CN107320131B - Fundamental harmonic separation method and device - Google Patents
Fundamental harmonic separation method and device Download PDFInfo
- Publication number
- CN107320131B CN107320131B CN201710717595.6A CN201710717595A CN107320131B CN 107320131 B CN107320131 B CN 107320131B CN 201710717595 A CN201710717595 A CN 201710717595A CN 107320131 B CN107320131 B CN 107320131B
- Authority
- CN
- China
- Prior art keywords
- echo signal
- signal
- segment
- backward
- filtering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/52—Devices using data or image processing specially adapted for diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/5207—Devices using data or image processing specially adapted for diagnosis using ultrasonic, sonic or infrasonic waves involving processing of raw data to produce diagnostic data, e.g. for generating an image
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Radiology & Medical Imaging (AREA)
- Heart & Thoracic Surgery (AREA)
- Biophysics (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Pathology (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Biomedical Technology (AREA)
- Physics & Mathematics (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
Abstract
The application provides a fundamental harmonic separation method and a device, wherein the method comprises the following steps: according toFocal position O of forward echo signal1Dividing the forward echo signal into N forward echo signal segments, wherein N is a natural number not less than 2; focal position O based on a backward echo signal2Dividing the backward echo signal into N backward echo signal segments, wherein the forward echo signal and the backward echo signal correspond to the same scanning line; adjusting the phase of the forward echo signal segment by adopting a phase adjusting filter so as to ensure that the phase of the forward echo signal segment after phase adjustment is completely opposite to that of the corresponding reverse echo signal segment; superposing the forward echo signal segment after the phase adjustment and the corresponding reverse echo signal segment to offset a fundamental wave signal to obtain a harmonic signal segment; and combining the harmonic signal sections to obtain the harmonic signal of the scanning line. By applying the method, high-quality harmonic signals can be extracted from the echo signals received by the ultrasonic probe.
Description
Technical Field
The application relates to the technical field of ultrasonic imaging, in particular to a fundamental wave and harmonic wave separation method and device.
Background
For an ultrasonic system, a human body is a complex medium, and different organs and tissues in the human body have different acoustic impedances and attenuation characteristics, so that when ultrasonic waves enter the human body and pass through different organs and tissues from the surface to the deep part, the sound waves are reflected and attenuated differently, and the different reflection and attenuation are the basis for forming an ultrasonic image. Meanwhile, different tissues and organs of the human body are non-rigid media, so that when the sound wave is reflected, the sound wave itself generates resonance due to oscillation and excitation of the sound wave, and harmonic waves with higher frequency are generated, so that the fundamental wave and the harmonic waves generated by the human body exist in echo signals received by the ultrasonic probe. Research shows that compared with common fundamental wave imaging, harmonic imaging has the advantages of high imaging frequency, high resolution, less noise interference, high inherent image signal-to-noise ratio and the like, particularly, harmonic imaging by using second harmonic has good biomedical application prospect for early diagnosis or postoperative treatment monitoring of certain diseases, so that the harmonic is significant in extracting the echo signals.
In the related art, a reverse pulse method is used, that is, an ultrasonic probe sequentially transmits two sets of ultrasonic waves with opposite phases, and then the ultrasonic probe receives two sets of echo signals with opposite phases and superposes the two sets of echo signals with opposite phases, so that fundamental waves in the two sets of echo signals are cancelled out due to opposite phases, and harmonic waves are not cancelled out or even enhanced, and accordingly, the harmonic waves can be extracted from the echo signals.
However, due to the relative motion between the ultrasound probe and the human body, the phases of the two sets of echo signals received by the ultrasound probe cannot be strictly opposite, so that the fundamental waves cannot be completely cancelled out by the superposition, that is, high-quality harmonics cannot be extracted from the echo signals.
Disclosure of Invention
In view of this, the present application provides a harmonic imaging method and apparatus to extract a high-quality harmonic signal from an echo signal received by an ultrasound probe.
