12 research outputs found

    Eye movements as a window to cognitive processes

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    Eye movement research is a highly active and productive research field. Here we focus on how the embodied nature of eye movements can act as a window to the brain and the mind. In particular, we discuss how conscious perception depends on the trajectory of fixated locations and consequently address how fixation locations are selected. Specifically, we argue that the selection of fixation points during visual exploration can be understood to a large degree based on retinotopically structured models. Yet, these models largely ignore spatiotemporal structure in eye-movement sequences. Explaining spatiotemporal structure in eye-movement trajectories requires an understanding of spatiotemporal properties of the visual sampling process. With this in mind, we discuss the availability of external information to internal inference about causes in the world. We demonstrate that visual foraging is a dynamic process that can be systematically modulated either towards exploration or exploitation. For an analysis at high temporal resolution, we suggest a new method: The renewal density allows the investigation of precise temporal relation of eye movements and other actions like a button press. We conclude with an outlook and propose that eye movement research has reached an appropriate stage and can easily be combined with other research methods to utilize this window to the brain and mind to its fullest

    Selection of systems to perform extravehicular activities, man and manipulator. Volume 2 - Final report

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    Technologies for EVA and remote manipulation systems - handbook for systems designer

    Eye Gaze Tracking for Human Computer Interaction

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    With a growing number of computer devices around us, and the increasing time we spend for interacting with such devices, we are strongly interested in finding new interaction methods which ease the use of computers or increase interaction efficiency. Eye tracking seems to be a promising technology to achieve this goal. This thesis researches interaction methods based on eye-tracking technology. After a discussion of the limitations of the eyes regarding accuracy and speed, including a general discussion on Fitts’ law, the thesis follows three different approaches on how to utilize eye tracking for computer input. The first approach researches eye gaze as pointing device in combination with a touch sensor for multimodal input and presents a method using a touch sensitive mouse. The second approach examines people’s ability to perform gestures with the eyes for computer input and the separation of gaze gestures from natural eye movements. The third approach deals with the information inherent in the movement of the eyes and its application to assist the user. The thesis presents a usability tool for recording of interaction and gaze activity. It also describes algorithms for reading detection. All approaches present results based on user studies conducted with prototypes developed for the purpose

    Modelling and simulation of flexible instruments for minimally invasive surgical training in virtual reality

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    Improvements in quality and safety standards in surgical training, reduction in training hours and constant technological advances have challenged the traditional apprenticeship model to create a competent surgeon in a patient-safe way. As a result, pressure on training outside the operating room has increased. Interactive, computer based Virtual Reality (VR) simulators offer a safe, cost-effective, controllable and configurable training environment free from ethical and patient safety issues. Two prototype, yet fully-functional VR simulator systems for minimally invasive procedures relying on flexible instruments were developed and validated. NOViSE is the first force-feedback enabled VR simulator for Natural Orifice Transluminal Endoscopic Surgery (NOTES) training supporting a flexible endoscope. VCSim3 is a VR simulator for cardiovascular interventions using catheters and guidewires. The underlying mathematical model of flexible instruments in both simulator prototypes is based on an established theoretical framework – the Cosserat Theory of Elastic Rods. The efficient implementation of the Cosserat Rod model allows for an accurate, real-time simulation of instruments at haptic-interactive rates on an off-the-shelf computer. The behaviour of the virtual tools and its computational performance was evaluated using quantitative and qualitative measures. The instruments exhibited near sub-millimetre accuracy compared to their real counterparts. The proposed GPU implementation further accelerated their simulation performance by approximately an order of magnitude. The realism of the simulators was assessed by face, content and, in the case of NOViSE, construct validity studies. The results indicate good overall face and content validity of both simulators and of virtual instruments. NOViSE also demonstrated early signs of construct validity. VR simulation of flexible instruments in NOViSE and VCSim3 can contribute to surgical training and improve the educational experience without putting patients at risk, raising ethical issues or requiring expensive animal or cadaver facilities. Moreover, in the context of an innovative and experimental technique such as NOTES, NOViSE could potentially facilitate its development and contribute to its popularization by keeping practitioners up to date with this new minimally invasive technique.Open Acces

    Powerskin Conference: Proceedings

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    The “third skin†of human beings – the building envelope – has a long history of development with a major impact on architecture. As an interface between inside and outside, facades not only determine aspects such as performance and energy efficiency, they also determine the aesthetics of buildings and cities; to the extend that they can create cultural identity. The invention of the curtain wall made facades independent from the building structure, but it remained an important – yet passive – element.  Powerskin Conference: Proceedings, January 19th 2017– Munich &nbsp

    Soft Robotics: Design for Simplicity, Performance, and Robustness of Robots for Interaction with Humans.

