Ultrasonic flow imaging
First Claim
1. In a coherent imaging system using vibratory energy for producing an image, a method of obtaining an indication of magnitude and direction of flowing reflectors, comprising the steps of:
- a) producing a plurality of vibratory energy pulses at time intervals (Δ
T);
b) receiving echo signals resulting from reflection of the vibratory energy pulses by the flowing reflectors;
c) forming a plurality of signals representative of a plurality of receive beams produced from each echo signal steered in a corresponding plurality of beam angles;
d) sampling the plurality of signals representative of receive beams for a set of successive ranges along each receive beam;
e) correlating a central sample from signals representative of one of the receive beams formed from one of the echo signals with a corresponding sample from signals representative of said one of the receive beams formed from another one of the echo signals and the surrounding samples from signals representative of the plurality of receive beams formed from said another one of the echo signals to produce a set of correlation values;
f) calculating velocity of the reflectors at the central sample in both the range direction and cross range direction from the set of correlation values;
g) controlling intensity of an image pixel which corresponds to location of the central sample with the calculated velocity;
h) repeating steps e), f) and g) for central samples located at successive range values along said one of the receive beams; and
i) repeating steps a) through h) in which the plurality of receive beams formed in step c) are steered in a different beam angle.
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Accused Products
Abstract
A phased array sector scanning ultrasonic imaging system produces simultaneously, and samples, three receive beams for each transmitted ultrasonic pulse directed upon flowing reflectors. Flow velocity is measured in the cross range direction using a correlation technique while flow velocity in the range direction is simultaneously measured using a Doppler method. By performing cross correlation in both the range and cross range directions with data acquired from a set of such multi-beam acquisitions, a B-scan image is produced which indicates both magnitude and direction of the flowing reflectors.
62 Citations
9 Claims
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1. In a coherent imaging system using vibratory energy for producing an image, a method of obtaining an indication of magnitude and direction of flowing reflectors, comprising the steps of:
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a) producing a plurality of vibratory energy pulses at time intervals (Δ
T);b) receiving echo signals resulting from reflection of the vibratory energy pulses by the flowing reflectors; c) forming a plurality of signals representative of a plurality of receive beams produced from each echo signal steered in a corresponding plurality of beam angles; d) sampling the plurality of signals representative of receive beams for a set of successive ranges along each receive beam; e) correlating a central sample from signals representative of one of the receive beams formed from one of the echo signals with a corresponding sample from signals representative of said one of the receive beams formed from another one of the echo signals and the surrounding samples from signals representative of the plurality of receive beams formed from said another one of the echo signals to produce a set of correlation values; f) calculating velocity of the reflectors at the central sample in both the range direction and cross range direction from the set of correlation values; g) controlling intensity of an image pixel which corresponds to location of the central sample with the calculated velocity; h) repeating steps e), f) and g) for central samples located at successive range values along said one of the receive beams; and i) repeating steps a) through h) in which the plurality of receive beams formed in step c) are steered in a different beam angle. - View Dependent Claims (2)
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3. In a vibratory energy imaging system, a method of producing an image with an indication of magnitude and direction of flowing reflectors, comprising the steps of:
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transmitting a first vibratory energy beam toward said reflectors directed at an angle θ
so as to produce a first set of receive beams;sampling said set of receive beams disposed around said angle θ
;storing said samples in a first input buffer; transmitting a second vibratory energy beam toward said reflectors directed at said angle θ
so as to produce a second set of receive beams;sampling said second set of receive beams disposed around said angle θ
,storing said samples in a second input buffer; correlating flow of a reflector at a sample range of each of said receive beams at angle θ
in both range and cross range directions using the stored samples in the first and second input buffers; andcontrolling, in accordance with the range and cross range flow measurements, a pixel in a two-dimensional image which corresponds in location to said samples range and beam angle θ
. - View Dependent Claims (4, 5)
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6. In a coherent imaging system using vibratory energy for producing an image, apparatus for obtaining an indication of magnitude and direction of flowing reflectors, comprising:
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transmitter means for producing a plurality of vibratory energy pulses at time intervals of duration Δ
T;receiver means for receiving echo signals which result from reflection of the vibratory energy pulses by the flowing reflectors and for forming a plurality of sampled receive beam signals for beams steered in a corresponding plurality of beam angles; a mid processor for receiving the sampled receive beam signals from the receiver means, correlating samples from one echo signal with corresponding samples from another echo signal, and calculating velocity of the reflectors at a central sample in both the range and cross range directions; and display means for receiving the calculated velocities from the mid processor and being operable in response thereto to control brightness and color of pixels in an image in accordance with said calculated velocities. - View Dependent Claims (7, 8, 9)
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Specification