Separable beamforming for ultrasound array

1. An ultrasonic imaging system for use with an ultrasonic transducer array, the ultrasonic transducer array including transducer elements arranged in a two-dimensional array defining a transducer plane and configured to insonify a tissue region with ultrasonic energy, the system comprising a processor circuit configured to:

obtain, from the ultrasonic transducer array, information indicative of the reflected ultrasonic energy, including obtaining complex samples of the reflected ultrasonic energy; and

construct a representation of an imaging plane, within the tissue region, including using the obtained information indicative of the reflected ultrasonic energy including:

separately determining, for respective focusing locations in an imaging plane including a specified focusing location, respective first sums of complex samples of reflected ultrasonic energy obtained via respective first lines of transducers in the ultrasonic transducer array, the complex samples obtained via respective first lines of transducers corresponding to respective orthogonal projections of the respective focusing locations in the imaging plane onto the respective first lines in the transducer plane; and

separately determining, for the specified focusing location in the imaging plane, a second sum of at least some the respective first sums of complex samples of reflected ultrasonic energy, the second sum corresponding to a second line of transducers in the ultrasonic transducer array, the second line of transducers aligned along an axis different from an axis of the respective first lines in the transducer plane and corresponding to the orthogonal projection of the specified focusing location in the imaging plane onto the transducer plane;

wherein the separately determining the first or second sums of complex samples includes phase-rotating at least some of the complex samples.

2. The ultrasound imaging system of claim 1 , wherein the processor circuit is configured to obtain complex samples of the reflected ultrasonic energy using Direct-Sampled In-phase and Quadrature (DSIQ) sampling.

3. The ultrasound imaging system of claim 1 , comprising:

the ultrasonic transducer array; and

a display configured to display an image of the representation of the plane within the tissue region constructed by the processor circuit;

wherein the ultrasonic transducer array, processor circuit, and display comprise a hand-held assembly configured to operate without requiring power obtained contemporaneously from an Alternating Current (AC) mains supply.

4. The ultrasound imaging system of claim 1 , wherein the phase-rotating at least some of the samples includes determining a respective phase-rotation factors using a truncated Taylor series expansion corresponding to an approximation of a geometric acoustic propagation time delay from respective focusing locations to respective transducer locations; and

wherein the truncated Taylor series expansion is separated into a first set of respective phase rotations corresponding to respective complex samples obtained via respective transducers comprising the respective first lines including an orthogonal projection of the respective focusing locations, and a second set of respective phase rotations corresponding to respective complex samples obtained via respective transducer comprising the second line corresponding to an orthogonal projection of the specified focusing location onto the transducer array.

5. The ultrasound imaging system of claim 1 , wherein the processor circuit is configured to construct a C-mode representation by, for each focusing location in a C-mode imaging plane:

separately determining respective first sums of complex samples of reflected ultrasonic energy obtained via respective first lines of transducers; and

separately determining respective second sums of the at least some of the respective first sums corresponding to respective second lines of transducers in the ultrasonic array corresponding to the orthogonal projection of a respective focusing location in the C-mode imaging plane onto the transducer array.

6. The ultrasound imaging system of claim 1 , wherein the separately determining the respective first sums includes using respective first apodization weighting factors specified corresponding to the respective first lines; and

wherein the separately determining the second sum includes using respective second apodization weighting factors specified corresponding to the second line.

7. The ultrasound imaging system of claim 1 , wherein the processor circuit is configured to construct at least a portion of a first C-mode representation of at least a portion of a first plane at a first specified depth within the tissue region, and configured to construct at least a portion of a second C-mode representation of at least a portion of a second plane at a second specified depth within the tissue region.

8. The ultrasound imaging system of claim 7 , wherein the processor circuit is configured to construct a representation of a specified plane other than a C-mode imaging plane within the tissue using information from the first and second C-mode representations.

9. The ultrasound imaging system of claim 1 , wherein the processor circuit is configured to obtain information from the ultrasonic transducer array indicative of the reflected ultrasonic energy including obtaining a real time-series of samples of the reflected ultrasonic energy;

wherein the processor circuit is configured to construct the representation of the imaging plane including determining a third sum of at least some of the real time-series of samples; and

wherein the determining the third sum includes applying a specified time delay to at least some of the real time-series of samples.

10. The ultrasound imaging system of claim 1 , wherein the first lines are orthogonal to the second line in the plane defined by the transducer array.

11. A method for ultrasonic imaging using an ultrasonic transducer array comprising transducer elements arranged in a two-dimensional array defining a transducer plane, the ultrasonic transducer array configured to insonify a tissue region with ultrasonic energy, the method comprising:

obtaining, from the ultrasonic transducer array, information indicative of the reflected ultrasonic energy, including obtaining complex samples of the reflected ultrasonic energy; and

constructing a representation of an imaging plane, within the tissue region, including using the obtained information indicative of the reflected ultrasonic energy including:

separately determining, for respective focusing locations in an imaging plane including a specified focusing location, respective first sums of complex samples of reflected ultrasonic energy obtained via respective first lines of transducers in the ultrasonic transducer array, the complex samples obtained via respective first lines of transducers corresponding to respective orthogonal projections of the respective focusing locations in the imaging plane onto the respective first lines in the transducer plane; and

separately determining, for the specified focusing location in the imaging plane, a second sum of at least some the respective first sums of complex samples of reflected ultrasonic energy, the second sum corresponding to a second line of transducers in the ultrasonic transducer array, the second line of transducers aligned along an axis different from an axis of the respective first lines in the transducer plane and corresponding to the orthogonal projection of the specified focusing location in the imaging plane onto the transducer plane;

wherein the separately determining the first or second sums of complex samples includes phase-rotating at least some of the complex samples.

