as quantitative approaches. The analysis and discussion revealed the potential of the thermal IR radiation in detecting skin cancer existence. The thesis was supported with significant evidence and achieved its target. Furthermore, it was clear that the functional nature of thermal IR detection constitutes another advantage for this method that can be used in the future to develop an objective and automated method for detection of skin cancer in a straight forward and cost effective manner.
73

Exploring Ethical Hacking by Identifying Vulnerabilities in Motorola BabyMonitor MBP855CONNECT(4855) / Studie av etisk hackning genom att identifiera sårbarheter i Motorola BabyMonitor MBP855CONNECT(4855)

Hilding, Martin, Nordström, Mattias January 2021 (has links)
As IoT is implemented into more of our daily-use devices, so too should the understanding of potential risks caused by interconnectivity. Securing an IoT device is no simple feat, it is therefore important to understand the complexities of cyber security.   This thesis has itemized the basics of IoT penetration testing using the Motorola MBP855CONNECT as an example device. The thesis includes a basic theoretical introduction to ethical hacking, coupled with the exploration of a few fundamental penetration testing techniques described in the STRIDE threat modeling framework. These threats consists of spoofing, tampering, repudiation, information disclosure, denial of service, and escalation of privilege. No significant vulnerabilities were found in this example. / I takt med att IoT implementeras i allt fler enheter som används för vardagligt bruk, bör även förståelsen för potentiella risker orsakade av sammankoppling mellan olika enheter också öka. Det är inte en helt enkel uppgift att säkra en IoT-enhet och det är därför viktigt att förstå komplexiteten när det gäller cybersäkerhet.   Det här examensarbetet har specificerat grunderna för IoT-penetrationstestning användande Motorola MBP855CONNECT som exempelenhet. Rapporten innehåller en grundläggande teoretisk introduktion till etisk hacking, tillsammans med utforskning av några grundläggande tekniker för penetrationstestning bekrivna i STRIDEs modell över hot. Dessa hot består av förfalskning, modifiering, förnekande, utlämning av information, blockering av tjänst, och utökad behörighet. Inga betydande sårbarheter hittades i det här exemplet.
74

Scale-up of Micro-structured Synthetic Paper / Uppskalning av syntetiskt papper för patientnära medicinsk diagnostik

Cai, Yusi January 2017 (has links)
No description available.
75

Improving the alignment of the linear accelerator and the bending magnets in the Elekta Synergy : Förbättring av inriktningen av linjäracceleratorn och böjmagneterna i Elekta Synergy

Schuetz, Carmen January 2017 (has links)
The Elekta Synergy is a linear accelerator used in radiation therapy. It is constructed fromvarious mechanical components, including a set of 112.5° bending magnets, which need tobe aligned correctly in order to produce an efficient treatment beam. The current alignmentprocess is outdated and results in inconsistencies, which leads to prolonged assembly timesand the need to correct alignment errors. This paper details the study, design andconstruction of a new bending magnet alignment approach and thereby serves to introducea replacement for the current system. The proposed solution consists of an optimizedmechanical jig in conjunction with image processing software.
76

Materialkarakterisering av skum i ishockeyhjälmar

Magnusson, Carl, Söderström, Gustav January 2017 (has links)
The brain is one of the most important organ in the human body. During sports, athletes lead a risk of suffering from blows to the head that cause injuries. To protect the athletes from head injuries, the helmet plays an important role. During this study, different parts of the liners have been examined to see if the liner is composed of one single material. Tests have also been done to analyze if the liners behave differently during different strain rates. To investigate the issues mentioned above, samples from four different liners were gathered. The samples were examined by doing compression tests and the results were used to calculate Young’s Modulus, Poisson’s ratio and stress-strain curves. This paper does not include testing of the outer shell of the helmet, but is solely about the liner.   The results of the tests show that the difference in the amount of absorbed energy, can vary depending on what material the liner is made of. Also, depending on the material, different liners behave differently when the strain rate is varied.
77

Multigrid reconstruction of micro-CT data / Multigrid-rekonstruktion av microCT-data

Gao, Bo January 2017 (has links)
The group of Medical Imaging at School of Health and Technology is developing a micro-CT scanner for small animal imaging. Micro-CT refers to reconstructing CT image with resolution in scale of micrometer, and this goal is achieved by acquiring projection data with high resolution. Nevertheless, high resolution projection data and high resolution recon- struction image have introduced the problem of memory insufficiency, as more points need to be processed during micro-CT reconstruction. For this reason, this paper has investigated how to alleviate the burden on computers memory through applying multi-grid reconstruction algo- rithms, which means to reconstruct region of interest (ROI) with high resolution while reconstructing background with lower resolution. By do- ing that, pixels being considered in the reconstruction space has been decreased and normal computers will be capable to handle reconstruction of micro-CT image. Through testing on numerical data (Shepp Logan Phantom), it can be concluded that multi-grid reconstruction algorithm could reconstruct high fidelity ROI with much faster speed comparing to full resolution reconstruction. Moreover, this proposed technique can also give decent reconstruction to data acquired from micro-CT scanner.
78