Specifically, the method is realized through the following technical scheme:
according to a first aspect of embodiments of the present application, there is provided a harmonic imaging method, the method including:
focal position O based on forward echo signal1Dividing the forward echo signal into N forward echo signal segments, wherein N is a natural number not less than 2;
focal position O based on a backward echo signal2Dividing the backward echo signal into N backward echo signal segments, wherein the forward echo signal and the backward echo signal correspond to the same scanning line;
adjusting the phase of the forward echo signal segment by adopting a phase adjusting filter so as to ensure that the phase of the forward echo signal segment after phase adjustment is completely opposite to that of the corresponding reverse echo signal segment;
superposing the forward echo signal segment after the phase adjustment and the corresponding reverse echo signal segment to offset a fundamental wave signal to obtain a harmonic signal segment;
and combining the harmonic signal sections to obtain the harmonic signal of the scanning line.
According to a second aspect of embodiments of the present application, there is provided a fundamental harmonic separation apparatus including:
a first segmentation module for determining a focus position O according to the forward echo signal1Dividing the forward echo signal into N forward echo signalsA number segment, wherein N is a natural number not less than 2;
a second segmentation module for determining a focus position O according to the backward echo signal2Dividing the backward echo signal into N backward echo signal segments, wherein the forward echo signal and the backward echo signal correspond to the same scanning line;
the phase adjusting module is used for adjusting the phase of the forward echo signal segment by adopting a phase adjusting filter so as to ensure that the phase of the forward echo signal segment after phase adjustment is completely opposite to that of the corresponding reverse echo signal segment;
the signal superposition module is used for superposing the forward echo signal segment after the phase adjustment and the corresponding reverse echo signal segment so as to offset a fundamental wave signal and obtain a harmonic signal segment;
and the signal merging module is used for merging the harmonic signal sections to obtain the harmonic signals of the scanning lines.
It is visible by above-mentioned embodiment, through segmenting to forward echo signal and reverse echo signal, obtain forward echo signal section and reverse echo signal section, carry out phase adjustment with the reverse echo signal section that corresponds as the unit with the forward echo signal section, make each forward echo signal section totally opposite with the phase place of the reverse echo signal section that corresponds, in order to realize follow-up back that superposes, make fundamental wave signal accomplish the elimination because of the phase place is opposite, obtain high-quality harmonic signal section, merge the harmonic signal section that obtains at last again, can obtain complete high-quality harmonic signal, it is thus visible, this application can realize extracting high-quality harmonic signal from the echo signal that ultrasonic probe received.
Drawings
FIG. 1 is a schematic diagram of an inverted pulse system according to the related art;
FIG. 2 is a schematic view of an ultrasonic wave transmission/reception flow;
FIG. 3 is a flow chart of one embodiment of a fundamental harmonic separation method of the present application;
FIG. 4 is a schematic diagram of the shape of the wave surface of the focused wave;
FIG. 5 is an exemplary flow chart for adjusting filter coefficients of an adaptive filter;
fig. 6 is a system architecture for implementing the fundamental harmonic separation method provided in the embodiments of the present application;
fig. 7 is a block diagram of an embodiment of a fundamental harmonic separation apparatus according to the present application.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.
Because different tissues and organs of a human body are non-rigid media, when the acoustic wave is reflected, the acoustic wave itself generates resonance due to oscillation and excitation of the acoustic wave, and harmonic waves with higher frequency are generated. Research shows that the harmonic waves have smaller amplitude and faster attenuation compared with the fundamental waves; compared with fundamental wave imaging, harmonic imaging can improve the signal-to-noise ratio and the definition of tissue edges and highlight detail resolution, so that harmonic imaging, particularly second harmonic imaging, has a good biomedical application prospect for early diagnosis or postoperative treatment monitoring of certain diseases.
When the human tissue is scanned by ultrasound, the fundamental wave reflected by the human tissue and the generated harmonic wave are received by the ultrasound probe, so that the fundamental wave and the harmonic wave need to be separated to realize high-quality harmonic wave imaging. Since the harmonic wave has a higher frequency than the fundamental wave, for example, the fundamental wave frequency is F0, and the harmonic wave frequency is 2F0, the fundamental wave harmonic separation can be theoretically achieved by using a simple high-pass filter, for example, by passing the echo signal received by the ultrasonic probe through the high-pass filter, the fundamental wave signal with the frequency of F0 can be filtered out, and the harmonic wave signal with the frequency of 2F0 is retained, thereby achieving the fundamental wave harmonic separation. However, since the human body is a complex medium and the requirement for the control of the emission spectrum is high, it is practically difficult to realize the fundamental harmonic separation by the above simple high-pass filter.