12. The method of claim 11 , comprising obtaining complex samples of the reflected ultrasonic energy using Direct-Sampled In-phase and Quadrature (DSIQ) sampling.

13. The method of claim 11 , comprising:

constructing the image plane representation using a hand-held assembly comprising a processor circuit and the transducer array; and

displaying an image of the representation using the hand-held assembly, the hand-held assembly configured to operate without requiring power obtained contemporaneously from an Alternating Current (AC) mains supply.

14. The method of claim 11 , wherein the phase-rotating at least some of the samples includes determining a respective phase-rotation factors using a truncated Taylor series expansion corresponding to an approximation of a geometric acoustic propagation time delay from respective focusing locations to respective transducer locations; and

wherein the truncated Taylor series expansion is separated into a first set of respective phase rotations corresponding to respective complex samples obtained via respective transducers comprising the respective first lines including an orthogonal projection of the respective focusing locations, and a second set of respective phase rotations corresponding to respective complex samples obtained via respective transducer comprising the second line corresponding to an orthogonal projection of the specified focusing location onto the transducer array.

15. The method of claim 11 , comprising constructing a C-mode representation by, for each focusing location in a C-mode imaging plane:

separately determining respective first sums of complex samples of reflected ultrasonic energy obtained via respective first lines of transducers; and

separately determining respective second sums of the at least some of the respective first sums corresponding to respective second lines of transducers in the ultrasonic array corresponding to the orthogonal projection of a respective focusing location in the C-mode imaging plane onto the transducer array.

16. The method of claim 11 , wherein the separately determining the respective first sums includes using respective first apodization weighting factors specified corresponding to the respective first lines; and

wherein the separately determining the second sum includes using respective second apodization weighting factors specified corresponding to the second line.

17. The method of claim 11 , comprising constructing at least a portion of a first C-mode representation of at least a portion of a first plane at a first specified depth within the tissue region, and configured to construct at least a portion of a second C-mode representation of at least a portion of a second plane at a second specified depth within the tissue region.

18. The method of claim 17 , constructing a representation of a specified plane other than a C-mode imaging plane within the tissue using information from the first and second C-mode representations.

19. The method of claim 11 , comprising:

obtaining information from the ultrasonic transducer array indicative of the reflected ultrasonic energy including obtaining a real time-series of samples of the reflected ultrasonic energy; and

constructing the representation of the imaging plane including determining a third sum of at least some of the real time-series of samples;

wherein the determining the third sum includes applying a specified time delay to at least some of the real time-series of samples.

20. The method of claim 11 , wherein the first lines are orthogonal to the second line in the plane defined by the transducer array.

21. A processor-readable medium including instructions that, when performed by at least one processor included as a portion of a hand-held assembly, cause the hand-held assembly to:

control an ultrasonic transducer array included as a portion of the hand-held assembly to generate the ultrasonic energy or to receive reflected ultrasonic energy, the ultrasonic transducer array comprising transducer elements arranged in a two-dimensional array comprising a transducer plane, the ultrasonic transducer array configured to insonify a tissue region with ultrasonic energy;

obtain, from the ultrasonic transducer array, information indicative of the reflected ultrasonic energy, including obtaining complex samples of the reflected ultrasonic energy using Direct-Sampled In-phase and Quadrature (DSIQ) sampling; and

construct a representation of an imaging plane, within the tissue region, including using the obtained information indicative of the reflected ultrasonic energy including:

separately determining, for respective focusing locations in an imaging plane including a specified focusing location, respective first sums of complex samples of reflected ultrasonic energy obtained via respective first lines of transducers in the ultrasonic transducer array, the complex samples obtained via respective first lines of transducers corresponding to respective orthogonal projections of the respective focusing locations in the imaging plane onto the respective first lines in the transducer plane; and

separately determining, for the specified focusing location in the imaging plane, a second sum of at least some the respective first sums of complex samples of reflected ultrasonic energy, the second sum corresponding to a second line of transducers in the ultrasonic transducer array, the second line of transducers aligned along an axis different from an axis of the respective first lines in the transducer plane and corresponding to the orthogonal projection of the specified focusing location in the imaging plane onto the transducer plane;

wherein the separately determining the first or second sums of complex samples includes phase-rotating at least some of the complex samples.

22. The processor-readable medium of claim 21 , wherein the instructions include instructions that cause the hand-held assembly to:

obtain information from the ultrasonic transducer array indicative of the reflected ultrasonic energy including obtaining a real time-series of samples of the reflected ultrasonic energy; and

construct the representation of the imaging plane including determining a third sum of at least some of the real time-series of samples;

wherein the determining the third sum includes applying a specified time delay to at least some of the real time-series of samples.

23. The processor-readable medium of claim 20 , wherein the first lines are orthogonal to the second line in the plane defined by the transducer array.