Method and apparatus for abberation correction in the presence of a distributed aberrator
First Claim
1. A method for phase aberration correction for use with medical ultrasound imaging systems employing a probe in contact with the body of a subject, comprising:
- generating a first ultrasound pulse at a first set of preselected transmit elements to define a first transmit aperture;
focusing said first ultrasound pulse to a predetermined target point in said subject;
transmitting said first focused ultrasound pulse from said first aperture to said target location;
receiving echoes of said first ultrasound at a first plurality of receive transducer elements;
storing electronic signal data corresponding to said first pulse echoes measured by a predetermined number of said first plurality of receive elements;
generating a second ultrasound pulse at a second set of preselected transmit elements different from said first set of preselected transmit elements to define a second transmit aperture spatially translated relative to said first transmit aperture;
focusing said second ultrasound pulse to said target location;
transmitting said second focused ultrasound pulse from said second transmit aperture to said target location;
receiving echoes of said second ultrasound pulse at a second plurality of receive transducer elements;
processing electronic signal data corresponding to said second pulse echo measured by each of a predetermined number of said second plurality of receive elements;
comparing variations of electronic signal data between said first and second echoes to estimate signal variations; and
correcting said phase aberrations with said estimated signal variations.
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Accused Products
Abstract
Disclosed is an ultrasonic phase aberration correction method and apparatus. One preferred embodiment employs a translating transmit aperture for transmitting two separately transmitted pulses through two different transmit apertures but which are focused to the same predetermined target in the human body. A receiver element measuring a first echo from a first transmit pulse is matched with a receiver element measuring a second echo from a second transmit pulse from a translated aperture, the match corresponding to receivers with a separation equal and opposite to the spatial translations of the translated transmit apertures. The matched elements are compared for signal variations which estimate phase aberrations and especially improve on estimates of distributed aberrations. The transmit or receive signals can then be compensated for or adjusted based on the signal comparison and variation estimates. It is also disclosed that the use of phase spectra analysis with a translating aperture improves aberration correction. Further, the use of a translating aperture with cross-correlation techniques also indicates improved correlations.
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Citations
28 Claims
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1. A method for phase aberration correction for use with medical ultrasound imaging systems employing a probe in contact with the body of a subject, comprising:
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generating a first ultrasound pulse at a first set of preselected transmit elements to define a first transmit aperture; focusing said first ultrasound pulse to a predetermined target point in said subject; transmitting said first focused ultrasound pulse from said first aperture to said target location; receiving echoes of said first ultrasound at a first plurality of receive transducer elements; storing electronic signal data corresponding to said first pulse echoes measured by a predetermined number of said first plurality of receive elements; generating a second ultrasound pulse at a second set of preselected transmit elements different from said first set of preselected transmit elements to define a second transmit aperture spatially translated relative to said first transmit aperture; focusing said second ultrasound pulse to said target location; transmitting said second focused ultrasound pulse from said second transmit aperture to said target location; receiving echoes of said second ultrasound pulse at a second plurality of receive transducer elements; processing electronic signal data corresponding to said second pulse echo measured by each of a predetermined number of said second plurality of receive elements; comparing variations of electronic signal data between said first and second echoes to estimate signal variations; and correcting said phase aberrations with said estimated signal variations. - 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. A method for estimating and correcting phase aberrations in signals, comprising:
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generating a first ultrasound pulse; focusing said first ultrasound pulse to a predetermined target location; transmitting said first focused ultrasound pulse into the target; receiving first pulse echoes of said first ultrasound pulse at a plurality of receive transducer elements; storing electronic signal data corresponding to said first pulse echoes measured by a predetermined number of said plurality of receive elements; comparing phase spectra variations of said electronic signal data between a predetermined number of receive elements to estimate signal variations; and correcting said phase aberrations with said estimated signal variations by providing frequency dependent phase spectra compensating adjustment to a signal. - View Dependent Claims (21)
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22. A method for correcting distributed aberrations in ultrasound imaging systems, comprising:
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generating a first ultrasound pulse at a first set of preselected transmit elements to define a first transmit aperture; focusing said first ultrasound pulse to a predetermined target location in a target object; transmitting said first focused ultrasound pulse from said first aperture into said target; receiving first pulse echoes of said first ultrasound pulse at a first plurality of receive transducer elements; storing electronic signal data corresponding to said first pulse echoes measured by each of a predetermined number of said plurality of receive elements; generating a second ultrasound pulse at second set of preselected transmit elements different from said first set of transmit elements to define a second transmit aperture having substantially the same size and shape and spatially translated relative to said first aperture; focusing said second ultrasound pulse to said target location; transmitting said second focused ultrasound pulse from said second aperture into said target; receiving second pulse echoes of said second ultrasound pulse at a second plurality of receive transducer elements; processing electronic signal data corresponding to said second echo measured by a predetermined number of said second plurality of receive elements, wherein each of said first plurality of receive elements is matched with a respective one of said second plurality of receive elements corresponding to said transmit aperture translation; comparing signal phase spectra included in said electronic signal data between said first and second pulse echoes at a preselected number of matched receive elements to estimate signal variations; and correcting phase aberrations with said estimated signal variations. - View Dependent Claims (23, 24, 25)
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26. Art ultrasonic phased array imaging system having a translating aperture adaptive mode of operation, said system comprising:
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a transducer array having a plurality of elements; a transmitter for generating and transmitting ultrasound pulses operably associated with said transducer array; an aperture translator electrically associated with said transmitter and said transducer array for adjusting transmit apertures to spatially shift at least two separate transmit pulses to fire from array transducer elements contained in transmit apertures spatially shifted relative to each other; a receiver for receiving echoes of transmitted pulses operably associated with said transducer array and electronic circuitry for storing echo signal data received from a target; a signal processor, said signal processor comprising; (a) comparison means for estimating received echo data signal variations from translated transmit pulses and measured by receive elements, wherein said comparison means compares signal variations between matched sets of receive elements; a beamformer operably associated with said signal processor for compensating for geometric array configurations and target relationships; and a correcting means operably associated with said signal processor for adjusting a signal to compensate for aberrator caused signal variations. - View Dependent Claims (27, 28)
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Specification