In the related art, a reverse pulse method is proposed, and as shown in fig. 1, a schematic structural diagram of a reverse pulse system in the related art is shown. In the reverse pulse system 100 illustrated in fig. 1, the transmitting module 110 controls the ultrasound probe 120 to sequentially transmit two sets of ultrasound waves with opposite phases in each scan line direction, for example, a set of forward ultrasound waves in the scan line direction "1", followed by a set of reverse ultrasound waves, followed by a set of forward ultrasound waves in the scan line direction "2", followed by a set of reverse ultrasound waves … …, which are relatively general terms as will be understood by those skilled in the art. Taking one transmission as an example, for example, after two sets of ultrasonic waves with opposite phases are transmitted along the direction of the scan line No. 1, the ultrasonic probe 120 will also receive two sets of echo signals with opposite phases (the echo signal corresponding to the forward ultrasonic wave may be referred to as a forward echo signal, and the echo signal corresponding to the backward ultrasonic wave may be referred to as a backward echo signal); the two sets of echo signals with opposite phases sequentially pass through the receiving module 130 and the beam forming module 140 to reach the fundamental wave separation module 150; the fundamental wave and harmonic separation module 150 includes a superposition module 151 and two memories, namely a memory 152 and a memory 153, provided that the memory 152 is used for storing a forward echo signal and the memory 153 is used for storing a backward echo signal, the forward echo signal will enter the memory 152, and the backward echo signal will enter the memory 153; the two subsequent memories respectively transmit the stored echo signals to the superposition module 151, and the superposition module 151 superposes the forward echo signal and the backward echo signal, so that the fundamental waves in the forward echo signal and the backward echo signal are cancelled out due to opposite phases, but the harmonic waves are not cancelled out, even enhanced, and the separation of the fundamental wave and the harmonic waves is realized; subsequently, the fundamental harmonic separation module 150 transmits the separated harmonic signal to the harmonic envelope transform module 160, and the harmonic envelope transform module 160 performs envelope transform on the harmonic signal by using methods such as I/Q demodulation or hilbert transform, so as to obtain a final harmonic signal of the scan line "No. 1".
However, due to the relative motion between the ultrasonic probe and the human body, the phases of two sets of echo signals received by the ultrasonic probe cannot be strictly opposite, so that the fundamental waves cannot be completely cancelled out by the superposition, that is, high-quality harmonics cannot be extracted from the echo signals; meanwhile, in the above process, the ultrasonic probe may obtain a harmonic signal of one scan line by transmitting the ultrasonic wave twice consecutively along the scan line, thereby causing a frame rate of the ultrasonic imaging system to decrease.
Based on this, the present application provides a fundamental wave harmonic separation method, in the method, firstly, in order to solve the problem that the ultrasonic probe in the related art can obtain the harmonic signal of one scanning line only by transmitting the ultrasonic wave twice continuously along the one scanning line, which results in the frame rate of the ultrasonic imaging system being lowered, the echo signals of a plurality of scanning lines can be received simultaneously after one transmission, for example, as shown in the ultrasonic transmission/reception flow diagram shown in fig. 2, the forward ultrasonic wave is transmitted at the frequency of F0 along the direction of the a line, and then the forward echo signals are received along the directions of the a-1 line, the a line, and the a +1 line, respectively; transmitting reverse ultrasonic waves at the frequency of F0 along the direction of the line A +1, and then respectively receiving reverse echo signals along the directions of the line A, the line A +1 and the line A + 2; forward ultrasonic waves are transmitted at the frequency of F0 along the line A +2, and then forward echo signals are respectively received along the line A +1, the line A +2 and the line A + 3. Therefore, 3 times of emission is carried out along 3 scanning lines respectively, each emission receives echo signals on a plurality of scanning lines with the emission position as the center, respective harmonic signals of the 3 scanning lines can be obtained at most, and the problem of frame rate reduction in the related technology is solved.
