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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.
671

Towards Intracorporeal Additive Manufacturing of Tissue Engineering Scaffolds

Asghari Adib, Ali January 2022 (has links)
No description available.
672

Développement et validation de sondes en fibre optique miniaturisées pour le guidage intra-opératoire d’interventions intraoculaires

Abid, Alexandre 03 1900 (has links)
Les procédures chirurgicales intraoculaires sont des procédures difficiles par la précision qu’elles demandent, on parle de microchirurgie, mais aussi par la difficulté et la faible qualité de visualisation des tissus à traiter. En effet, dans la plupart des procédures intraoculaires le chirurgien utilise uniquement un microscope ophtalmologique qui ne permet la visualisation des tissus que par la pupille du patient et offre une perception limitée de la profondeur. La Tomographie en Cohérence Optique (OCT) fournit des images en profondeur des tissus sains de manière non invasive, elle est utilisée couramment en diagnostic ophtalmologique et est de plus en plus utilisée intra-opérativement. Dans cette thèse nous allons présenter deux systèmes OCT intra-opératifs qui visent à assister les chirurgiens sur deux procédures intraoculaires, la vitrectomie et l’injection sous-rétinienne. Pour ces deux projets nous avons utilisé le matériel chirurgical utilisé cliniquement pour plusieurs raisons : s’assurer d’utiliser des outils adéquats (dimensions, efficacité, sécurité) pour la procédure, garder des outils que les chirurgiens utilisent régulièrement et avec lesquels ils sont familiers et limiter les coûts de développement. Pour le système OCT nous avons utilisé des sondes OCT en fibre optique car elles sont flexibles, bon marché et de petit diamètre. Leur focalisation peut également être modifiée dépendamment de l’application avec une fibre optique GRIN à leur extrémité pour augmenter le signal OCT. Nous avons ainsi attaché à ces outils chirurgicaux des sondes OCT en fibre optique. Pour le projet portant sur les injections sous-rétiniennes il a fallu dans un premier temps développer des sondes OCT avec des diamètres plus petits que ceux existant. Pour ce faire nous avons développé une méthode permettant de réduire le diamètre des sondes avec de l’acide fluorhydrique et grâce à un design permettant de conserver les propriétés optiques des sondes. Ce travail est présenté dans le premier article. Le second article présente un système permettant de guider les injections sous-rétiniennes. L’injection sous-rétinienne est une intervention chirurgicale de haute précision visant à restaurer et/ou préserver la vision des patients souffrant de maladies rétiniennes. Néanmoins, l’injection sous-rétinienne reste à la limite des capacités physiologiques humaines en raison des tremblements de la main et peut être compromise par le reflux du médicament si l’injection n’est pas assez profonde dans la rétine. Nous avons développé un système pour guider l’injection avec un micromanipulateur et donner des informations précises sur la profondeur au chirurgien avec l’OCT intra-opératif. Après avoir miniaturisé une sonde OCT en fibre optique avec la méthode présentée dans l’article 1 nous avons pu l’insérer dans une canule utilisée cliniquement. La sonde couplée à un système OCT que nous avons développé acquiert un signal A-scan qui va permettre de connaitre la distance entre la canule et la rétine mais aussi de sélectionner la profondeur de l’injection dans les couches rétiniennes. La canule est attachée à un micromanipulateur qui assure son déplacement dans l’œil. Une image M-scan est construite avec le signal OCT et le chirurgien peut directement sélectionner sur l’image la profondeur de l’injection. Nous avons développé l’interface sur Labview. Après avoir sélectionné la cible de l’injection le programme de guidage va déplacer la canule et injecter le volume adéquat grâce à une pompe contrôlable. Nous avons validé notre système de guidage sur des yeux de porcs ex-vivo. Sur 40 injections 38 présentaient un décollement rétinien ciblé et localisé, preuve de la réussie de l’injection rétinienne ce qui représente un taux de succès de 95% (CI : 83.1 – 99.4). Nous avons aussi grâce à un algorithme de traitement de l’image calculé le volume présent sous la rétine après l’injection que nous avons comparé au volume injecté. Nous avons ainsi trouvé que 75% du volume initialement injecté se retrouve bien sous la rétine. Le troisième article présente un système permettant d’arrêter automatiquement le vitrecteur lors d’une vitrectomie pour réduire les dommages accidentels sur la rétine. La survenue de déchirures rétiniennes iatrogèniques dans la vitrectomie par la pars plane est une complication qui compromet l’efficacité globale de la chirurgie. Un certain nombre de déchirures rétiniennes iatrogènes se produisent lorsque la rétine est coupée accidentellement par le vitrecteur. Nous avons développé un vitrecteur intelligent capable de détecter en temps réel une coupure rétinienne accidentelle et de désactiver rapidement la machine de vitrectomie pour les prévenir. Ce vitrecteur intelligent est composé d’une sonde OCT attachée au vitrecteur et va avoir comme rôle de détecter si le vitrecteur aspire la rétine et va endommager ces tissus sains. La sonde OCT agit comme un détecteur de présence devant l’ouverture du vitrecteur, ceci en comparant un signal de référence avec le signal en direct. Cette comparaison de signal OCT va commander un bras robotique pour actionner la pédale d’arrêt du vitrecteur. Ainsi le chirurgien n’a pas besoin d’interpréter un signal, la décision d’arrêt du vitrecteur dû à la présence de la rétine est prise automatiquement. Ceci va permettre de réduire grandement, de 300 ms à 29 ms, le délai de la prise de décision d’arrêt du vitrecteur précédemment limité par le temps de réaction du chirurgien. Nous avons développé les sondes OCT, le système OCT ainsi que l’algorithme d’arrêt automatique de ce système. Nous avons validé sur des yeux porcins in-vivo, deux chirurgiens ont utilisé notre système en essayant d’endommager les tissus rétiniens. 