3119 results about "Asymmetry" patented technology

Alignment accuracy between two or more patterned layers is measured using a metrology target comprising substantially overlapping diffraction gratings formed in a test area of the layers being tested. An optical instrument illuminates all or part of the target area and measures the optical response. The instrument can measure transmission, reflectance, and / or ellipsometric parameters as a function of wavelength, polar angle of incidence, azimuthal angle of incidence, and / or polarization of the illumination and detected light. Overlay error or offset between those layers containing the test gratings is determined by a processor programmed to calculate an optical response for a set of parameters that include overlay error, using a model that accounts for diffraction by the gratings and interaction of the gratings with each others' diffracted field. The model parameters might also take account of manufactured asymmetries. The calculation may involve interpolation of pre-computed entries from a database accessible to the processor. The calculated and measured responses are iteratively compared and the model parameters changed to minimize the difference.

A method for detecting noise location information in a power line distribution system is disclosed. In one embodiment, the method includes the steps of receiving link quality data for a first power line communication link between a first and second power line communications device, determining an asymmetry in the link quality data of the link, and determining location information for the noise source based on the location of the first power line communications device or the location of the second power line communications device.

The specification and drawings present a new apparatus and method for providing a wide field-of-view as well as illumination uniformity in exit pupil expanders (EPE) using stacked EPE substrates (or plates) with non-symmetric exit pupil expansion that use a plurality of diffractive elements for expanding the exit pupil of a display for viewing.

Disclosed is an ultrasonic surgical instrument that combines end-effector geometry to best affect the multiple functions of a shears-type configuration. The shape of the blade is characterized by a radiused cut offset by some distance to form a curved geometry. The cut creates a curved surface with multiple asymmetries causing multiple imbalances within the blade. Imbalance due to the curve of the instrument is corrected by a non-functional asymmetry proximal to the functional asymmetry. Imbalance due to the asymmetric cross-section of the blade is corrected by the appropriate selection of the volume and location of material removed from a functional asymmetry. The shape of the blade in one embodiment of the present invention is characterized by two radiused cuts offset by some distance to form a curved and potentially tapered geometry. These two cuts create curved surfaces including a concave surface and a convex surface. The length of the radiused cuts affects, in part, the acoustic balancing of the transverse motion induced by the curved shape.

Systems and methods that utilize asymmetric geometry to acquire radiographic tomosynthesis images are described. Embodiments comprise tomosynthesis systems and methods for creating a reconstructed image of an object from a plurality of two-dimensional x-ray projection images. These systems comprise: an x-ray detector; and an x-ray source capable of emitting x-rays directed at the x-ray detector; wherein the tomosynthesis system utilizes asymmetric image acquisition geometry, where θ1≠θ0, during image acquisition, wherein θ1 is a sweep angle on one side of a center line of the x-ray detector, and θ0 is a sweep angle on an opposite side of the center line of the x-ray detector, and wherein the total sweep angle, θasym, is θasym=θ1+θ0. Reconstruction algorithms may be utilized to produce reconstructed images of the object from the plurality of two-dimensional x-ray projection images.

Induced movement in a patient is detected and correlated with a TMS stimulating pulse so as to determine the patient's motor threshold stimulation level. Direct visual or audible feedback is provided to the operator indicating that a valid stimulation has occurred so that the operator may adjust the stimulation accordingly. A search algorithm may be used to direct a convergence to the motor threshold stimulation level with or without operator intervention. A motion detector is used or, alternatively, the motion detector is replaced with a direct motor evoked potential (MEP) measurement device that measures induced neurological voltage and correlates the measured neurological change to the TMS stimulus. Other signals indicative of motor threshold may be detected and correlated to the TMS stimulus pulses. For example, left / right asymmetry changes in a narrow subset of EEG leads placed on the forehead of the patient or fast autonomic responses, such as skin conductivity, modulation of respiration, reflex responses, and the like, may be detected. The appropriate stimulation level for TMS studies are also determined using techniques other than motor cortex motor threshold methods. For example, a localized ultrasound probe may be used to determine the depth of cortical tissue at the treatment site. When considered along with neuronal excitability, the stimulation level for treatment may be determined. Alternatively, a localized impedance probe or coil and detection circuit whose Q factor changes with tissue loading may be used to detect cortical depth.