224 research outputs found

    Medical robots for MRI guided diagnosis and therapy

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    Magnetic Resonance Imaging (MRI) provides the capability of imaging tissue with fine resolution and superior soft tissue contrast, when compared with conventional ultrasound and CT imaging, which makes it an important tool for clinicians to perform more accurate diagnosis and image guided therapy. Medical robotic devices combining the high resolution anatomical images with real-time navigation, are ideal for precise and repeatable interventions. Despite these advantages, the MR environment imposes constraints on mechatronic devices operating within it. This thesis presents a study on the design and development of robotic systems for particular MR interventions, in which the issue of testing the MR compatibility of mechatronic components, actuation control, kinematics and workspace analysis, and mechanical and electrical design of the robot have been investigated. Two types of robotic systems have therefore been developed and evaluated along the above aspects. (i) A device for MR guided transrectal prostate biopsy: The system was designed from components which are proven to be MR compatible, actuated by pneumatic motors and ultrasonic motors, and tracked by optical position sensors and ducial markers. Clinical trials have been performed with the device on three patients, and the results reported have demonstrated its capability to perform needle positioning under MR guidance, with a procedure time of around 40mins and with no compromised image quality, which achieved our system speci cations. (ii) Limb positioning devices to facilitate the magic angle effect for diagnosis of tendinous injuries: Two systems were designed particularly for lower and upper limb positioning, which are actuated and tracked by the similar methods as the first device. A group of volunteers were recruited to conduct tests to verify the functionality of the systems. The results demonstrate the clear enhancement of the image quality with an increase in signal intensity up to 24 times in the tendon tissue caused by the magic angle effect, showing the feasibility of the proposed devices to be applied in clinical diagnosis

    Command and Control Systems for Search and Rescue Robots

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    The novel application of unmanned systems in the domain of humanitarian Search and Rescue (SAR) operations has created a need to develop specific multi-Robot Command and Control (RC2) systems. This societal application of robotics requires human-robot interfaces for controlling a large fleet of heterogeneous robots deployed in multiple domains of operation (ground, aerial and marine). This chapter provides an overview of the Command, Control and Intelligence (C2I) system developed within the scope of Integrated Components for Assisted Rescue and Unmanned Search operations (ICARUS). The life cycle of the system begins with a description of use cases and the deployment scenarios in collaboration with SAR teams as end-users. This is followed by an illustration of the system design and architecture, core technologies used in implementing the C2I, iterative integration phases with field deployments for evaluating and improving the system. The main subcomponents consist of a central Mission Planning and Coordination System (MPCS), field Robot Command and Control (RC2) subsystems with a portable force-feedback exoskeleton interface for robot arm tele-manipulation and field mobile devices. The distribution of these C2I subsystems with their communication links for unmanned SAR operations is described in detail. Field demonstrations of the C2I system with SAR personnel assisted by unmanned systems provide an outlook for implementing such systems into mainstream SAR operations in the future

    Adaptive Shared Autonomy between Human and Robot to Assist Mobile Robot Teleoperation

