Method and System For Estimating Cardiac Ejection Volume Using Ultrasound Spectral Doppler Image Data
First Claim
Patent Images
1. An ultrasound imaging system suitable for estimating cardiac output of a patient'"'"'s heart, comprising:
- an intracardiac ultrasound system configured to receive ultrasound signals from an intracardiac ultrasound transducer when positioned within the patient'"'"'s heart, and output Doppler frequency shift data at each of a plurality of sub-second intervals of received ultrasound signals for at least one cardiac cycle; and
a computer configured to;
receive the Doppler frequency shift data;
process the Doppler frequency shift data at each of the plurality of sub-second intervals to compute an amplitude-weighted average frequency shift at each of the plurality of sub-second intervals;
convert the amplitude-weighted average frequency shift to an average velocity for each of the plurality of sub-second intervals;
sum the average velocities of the plurality of sub-second intervals over a cardiac cycle; and
estimate the cardiac output from the sum of the average velocities and the durations of the plurality of sub-second intervals.
5 Assignments
0 Petitions
Accused Products
Abstract
A method and system for estimating the volume of blood ejected from a cardiac ventricle or atrium uses spectral Doppler ultrasound while imaging a portion of the heart. The method computes the mean ejection velocity Vavg(t) at time t from the spectral Doppler data. The process may further utilize a discrete graphical technique to compute a measure of cardiac output. Further, the measure of cardiac output can yield an approximation to the mean-ejection-velocity integral, which is the area under the curve Vavg(t) for all moments t within a cardiac cycle.
110 Citations
12 Claims
-
1. An ultrasound imaging system suitable for estimating cardiac output of a patient'"'"'s heart, comprising:
-
an intracardiac ultrasound system configured to receive ultrasound signals from an intracardiac ultrasound transducer when positioned within the patient'"'"'s heart, and output Doppler frequency shift data at each of a plurality of sub-second intervals of received ultrasound signals for at least one cardiac cycle; and
a computer configured to;
receive the Doppler frequency shift data;
process the Doppler frequency shift data at each of the plurality of sub-second intervals to compute an amplitude-weighted average frequency shift at each of the plurality of sub-second intervals;
convert the amplitude-weighted average frequency shift to an average velocity for each of the plurality of sub-second intervals;
sum the average velocities of the plurality of sub-second intervals over a cardiac cycle; and
estimate the cardiac output from the sum of the average velocities and the durations of the plurality of sub-second intervals. - View Dependent Claims (2, 3)
-
-
4. An ultrasound imaging system suitable for estimating cardiac output of a patient'"'"'s heart, comprising:
-
an intracardiac ultrasound imaging catheter including at least one ultrasound transducer;
an ultrasound scanner configured to receive ultrasound signals from the intracardiac ultrasound imaging catheter, the ultrasound scanner comprising a spectral Doppler processor configured to generate ultrasound amplitude and Doppler frequency shift data at each of a plurality of sub-second intervals spanning at least one cardiac cycle based on the received ultrasound signals; and
a computer configured to;
process the Doppler frequency shift data at each of the plurality of sub-second intervals;
compute a set of velocities based on the Doppler frequency shift data at each of the plurality of sub-second intervals of the at least one cardiac cycle;
compute an amplitude-weighted average velocity over the cardiac cycle; and
estimate the cardiac output from the amplitude-weighted average velocity. - View Dependent Claims (5, 6)
-
-
7. An ultrasound imaging system suitable for estimating cardiac output of a patient'"'"'s heart, comprising:
-
an intracardiac ultrasound imaging catheter including at least one ultrasound transducer;
an ultrasound scanner configured to receive ultrasound signals from the intracardiac ultrasound imaging catheter at each of a plurality of sub-second intervals spanning at least one cardiac cycle, the ultrasound scanner comprising a spectral Doppler processor configured to generate Doppler frequency shift data at each of sub-second intervals spanning the at least one cardiac cycle, and generate a pixel-based plot of the Doppler frequency shift data, wherein the pixel-based plot comprises a plurality of columns of pixels; and
a computer configured to;
receive the pixel-based plot of the Doppler frequency shift data;
select a representative pixel in each column of the plurality of columns of pixels;
in each one of the plurality of columns, mark all pixels in the one column equal to or below the representative pixel selected for the one column and disregard all pixels in the one column above the representative pixel selected for the one column; and
sum the marked pixels as an estimated measure of cardiac output. - View Dependent Claims (8, 9, 10)
-
-
11. A method for measuring cardiac output of a patient'"'"'s heart, comprising:
-
positioning an intracardiac ultrasound imaging catheter in or near the patient'"'"'s heart;
obtaining a pixel-based plot of Doppler frequency shift data using ultrasound data obtained from the intracardiac ultrasound imaging catheter at each of a plurality of sub-second intervals spanning at least one cardiac cycle, wherein the pixel-based plot comprises a plurality of columns of pixels;
processing each one column of the plurality of columns to select a representative pixel for the one column, wherein the representative pixel is selected as the pixel in the one column which is closest to a pixel-intensity-weighted average for the one column;
marking each representative pixel and all pixels between the representative pixel and a pixel row representing a zero Doppler shift frequency in each of the plurality of columns; and
counting the number of marked pixels as a measure of cardiac output. - View Dependent Claims (12)
-
Specification