Adaptive persistence processing
May 2, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3690153 Ultrasonic pulse-echo apparatus Ultrasonic echogram display Method and means for generating time gain compensation control signal for use in ultrasonic scanner and the like Precision ultrasound attenuation measurement Signal processing equipment for ultrasonic visualization Method and means for determining ultrasonic wave attenuation in tissue Method and means for generating time gain compensation control signal for use in ultrasonic scanner and the like Quantitative volume backscatter imaging Method and means for improving image in an ultrasonic scanning system Inventors
ApplicationNo. 433217 filed on 05/02/1995US Classes:600/443Anatomic image produced by reflective scanningExaminersPrimary: Jaworski, Francis J.Attorney, Agent or FirmForeign Patent References
International ClassA61B 008/00AbstractThe invention provides a method and system for adaptive persistence processing in an ultrasound imaging system. Acoustic signals are temporally filtered using an adaptive persistence filter, having a recursive stage followed by a nonrecursive stage. A set of filtering coefficients for each stage are supplied by a look-up table in a memory, addressed or indexed in response to a plurality of input or output pixel values. The look-up table may therefore embody any selected function of its input variables. The input variables for the look-up table function are a current input pixel value Xn and a previous intermediate pixel value Wn-1, and the function embodied by the look-up table includes a relative first difference function for selecting a filter coefficient. A recursive filtering coefficient is held constant over time, while a nonrecursive filtering coefficient γ is adjusted dynamically in response to the current input pixel value Xn and the previous intermediate pixel value Wn-1. The nonrecursive stage filter has a frequency response that attenuates higher frequency components without attenuating a broad range of lower frequency components, relative to the recursive stage frequency response. The step response or settling time of the nonrecursive stage filter always spans one frame interval, independent of the nonrecursive filtering coefficient, while the step response or settling time for the recursive stage filter is generally longer and is dependent on the recursive filtering coefficient.Other References
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