Ultrasound system for high-speed and high resolution imaging applications

Patent metadata

Field	Value
Publication number	US-2017363725-A1
Application number	US-201515529174-A
Country	US
Kind code	A1
Filing date	Dec 15, 2015
Priority date	Dec 19, 2014
Publication date	Dec 21, 2017
Grant date	—

Abstract

An ultrasound imaging system includes an array of ultrasound transducer elements chat send ultrasound energy into an object when energized for respective transmission time periods and provide responses to ultrasound energy emitted from the object for respective reception time periods, a reception modulation circuit modulating the responses with irregular sequences of modulation coefficients, a combiner circuit combining the modulated responses, and an image reconstruction processor configured to computer-process the combined modulated responses into one or more images of the object.

First claim

1 . An ultrasound imaging system comprising:
an array of ultrasound transducer elements that send ultrasound energy into an object when energized for respective transmission time periods and provide responses to ultrasound energy emitted from the object for respective reception time periods; a reception modulation circuit modulating the responses with irregular sequences of modulation coefficients; a combiner circuit combining the modulated responses; and an image reconstruction processor configured to computer-process the combined modulated responses into one or more images of the object.

2 . The system of claim 1 , in which the combiner circuit is configured to combine the modulated responses in the analog domain.

3 . The system of claim 1 , in which the combiner circuit comprises at least two combiner channels each combining a respective subset of the responses.

4 . The system of claim 1 , in which the reception modulation circuit is configured to modulate the response with a sequence of pseudo-random modulation coefficients.

5 . The system of claim 1 , in which the reception modulation circuit is configured to modulate the response with coefficients related to columns of Hadamard matrices.

6 . The system of claim 1 , further including a transmission modulation circuit configured to select for energizing in each transmission period only plural-element subsets of the transducer elements, which subsets differ between transmission time periods.

7 . The system of claim 1 , in which the modulation circuit is configured to energize only pseudo-randomly selected different subsets of the transducer elements for different transmission time periods.

8 . The system of claim 1 , in which the modulation circuit is configured to modulate the responses with waveforms of positive and negative levels.

9 . The system of claim 8 , in which the combiner circuit comprises at least one amplifier having a positive input receiving the portions of the responses modulated with the positive levels and a negative input receiving the portions of the responses modulated with the negative levels of the modulating waveforms.

10 . The system of claim 1 , in which the reconstruction processor is configured to apply an imaging matrix to the combined modulated responses to thereby generate the one or more images of the object.

11 . An ultrasound imaging system comprising:
a multi-element set of ultrasound transducer elements; an excitation pulse generator providing a succession of excitation pulses to the transducer elements; a receiving switch matrix modulating echoes received by the transducer elements in response to the excitation pulses applied to an object, with an essentially random sequence of modulation coefficients; a circuit summing the modulated echoes in the analog domain; and an image reconstruction processor configured to computer-process the summed modulated echoes into one or more images of the object.

12 . The system of claim 11 , in which the receiving switch matrix modulates the echoes with modulating waveforms having irregular periods.

13 . The system of claim 12 , in which the modulating waveforms comprise waveforms of a succession of positive and negative levels.

14 . The system of claim 13 , including a differential charge amplifier, wherein the echoes modulated with the positive levels are supplied to a positive input and the echoes modulated with the negative levels are supplied to a negative input of the differential amplifier.

15 . The system of claim 11 , in which the image reconstruction processor is configured to apply an image matrix to the summed modulated echoes to generate an image of the object.

16 . The system of claim 15 , in which the image matrix is selected to relate summed echoes from a known object to an expected image of the object generated with the image reconstruction processor.

17 . The system of claim 11 , including an analog-to-digital converter (ADC) converting the summed echoes into a digital sequence supplied to the image reconstruction processor.

18 . The system of claim 11 , further including a transmission switch matrix transmitting each excitation pulse only to a respective, essentially randomly selected subset of the elements in the set.

19 . An ultrasound imaging system having an echo-signal receiving chain comprising:
an array containing a total of L acoustic transducer elements configured to receive echo acoustic pressure waves from an imaged target and convert the received pressure waves to electrical signals, where L is a positive integer greater than one; a switch matrix configured to modulate the electrical signals from the transducer elements and supply the modulated signals to one or more summation nodes; one or more amplifiers performing summation and amplification of the modulated echo signals from the switch matrix summed at the summation nodes; an analog-to-digital converter configured to convert an output signal from the one or more amplifiers to digital form; and an image reconstruction module configured to reconstruct an ultrasound image of the target from an output of the analog-to-digital converter according to a reconstruction algorithm.

20 . The ultrasound imaging system of claim 19 , in which the switch matrix is configured to change the polarity of the received echo signals by multiplying the electrical signals from the transducer elements with modulation coefficients equal to 1 or −1.

21 . The ultrasound imaging system of claim 20 , in which the modulation coefficients are changed over N time samples during a single echo-signal receive operation, where N is an integer greater than one.

22 . The ultrasound imaging system of claim 21 , in which the modulation coefficients are a total of N modulation coefficients for each of the L elements of the array, where N is an integer greater than one, and are changed in a pseudo-random manner.

23 . The ultrasound imaging system of claim 21 , in which the modulation coefficients associated to one element of the transducer array are elements of columns of N×N Hadamard matrix, where N is an integer greater than one.

24 . The ultrasound imaging system of claim 20 , in which the modulation coefficients are changed over N time samples and across all or some of the elements of the transducer array during a single echo-signal receive operation, where N is a positive integer greater than one.

25 . The ultrasound imaging system of claim 24 , in which the modulation coefficients across different elements of the transducer array are changed in a pseudo-random manner.

26 . The ultrasound imaging system of claim 24 , in which the modulation coefficients over time and across different elements of the transducer array correspond to an N×L submatrix of a N×N Hadamard matrix H obtained by removing some columns of the matrix H.

27 . The ultrasound imaging system of claim 19 , in which the image reconstruction module uses a least-squares estimation algorithm to estimate the image of the target.

28 . The ultrasound imaging system of claim 19 , in which the image reconstruction module operates an image reconstruction algorithm utilizing sparsity of signals for improved imaging resolution.

29 . The ultrasound imaging system of claim 19 , in which the image reconstruction module comprises one or more remote image reconstruction

Assignees

• Univ Rochester

Inventors

• Ignjatovic Zeljko
• Huang Michael
• Swetha George

Classifications

• G01S15/8993

  Three dimensional imaging systems · CPC title

• G01S15/8918

  the array being linear · CPC title

• G01S7/52047 Primary

  for elimination of side lobes or of grating lobes; for increasing resolving power · CPC title

• G01S15/8925

  the array being a two-dimensional transducer configuration, i.e. matrix or orthogonal linear arrays · CPC title

• A61B8/5207

  involving processing of raw data to produce diagnostic data, e.g. for generating an image · CPC title