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:
Feb. 15, 2000
Filed:
Nov. 22, 1995
Ray Steven Spratt, San Jose, CA (US);
Gregory Sharat Lin, Fremont, CA (US);
Steven F Forestieri, Santa Clara, CA (US);
Diasonics Ultrasound, Inc., Milpitas, CA (US);
Abstract
A method and apparatus for determining resistance and pulsatility indices of a flow of material, such as the flow of blood in the human body. This may be implemented, for example, in a color flow module in an ultrasonic imaging system for display of the pulsatility or resistance index in two dimensions and in different colors to allow discrimination between veins and arteries and detection of pathologic elevation of vascular resistance in a clinical survey mode of the system. The resistance index is determined from the ratio of a unipolar variation estimate of a velocity of the flow material divided by a peak velocity. The variation estimate may be one of the following: a difference between a peak velocity of the flow of material and a second minimum (if unipolar) or negative (if bipolar) velocity of the flow of material, a standard deviation .rho. of the velocity of the flow of material, a square root of a value at a first peak of an autocorrelator of the velocity of the flow of material, and a square root of a value at a second peak of the autocorrelator of the velocity of the flow of material.