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    Die Teleoperation vom mobilen Roboter wird in großem Umfang eingesetzt, wenn es fĂŒr Mensch unpraktisch oder undurchfĂŒhrbar ist, anwesend zu sein, aber die Entscheidung von Mensch wird dennoch verlangt. Es ist fĂŒr Mensch stressig und fehleranfĂ€llig wegen Zeitverzögerung und Abwesenheit des Situationsbewusstseins, ohne UnterstĂŒtzung den Roboter zu steuern einerseits, andererseits kann der völlig autonome Roboter, trotz jĂŒngsten Errungenschaften, noch keine Aufgabe basiert auf die aktuellen Modelle der Wahrnehmung und Steuerung unabhĂ€ngig ausfĂŒhren. Deswegen mĂŒssen beide der Mensch und der Roboter in der Regelschleife bleiben, um gleichzeitig Intelligenz zur DurchfĂŒhrung von Aufgaben beizutragen. Das bedeut, dass der Mensch die Autonomie mit dem Roboter wĂ€hrend des Betriebes zusammenhaben sollte. Allerdings besteht die Herausforderung darin, die beiden Quellen der Intelligenz vom Mensch und dem Roboter am besten zu koordinieren, um eine sichere und effiziente AufgabenausfĂŒhrung in der Fernbedienung zu gewĂ€hrleisten. Daher wird in dieser Arbeit eine neuartige Strategie vorgeschlagen. Sie modelliert die Benutzerabsicht als eine kontextuelle Aufgabe, um eine Aktionsprimitive zu vervollstĂ€ndigen, und stellt dem Bediener eine angemessene Bewegungshilfe bei der Erkennung der Aufgabe zur VerfĂŒgung. Auf diese Weise bewĂ€ltigt der Roboter intelligent mit den laufenden Aufgaben auf der Grundlage der kontextuellen Informationen, entlastet die Arbeitsbelastung des Bedieners und verbessert die Aufgabenleistung. Um diese Strategie umzusetzen und die Unsicherheiten bei der Erfassung und Verarbeitung von Umgebungsinformationen und Benutzereingaben (i.e. der Kontextinformationen) zu berĂŒcksichtigen, wird ein probabilistischer Rahmen von Shared Autonomy eingefĂŒhrt, um die kontextuelle Aufgabe mit Unsicherheitsmessungen zu erkennen, die der Bediener mit dem Roboter durchfĂŒhrt, und dem Bediener die angemesse UnterstĂŒtzung der AufgabenausfĂŒhrung nach diesen Messungen anzubieten. Da die Weise, wie der Bediener eine Aufgabe ausfĂŒhrt, implizit ist, ist es nicht trivial, das Bewegungsmuster der AufgabenausfĂŒhrung manuell zu modellieren, so dass eine Reihe von der datengesteuerten AnsĂ€tzen verwendet wird, um das Muster der verschiedenen AufgabenausfĂŒhrungen von menschlichen Demonstrationen abzuleiten, sich an die BedĂŒrfnisse des Bedieners in einer intuitiven Weise ĂŒber lange Zeit anzupassen. Die Praxistauglichkeit und Skalierbarkeit der vorgeschlagenen AnsĂ€tze wird durch umfangreiche Experimente sowohl in der Simulation als auch auf dem realen Roboter demonstriert. Mit den vorgeschlagenen AnsĂ€tzen kann der Bediener aktiv und angemessen unterstĂŒtzt werden, indem die KognitionsfĂ€higkeit und AutonomieflexibilitĂ€t des Roboters zu erhöhen

    Investigating perceptual congruence between information and sensory parameters in auditory and vibrotactile displays

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    A fundamental interaction between a computer and its user(s) is the transmission of information between the two and there are many situations where it is necessary for this interaction to occur non-visually, such as using sound or vibration. To design successful interactions in these modalities, it is necessary to understand how users perceive mappings between information and acoustic or vibration parameters, so that these parameters can be designed such that they are perceived as congruent. This thesis investigates several data-sound and data-vibration mappings by using psychophysical scaling to understand how users perceive the mappings. It also investigates the impact that using these methods during design has when they are integrated into an auditory or vibrotactile display. To investigate acoustic parameters that may provide more perceptually congruent data-sound mappings, Experiments 1 and 2 explored several psychoacoustic parameters for use in a mapping. These studies found that applying amplitude modulation — or roughness — to a signal, or applying broadband noise to it resulted in performance which were similar to conducting the task visually. Experiments 3 and 4 used scaling methods to map how a user perceived a change in an information parameter, for a given change in an acoustic or vibrotactile parameter. Experiment 3 showed that increases in acoustic parameters that are generally considered undesirable in music were perceived as congruent with information parameters with negative valence such as stress or danger. Experiment 4 found that data-vibration mappings were more generalised — a given increase in a vibrotactile parameter was almost always perceived as an increase in an information parameter — regardless of the valence of the information parameter. Experiments 5 and 6 investigated the impact that using results from the scaling methods used in Experiments 3 and 4 had on users' performance when using an auditory or vibrotactile display. These experiments also explored the impact that the complexity of the context which the display was placed had on user performance. These studies found that using mappings based on scaling results did not significantly impact user's performance with a simple auditory display, but it did reduce response times in a more complex use-case

    Evaluation of modern intraocular lenses

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    Accommodating Intraocular Lenses (IOLs), multifocal IOLs (MIOLs) and toric IOLs are designed to provide a greater level of spectacle independency post cataract surgery. All of these IOLs are reliant on the accurate calculation of intraocular lens power determined through reliable ocular biometry. A standardised defocus area metric and reading performance index metric were devised for the evaluation of the range of focus and the reading ability of subjects implanted with presbyopic correcting IOLs. The range of clear vision after implantation of an MIOL is extended by a second focal point; however, this results in the prevalence of dysphotopsia. A bespoke halometer was designed and validated to assess this photopic phenomenon. There is a lack of standardisation in the methods used for determining IOL orientation and thus rotation. A repeatable, objective method was developed to allow the accurate assessment of IOL rotation, which was used to determine the rotational and positional stability of a closed loop haptic IOL. A new commercially available biometry device was validated for use with subjects prior to cataract surgery. The optical low coherence reflectometry instrument proved to be a valid method for assessing ocular biometry and covered a wider range of ocular parameters in comparison with previous instruments. The advantages of MIOLs were shown to include an extended range of clear vision translating into greater reading ability. However, an increased prevalence of dysphotopsia was shown with a bespoke halometer, which was dependent on the MIOL optic design. Implantation of a single optic accommodating IOL did not improve reading ability but achieved high subjective ratings of near vision. The closed-loop haptic IOL displayed excellent rotational stability in the late period but relatively poor rotational stability in the early period post implantation. The orientation error was compounded by the high frequency of positional misalignment leading to an extensive overall misalignment of the IOL. This thesis demonstrates the functionality of new IOL lens designs and the importance of standardised testing methods, thus providing a greater understanding of the consequences of implanting these IOLs. Consequently, the findings of the thesis will influence future designs of IOLs and testing methods