Att förbättra hjälpmedel inför undersökningar inom bäckenbottens sjukdomar

Sarbalin Dar, Fereshteh January 2016 (has links)
Bäckenbotten är en serie av muskelplattor i botten på bukhålan och fungerar som stöd för de inreorganen. Dessa organ är lite annorlunda hos män och kvinnor. En grupp av muskler bildarbäckenbottenmuskulaturen och kan liknas vid en hängmatta. Bäckenbottenmuskulaturen harmånga viktiga uppgifter, såsom kontroll över tarmarna och urinblåsa, stabilisering och stödjandetav ryggraden genom att hålla de inre organen på plats, men även stöd under graviditet.Om bäckenbottens vävnader är försvagade och de utsätts för påfrestningar kan ett eller fleraorgan sjunka ned i bäckenbotten. Detta tillstånd kallas Prolaps (framfall) och tre typerförekommer: Analprolaps, Rektalprolaps och livmoderframfall. Dessa tillstånd undersöks med enstol, en så kallas kryststol. En kryststol består i princip av en hygienstol med en monterad spegelunder stolen.I dagsläget används en kryststol på Kirurgmottagningen på Södersjukhuset. Denna kryststolhar brister och är i behov av förbättringar. Stolen är gammal och ergonomin är inte den bästa. Dettamedför obehag och obekvämlighet för såväl vårdpersonalen som patienter.Denna rapport beskriver arbetet med att ta fram en ny kryststol för användning iKirurgmottagningen på Södersjukhuset.Resultatet av arbetet har visat att en ny kryststol bör vara höj- och sänkbar. Denna lösning ledertill en minskning av de dåliga arbetsställningarna som vårdpersonal tvingas leva med i dagsläget.En höj- och sänkfunktion medför också att patienter med lätthet kan komma på och av stolen.Montering av en lampa på/under kryststolen är en lösning för att underlätta undersökning ochdiagnostisering. Även montering av en spegel under stolen är nödvändig för undersökning. Medavseende på ovanstående information har några lösningar tagits fram.Denna rapport går noggrant igenom lösningarna. För att ta fram dessa lösningar harlitteraturundersökningar och intervjuer med vårdpersonal varit till stor hjälp. / The pelvic floor muscle is a series of muscle plates in the bottom of the abdominal cavity that supportthe internal organs. These organs are slightly different in men and women. A group of muscles formthe pelvic floor muscles and can be seen as a hammock. The pelvic floor muscles have many importantfunctions, such as control of the intestines and urinary bladder, stabilization and support of the spineby keeping the internal organs in place, but also, support during pregnancy.If the pelvic floor tissues are weakened and exposed to stress, one or more organs may descend intothe pelvic floor. This condition is called Prolapse and three types are presented: Anal prolapse, Rectalprolapse, and uterine prolapse. These conditions are examined with a chair, that called strain chair(kryststol). A strain chair consists basically of a hygiene chair with a mirror mounted under the seat.Today a strain chair is used at the surgery clinic at Södersjukhuset. This chair has someflaws andneeds some improvement. The chair is old and the ergonomics are not the best, which causesunpleasant and uncomfortable conditions for both healthcare professionals and patients.This report describes the development of a new strain chair (kryststol) for use in the surgery clinic atSödersjukhuset.The result of this work has shown that a new strain chair (kryststol) should be height adjustable.This solution result in a reduction of the poor working positions for the healthcare professionals thatare forced to cope with at present. An adjustable height function also means that patients can easilyget on and off the chair. Mounting a lamp on/under the seat is a solution to facilitate examination anddiagnosis. Even, mounting a mirror under the seat is also essential for examination. Regarding theabove information, some solutions have been developed. This report investigated the solutionscarefully. To develop these
79

Evaluation of and Improvements for Procedures for Preoperative Body Wash to Prevent Surgical Site Infections / Utvärdering och förbättring av tillvägagångssätt för preoperativhelkroppstvätt för att förhindra postoperativa infektioner

