Elevation focusing by beamformer channel sharing
First Claim
1. An imaging system for focusing ultrasound beams in elevational and azimuthal planes;
- the system comprising;
an array having a plurality of rows of imaging elements in an elevational direction and a plurality of columns of imaging elements in an azimuthal direction;
a plurality of beamformer channels, each beamformer channel including a transmit beamformer and a receive beamformer;
a switching circuit, including a plurality of switches, that allocates, in response to a control signal, at least one beamformer channel to an elevational element of a first aperture having a predetermined number of columns and rows for scanning a first depth of an imaging field, and to an azimuthal element of a column added to the first aperture to form a second aperture for scanning a second depth of the imaging field;
a controller providing a control signal for allocating the at least one beamformer channel between the elevational element and the azimuthal element of the array.
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Accused Products
Abstract
An ultrasound imaging system provides for depth-variable elevational and azimuthal focusing by combining electronic beamforming and fixed mechanical lens (or element shaping). The imaging system includes a plurality of beamformer channels that are selectively allocated to the imaging elements of an array. For phased arrays, a switching circuit controls the allocation of the beamformers, while a linear/convex array also requires an aperture shifting circuit for shifting the aperture along the array. The elevational focusing is achieved using a small number of beamformer channels by sharing the beamformer channels assigned to azimuthal elements for far field imaging and to elevational elements for near field imaging. A portion of the beamformer channels are connected to elevational elements (elements in the off-center rows) during near-field imaging. During far-field imaging, these channels connected to the elevational elements are allocated to the lateral elements for azimuthal focusing, and the elevational elements are allocated directly to the center-row elements of their column. The mechanical focus depth is chosen to be in the far field to provide improved elevation focusing in the far field without the need for electronic beamforming delays. In addition, since the f-number is large in the far field, the depth of focus will be large.
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Citations
61 Claims
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1. An imaging system for focusing ultrasound beams in elevational and azimuthal planes;
- the system comprising;
an array having a plurality of rows of imaging elements in an elevational direction and a plurality of columns of imaging elements in an azimuthal direction; a plurality of beamformer channels, each beamformer channel including a transmit beamformer and a receive beamformer; a switching circuit, including a plurality of switches, that allocates, in response to a control signal, at least one beamformer channel to an elevational element of a first aperture having a predetermined number of columns and rows for scanning a first depth of an imaging field, and to an azimuthal element of a column added to the first aperture to form a second aperture for scanning a second depth of the imaging field; a controller providing a control signal for allocating the at least one beamformer channel between the elevational element and the azimuthal element of the array. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
- the system comprising;
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39. An imaging system for focusing ultrasound beams in elevational and azimuthal planes;
- the system comprising;
an array having a plurality of rows of imaging elements in an elevational direction and a plurality of columns of imaging elements in an azimuthal direction; a plurality of transmit beamformer channels including a transmit switching circuit, having a plurality of switches, that allocates, in response to a control signal, at least one transmit beamformer channel to an elevational element of a first aperture having a predetermined number of columns and rows for scanning a first depth of an imaging field, and to an azimuthal element of a column added to the first aperture to form a second aperture for scanning a second depth of the imaging field; a plurality of receive beamformer channels including a receive switching circuit, having a plurality of switches, that allocates, in response to a control signal, at least one receive beamformer channel to an elevational element of a first aperture having a predetermined number of columns and rows for scanning a first depth of an imaging field, and to an azimuthal element of a column added to the first aperture to form a second aperture for scanning a second depth of the imaging field; and a controller providing a control signals for allocating the at least one transmit beamformer channel and at least one receive beamformer channel between the elevational element and the azimuthal element of the array.
- the system comprising;
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40. A method for focusing ultrasound beams for an array having a plurality of rows of imaging elements in an elevational direction and a plurality of columns of imaging elements in an azimuthal direction;
- said method comprising;
allocating each of a plurality of beamformer channels to elevational and azimuthal elements defining a first aperture having a predetermined number of rows and columns of elements for scanning a first depth of an imaging field; focusing an ultrasound beam in the elevational and azimuthal planes at the first depth of the imaging field; reallocating at least one beamformer channel of an elevational element of the first aperture to at least one azimuthal element of an added column to form a second aperture for scanning a second depth of the imaging field; and focusing an ultrasound beam in the elevational direction and azimuthal direction at the second depth of the imaging field. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61)
- said method comprising;
Specification