70% (CI : 56.39 – 82.02) des tentatives de dommages rétiniens des chirurgiens furent atténuées ou empêchées par notre système. Ce projet a abouti au dépôt d’un brevet ("Smart Vitrector", Provisional patent application, US 63109040). / Intraocular surgical procedures are difficult procedures because of the precision they require, they are often referred as microsurgery, but also by the little information available to the surgeon. In most intraocular procedures the surgeon only uses an ophthalmic microscope which allows visualization of tissue just through the patient’s pupil and offers limited depth perception. Optical Coherence Tomography (OCT) provides in-depth images of healthy tissue in a non-invasive manner, is commonly used in ophthalmologic diagnostics, and is increasingly used intraoperatively. In this thesis we will present two intraoperative OCT systems that aim to assist surgeons with two intraocular procedures, vitrectomy and subretinal injection. For these two projects we used the surgical equipment used clinically for several reasons : to make sure to use adequate tools (dimensions, efficiency, safety) for the procedure, to keep tools that surgeons use regularly and with which they are familiar and limit development costs. For the OCT system we used fiber optic OCT probes as they are flexible, cheap and small in diameter. Their focus can also be modified, depending the application, with a GRIN fiber at their tip to increase the OCT signal. We have attached optical fiber OCT probes to these surgical tools. For the subretinal injections project it was first necessary to develop OCT probes with smaller diameters than existing ones. To do this, we have developed a method to reduce the diameter of the probes with hydrofluoric acid and a design to maintain the optical properties of the probes. This work is presented in the first article. The second article presents a system for guiding subretinal injections. Subretinal injection of drugs is a challenging surgical intervention aiming to restore and/or preserve the vision of patients suffering from retinal diseases. Nevertheless, the subretinal injection remains at the edge of human physiological capacity because of hand tremor and can be mitigated by drug reflux if the injection is not deep enough in the retina. We developed a system to guide the injection with a micromanipulator and give precise depth information to the surgeon with intraoperative OCT. To do so we first miniaturized an optical fiber OCT probe with the method presented in article 1, we were able to insert it into a cannula used clinically. The probe coupled to an OCT system that we have developed acquires an A-scan signal which enables to know the distance between the cannula and the retina but also to select the depth of the injection into the retinal layers. The cannula is attached to a micromanipulator that moves it inside the eye. An M-scan image is built with the OCT signal and the surgeon can directly select on the image the depth of the injection. We developed the interface on Labview. After selecting the injection target, the guidance program will move the cannula and inject the appropriate volume using a controllable pump.We have validated our guidance system on pig eyes ex-vivo. Out of 40 injections, 38 presented a retinal detachment, proof of a successful retinal injection, which represents a success rate of 95% (CI : 83.1 – 99.4). Thanks to an image processing algorithm, we also calculated the bleb volume under the retina after the injection, which we compared to the initial injected volume. We have found that 75% of the injected volume ends in the subretinal space. The third article presents for automatically stopping the vitrector during a vitrectomy. The occurrence of iatrogenic retinal breaks in pars plana vitrectomy is a complication that compromises the overall efficacy of the surgery. A subset of iatrogenic retinal break occurs when the retina is cut accidentally by the vitrector. We developed a smart vitrector that can detect in real-time potential accidental retinal cut and activate promptly a vitrectomy machine to prevent them. To do so an OCT probe is attached to the vitrector and will have the role of detecting if the vitrector sucks the retina and will damage these healthy tissues. The OCT probe acts as a presence detector in front of the vitrector opening, by comparing a reference signal with the live signal. This OCT signal comparison will control a robotic arm to operate the vitrector stop pedal. Thus, the surgeon does not need to interpret a signal, the decision to stop the vitrector due to the presence of the retina is taken automatically. This will greatly reduce, from 300 ms to 29 ms, the delay to stop the vitrector previously limited by the reaction time of the surgeon. We have developed the OCT probes, the OCT system, and the automatic shutdown algorithm for this system. We validated our system on in-vivo porcine eyes, two surgeons used the modified vitrector trying to damage retinal tissue. 70% (CI : 56.39 – 82.02) of surgeons’ retinal damage attempts were mitigated or prevented by our system. This project resulted in a patent ("Smart Vitrector", Provisional patent application, US 63109040).
673

