Signal processing apparatus

Patent metadata

Field	Value
Publication number	US-9448100-B2
Application number	US-201213981233-A
Country	US
Kind code	B2
Filing date	Feb 1, 2012
Priority date	Feb 4, 2011
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

Provided is a signal processing apparatus including: a transducer that performs scanning through the interior of an object and acquires received waveform data of a plurality of scanlines; an intensity screening unit that outputs a high intensity position at which signal intensity calculated from the received waveform data is higher than a first predetermined value; a correlation calculation unit that calculates a correlation value in a constant-width division for received waveform data of a first scanline and of a second scanline having a predetermined correlation with the first scanline; a position extraction unit that extracts, as a candidate position of a singular region, a position which corresponds to a high intensity position and for which the correlation value is lower than a second predetermined value; and an image processor that performs signal processing of generating image data of the object on the basis of the received waveform data.

First claim

The invention claimed is:

1. A signal processing apparatus, comprising:
a transducer that scans an elastic wave beam through an interior of an object and acquires received waveform data of a plurality of scanlines;
an intensity screening unit that calculates signal intensities on the basis of the received waveform data of the plurality of scanlines, and outputs, as a high intensity position, a position at which a calculated signal intensity is higher than a first predetermined value;
a correlation calculation unit that selects, from among the plurality of scanlines, a first scanline and a second scanline having a predetermined correlation with the first scanline, and that calculates a correlation value between received waveform data of the first scanline and the second scanline, at a plurality of constant-width divisions;
a position extraction unit that extracts, as a candidate position at which a singular region is likely to be present, a position corresponding to the high intensity position outputted by the intensity screening unit, at a division where the correlation value is lower than a second predetermined value; and
an image processing unit that performs signal processing for generating image data of the object from the received waveform data of the plurality of scanlines.

2. The signal processing apparatus according to claim 1 , wherein said correlation calculation unit calculates only a correlation value in a division including a position that corresponds to the high intensity position outputted by said intensity screening unit.

3. The signal processing apparatus according to claim 1 , wherein the first predetermined value is a value that is within 10% from the top of the calculated signal intensities.

4. The signal processing apparatus according to claim 1 , wherein said position extraction unit determines the second predetermined value using a mean value and standard deviation of correlation values that are calculated by said correlation calculation unit.

5. The signal processing apparatus according to claim 4 , wherein
said intensity screening unit outputs, as a threshold value signal intensity, a smallest signal intensity from among signal intensities that are higher than the first predetermined value;
said correlation calculation unit calculates, in addition to the correlation value, signal power of the first scanline and the second scanline included in the constant-width division; and
said position extraction unit determines the second predetermined value using only a correlation value selected according to a predetermined condition that uses the calculated signal power and the threshold value signal intensity.

6. The signal processing apparatus according to claim 1 , further comprising:
a continuity determination unit that extracts, from among candidate positions extracted by said position extraction unit, a position candidate for which there exists another candidate position, at a higher proportion than a third predetermined value, in a division corresponding to the extracted candidate position.

7. The signal processing apparatus according to claim 1 , wherein the predetermined correlation between the first scanline and the second scanline has a correlation value of 0.5 or greater between the first scanline and the second scanline.

8. The signal processing apparatus according to claim 1 , wherein the first scanline and the second scanline are adjacent to each other.

9. The signal processing apparatus according to claim 1 , wherein said image processing unit displays the candidate position superposed on an image of the object.

10. The signal processing apparatus according to claim 1 , wherein a transmission beam is formed in such a manner that a transmission focus matches the candidate position, and received waveform data based on the transmission beam is used for calculation of a correlation value performed by said correlation calculation unit.

11. The signal processing apparatus according to claim 1 , wherein the singular region is a region, inside the object, that constitutes a high-reflection body for elastic waves.

12. The signal processing apparatus according to claim 11 , wherein the singular region is a calcified region having a diameter of 2 mm or less in an approximation when the singular region has a spherical shape.

13. The signal processing apparatus according to claim 1 , wherein the second predetermined value is a value resulting from subtracting an X-multiple of a standard deviation of the correlation values from a mean value of the correlation values, wherein X is a value ranging from 1 to 3.

14. The signal processing apparatus according to claim 6 , wherein the third predetermined value is 50% or greater.

15. The signal processing apparatus according to claim 5 , wherein the predetermined condition is
√{square root over ( P 1 ×P 2 )} >αI t ,

where α is a constant greater than 1, I t is the threshold value signal intensity, P 1 is the signal power of the first scanline, and P 2 is the signal power of the second scanline.

Assignees

• Nagae Kenichi
• Taki Hirofumi
• Sato Toru
• Canon Kk

Inventors

• Nagae Kenichi
• Taki Hirofumi
• Sato Toru

Classifications

• A61B8/14 Primary

  Echo-tomography · CPC title

• A61B8/483

  involving the acquisition of a 3D volume of data · CPC title

• A61B8/4488

  the transducer being a phased array · CPC title

• A61B8/5207

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

• G01H1/00 Primary

  Measuring {characteristics of} vibrations in solids by using direct conduction to the detector (G01H9/00, G01H11/00 take precedence) · CPC title