ADAPTIVELY PERFORMING CLUTTER FILTERING IN AN ULTRASOUND SYSTEM

• US 20110118606A1
• Filed: 09/09/2010
• Published: 05/19/2011
• Est. Priority Date: 11/16/2009
• Status: Active Grant

• Current Assignee: Medison Co., Ltd. (Samsung Electronics Co. Ltd.)
• Original Assignee: Medison Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Tae Yun
• Granted Patent: US 8,684,934 B2
• Time in Patent Office: Days
• 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 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.

2. The ultrasound system of claim 1, wherein the first clutter filtering comprises singular value decomposition (SVD) clutter filtering, and

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 processing unit comprises:

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

a SVD processing section configured to perform the SVD upon the matrix to form a plurality of sub matrixes corresponding to each of the matrixes;

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

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

a first filtering section configured to, if the power difference value is equal to or larger than the first threshold value, perform the first clutter filtering upon the plurality of sub matrixes by using the mean frequency and the power.

4. The ultrasound system of claim 3, wherein the first filtering section is configured to:

compare the mean frequency with a predetermined first cutoff frequency;

if it is determined that the mean frequency is equal to or less than the first cutoff frequency, perform first SVD clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component;

if it is determined that the mean frequency is larger than the first cutoff frequency, compare the mean frequency with a predetermined second cutoff frequency, wherein the second cutoff frequency is larger than the first cutoff frequency; and

if it is determined that the mean frequency is equal to or less than the second 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.

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 first filtering section is further configured to:

if it is determined that the mean frequency is larger than the second cutoff frequency, compare the power of the sub matrix corresponding to the mean frequency with a predetermined second threshold value;

if it is determined that the power is less than the second threshold value, perform third SVD clutter filtering for removing the sub matrix as a noise component; and

if it is determined that the power is equal to or larger than the second threshold value, perform the second SVD clutter filtering upon the sub matrix corresponding to the power.

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) calculating a power difference value corresponding to each of the pixels based on the plurality of ultrasound data;

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

d) if the power difference value is equal to or larger than the first threshold value, then performing first clutter filtering upon the plurality of ultrasound data, or if the power difference value is less than the first threshold value, then performing second clutter filtering upon the plurality of ultrasound data.

8. The method of claim 7, wherein the first clutter filtering comprises singular value decomposition (SVD) clutter filtering, and

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

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

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

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

calculating a power and a mean frequency corresponding to each of the plurality of sub matrixes; and

calculating the power difference value among the plurality of sub matrixes based on the power.

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

d1) comparing the mean frequency with a predetermined first cutoff frequency;

d2) if it is determined that the mean frequency is equal to or less than the first cutoff frequency, performing first SVD clutter filtering for removing the sub matrix corresponding to the mean frequency as a clutter signal component;

d3) if it is determined that the mean frequency is larger than the first cutoff frequency, comparing the mean frequency with a predetermined second cutoff frequency, wherein the second cutoff frequency is larger than the first cutoff frequency; and

d4) if it is determined that the mean frequency is equal to or less than the second cutoff frequency, performing second SVD clutter filtering for performing a matrix operation upon the sub matrix corresponding to the mean frequency as a Doppler signal component.

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

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

d5) if it is determined that the mean frequency is larger than the second cutoff frequency, comparing the power of the sub matrix corresponding to the mean frequency with a predetermined second threshold value;

d6) if it is determined that the power is less than the second threshold value, performing third SVD clutter filtering for removing the sub matrix as a noise component; and

d7) if it is determined that the power is equal to or larger than the second threshold value, performing the second SVD clutter filtering upon the sub matrix corresponding to the power.

13. A computer readable medium comprising computer executable instructions configured 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) calculating a power difference value corresponding to each of the pixels based on the plurality of ultrasound data;

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

d) if the power difference value is equal to or larger than the first threshold value, then performing first clutter filtering upon the plurality of ultrasound data, or if the power difference value is less than the first threshold value, then performing second clutter filtering upon the plurality of ultrasound data.