914 research outputs found

    Bar-holding prosthetic limb

    Get PDF
    A prosthetic device for below-the-elbow amputees is disclosed. The device has a removable effector, which is attached to the end of an arm cuff. The effector is comprised of a pair of C-shaped members that are oriented so as to face each other. Working in concert, the C-shaped members are able to hold a bar such as a chainsaw handle. A flat spring is fitted around the C-shaped members to hold them together

    Rotationally actuated prosthetic helping hand

    Get PDF
    A prosthetic device has been developed for below-the-elbow amputees. The device consists of a cuff, a stem, a housing, two hook-like fingers, an elastic band for holding the fingers together, and a brace. The fingers are pivotally mounted on a housing that is secured to the amputee's upper arm with the brace. The stem, which also contains a cam, is rotationally mounted within the housing and is secured to the cuff, which fits over the amputee's stump. By rotating the cammed stem between the fingers with the lower arm, the amputee can open and close the fingers

    Optimizing collective fieldtaxis of swarming agents through reinforcement learning

    Full text link
    Swarming of animal groups enthralls scientists in fields ranging from biology to physics to engineering. Complex swarming patterns often arise from simple interactions between individuals to the benefit of the collective whole. The existence and success of swarming, however, nontrivially depend on microscopic parameters governing the interactions. Here we show that a machine-learning technique can be employed to tune these underlying parameters and optimize the resulting performance. As a concrete example, we take an active matter model inspired by schools of golden shiners, which collectively conduct phototaxis. The problem of optimizing the phototaxis capability is then mapped to that of maximizing benefits in a continuum-armed bandit game. The latter problem accepts a simple reinforcement-learning algorithm, which can tune the continuous parameters of the model. This result suggests the utility of machine-learning methodology in swarm-robotics applications.Comment: 6 pages, 3 figure

    Prosthetic helping hand

    Get PDF
    A prosthetic device for below-the-elbow amputees, having a C-shaped clamping mechanism for grasping cylindrical objects, is described. The clamping mechanism is pivotally mounted to a cuff that fits on the amputee's lower arm. The present invention is utilized by placing an arm that has been amputated below the elbow into the cuff. The clamping mechanism then serves as a hand whenever it becomes necessary for the amputee to grasp a cylindrical object such as a handle, a bar, a rod, etc. To grasp the cylindrical object, the object is jammed against the opening in the C-shaped spring, causing the spring to open, the object to pass to the center of the spring, and the spring to snap shut behind the object. Various sizes of clamping mechanisms can be provided and easily interchanged to accommodate a variety of diameters. With the extension that pivots and rotates, the clamping mechanism can be used in a variety of orientations. Thus, this invention provides the amputee with a clamping mechanism that can be used to perform a number of tasks

    Wavelength-Scale Imaging of Trapped Ions using a Phase Fresnel lens

    Full text link
    A microfabricated phase Fresnel lens was used to image ytterbium ions trapped in a radio frequency Paul trap. The ions were laser cooled close to the Doppler limit on the 369.5 nm transition, reducing the ion motion so that each ion formed a near point source. By detecting the ion fluorescence on the same transition, near diffraction limited imaging with spot sizes of below 440 nm (FWHM) was achieved. This is the first demonstration of imaging trapped ions with a resolution on the order of the transition wavelength.Comment: 8 pages, 3 figure

    Histological Examination of Collagen and Proteoglycan Changes in Osteoarthritic Menisci

    Get PDF
    This study sought to examine collagen and proteoglycan changes in the menisci of patients with osteoarthritis (OA). Collagens were examined using picrosirius red, and hematoxylin and eosin. Proteoglycans were examined using safranin-O and alcian blue. Types I and II collagens and aggrecan were examined using immunochemistry. Severe loss of collagens was observed to occur in OA menisci, particularly in the middle and deep zones and collagen networks were less organized than those of normal menisci. In contrast, proteoglycan staining in the middle and deep zones of OA meniscus increased compared to normal control menisci. Immunohistochemistry indicated that types I and II collagens were co-localized and the loss of types I collagen in OA menisci appeared more severe in the middle and deep zones than that in the surface zones. The loss of type II collagen however was severe across all three zones. Immunohistochemistry also indicated elevated aggrecan staining in OA menisci. These findings together indicate that severe loss of collagens and intrameniscal degeneration are hallmarks of OA menisci and that extracellular matrix degeneration occurred in OA menisci follows a pathway different from that occurred in OA articular cartilage. These findings are not only important for a better understanding of the disease process but also important for the development of novel structure-modifying drugs for OA therapy

    TFTR 60 GHz alpha particle collective Thomson scattering diagnostic

    Get PDF
    A 60 GHz gyrotron collective Thomson Scattering alpha particle diagnostic has been implemented for the D-T period on TFM. Gyrotron power of 0.1-1 kW in pulses of up to 1 second can be launched in X-mode. Efficient corrugated waveguides are used with antennaes and vacuum windows of the TFTR Microwave Scattering system. A multichannel synchronous detector receiver system and spectrum analyzer acquire the scattered signals. A 200 Megasample/sec digitizer is used to resolve fine structure in the frequency spectrum. By scattering nearly perpendicular to the magnetic field, this experiment will take advantage of an enhancement of the scattered signal which results from the interaction of the alpha particles with plasma resonances in the lower hybrid frequency range. Significant enhancements are expected, which will make these measurements possible with gyrotron power less than 1 kW, while maintaining an acceptable signal to noise ratio. We hope to extract alpha particle density and velocity distribution functions from the data. The D and T fuel densities and temperatures may also be obtainable by measurement of the respective ion cyclotron harmonic frequencies

    Research Needs for Effective Transition in Lifelong Care of Congenital Genitourinary Conditions: A Workshop Sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases

    Get PDF
    Over the last 5 decades, health-care advances have yielded quantum improvements in the life expectancy of individuals with congenital genitourinary conditions (CGCs), leading to a crisis of care. Many individuals with CGC enter adulthood unprepared to manage their condition. Pediatric CGC specialists lack training to manage adulthood-related health-care issues, whereas adult genitourinary specialists lack training within the context of CGCs. To address these challenges, the National Institutes of Diabetes and Digestive and Kidney Diseases convened individuals with CGCs and experts from a variety of fields to identify research needs to improve transitional urology care. This paper outlines identified research needs
    corecore