120 research outputs found

    A Characterization of Actuation Techniques for Generating Movement in Shape-Changing Interfaces

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    Abstract This article characterizes actuation techniques for generating movement in shape-changing displays with physically reconfigurable geometry. To date, few works in Human Computer Interaction literature provide detailed and reflective descriptions of the implementation techniques used in shape-changing displays. This hinders the rapid development of novel interactions as researchers must initially spend time understanding technologies before prototyping new interactions and applications. To bridge this knowledge gap, we propose a taxonomy that classifies actuator characteristics and simplifies the process for designers to select appropriate technologies that match their requirements for developing shape-displays. We scope our investigation to linear actuators that are used in grid configurations. The taxonomy is validated by (a) examining current implementation techniques of motorized, pneumatic, hydraulic, magnetic, and shape-memory actuators in the literature, (b) constructing prototypes to address limited technical details and explore actuator capabilities in depth, (c) describing a use-case scenario through a case study that details the construction of a 10 ? 10 actuator shape-display, and (d) a set of guidelines to aid researchers in selecting actuation techniques for shape-changing applications. The significance of our taxonomy is twofold. First, we provide an original contribution that enables HCI researchers to appropriately select actuation techniques and build shape-changing applications. This is situated amongst other past works that have investigated broader application scenarios such as a shape-changing vocabulary, a framework for shape transformations, material properties, and technical characteristics of various actuators. Second, we carry out in-depth investigations to validate our taxonomy and expand the knowledge of vertical actuation in shape-changing applications to enable rapid development

    A Breathing Stabilization System

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    Breathing Stabilization System is a new idea and method. The purpose of this system is to produce a device to control a patient’s breathing for gated radiotherapy. This thesis focuses on building a simple Breathing Stabilization System that includes five solenoids, a power supply and five force sensors to build up the whole system. Significantly, this thesis will introduce the modeling of solenoids in detail that include how to build a mathematical model of the solenoids. The simulation of the electromagnetic in professional multi-physics software COMSOL will also be explained. To drive the solenoid system, a voltage-to-current converter is used. This part will be introduced as well as the operational amplifier circuit used by the force sensors

    Real-Time Numerical Simulation for Accurate Soft Tissues Modeling during Haptic Interaction

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    The simulation of fabrics physics and its interaction with the human body has been largely studied in recent years to provide realistic-looking garments and wears specifically in the entertainment business. When the purpose of the simulation is to obtain scientific measures and detailed mechanical properties of the interaction, the underlying physical models should be enhanced to obtain better simulation accuracy increasing the modeling complexity and relaxing the simulation timing constraints to properly solve the set of equations under analysis. However, in the specific field of haptic interaction, the desiderata are to have both physical consistency and high frame rate to display stable and coherent stimuli as feedback to the user requiring a tradeoff between accuracy and real-time interaction. This work introduces a haptic system for the evaluation of the fabric hand of specific garments either existing or yet to be produced in a virtual reality simulation. The modeling is based on the co-rotational Finite Element approach that allows for large displacements but the small deformation of the elements. The proposed system can be beneficial for the fabrics industry both in the design phase or in the presentation phase, where a virtual fabric portfolio can be shown to customers around the world. Results exhibit the feasibility of high-frequency real-time simulation for haptic interaction with virtual garments employing realistic mechanical properties of the fabric materials

    An Untethered Multimodal Haptic Hand Wearable

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    Haptic primary colors correspond to temperature, vibration, and force. Previous studies combined these three haptic primary colors to produce different types of cutaneous sensations without the need to touch a real object. This study presents a low-cost untethered hand wearable with temperature, vibration, and force feedback. It is made from low-cost and commercial off-the-shelf components. A 26 mm annular Peltier element with a 10 mm hole is coupled to an 8 mm mini disc vibration motor, forming vibro-thermal tactile feedback for the user. All the other fingertips have an 8 mm disc vibration motor strapped on them using Velcro. Moreover, kinesthetic feedback extracted from a retractable ID badge holder with a small solenoid stopper is used as force feedback that restricts the fingers’ movement. Hand and finger tracking is done using Leap Motion Controller interfaced to a virtual setup with different geometric figures developed using Unity software. Therefore, we argue this prototype as a whole actuates cutaneous and kinesthetic feedback that would be useful in many virtual applications such as Virtual Reality (VR), teleoperated surgeries, and teleoperated farming and agriculture

    Conceptual design study of a Harrier V/STOL research aircraft

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    MCAIR recently completed a conceptual design study to define modification approaches to, and derive planning prices for the conversion of a two place Harrier to a V/STOL control, display and guidance research aircraft. Control concepts such as rate damping, attitude stabilization, velocity command, and cockpit controllers are to be demonstrated. Display formats will also be investigated, and landing, navigation and guidance systems flight tested. The rear cockpit is modified such that it can be quickly adapted to faithfully simulate the controls, displays and handling qualities of a Type A or Type B V/STOL. The safety pilot always has take command capability. The modifications studied fall into two categories: basic modifications and optional modifications. Technical descriptions of the basic modifications and of the optional modifications are presented. The modification plan and schedule as well as the test plan and schedule are presented. The failure mode and effects analysis, aircraft performance, aircraft weight, and aircraft support are discussed

