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:
Aug. 04, 1987
Filed:
Jun. 30, 1986
William T Mayo, Seal Beach, CA (US);
North American Philips Corporation, New York, NY (US);
Abstract
In an ultrasonic diagnostic system the invention utilizes the concept that for pulse echo medical ultrasound signals the mean instantaneous frequency estimates are improved by imposing the condition that a local frequency estimate is ignored unless a condition of the amplitude exceeding some threshold is met. It provides for the use of conditional frequency or zero crossing rate measurement as applied to ultrasound attenuation measurement and also to local frequency shift measurement due to frequency dependent scattering. The system simultaneously detects the amplitude of the signal, delays the RF waveform to satisfy causality and then conditionally accepts the frequency demodulated image only when a preselected amplitude is exceeded. The system requires that the amplitude of the instantaneous RF signal exceed a set threshold in order for the half cycle of the signal to be processed. It then uses a threshold comparator which causes a track and hold signal to hold during the period when the RF signal amplitude is below the threshold and which tracks the RF signal when its amplitude exceeds the threshold.