Processing velocity information in an ultrasonic system
First Claim
1. A method of making vascular measurements within a living subject in an ultrasonic system comprising the following steps:
- a. determining peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination, determining said peak velocities includes dividing said spectra into a plurality of regions to determine a threshold magnitude of said peak velocities and identifying a first velocity that exceeds said threshold magnitude;
b. based upon said peak velocities of said spectra over said period of time, determining a time series of said peak velocities representing an optimum cardiac cycle for said subject under examination; and
c. based upon said time series of said peak velocities representing said optimum cardiac cycle, performing vascular measurements of said peak velocities for said optimum cardiac cycle.
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Accused Products
Abstract
A method and apparatus in an ultrasonic system for determining an optimum cardiac cycle of a living subject, and for performing vascular measurements. Peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination are determined. Based upon the peak velocities of the spectra over the period of time, a time series of the peak velocities are determined representing an optimum cardiac cycle. In addition, vascular measurements of the peak velocities for the optimum cardiac cycle can be determined from the optimum cardiac cycle. The peak velocities of the spectra can be performed by dividing the spectra in a plurality of regions according to ranges of the velocity information. A threshold magnitude of the peak velocities is determined by adding a predetermined value to a minimum magnitude. The threshold magnitude is used to find a peak velocity by searching for the peak velocity from a Nyquist velocity of the spectra, identifying a first velocity which has an magnitude exceeding the threshold magnitude, and using the first velocity as the peak velocity. Determining the optimum cardiac cycle of the living subject includes setting a threshold velocity identifying each the peak velocities which exceed the threshold to form a set of candidate peak velocities. Discontinuities in the set of candidate peak velocities are determined, and the optimum cardiac cycle can be determined therefrom. Various vascular measurements for the optimum cardiac cycle include the peak systole (PS) end diastole (ED), include a minimum diastolic deflection (MDD), a rise time, an acceleration index, a pulsatility index, or a resistivity index.
108 Citations
76 Claims
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1. A method of making vascular measurements within a living subject in an ultrasonic system comprising the following steps:
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a. determining peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination, determining said peak velocities includes dividing said spectra into a plurality of regions to determine a threshold magnitude of said peak velocities and identifying a first velocity that exceeds said threshold magnitude; b. based upon said peak velocities of said spectra over said period of time, determining a time series of said peak velocities representing an optimum cardiac cycle for said subject under examination; and c. based upon said time series of said peak velocities representing said optimum cardiac cycle, performing vascular measurements of said peak velocities for said optimum cardiac cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. An apparatus for making vascular measurements within a living subject in an ultrasonic system comprising:
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a. a first circuit for determining peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination and storing said peak velocities into an array of peak velocities, said first circuit is further configured to divide said spectra into a plurality of regions to determine a threshold magnitude of said peak velocities and identify a first velocity that exceeds said threshold magnitude; b. a second circuit coupled to said first circuit for determining an optimum cardiac cycle for said subject under examination based upon said time series of said peak velocities; and c. a third circuit coupled to said second circuit for performing vascular measurements of said optimum cardiac cycle. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A method in an ultrasonic system comprising the following steps:
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a. determining peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination, determining said peak velocities further includes dividing said spectra into a plurality of regions to determine a threshold magnitude of said peak velocities and identifying a first velocity that exceeds said threshold magnitude; and b. based upon said peak velocities of said spectra over said period of time, determining a set of said peak velocities representing and optimum cardiac cycle for said subject under examination. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46, 47, 48)
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49. An apparatus in an ultrasonic system comprising:
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a. a first circuit for determining peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination and storing said peak velocities into an array of peak velocities, said first circuit is further configured to divide said spectra into a plurality of regions to determine a threshold magnitude of said peak velocities and identify a first velocity that exceeds said threshold magnitude; and b. a second circuit coupled to said first circuit for determining an optimum cardiac cycle for said subject under examination based upon said time series of said peak velocities. - View Dependent Claims (50, 51, 52, 53, 54, 55, 56, 57, 58)
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59. A method in an ultrasonic system of determining an optimum cardiac cycle comprising the following steps:
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a. determining a time series of velocities over a period of time due to pulses emitted into a subject under examination; b. identifying discontinuities in said time series of peak velocities which exceeds a threshold; c. determining a candidate peak velocity between said each of said discontinuities to form a set of peak systoles; d. determining a peak systole in said set of peak systoles which is followed by a second peak systole and which is preceded by a minimum peak velocity which occurs within a predetermined time before said peak systole and identifying said minimum peak velocity as an end diastole (ED); e. locating a second minimum velocity which occurs before said second peak systole and identifying said second minimum velocity as a second end diastole (ED); and f. identifying a time period between said end diastole and said second end diastole as said optimum cardiac cycle. - View Dependent Claims (60, 61, 62, 63, 64, 65, 66, 67)
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68. An apparatus for determining an optimum cardiac cycle comprising:
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a. an input means for determining a time series of velocities over a period of time due to pulses emitted into a subject under examination; b. an identification means coupled to said input means for identifying discontinuities in said time series of peak velocities which exceeds a threshold; c. a peak detection means coupled to said identification means for determining a peak velocity between said each of said discontinuities to form a set of peak systoles; d. a determination means coupled to said peak detection means for determining a peak systole in said set of peak systoles which is followed by a second peak systole and which is preceded by a minimum peak velocity which occurs within a predetermined time before said peak systole and identifying said minimum peak velocity as an end diastole (ED); e. a second minimum velocity detection means coupled to said determination means for locating a second minimum velocity which occurs before said second peak systole and identifying said second minimum velocity as a second end diastole (ED); and f. an optimum cardiac cycle identifying means coupled to said minimum velocity detection means for identifying a time period between said end diastole and said second end diastole as said optimum cardiac cycle. - View Dependent Claims (69, 70, 71, 72, 73, 74, 75, 76)
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Specification