High resolution 3D ultrasound imaging system deploying a multi-dimensional array of sensors and method for multi-dimensional beamforming sensor signals

A field deployable 3D ultrasound imaging system for producing high resolution 3D images of an object iii real time, the ultrasound system comprising:

• a source for emitting ultrasound waves;
• a compact adaptive multidimensional sensor array for capturing reflections of the ultrasound waves, the ultrasound waves being reflected by different structures within the object, and for providing sensor time series indicative of the reflected ultrasound waves;
• a compact processing unit for:
• receiving the sensor time series produced by the multidimensional sensor array;
• processing the sensor time series in read time in order to produce continuous beamtime series by:
• a) dividing the multidimensional sensor array into a plurality of subsequent sub-apertures;
• b) decomposing each sub-aperture into two coherent subsets of at least one of circular array beamformers and line array beamformers, a first subset comprising subsequent beamformers in a first coordinate direction of the multidimensional array and a second subset comprising subsequent beamformers in a second other coordinate direction of the sub-aperture;
• c) conventional beamforming each sub-aperture for a predetermined beam steering direction a Fourier transform of the sensor time series by applying the subsequent beamformers of the first subset each beamformer producing a beam time series;
• d) conventional beamforming each sub-aperture liar the predetermined beam steering direction of the beaux time series produced by the beamformers of step c) by applying the subsequent beamformers of the second subset for the steered direction producing one beam time series for the beam steering direction for each sub-aperture;
• e) adaptive beamforming on line arrays, each line array comprising beam time series of different subsequent sub-apertures in one coordinate direction, providing one or more beam time series for the beam steering direction;
• and,
• reconstructing 3D images from the beam time series in real time;
• and,
• a display for displaying the reconstructed 3D images in real time.

A field deployable 3D ultrasound imaging system for producing high resolution 3D images of an object in real time, the ultrasound system comprising:

• a source for emitting ultrasound waves;
• a compact adaptive multidimensional sensor array for capturing reflections of the ultrasound waves, the ultrasound waves being reflected by different structures within the object, and for providing sensor time series indicative of the reflected ultrasound waves;
• a compact processing unit for:
• receiving the sensor time series produced by the multidimensional sensor array;
• processing the sensor time series in real time in order to produce continuous beamtime series by:
• segmenting the continuous sensor time series into a set of overlapped data sets;
• calculating a FFT of each overlapped data set producing a set of Fourier transforms of the overlapped data sets for different frequency bins;
• forming a cross spectral density matrix from the Fourier transforms of the overlapped data sets for each frequency bin and each predetermined steering direction;
• forming a steering covariance matrix using the cross spectral density matrix and a diagonal matrix of conventional steering vectors, one steering covariance matrix for each steering direction and a frequency band of interest;
• inverting the steering covariance matrices;
• estimating adaptive steering vectors by assuming stationarity across frequency bins of a frequency band of interest and considering an estimate of the steering covariance matrix being the same as a narrow band estimate for a center frequency of the frequency band of interest;
• determining narrow band adaptive steering weights using the estimate of the adaptive steering vectors;
• forming adaptive beams in frequency domain from the Fourier transform of the overlapped data sets and the adaptive steering weights;
• forming adaptive beams in time domain through IFFT;
• determining continuous beam time series by discarding overlap and concatenation of segments;
• and,
• reconstructing 3D images from the beam time series in real time;
• and,
• a display for displaying the reconstructed 3D images in real time.