Design of a Self-Regulating Robotic Arm / Design av en självreglerande robotarm

Naesenius, Ludvig, Wikström, Viktor January 2022 (has links)
As the world rapidly propels further through the ever-evolving field of automation, there is also an increased demand for properly regulated robots. While the use of automated machines is nothing new, the industry remains in a continuous effort to develop systems that both push the number of manageable inputs and the limits of optimization. One of the most foundational parts of many automated machines is the robotic arm. During this project, a self-regulating robot arm with the ability to maintain a desired position based on multiple inputs was constructed and tested. The resulting design managed to maintain a set height with varying levels of flow and precision, enabling further development and optimization with stronger components. / I takt med att världen snabbt genomgår det ständigt föränderliga automationsområdet, finns det också en ökad efterfrågan på korrekt reglerade robotar. Även om användningen av automatiserade maskiner inte är något nytt, fortsätter branschen att arbeta kontinuerligt med att utveckla system som både ökar mängden hanterbar indata och tänjer på gränserna för optimering. En av de mest fundamentala delarna i många automatiserade maskiner är robotarmen. Under detta projekt konstruerades och testades en självreglerande robotarm med förmågan att bibehålla en önskad position baserat på flera insignaler. Den resulterande designen lyckades bibehålla en inställd höjd med varierande nivåer av jämnhet och precision, vilket möjliggör vidareutveckling och optimering med starkare komponenter.
674

AntiKli-MAX 5000 : A robotic head massager with an implemented distance sensor / AntiKli-MAX 5000 : En robot huvudmasserare med en implementerad distanssensor

Brehmer, Mathilda, Mattsson, Sara January 2022 (has links)
Robots are increasingly being used in personal households for service-related tasks such as floor cleaning, lawn mowing or entertainment. However, there is still a lack of household robots performing tactile service-related tasks that requires human-robot interaction. This bachelor’s thesis considers the possible improvement of a robotic head massager performing a head massage by using feedback from a distance sensor. The construction consists of a robot arm with two degrees of freedom. The robot arm is holding a head massager that is implemented with a distance sensor. The distance sensor is used to explore the possible improvement of the safety of the product by stopping the massage whenever the distance to the head was less or equal to 3 cm. The embedded system was controlled by an Arduino Uno that was connected to a computer. The results showed that the distance sensor can in fact improve the safety of the robotic head massager, however it did not always work which opened up a discussion about counter productivity to claim the product as safer. / Användandet av robotar ökar mer och mer i privata hushåll för service-relaterade uppgifter såsom dammsugning, gräsklippning och underhållning. Emellertid finns det fortfarande en brist på hushållsrobotar som utför taktila service-relaterade uppgifter som kräver människa-robot interaktion. Den här kandidatuppsatsen undersöker en möjlig förbättring av en robotarm som utför huvudmassage med hjälp av en huvudkliare och återkoppling. Konstruktionen består av en robot arm med två frihetsgrader. Robotarmen håller en huvudkliare som är implementerad med en distanssensor. Distanssensorn används för att undersöka möjligheten att förbättra säkerheten hos produkten genom att stoppa massagen när avståndet till huvudet var mindre eller lika med 3 cm. Det inbyggda systemet kontrolleras av en Arduino Uno som är kopplad till en dator. Resultaten visar att en distanssensor faktiskt kan förbättra säkerheten hos robot-kliaren, däremot fungerar den inte varje gång vilket öppnar upp för diskussion gällande kontraproduktivitet att benämna produkten som mer säker.
675