Taking the 3-time echo signal received on the a +1 line as an example, because the scan lines along which the three-time transmission is performed are not consistent, the phases of the forward echo signal and the backward echo signal in the 3-time echo signal received on the a +1 line are not completely opposite, and thus, the fundamental wave and harmonic separation method provided by the application can be applied, and the phases of the forward echo signal and the backward echo signal on the a +1 line are completely opposite by performing phase adjustment on the forward echo signal or the backward echo signal on the a +1 line, and then, the phases are overlapped, so that the fundamental wave can be completely cancelled due to the opposite phases, and thus, a high-quality harmonic signal can be extracted from the echo signal received by the ultrasonic probe.
As follows, the fundamental harmonic separation method provided in the present application will be described in detail by referring to the following embodiments with reference to the example of fig. 2.
Referring to fig. 3, a flowchart of an embodiment of a fundamental harmonic separation method according to the present application is shown, taking processing of a forward echo signal and a backward echo signal of the same scan line as an example, the method includes the following steps:
step 301: focal position O based on forward echo signal1And dividing the forward echo signal into N forward echo signal segments, wherein N is a natural number not less than 2.
Step 302: focal position O based on a backward echo signal2The echo signal is divided into N echo signal segments.
The above steps 301 and 302 are explained as follows:
when the generated ultrasonic wave is a focused wave, because the wave surface of the focused wave is not consistent before/after the focus, for example, see fig. 4, which is a schematic diagram of the wave surface shape of the focused wave, when the phase of the echo signal is adjusted, the adjustment directions of the echo signal before/after the focus are not consistent, based on which, the embodiment of the present application proposes to segment the echo signal according to the focus position, so as to perform the phase adjustment on each echo signal segment obtained by segmentation, respectively, and improve the accuracy of the phase adjustment.
In an embodiment, taking the forward echo signal and the backward echo signal on the a line as an example, the focus position O of the forward echo signal can be determined1Dividing the forward echo signal into N (N is a natural number not less than 2) segments, and for the convenience of description, referring to the obtained segments as forward echo signal segments; accordingly, based on the focal position O of the backward echo signal2The echo signal is also divided into N segments, and for the convenience of description, the resulting segments are referred to as echo signal segments.
In an alternative implementation, if N is 2, then the focus position O is the focal position1Dividing the forward echo signal into 2 forward echo signal segments as a division point; correspondingly, in the focal position O2The backward echo signal is divided into 2 backward echo signal segments for the division points.
In another alternative implementation, if N is greater than 2, the focus position O of the forward echo signal may be first determined1The forward echo signal is divided into two sections, and then the two sections are located at the focus position O1The former part is divided into A (A is a natural number greater than 1) forward echo signal segments to be located at a focus position O1The latter part is divided into B (B is a natural number greater than 1) segments of the forward echo signal. Correspondingly, from the focal position O of the back echo signal2The backward echo signal is divided into two parts, and then the backward echo signal is positioned at the focus position O2The previous part is divided into a segment of a reverse echo signal to be located at the focal position O2The latter part is divided into B segments of the reverse echo signal.
When segmenting the forward echo signal and the backward echo signal on the same scan line, the segmentation method is kept consistent, and the keeping of the segmentation method in consistency here includes: the number of resulting segments is the same, and the number of segments located in front of/behind the focal position is also the same, respectively.
In addition, the length of the forward echo signal segment/the reverse echo signal segment is not limited in the application, and the lengths of the forward echo signal segments obtained by segmenting the same forward echo signal can be the same or different; similarly, the lengths of the segments of the same backward echo signal obtained by segmenting the same backward echo signal may be the same or different, which is not limited in this application.
Step 303: and adjusting the phase of the forward echo signal segment by adopting a phase adjusting filter so as to ensure that the phase of the forward echo signal segment after phase adjustment is completely opposite to that of the corresponding reverse echo signal segment.
First, it is assumed that the forward echo signal segment obtained in step 301 includes Y1And Y2The segment of the backward echo signal obtained in step 302 includes D1And D2Then, Y1And D1Corresponding to, Y2And D2And correspondingly.
In this step, the phase adjustment filter may be used to adjust the forward echo signal segment so that the phase of the phase-adjusted forward echo signal segment is completely opposite to the phase of the corresponding backward echo signal segment, where "completely opposite" means that the phase difference is 180 degrees.