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    This thesis deals with the design possibilities concerning the next generation of advanced Robots. Aim of the work is to study, analyse and realise artificial systems that are essentially simple, performing and robust and can live and coexist with humans. The main design guideline followed in doing so is the Soft Robotics Approach, that implies the design of systems with intrinsic mechanical compliance in their architecture. The first part of the thesis addresses design of new soft robotics actuators, or robotic muscles. At the beginning are provided information about what a robotic muscle is and what is needed to realise it. A possible classification of these systems is analysed and some criteria useful for their comparison are explained. After, a set of functional specifications and parameters is identified and defined, to characterise a specific subset of this kind of actuators, called Variable Stiffness Actuators. The selected parameters converge in a data-sheet that easily defines performance and abilities of the robotic system. A complete strategy for the design and realisation of this kind of system is provided, which takes into account their me- chanical morphology and architecture. As consequence of this, some new actuators are developed, validated and employed in the execution of complex experimental tasks. In particular the actuator VSA-Cube and its add-on, a Variable Damper, are developed as the main com- ponents of a robotics low-cost platform, called VSA-CubeBot, that v can be used as an exploratory platform for multi degrees of freedom experiments. Experimental validations and mathematical models of the system employed in multi degrees of freedom tasks (bimanual as- sembly and drawing on an uneven surface), are reported. The second part of the thesis is about the design of multi fingered hands for robots. In this part of the work the Pisa-IIT SoftHand is introduced. It is a novel robot hand prototype designed with the purpose of being as easily usable, robust and simple as an industrial gripper, while exhibiting a level of grasping versatility and an aspect comparable to that of the human hand. In the thesis the main theo- retical tool used to enable such simplification, i.e. the neuroscience– based notion of soft synergies, are briefly reviewed. The approach proposed rests on ideas coming from underactuated hand design. A synthesis method to realize a desired set of soft synergies through the principled design of adaptive underactuated mechanisms, which is called the method of adaptive synergies, is discussed. This ap- proach leads to the design of hands accommodating in principle an arbitrary number of soft synergies, as demonstrated in grasping and manipulation simulations and experiments with a prototype. As a particular instance of application of the method of adaptive syner- gies, the Pisa–IIT SoftHand is then described in detail. The design and implementation of the prototype hand are shown and its effec- tiveness demonstrated through grasping experiments. Finally, control of the Pisa/IIT Hand is considered. Few different control strategies are adopted, including an experimental setup with the use of surface Electromyographic signals

    Proceedings of the European Conference on Agricultural Engineering AgEng2021

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    This proceedings book results from the AgEng2021 Agricultural Engineering Conference under auspices of the European Society of Agricultural Engineers, held in an online format based on the University of Évora, Portugal, from 4 to 8 July 2021. This book contains the full papers of a selection of abstracts that were the base for the oral presentations and posters presented at the conference. Presentations were distributed in eleven thematic areas: Artificial Intelligence, data processing and management; Automation, robotics and sensor technology; Circular Economy; Education and Rural development; Energy and bioenergy; Integrated and sustainable Farming systems; New application technologies and mechanisation; Post-harvest technologies; Smart farming / Precision agriculture; Soil, land and water engineering; Sustainable production in Farm buildings

    The Shadow Space of Allegorical Machines: Situating Locative Media

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    This dissertation utilizes a media archaeological approach to the analysis of locative media, which are technologies that organize an experience of spatial orientation. For instance, a user can use a mobile phone to connect to a cellular network and generate a visualization of the material space in which he or she is positioned with annotated or interactive information on the screen. My critical approach to locative media is influenced by a historical constellation of orientation technologies, their contributions to the social imaginations of space, and the resulting experiences and expectations that are negotiated by the material, symbolic, and ideal. Four case studies on the astrolabe, magnetic compass, divining rod, and digital locative media make up a broader historical arrangement of which, I argue, digital locative media are the latest manifestation. Like other media technologies such as radio or television, these spatial technologies offer a window onto another world while also offering (other)spaces of symbolic and cultural codes that are layered over material space. The ability to reveal these otherspaces is associated with the recurring transcendent logic of locative media as individuals are encouraged to unveil the real behind the apparent in order to become united with a hybrid (and enchanted) ecology of the virtual and real. My locative media archaeology involves a theorization of allegorical machines, which is a term I use to analyze the interfaced interpretation of a shadow (imagined or informational) otherspace in relation to a porous correspondence between subject and space. This theorization is an interrogation of how engineers, technological promoters, and users position allegorical machines as making the supersensible sensible through an interface with the sublime. In other words, locative media are technological attempts to make the vague intelligible by bringing what lies outside the realm of physical experience into contact with the senses. Transcending to otherspaces such as the electromagnetic spectrum or the digital network involves an inherent metaphysics of the interface, which as liaisons between bodies and spaces generate animations such as the one that is the focus of this dissertation: the sublime desire or fear of unveiling the unknown space beyond space.Doctor of Philosoph
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