Method and apparatus for transmitting multiple beams
A method is provided for acquiring ultrasonic data using multi-beam transmission. The method includes transmitting a first transmit beam using a first subset of element and transmitting a second transmit beam using a second subset of the elements. The first and second subsets of elements comprising at least one common element. The first and second beams are transmitted simultaneously. The elements are divided into the first and second subsets that may comprise at least partially different subsets of elements. An ultrasonic system is also provided that comprises a transducer comprising an array of elements and a beamformer for dividing the array of elements into at least first and second subsets of elements. The first and second subsets of elements at least partially overlapping. A transmitter drives the first and second subsets of elements to simultaneously transmit different first and second transmit beams, respectively. A receiver receives receive lines representative of the first and second transmit beams. The transmitter may transmit different first and second coded transmit waveforms from the first and second subsets of elements.
1. A method for acquiring ultrasonic data using multi-beam transmission, comprising:
transmitting a first transmit beam using a first subset of elements;
transmitting a second transmit beam using a second subset of said elements, said first and second subsets of elements comprising at least one common element, said first and second transmit beams being transmitted simultaneously;
encoding within said first and second transmit beams different first and second transmit waveforms, said at least one common element transmitting a pulse that is a combination of said first and second transmit waveforms;
receiving at least one receive line based on said pulse;
convolving said at least one receive line based on a shape of the first transmit waveform to output a signal representative of said first transmit beam; and
convolving said at least one receive line based on a shape of the second transmit waveform to output a signal representative of said second transmit beam.
2. The method of claim 1 , further comprising dividing said elements into said first and second subsets, said first and second subsets comprising at least partially different subsets of elements, said first and second subsets of elements each comprising contiguous said elements.
3. The method of claim 1 , said first and second transmit beams further comprising multiple transmit lines, said method further comprising receiving at least two receive lines for each of said multiple transmit lines.
4. The method of claim 1 , further comprising dividing said elements into said first and second subsets that each comprise a different number of said elements.
5. The method of claim 1 , wherein said elements comprising said first subset of elements are all common with respect to said elements comprising said second subset of elements.
6. The method of claim 1 , the method further comprising steering said first and second transmit beams in first and second directions, respectively, said first and second directions being different.
7. The method of claim 1 , wherein the combined signal utilizes 2N+1 voltage levels to transmit said first and second transmit beams, where N is at least 1.
8. The method of claim 1 , further comprising producing said first and second transmit waveforms from first and second signals that comprise different frequency modulated chirp signals.
9. The method of claim 1 , wherein the first and second beams are transmitted at least partially overlapping in time.
10. The method of claim 1 , wherein said combined signal comprises a single pulse.