1,553,521 research outputs found

    Mechanics of Hip Dysplasia Reduction in Infants Using the Pavlik Harness: A Physics Based Computational Model

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    Biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of Developmental Dysplasia of the Hip (DDH) were studied using a three-dimensional computer model simulating hip reduction dynamics in (1) subluxated and (2) fully dislocated hip joints. Five hip adductor muscles were identified as key mediators of DDH prognosis, and the non-dimensional force contribution of each in the direction necessary to achieve concentric hip reductions was determined. Results point to the adductor muscles as mediators of subluxated hip reductions, as their mechanical action is a function of the degree of hip dislocation. For subluxated hips in abduction and flexion, the Pectineus, Adductor Brevis, Adductor Longus, and proximal Adductor Magnus contribute positively to reduction, while the rest of the Adductor Magnus contributes negatively. In full dislocations all muscles contribute detrimentally to reduction, elucidating the need for traction to reduce Graf IV type dislocations. Reduction of dysplastic hips was found to occur in two distinct phases: (a) release phase and (b) reduction phase

    Apparatus and Method of Fabricating Directional Fiber Optic Taps, Sensors and Other Devices with Variable Angle Output

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    An apparatus and method for fabricating directional fiber optic taps having a variety of output angles. The taps can be used to monitor losses due to misalignment of the fiber or losses due to bending and straining of the fiber. The apparatus and method can also be used to fabricate taps which filter out higher order modes in a fiber. The apparatus and method can also be used to produce taps which can be used in a position or refractive index measuring system

    Laser-Assisted Fabrication of NMR Resonators

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    A detection coil for use in nuclear resonance magnetic (NMR) spectroscopy and a method of manufacture thereof. At least two film layers of material are deposited on an outer surface of a cylindrical tube of dielectric material. The layers are patterned to form a solenoid on the tube. At least one of the deposited materials is a conductor

    A Novel Method for Prediction of Mobile Robot Maneuvering Spaces

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    As the operational uses of mobile robots continue to expand, it becomes useful to be able to predict the admissible maneuvering space to prevent the robot from executing unsafe maneuvers. A novel method is proposed to address this need by using force-moment diagrams to characterize the robot’s maneuvering space in terms of path curvature and curvature rate. Using the proposed superposition techniques, these diagrams can then be transformed in real-time to provide a representation of the permissible maneuvering space while allowing for changes in the robot’s loading and terrain conditions. Simulation results indicate that the technique can be applied to determine the appropriate maneuvering space for a given set of loading conditions, longitudinal acceleration, and tire-ground coefficient of friction. This may lead to potential expansion in the ability to integrate predictive vehicle dynamics into autonomous controllers for mobile robots and a corresponding potential to safely increase operating speeds

    Optical Transmission Measurements of Explosive Boiling and Liftoff of a Layer of Micron-Scale Water Droplets from a KrF Laser-Heated Si Substrate

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    Water plume velocities were measured in air by optical transmission as a function of laser fluence using a KrF laser for explosive boiling and liftoff of a layer of micron-scale waterdroplets from a laser-heated Si substrate of interest for laser particle removal. The thickness of the superheated water layer near the water/Si interface determines acceleration and removal of the waterdroplets from the Si substrate. © 2003 American Institute of Physic

    Body Limb Movement Limiter

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    A body limb movement limiter restrains the movement of a person\u27s arm so as to protect the person\u27s shoulder or restrains the movement of a person\u27s lower leg with respect to the upper leg so as to protect the person\u27s knee. The device uses a housing having a reel disposed therein with a tether attached thereto and a shear thickening non-Newtonian fluid disposed within the housing so that the fluid acts on the reel during a payout procedure of the tether. The housing is attached to a strap secured about the torso of the person while the free end of the tether is secured about the person\u27s arm. Alternately, a pair of arms are pivotally secured to each other within a housing having the non-Newtonian fluid therein for limiting movement of one arm with respect to the other

    Method for Producing Conductive or Insulating Feedthroughs in a Substrate

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    A method for producing feedthroughs in a substrate having a front and back surface, wherein the substrate either has a hole or absorbs radiation at a given wavelength. The method includes selecting and intimately bonding a sheet to the back surface of the substrate with an adhesive which is absorptive at the given wavelength. If the substrate has a hole, an exposed area of the sheet is illuminated with laser radiation at the given wavelength and at a power level sufficient to ablate a portion of the sheet behind the exposed area, thereby creating the feedthrough in the substrate. If the substrate has no hole, an area on the front surface of the substrate is illuminated with laser radiation at the given wavelength and at a power level sufficient to ablate a portion of the substrate and a portion of the sheet behind the area, thereby creating the feedthrough in the substrate. The sheet can then be removed from the substrate. Alternatively, if the sheet is conductive, the sheet can remain bonded to the substrate and can serve as a ground plane for the substrate. If the sheet is an insulator, the feedthrough is an insulated feedthrough and if the sheet is conductive, the feedthrough is a conductive feedthrough. This procedure can be extended to produce a two conductor feedthrough
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