The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 02, 2001
Filed:
Jul. 09, 1999
Larry Y. L. Mo, Waukesha, WI (US);
Richard M. Kulakowski, Richfield, WI (US);
General Electric Company, Milwaukee, WI (US);
Abstract
A method and an apparatus for adaptive wall (high-pass) filtering to remove low-frequency clutter in spectral Doppler I/Q data prior to FFT processing. The I/Q data is passed through a low-pass filter which rejects the flow frequency components above the clutter frequency range. The total power of the low-pass filter output is then computed. A system noise model is used to predict the mean system noise power in the low-pass filter output. The predicted mean noise power provides a noise threshold to gage how much clutter power is present in the current FFT packet. If no significant clutter is present, then wall filter selection logic will automatically select the lowest wall filter cutoff frequency stored in a filter coefficient LUT. If significant clutter power is present in the FFT packet, then the mean and variance of the clutter frequency over the FFT packet are estimated and then input into the filter selection logic, which selects the most suitable filter cutoff for the current clutter signal.