Adaptively performing clutter filtering in an ultrasound system

• US 8,684,934 B2
• Filed: 09/09/2010
• Issued: 04/01/2014
• Est. Priority Date: 11/16/2009
• Status: Active Grant

• Current Assignee: Medison Co., Ltd. (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Medison Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Tae Yun
• Primary Examiner(s): Jung, Unsu
• Assistant Examiner(s): FISHER, MICHAEL NAPOLEON
• Application Number:
  US12/878,903
• Publication Number:
  US 20110118606A1
• Time in Patent Office: 1,300 Days
• Field of Search: None
• US Class Current: 600/453
• CPC Class Codes: G01S 15/8981 Discriminating between fixed and moving objects or between objects moving at different speeds, e.g. wall clutter filter

Abstract

Embodiments of adaptively performing clutter filtering are disclosed. In one embodiment, by way of non-limiting example, an ultrasound system comprises: an ultrasound data acquisition unit configured to transmit and receive ultrasound signals to and from a target object to output a plurality of ultrasound data corresponding to each pixel of a color Doppler mode image; and a processing unit in communication with the ultrasound data acquisition unit and being configured to calculate a power difference value corresponding to each of the pixels based on the plurality of ultrasound data, determine whether the power difference value is equal to or larger than a first threshold value, and if the power difference value is equal to or larger than the first threshold value, then perform first clutter filtering upon the plurality of ultrasound data, or if the power difference value is less than the first threshold value, then perform second clutter filtering upon the plurality of ultrasound data.

Claims

1. An ultrasound system, comprising:

an ultrasound data acquisition device configured to transmit and receive ultrasound signals to and from a target object to output a plurality of ultrasound data corresponding to each pixel of a color Doppler mode image; and

a processor in communication with the ultrasound data acquisition device and being configured to;

form a matrix corresponding to each of the pixels based on the plurality of ultrasound data;

form a plurality of sub matrixes corresponding to each of the matrixes;

calculate a power difference value among the plurality of sub matrixes based on a mean frequency and a power corresponding to each of the plurality of sub matrixes;

determine whether the power difference value is equal to or larger than a first threshold value;

perform first singular value decomposition (SVD) clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component and second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component based on the mean frequency, a predetermined first cutoff frequency and a predetermined second cutoff frequency when the power difference value is equal to or larger than the first threshold value; and

perform clutter filtering upon the plurality of ultrasound data when the power difference value is less than the first threshold value.

2. The ultrasound system of claim 1,

wherein the second clutter filtering comprises any one of infinite impulse response, regression filtering and eigenvector based filtering.

3. The ultrasound system of claim 2, wherein the processor is configured to:

perform SVD upon the matrix to form the plurality of sub matrixes corresponding to each of the matrixes; and

calculate the mean frequency and the power corresponding to each of the plurality of sub matrixes.

4. The ultrasound system of claim 3, wherein the processor is configured to:

compare the mean frequency with the predetermined first cutoff frequency when the power difference value is equal to or larger than the first threshold value;

perform the first SVD clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component when the mean frequency is equal to or less than the first cutoff frequency when the power difference value is equal to or larger than the first threshold value;

perform the first SVD clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component when

compare the mean frequency with the predetermined second cutoff frequency when the mean frequency is larger than the first cutoff frequency, wherein the second cutoff frequency is larger than the first cutoff frequency; and

perform the second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component when the mean frequency is equal to or less than the second cutoff frequency.

5. The ultrasound system of claim 4, wherein the matrix operation comprises a matrix addition operation.

6. The ultrasound system of claim 4, wherein the processor is further configured to:

compare the power of the sub matrix corresponding to the mean frequency with a predetermined second threshold value when the mean frequency is larger than the second cutoff frequency;

perform third SVD clutter filtering for removing the sub matrix as a noise component when the power is less than the second threshold value; and

perform the second SVD clutter filtering upon the sub matrix corresponding to the power when the power is equal to or larger than the second threshold value.

7. A method of performing clutter filtering, comprising:

a) acquiring a plurality of ultrasound data corresponding to each pixel of a color Doppler mode image for a target object;

b) forming a matrix corresponding to each of the pixels based on the plurality of ultrasound data;

c) forming a plurality of sub matrixes corresponding to each of the matrixes;

d) calculating a power difference value among the plurality of sub matrixes based on a mean frequency and a power corresponding to each of the plurality of sub matrixes;

e) determining whether the power difference value is equal to or larger than a first threshold value;

f) performing first singular value decomposition (SVD) clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component and second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component based on the mean frequency a redetermined first cutoff frequency and a predetermined second cutoff frequency when the power difference value is equal to or larger than the first threshold value; and

g) performing clutter filtering upon the plurality of ultrasound data when the power difference value is less than the first threshold value.