    Medical Robotics

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    The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

    An Agent-Based Variogram Modeller: Investigating Intelligent, Distributed-Component Geographical Information Systems

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    Geo-Information Science (GIScience) is the field of study that addresses substantive questions concerning the handling, analysis and visualisation of spatial data. Geo- Information Systems (GIS), including software, data acquisition and organisational arrangements, are the key technologies underpinning GIScience. A GIS is normally tailored to the service it is supposed to perform. However, there is often the need to do a function that might not be supported by the GIS tool being used. The normal solution in these circumstances is to go out and look for another tool that can do the service, and often an expert to use that tool. This is expensive, time consuming and certainly stressful to the geographical data analyses. On the other hand, GIS is often used in conjunction with other technologies to form a geocomputational environment. One of the complex tools in geocomputation is geostatistics. One of its functions is to provide the means to determine the extent of spatial dependencies within geographical data and processes. Spatial datasets are often large and complex. Currently Agent system are being integrated into GIS to offer flexibility and allow better data analysis. The theis will look into the current application of Agents in within the GIS community, determine if they are used to representing data, process or act a service. The thesis looks into proving the applicability of an agent-oriented paradigm as a service based GIS, having the possibility of providing greater interoperability and reducing resource requirements (human and tools). In particular, analysis was undertaken to determine the need to introduce enhanced features to agents, in order to maximise their effectiveness in GIS. This was achieved by addressing the software agent complexity in design and implementation for the GIS environment and by suggesting possible solutions to encountered problems. The software agent characteristics and features (which include the dynamic binding of plans to software agents in order to tackle the levels of complexity and range of contexts) were examined, as well as discussing current GIScience and the applications of agent technology to GIS, agents as entities, objects and processes. These concepts and their functionalities to GIS are then analysed and discussed. The extent of agent functionality, analysis of the gaps and the use these technologies to express a distributed service providing an agent-based GIS framework is then presented. Thus, a general agent-based framework for GIS and a novel agent-based architecture for a specific part of GIS, the variogram, to examine the applicability of the agent- oriented paradigm to GIS, was devised. An examination of the current mechanisms for constructing variograms, underlying processes and functions was undertaken, then these processes were embedded into a novel agent architecture for GIS. Once the successful software agent implementation had been achieved, the corresponding tool was tested and validated - internally for code errors and externally to determine its functional requirements and whether it enhances the GIS process of dealing with data. Thereafter, its compared with other known service based GIS agents and its advantages and disadvantages analysed

    Craft Sciences

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    The field of ‘Craft Sciences’ refers to research conducted across and within different craft subjects and academic contexts. This anthology aims to expose the breadth of topics, source material, methods, perspectives, and results that reside in this field, and to explore what unites the research in such diverse contexts as, for example, the arts, conservation, or vocational craft education. The common thread between each of the chapters in the present book is the augmented attention given to methods—the craft research methods—and to the relationship between the field of inquiry and the field of practice. A common feature is that practice plays an instrumental role in the research found within the chapters, and that the researchers in this publication are also practitioners. The authors are researchers but they are also potters, waiters, carpenters, gardeners, textile artists, boat builders, smiths, building conservators, painting restorers, furniture designers, illustrators, and media designers. The researchers contribute from different research fields, like craft education, meal sciences, and conservation crafts, and from particular craft subjects, like boat-building and weaving. The main contribution of this book is that it collects together a number of related case studies and presents a reflection on concepts, perspectives, and methods in the general fields of craft research from the point of view of craft practitioners. It adds to the existing academic discussion of crafts through its wider acknowledgement of craftsmanship and extends its borders and its discourse outside the arts and crafts context. This book provides a platform from which to develop context-appropriate research strategies and to associate with the Craft Sciences beyond the borders of faculties and disciplines
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