Wester, Malin, Nygren Wåhlin, Elin January 2018 (has links)
This report examines preoperative body wash performed by the patients themselves at home and itspotential to prevent surgical site infections. This was accomplished by studying current recommendedprotocols and active substances in Sweden in relation to a potential replacement product. Products identified and included in the report are Descutan, manufactured by Fresenius Kabi AB and Prontoderm by B. Braun Medical AB, with the active substances of chlorhexidine and polyhexanide.After comparisons, an experiment and evaluations, a new proposed protocol has been developed.The proposed protocol involves decolonization of bacteria, including multidrug resistant organisms.In that way, an alternative to handle the increased antibiotic resistance in the world is described. Inaddition, costs of the products have been compared and by avoiding surgical site infections, potentialsavings have been calculated.From the review, ambiguous results were obtained regarding the effect of preoperative body wash onsurgical site infections.In summary, there are many benefits and a lot of money to save, with the new active substance andby avoiding surgical site infections. The conclusion is that Prontoderm is more expensive, but thatthe total cost of the product kit could be reduced by adjusting the size of the products after protocoland dosage. Further, it was decided that three washes are sufficient for a full preoperative body wash.Keywords: surgical site infection, chlorhexidine, polyhexanide, decolonization, preoperative bodywash, Prontoderm, Descutan, patient protocol, multidrug resistant organisms.
80

The Performance of the Depth Camera in Capturing Human Body Motion for Biomechanical Analysis / Djupkamerans prestanda för att detektera kroppsrörelser för biomekanisk analys

Yuan, Qiantailang January 2018 (has links)
Three-dimensional human movement tracking has long been an important topic in medical and engineering field. Complex camera systems such as Vicon can be used to retrieve very precise motion data. However, the system is more commercial-oriented with a high cost. Besides, it would also be tedious and cumbersome to wear the special markers and suits for tracking. Therefore, there's an urgent need to investigate a cost-effective and markless tool for motion tracking. Microsoft Kinect provides a promising solution with a vast variety of libraries, allowing quick development of 3-D spatial modeling and analysis such as moving skeleton possible. For example, the kinematics of the joints such as acceleration, velocity, and angle changes can be deduced from the spatial position information acquired by the camera. In order to validate whether the Kinect system is sufficient for the analysis in practice, a micro-controller platform Arduino along with Intel® Curie™ IMU (Inertial Measurement Unit) module is developed. In particular, the velocity and Euler angels of joint movements, as well as head orientations are measured and compared between the two systems. In this paper, the goal is to present (i) the use of Kinect Depth sensor for data acquisition, (ii) post-processing with the retrieved data, (iii) validation of the Kinect camera. Results show that the RMS error of the velocity tracking ranges from 1.78% to 23.34%, presenting a good agreement of measurement between the two systems. Moreover, the relative error of the angle tracking is between 4.0% and 24.3%. The results of the head orientations tracking are hard to perform a mathematical analysis due to the noise and invalid data from the camera caused by the loss of tracking. Overall, the accuracy of joint movement tracked by the Kinect camera, particularly velocity, is proved to be acceptable and the depth camera has been found to be an effective tool for kinematic measurement as a cost-effective option. A platform and workflow are now established, thus making future work regarding validation and application possible when the advanced hardware is available. / Tre dimensionell rörelse spårning har alltid varit ett viktigt ämne inom medicinska och tekniska områden. Komplexa kamerasystem så som Vicon kan användas för att hämta exakta data för olika rörelser. Dessa system är dock mer kommersiellt orienterade, och är oftast dyra. Systemen är dessutom besvärliga eftersom man är tvungen att bära speciella dräkter med markörer, för att kunna spåra rörelser. Därav finns det ett stort intresse av att undersöka ett kostnadseffektivt och markörfria verktyg för rörelsespårning. Microsoft Kinect är en lovande lösning med en mängd olika bibliotek som möjliggör en snabb utveckling av 3D spatial modellering och analys. Från den spatiala positionsinformationen kan man få fram information om ledernas acceleration, hastighet och vinkelförändring. För att kunna validera om Kinect är passande för analysen, utvecklades en mikro-styrplattform Ardunino tillsammans med Intel R CurieTM IMU (tröghetsmätningsenhet). Hastigheten och Eulers vinkel vid rörelse av lederna, samt orienteringen av huvudet mättes och jämfördes mellan dessa två system. Målet med detta arbete är att presentera (i) användningen av Kinect Depth sensor för datainsamling, (ii) efterbehandling av inhämtad data, (iii) validering av Kinect Kamera. Resultatet visade att RMS-errorn av hastighetsspårningen varierade mellan 1.78% och 23.34%, vilket påvisar en god likhet mellan mätningarna av de två systemen. Det relativa felet i vinkelspårningen är mellan 4.0% och 24.3%. Resultatet för orienteringen av huvudet var svår att ta fram genom matematisk analys eftersom brus och invalid data från kameran uppstod pga förlust av spårning. Noggrannheten av ledrörelsen detekterad av Kinect kameran bevisas vara acceptabel, speciellt för hastighetsmätningar. Djupkameran har visat vara ett effektivt verktyg för kinematiks mätning som ett kostnadseffektivt alternativ. En plattform och arbetsflöde har tagits fram, vilket möjliggör validering och tillämpning när den avancerade hårdvaran är tillgänglig.

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