SYSTEM AND METHOD FOR PROCESSING A REAL-TIME ULTRASOUND SIGNAL WITHIN A TIME WINDOW
One embodiment is a method for real-time window processing and window definition that includes measuring a defining signal and an instantaneous tissue state signal, dynamically determining a time window from the defining signal, and processing instantaneous tissue state signal captured in the time window. Another embodiment is a system for processing a real-time ultrasound signal within a time window that includes a physiological signal monitor that measures a physiological signal, an ultrasound acquisition device that acquires an ultrasound signal, a window identifier that uses the physiological signal to identify boundary markers of the output of the physiological signal monitor that define a time window, and an ultrasound processor that processes the ultrasound signal within a time window and outputs a time window processed ultrasound signal. The embodiments have applications in the field of ultrasound tissue tracking and numerous other tissue monitoring fields.
1 . A method for processing a real-time ultrasound signal within a time window comprising the steps of:
measuring a physiological signal and an instantaneous ultrasound imaging signal;
identifying boundary markers in the physiological signal as the physiological signal is measured, wherein the boundary markers define a time window;
processing the ultrasound imaging signal captured in the time window; and
outputting an instantaneous ultrasound imaging signal with processed time windows.
2 . The method of claim 1 , wherein the step of identifying the boundary markers includes identifying a trigger event.
3 . The method of claim 2 , wherein the trigger event is identified by a signal edge detector.
4 . The method of claim 2 , wherein the step of identifying the boundary markers further includes identifying a start boundary marker and a stop boundary marker.
5 . The method of claim 2 , further comprising determining a plurality of time windows of varying types, each type having a set of boundary markers.
6 . The method of claim 5 , wherein the step of processing includes processing the ultrasound imaging signal according to the type of time window.
7 . The method of claim 1 , wherein the physiological signal is an electrocardiogram (ECG).
8 . The method of claim 7 , wherein the instantaneous measurement of the ultrasound imaging signal is a tissue velocity measurement.
9 . The method of claim 7 , wherein the instantaneous measurement of the ultrasound imaging signal is a strain rate measurement.
10 . The method of claim 9 , wherein the step of measuring the ultrasound imaging signal includes processing acquired ultrasound data to calculate the strain rate measurement.
11 . The method of claim 9 , wherein the strain rate measurement is at a frame rate of at least 100 Hz.
12 . The method of claim 9 , wherein the step of processing of the ultrasound imaging signal includes accumulating the ultrasound imaging signal over the time window.
13 . The method of claim 12 , wherein the time window has boundary markers positioned to capture a cardiac phase of a heart cycle.
14 . The method of claim 1 , wherein properties of a time window are predicted from a time window history.
15 . The method of claim 14 , including modifying a time window when the determined time window and a predicted time window differ more than a predetermined threshold.
16 . A method for processing a real-time ultrasound signal within a time window comprising the steps of:
measuring an electrocardiogram (ECG) and identifying the ventricular systole portion of a heart cycle;
measuring the strain rate of at least a portion of the heart;
dynamically determining a time window from the ventricular systole portion;
accumulating the strain rate measurement captured in the time window; and
outputting a strain measurement.
17 . A system for processing a real-time ultrasound signal within a time window comprising:
a physiological signal monitor that measures a physiological signal;
an ultrasound acquisition device that acquires an ultrasound signal;
a window identifier that uses the physiological signal to identify boundary markers of the output of the physiological signal monitor, wherein the boundary markers define a time window; and
an ultrasound processor that processes the ultrasound signal within a time window and outputs a time window processed ultrasound signal.
18 . The system of claim 17 , wherein the physiological signal monitor is an electrocardiogram (ECG).
19 . The system of claim 18 , wherein the window identifier is a signal edge detector.
20 . The system of claim 19 , wherein the window identifier is set to identify a cardiac phase of a heart cycle.
21 . The system of claim 18 , wherein the ultrasound signal is a measurement of the strain rate of at least a portion of a heart, and the ultrasound processor is an accumulator that outputs the accumulated strain during a time window.