Method and System For Estimating Cardiac Ejection Volume And Placing Pacemaker Electrodes Using Speckle Tracking
AssigneeEP MedSystems, Inc.
InventorPraveen Dala-Krishna
Life of this patent
Estimating the term…
Abstract
A method and system for estimating the volume of blood ejected from a cardiac ventricle or atrium uses ultrasound to track speckle patterns in the heart. The process utilizes the M-mode to estimate volume differences in a view of the ventricle or atrium over time using speckle pattern motion to estimate volume differences between systole and diastole. Alternatively, the ultrasound speckle tracking method may be used in combination with Doppler processing techniques or to obtain temporal flow profiles across flow cross-sectional areas, from which the flow volume is computed. The method can also measure the phase delay of motion of sites on the cardiac wall relative to each other or relative to an ECG signal.
Claims20
An ultrasound imaging system suitable for evaluating a patient's heart, comprising:
- an ultrasound imaging catheter including at least one ultrasound transducer;
- ultrasound processing electronics coupled to the ultrasound imaging catheter and configured to process electrical signals from the at least one ultrasound transducer to generate ultrasound image signals;
- and
- a computer coupled to the ultrasound processing electronics and configured to process the ultrasound image signals to measure a volume of a chamber of the heart using speckle tracking.
An ultrasound imaging system suitable for measuring cardiac output of a patient's heart, comprising:
- an ultrasound imaging catheter including at least one ultrasound transducer;
- an ultrasound processor coupled to the ultrasound imaging catheter, the ultrasound processor configured to receive signals from the at least one transducer and output speckle pattern tracking data;
- and
- a computer configured to receive the speckle pattern tracking data and use the speckle pattern tracking data to compute a measure of cardiac output of the patient's heart.
The ultrasound imaging system according to claim 11, wherein:
- the ultrasound processor is further configured to output a measure of blood flow across a cross-sectional area obtained from a transverse ultrasound image of a ventricle;
- and
- the computer is further configured to estimate blood flow velocity using speckle pattern tracking data obtained from a longitudinal image of a ventricle and the output blood flow measurement.
A method for measuring cardiac output of a patient's heart, comprising:
- imaging a portion of the patient's heart using an ultrasound imaging catheter which includes at least one transducer;
- obtaining dimensional measurements of at least 6 speckle spots corresponding to non-coplanar sites on a ventricular wall at a systole phase;
- obtaining dimensional measurements of the at least 6 speckle spots at a diastole phase;
- determining a first volume of a best-fit systole ellipsoid using the obtained dimensional measurements of the at least 6 speckle spots at the systole phase;
- determining a second volume of a best-fit diastole ellipsoid using the obtained dimensional measurements of the at least 6 sites at the diastole phase;
- computing a difference between the first and second volumes as the measure of cardiac output of the patient's heart.
The method of claim 16, further comprising autonomously selecting the at least 6 speckle spots corresponding to sites on the ventricle wall.
A method for placing cardiac pacing electrodes within a patient's heart, comprising:
- positioning an ultrasound imaging catheter near or within the patient's heart;
- obtaining an ultrasound image of a portion of a ventricle using the ultrasound imaging catheter for at least one cardiac cycle;
- selecting at least one speckle spot corresponding to a site on a wall of the ventricle within the ultrasound image of the ventricle;
- tracking motion of the at least one speckle spot for at least one cardiac cycle;
- determining a phase delay of the motion of the at least one speckle spot relative to a systole phase of the cardiac cycle;
- repeating the electing, tracking and determining steps for another speckle spot corresponding to another site on the wall of the ventricle until a speckle spot is discovered which has a maximal phase delay;
- and
- placing the cardiac pacing electrode at the discovered speckle spot with maximal phase delay.
Dependencies are inferred from the claim text.