Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
1998-12-31
2001-02-27
Jaworski, Francis J. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
Reexamination Certificate
active
06193665
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to acoustical Doppler velocity estimations and, more specifically, relates to the calculation of body fluid velocity, such as blood velocity and the like, based on the Doppler shift of ultrasonic signals.
Color flow and Doppler imaging in current ultrasound systems are both affected by the same limitation. If a Doppler style processing, such as a Fourier transform for Doppler or an autocorrelation for color flow (or exclusively down-range processing, such as a time domain cross correlation algorithm) are used to measure either blood flow or tissue motion, only the velocity component along the line of the ultrasound beam direction is measured, and any orthogonal component is not usually calculated. Various schemes have been proposed and even implemented to compensate for this problem. In Doppler, the user is typically given the opportunity to position a cursor indicating the direction of blood flow, so that the true velocity vector then can be adjusted by the cosine of the Doppler angle. In color flow, various schemes, including triangulation and lateral cross correlation, have been studied and published in the literature. However, none of the known systems effectively calculates the true velocity of blood flow in a manner which eliminates operator errors. This invention solves that problem.
BRIEF SUMMARY OF THE INVENTION
The present invention is useful in an ultrasound imaging system for calculating the velocity of fluid flow, such as blood flow, in at least a portion of a subject being studied. As used in the specification and claims, fluid flow includes blood flow, tissue flow and flow of contrast agents used in diagnosis, including those which result in bubbles in the blood stream. Preferably, ultrasound waves are transmitted from a first position toward a portion of the subject by a conventional ultrasound transducer. First reflected ultrasound waves traveling in a first direction are received from the portion of the subject in response to the transmitting of the ultrasound waves from the first position, preferably by an ultrasound transducer. Ultrasound waves are transmitted from a second position toward the portion of the subject. Second reflected ultrasound waves traveling in a second direction are received from the portion of the subject in response to the transmitting of the ultrasound waves from the second position. A first signal is generated having a first value related to the velocity component of the fluid flow in at least the portion of the subject in response to the first reflected ultrasound waves, preferably by a Doppler unit. A second signal is generated having a second value related to the velocity component of the fluid flow in at least the portion of the subject in response to the second reflected ultrasound waves, preferably by the Doppler unit. First scan data is generated and stored in response to the first ultrasound waves received from the portion of the subject in response to the transmitting of the ultrasound waves from the first position, preferably by a B-mode or color ultrasound scanner and memory. Second scan data is generated and stored responsive to the second ultrasound waves received from the portion of the subject in response to the transmitting of the ultrasound waves from the second position. The angle of rotation between the first position and the second position is calculated in response to the first and second scan data, preferably by a logic unit, such as a processor. The velocity of the fluid flow in at least the portion of the subject is estimated based on the angle of rotation and the first and second values of the first and second signals.
The advantage of this technique is that a more accurate estimate of the fluid flow/tissue velocity is obtained by the system, thus aiding the diagnosis of the disease state being studied. With additional information, such as vessel cross-sectional area, estimates of quantitative fluid flow, such as blood flow, can potentially be obtained.
REFERENCES:
patent: 4622978 (1986-11-01), Matsuo et al.
patent: 5038788 (1991-08-01), Satake
patent: 5349524 (1994-09-01), Daft et al.
patent: 5441052 (1995-08-01), Miyajima
patent: 5454372 (1995-10-01), Banjanin et al.
patent: 5522393 (1996-06-01), Phillips et al.
patent: 5538004 (1996-07-01), Bamber
patent: 5555886 (1996-09-01), Weng et al.
patent: 5910119 (1999-06-01), Lin
patent: 5997480 (1999-12-01), Sumanaweera et al.
patent: WO 97/32777 (1997-09-01), None
LEAVITT et al.A Scan Coversion Algorithm for Displaying Ultrasound Images, Hewlett-Packard Journal, Oct. 1983, vol. 34, No. 10, 1266 Amstelveen, Nederland.
OVERBECK et al.Vector Doppler: Accurate Mesasurement of Blood Velocity In Two Dimensions, Ultrasound in Med. & Biol., 1992, Vol, 18, No. 1, pp. 19-31, U.S.A.
CHEN et al.Symmetric Phase-Only Matched Fitlering of Fourier-Mellin Transforms for Image Registration and Recognition, 8180 IEEE Transactions on Pattern Analysis and Machine Intelligence, (1994) Dec., No. 12, U.S.A.
Dong Fang
Hall Anne Lindsay
Cabou Christian G.
General Electric Company
Jaworski Francis J.
McAndrews Held and Malloy
Price Phyllis Y.
LandOfFree
Doppler angle unfolding in ultrasound color flow and Doppler does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Doppler angle unfolding in ultrasound color flow and Doppler, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Doppler angle unfolding in ultrasound color flow and Doppler will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2563399