Wireless Model-Controlled Robotic Arm via IoT : Controlling a robotic arm with a model arm via the Internet of Things / Trådlös modellkontrollerad robotarm via IoT : Styrning av en robotarm med en modell-arm via Internet ofthings

Druschke, Mattis, Voigt, Karl January 2022 (has links)
As the Internet of Things (IoT) is revolutionising and digitalising industry and the need for remote connectivity is increasing, there is an opportunity for new solutions for remotely controlled industrial equipment. One possible way of controlling industrial robot arms is by using a universal model arm input device of a different scale. The question this can lead to is, how a wireless IoT solution for a model-controlled robot arm can perform. This thesis realises this concept with a working demonstrator consisting of a model arm and a robot arm, connected through a third party IoT service. Tests, measuring the precision of the replicated motion and the time delay are used to evaluate the performance. The results lead to the conclusion, that the envisioned concept has merit, but is restricted by limitations such as the transmission interval of the used IoT service. Further, the conclusions and accomplishments of this thesis could serve as a basis for additional research on this method of remotely controlling industrial equipment. / Sakernas internet (IoT) revolutionerar och digitaliserar industrin, samtidigt som behovet av fjärranslutning ökar. Detta öppnar möjligheter till nya lösningar för fjärrstyrd industriell utrustning. Ett sätt att styra industrirobotar är att använda en universell modellarm i annan skala än robotarmen. Detta leder till frågan hur en trådlös IoT-lösning för en modellstyrd robotarm kan fungera. I detta projekt förverkligas konceptet med hjälp av en prototyp som består av en modellarm och en robotarm. Dessa är anslutna via en IoT-tjänst från en tredje part. Prestandan och precisionen av den återskapade rörelsen och tidsfördröjningen utvärderas genom tester. Slutsatsen dras att konceptet har fördelar, men begränsas av bland annat överföringsintervallet på grund av den valda IoT-tjänsten. Slutsatserna och resultaten från projektet skulle kunna användas för ytterligare forskning kring denna metod av fjärrstyrning.
676

DEFEATING CYBER AND PHYSICAL ATTACKS IN ROBOTIC VEHICLES

Hyungsub Kim (17540454) 05 December 2023 (has links)
<p dir="ltr">The world is increasingly dependent on cyber-physical systems (CPSs), e.g., robotic vehicles (RVs) and industrial control systems (ICSs). CPSs operate autonomously by processing data coming from both “cyberspace”—such as user commands—and “physical space”—such as sensors that measure the physical environment in which they operate. However, even after decades of research, CPSs remain susceptible to threats from attackers, primarily due to the increased complexity created by interaction with cyber and physical space (e.g., the cascading effects that changes in one space can impact on the other). In particular, the complexity causes two primary threats that increase the risk of causing physical damage to RVs: (1) logic bugs causing undesired physical behavior from the developers expectations; and (2) physical sensor attacks—such as GPS or acoustic noise spoofing—that disturb an RV’s sensor readings. Dealing with these threats requires addressing the interplay between cyber and physical space. In this dissertation, we systematically analyze the interplay between cyber and physical space, thereby tackling security problems created by such complexity. We present novel algorithms to detect logic bugs (PGFuzz in Chapter 2), help developers fix them (PGPatch in Chapter 3), and test the correctness of the patches attempting to address them (PatchVerif in Chapter 4). Further, we explain algorithms to discover the root causes and formulate countermeasures against physical sensor attacks that target RVs in Chapter 5.</p>
677

PhenoBee: Drone-Based Robot for Advanced Field Proximal Phenotyping in Agriculture

