Abstract: Disclosed are novel molding methods for injection molding thermoplastic lens elements and particularly adapted for the manufacture of steeply curved and/or thin-centered lenses.

Abstract: A method and apparatus for displaying an image representing the flow of a substance in a scanned area. An Angio scanner scans a region of tissue and generates Ultrasound Angio data representing the flow of blood in the region of tissue. Relatively small blood flows are difficult to detect in images based solely on Angio data. To enhance the visibility of small blood flows, spatial derivative values are calculated from the Angio data. A fraction of the original Angio data plus a bias is summed with the spatial derivative values to generate composite values. An image of the scanned region is displayed with colors or grayscale shades based on the composite values. The resulting image depicts blood vessels in an edge-enhanced format, giving a three-dimensional appearance.

Abstract: Method and apparatus for performing angiography of a subject under examination in an ultrasonic imaging apparatus. A set of ultrasonic reference pulses along each of a series of parallel vectors is emitted into the subject under examination, echoes are received, and a plurality of data samples are obtained. From each of the plurality of data samples a plurality of basis functions are removed to remove clutter and generate a plurality of processed samples. The processed samples are averaged and temporally filtered with signals displayed in a previous time period to generate a second averaged signals. The temporal filtering is performed using a filter coefficient which approximates a full cardiac cycle of the subject under examination.

Abstract: An apparatus for temporal filtering in an ultrasonic imaging system. The apparatus has a means for storing previous imaging information from a previous time period and a means for storing current imaging information from a current time period. Means for determining the larger of the current and previous imaging information is provided and a means is provided for generating an alpha value responsive to the larger information. The alpha value ranges between a minimum and maximum values and has the maximum value when the larger information has a large frequency and has the minimum value when the larger information has a small frequency. Means for generating output imaging information is provided, the output imaging information generated by multiplying the current imaging information by alpha and summing it with the product of the maximum value minus alpha and the previous imaging information.

Abstract: An ultrasound imaging system for performing dynamic focusing of ultrasonic waves during transmit and receive. The present invention includes a method and a means for transmitting ultrasonic waves to a multiple depths within a body. The present invention optimizes the transmit frequency for each of the multiple depths to localize the energy of the ultrasonic waves. The present invention also includes a method and means for performing dynamic receive focusing of the reflected ultrasonic waves produced by discontinuities in the body, such that it is focused to receive ultrasonic waves from the depth at which the transmitted ultrasonic waves are focused.

Abstract: An apparatus and method for clutter elimination from signals which digitizes a signal to generate n samples of the signals. M basis functions (such as various levels of filters) are fit to the n samples. An i+1 basis function of the m basis functions is iteratively subtracted from each of the n samples, and the difference is stored in an i difference signal until the i+1 difference signal is less than a threshold. In various embodiments, the threshold may be an absolute noise floor (R.sub.O.sup.min) preset by a manufacturer or a user. In other embodiments, the threshold may be based upon an absolute or relative predictor error of the signal once the basis function (filter) has been removed. The i difference signal may be used for performing a frequency estimate of the signal.

Abstract: Signal processing apparatus and methods for elimination of undesirable clutter signals from desirable signals. This is performed without the use of filters by subtracting orthonormal basis functions from signal samples until the appropriate degree of clutter removal is achieved. Estimates of frequency information such as Doppler shifts due to fluid flow may thus be achieved with superior discrimination of true flow signals from sources of clutter or artifact, greater sensitivity to low flow rates, minimal computational effort and with fewer samples than the prior art.

Abstract: An improved method is disclosed for obtaining shear wave data from common depth point gathered compressional wave traces using variations in the amplitude of the gathered compressional waves with source receiver offset. The shear wave data is determined from measured compressional amplitude offset values and incident angles of shear wave data. The incident angles are determined from the offsets and smoothed interval velocity functions.

Abstract: An improved method is disclosed for obtaining shear wave data from common depth point gathered compressional wave traces using variations in the amplitude of the gathered compressional waves with source receiver offset. The gathered compressional waves are corrected for normal moveout and the normal moveout corrected waves are further corrected for residual normal moveout by correcting stacking velocities of the normal moveout corrected traces.

Abstract: A method is disclosed for obtaining shear wave data from common depth point gathered compressional wave traces using variations in the amplitude of the gathered compressional waves with source-receiver offset. The shear wave data can be used to generate pseudo-shear wave seismic sections.