    Haptic Hand Exoskeleton for Precision Grasp Simulation

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    This paper outlines the design and the development of a novel robotic hand exoskeleton (HE) conceived for haptic interaction in the context of virtual reality (VR) and teleoperation (TO) applications. The device allows exerting controlled forces on fingertips of the index and thumb of the operator. The new exoskeleton features several design solutions adopted with the aim of optimizing force accuracy and resolution. The use of remote centers of motion mechanisms allows achieving a compact and lightweight design. An improved stiffness of the transmission and reduced requirements for the electromechanical actuators are obtained thanks to a novel principle for integrating speed reduction into torque transmission systems. A custom designed force sensor and integrated electronics are employed to further improve performances. The electromechanical design of the device and the experimental characterization are presented

    Novel Artificial Urinary Sphincter for Stress Urinary Incontinence Treatment

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    University of Minnesota M.S.E.E. thesis. September 2017. Major: Electrical Engineering. Advisor: Gerald Timm. 1 computer file (PDF); xiv, 129 pages.The American Medical System’s AMS 800TM has been the gold standard for over 40 years with over 150,000 patients treated for Urinary Incontinence and is the leading treatment for male stress urinary incontinence (SUI) following prostate surgery. Type III SUI, or intrinsic sphincter deficiency, is the inability of the urethra to maintain closure pressure sufficient to keep the patient clinically dry at rest and during periods of heightened activity (~120 cmH2O; coughs, sneezes, posture changes, and exercises). The current AMS 800TM is not personalized to a patient’s needs and compromises with an in between pressure- as high (61-70 cmH2O) as it can be without exceeding safety threshold levels. As such many men still leak when they are active. The market is hungry for a device that can adapt to the patient’s level of activity, reducing pressure most of the day to protect the urethra and then briefly increasing the pressure when he is more active. We are developing a novel implantable pump (henceforth called “add-on device”) which will be an add-on to the AMS 800TM and it includes a solenoid coil-cum-plunger and a fluid reservoir within the pump body. The add-on device will be small, light-weight and battery powered, and maintain compatibility with the AMS 800TM device. The device idea is in its proof-of-concept stage. This add-on device can be a possible solution to reducing the risks including urethral atrophy (leading to return of incontinence) and erosion (leading to infection of the implant) resulting from the constant pressure

    Enabling wearable soft tactile displays with dielectric elastomer actuators

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    PhDTouch is one of the less exploited sensory channels in human machine interactions. While the introduction of the tactile feedback would improve the user experience in several fields, such as training for medical operators, teleoperation, computer aided design and 3D model exploration, no interfaces able to mimic accurately and realistically the tactile feeling produced by the contact with a real soft object are currently available. Devices able to simulate the contact with soft bodies, such as the human organs, might improve the experience. The existing commercially available tactile displays consist of complex mechanisms that limit their portability. Moreover, no devices are able to provide tactile stimuli via a soft interface that can also modulate the contact area with the finger pad, which is required to realistically mimic the contact with soft bodies, as needed for example in systems aimed at simulating interactions with virtual biological tissues or in robot-assisted minimally invasive surgery. The aim of this thesis is to develop such a wearable tactile display based on the dielectric elastomer actuators (DEAs). DEAs are a class of materials that respond to an electric field producing a deformation. In particular, in this thesis, the tactile element consists of a so-called hydrostatically coupled dielectric elastomer actuator (HC-DEAs). HC-DEAs rely on an incompressible fluid that hydrostatically couples a DEA-based active part to a passive part interfaced to the user. The display was also tested within a closed-loop configuration consisting of a hand tracking system and a custom made virtual environment. This proof of concept system allowed for a validation of the abilities of the display. Mechanical and psychophysical tests were performed in order to assess the ability of the system to provide tactile stimuli that can be distinguished by the users. Also, the miniaturisation of the HC-DEA was investigated for applications in refreshable Braille displays or arrays of tactile elements for tactile maps

    A Novel Untethered Hand Wearable with Fine-Grained Cutaneous Haptic Feedback

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    During open surgery, a surgeon relies not only on the detailed view of the organ being operated upon and on being able to feel the fine details of this organ but also heavily relies on the combination of these two senses. In laparoscopic surgery, haptic feedback provides surgeons information on interaction forces between instrument and tissue. There have been many studies to mimic the haptic feedback in laparoscopic-related telerobotics studies to date. However, cutaneous feedback is mostly restricted or limited in haptic feedback-based minimally invasive studies. We argue that fine-grained information is needed in laparoscopic surgeries to study the details of the instrument’s end and can convey via cutaneous feedback. We propose an exoskeleton haptic hand wearable which consists of five 4 ⇥ 4 miniaturized fingertip actuators, 80 in total, to convey cutaneous feedback. The wearable is described as modular, lightweight, Bluetooth, and WiFi-enabled, and has a maximum power consumption of 830 mW. Software is developed to demonstrate rapid tactile actuation of edges; this allows the user to feel the contours in cutaneous feedback. Moreover, to demonstrate the idea as an object displayed on a flat monitor, initial tests were carried out in 2D. In the second phase, the wearable exoskeleton glove is then further developed to feel 3D virtual objects by using a virtual reality (VR) headset demonstrated by a VR environment. Two-dimensional and 3D objects were tested by our novel untethered haptic hand wearable. Our results show that untethered humans understand actuation in cutaneous feedback just in a single tapping with 92.22% accuracy. Our wearable has an average latency of 46.5 ms, which is much less than the 600 ms tolerable delay acceptable by a surgeon in teleoperation. Therefore, we suggest our untethered hand wearable to enhance multimodal perception in minimally invasive surgeries to naturally feel the immediate environments of the instruments
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