Ziling Chen (8810570) 19 December 2023 (has links)
<p dir="ltr">The increasing global need for food security and sustainable agriculture underscores the urgency of advancing field phenotyping for enhanced plant breeding and crop management. Soybean, a major global protein source, is at the forefront of these advancements. Proximal sensing in soybean phenotyping offers a higher signal-to-noise ratio and resolution but has been underutilized in large-scale field applications due to low throughput and high labor costs. Moreover, there is an absence of automated solutions for in vivo proximal phenotyping of dicot plants. This thesis addresses these gaps by introducing a comprehensive, technologically sophisticated approach to modern field phenotyping.</p><p dir="ltr">Fully Automated Proximal Hyperspectral Imaging System: The first chapter presents the development of a cutting-edge hyperspectral imaging system integrated with a robotic arm. This system surpasses traditional imaging limitations, providing enhanced close-range data for accurate plant health assessment.</p><p dir="ltr">Robust Leaf Pose Estimation: The second chapter discusses the application of deep learning for accurate leaf pose estimation. This advancement is crucial for in-depth plant analysis, fostering better insights into plant health and growth, thereby contributing to increased crop yield and disease resistance.</p><p dir="ltr">PhenoBee – A Drone Mobility Platform: The third chapter introduces 'PhenoBee,' a dronebased platform designed for extensive field phenotyping. This innovative technology significantly broadens the capabilities of field data collection, showcasing its viability for widespread aerial phenotyping.</p><p dir="ltr">Adaptive Sampling for Dynamic Waypoint Planning: The final chapter details an adaptive sampling algorithm for efficient, real-time waypoint planning. This strategic approach enhances field scouting efficiency and precision, ensuring optimal data acquisition.</p><p dir="ltr">By integrating deep learning, robotic automation, aerial mobility, and intelligent sampling algorithms, the proposed solution revolutionizes the adaptation of in vivo proximal phenotyping on a large scale. The findings of this study highlight the potential to automate agriculture activities with high scalability and identify nutrient deficiencies, diseases, and chemical damage in crops earlier, thereby preventing yield loss, improving food quality, and expediting the development of agricultural products. Collectively, these advancements pave the way for more effective and efficient plant breeding and crop management, directly contributing to the enhancement of global food production systems. This study not only addresses current limitations in field phenotyping but also sets a new standard for technological innovation in agriculture.</p>
678

Organisatoriska effekter vid implementering av RPA : En kvalitativ studie om medarbetares upplevelser / Organizational effects when implementing RPA

Ekdahl, Irma, Wallin, Josefin January 2023 (has links)
Robotic Process Automation (RPA) is a growing field that is receiving more and more attention. The technology is complex and there can be many different reasons why an organization chooses to implement an RPA system. This study aims to investigate which organizational effects can occur when implementing an RPA solution in a business. The aim is to gain a clearer understanding of the factors that influence the employees' attitude towards the RPA system. By examining how the implementation has looked, the essay will draw attention to important aspects that may have an impact on how the RPA solution is perceived and accepted within the organization. This study also discusses how the implementation process has affected the employees' trust in the RPA robot.  Implementing an RPA robot can free up time from repetitive tasks for an organization's employees. Therefore, this study also aims to investigate what differences employees have experienced on their work motivation after the implementation. The result shows various aspects that affect the staff's ability to develop and build trust in an RPA robot. In addition to this, the study has found that it is of great importance that the organization's management possesses the ability to convey information and knowledge. Finally, the study has observed differences between employees' experiences of work motivation before and after the implementation.
679

Application of soft robotic sensors to predict foot and ankle kinematic measurements

Saucier, David 01 May 2020 (has links)
The ankle joint complex is a common source of injury for various demographics and is often observed during gait analysis. I investigate using soft robotic sensors as a means for collecting kinematic data at the ankle joint complex. I validate the linearity of these sensors by measuring stretch against extension and against stretch from frontal and sagittal planar foot movements using a wooden ankle mockup. I then conduct a study involving ten participants who perform repetitive trials of four foot movements (plantarflexion, dorsiflexion, inversion and eversion) using ten different locations. Four optimal locations were identified for these movements based on linearity, accuracy, robustness, and consistency. Lastly, I validated soft robotic sensors against the human gait cycle. Twenty participants were recruited and performed twelve trials, walking across a flat surface and a cross-sloped surface while motion capture data and soft robotic sensor data was collected.
680

Visual Search for Objects with Straight Lines

Melikian, Simon Haig January 2006 (has links)
No description available.

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