8. The method of claim 7,

wherein the clutter filtering comprises one of infinite impulse response, regression filtering and eigenvector based filtering.

9. The method of claim 8, wherein the step c) comprises:

performing SVD upon the matrix to thereby form the plurality of sub matrixes corresponding to each of the matrixes; and

calculating the mean frequency corresponding to each of the plurality of sub matrixes.

10. The method of claim 9, wherein the step comprises:

comparing the mean frequency with the predetermined first cutoff frequency;

performing the first SVD clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component when the mean frequency is equal to or less than the first cutoff frequency;

comparing frequency with the predetermined second cutoff frequency when the mean frequency is larger than the first cutoff frequency, wherein the second cutoff frequency is larger than the first cutoff frequency; and

performing the second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component when the mean frequency is equal to or less than the second cutoff frequency.

11. The method of claim 10, wherein the matrix operation comprises a matrix addition operation.

12. The method of claim 10, wherein the step f) further comprises:

comparing the power of the sub matrix corresponding to the mean frequency with a predetermined second threshold value when the mean frequency is larger than the second cutoff frequency;

performing third SVD clutter filtering for removing the sub matrix as a noise component when the power is less than the second threshold value; and

performing the second SVD clutter filtering upon the sub matrix corresponding to the power when the power is equal to or larger than the second threshold value.

13. A non-transitory computer readable medium comprising computer executable instructions, which causes a processor to perform following acts:

a) acquiring a plurality of ultrasound data corresponding to each pixel of a color Doppler mode image for a target object;

b) forming a matrix corresponding to each of the pixels based on the plurality of ultrasound data;

c) forming a plurality of sub matrixes corresponding to each of the matrixes;

d) calculating a power difference value among the plurality of sub matrixes based on a mean frequency and a power corresponding to each of the plurality of sub matrixes;

e) determining whether the power difference value is equal to or larger than a first threshold value;

f) performing first singular value decomposition (SVD) clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component and second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component based on the mean frequency, a predetermined first cutoff frequency and a predetermined second cutoff frequency when the power difference value is equal to or larger than the first threshold value; and

g) performing clutter filtering upon the plurality of ultrasound data when

the power difference value is less than the first threshold value.

14. An ultrasound system, comprising:

an ultrasound data acquisition device configured to transmit and receive ultrasound signals to and from a target object to output a plurality of ultrasound data corresponding to each of pixels of a color Doppler mode image; and

a processor in communication with the ultrasound data acquisition device and being configured to;

form a matrix corresponding to each of the pixels based on the plurality of ultrasound data;

form a plurality of sub matrixes corresponding to each of the matrixes;

calculate a power difference value among the plurality of sub matrixes based on a mean frequency and a power corresponding to each of the plurality of sub matrixes;

determine whether the power difference value is equal to or larger than a first threshold value;

compare the mean frequency with a predetermined first cutoff frequency when the power difference value is equal to or larger than the first threshold value;

perform first singular value decomposition (SVD) clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component when the mean frequency is equal to or less than the first cutoff frequency;

compare the mean frequency with a predetermined second cutoff frequency when the mean frequency is larger than the first cutoff frequency, wherein the second cutoff frequency is larger than the first cutoff frequency;

perform second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component when the mean frequency is equal to or less than the second cutoff frequency; and

perform clutter filtering upon the plurality of ultrasound data when the power difference value is less than the first threshold value.

15. A method of performing clutter filtering, comprising:

a) acquiring a plurality of ultrasound data corresponding to each of pixels of a color Doppler mode image for a target object;

b) forming a matrix corresponding to each of the pixels based on the plurality of ultrasound data;

c) forming a plurality of sub matrixes corresponding to each of the matrixes;

d) calculating a power difference value among the plurality of sub matrixes based on a mean frequency and a power corresponding to each of the plurality of sub matrixes;

e) determining whether the power difference value is equal to or larger than a first threshold value;

f) comparing the mean frequency with a predetermined first cutoff frequency when the power difference value is equal to or larger than the first threshold value;

g) performing first singular value decomposition (SVD) clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component when the mean frequency is equal to or less than the first cutoff frequency;

h) comparing the mean frequency with the predetermined second cutoff frequency when the mean frequency is larger than the first cutoff frequency, wherein the second cutoff frequency is larger than the first cutoff frequency;

i) performing second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component when the mean frequency is equal to or less than the second cutoff frequency; and

j) performing clutter filtering upon the plurality of ultrasound data when the power difference value is less than the first threshold value.