In one embodiment, the filter coefficients of the phase adjustment filter may be set by the ordinary experience of those skilled in the art.
In an embodiment, the phase adjustment filter may be obtained by adjusting a filter coefficient of the adaptive filter through an adaptive algorithm, and the process of adjusting the filter coefficient of the adaptive filter is described with emphasis as follows:
as shown in fig. 5, an exemplary flowchart for adjusting the filter coefficients of the adaptive filter includes the following steps:
step 501: and negating the forward echo signal segment.
In this application embodiment, can realize accurate, quick carry out phase adjustment to the forward echo signal section for follow-up step, at first get the opposite of forward echo signal section. For example, assuming that the data of the forward echo signal segment is "0, 20, 63, 42, -27, -55", the data of the inverted echo signal segment is "0, -20, -63, -42, 27, 55". For convenience of description, the forward echo signal segment Y may be aligned1The forward echo signal segment obtained after the negation is recorded as X1Then, X1And D1Correspondingly, in the embodiment of the present application, the other corresponding inverted forward echo signal segments and inverted echo signal segments are not described one by one.
Step 502: and filtering the inverted forward echo signal segment by using a set adaptive filter for phase adjustment to obtain a first forward filtered signal, and if the phase of the first forward filtered signal is not consistent with that of the corresponding reverse echo signal segment, executing a subsequent step 503.
In this step, the adaptive filter W set for phase adjustment may be employed1For the above X1The filtering is performed to obtain a filtered forward echo signal segment, and for the convenience of description, the filtered forward echo signal segment may be referred to as a first forward filtered signal, specifically, the first forward filtered signal is equal to X1*W1. If the first forward filtered signal corresponds to a corresponding segment of the backward echo signal, e.g. D1Is not consistent, the adaptive filter W can be considered to be1Is not appropriate, the following step 503 is continued.
Step 503: and modifying the filter coefficient of the adaptive filter according to a set algorithm.
In the embodiment of the present application, the setting algorithm may be W1-NEW＝W1+2*E1*X1。
Wherein, W1-NEWThe modified filter coefficients of the adaptive filter.
Step 504: and filtering the inverted forward echo signal section by adopting a set low-pass filter and a modified self-adaptive filter to obtain a second forward filtering signal.
In this step, a low-pass filter L is set1With the current adaptive filter W1For the above X1Filtering to obtain a filtered forward echo signal segment, and for convenience of description, referring the filtered forward echo signal segment as a second forward filtered signal and recording as Z1In particular, Z1＝X1*W1*L1。
The low-pass filter L is described above1The cutoff frequency of (2) is the fundamental frequency F0, and in practical applications, it is not strictly F0, and it may be up-down floating in the range around F0.
Step 505: and filtering the corresponding reverse echo signal section by adopting a low-pass filter to obtain a reverse filtering signal.
In step (ii), a low pass filter L is used1For corresponding reverse echo signal segment D1Filtering to obtain filtered reverse echo signal segment, and for description, referring the filtered reverse echo signal segment as reverse filtering signal and recording as P1In particular, P1＝D1*L1。
Step 506: obtaining an error signal according to the backward filtering signal and the second forward filtering signal, and returning to execute the step 503 if the modulus of the error signal exceeds a set error value; if the modulus of the error signal does not exceed the set error value, the process is ended.
In this step, an error signal, denoted as E, is obtained from the backward filtered signal and the second forward filtered signal1In particular, E1＝P1-Z1。
If E1Is greater than a predetermined error value (the predetermined error value is a constant, for example, 0.03), it is considered that the forward echo signal segment Y is divided into segments1After the phase adjustment is carried out by the current adaptive filter, the phase of the adaptive filter is still corresponding to the reverse echo signal segment D1Are not exactly opposite in phase and the phase difference is notNot within the acceptable range, therefore, the filter coefficients of the adaptive filter may be further modified, i.e. the above step 503 is executed again; if the error signal E1If the modulus does not exceed the set error value, the current process may be ended.
This completes the description of the embodiment shown in fig. 5.
According to the embodiment shown in fig. 5, phase adjustment filters corresponding to other forward echo signal segments can also be obtained, and the specific process is not described in this application one by one.
In an embodiment, considering that the phase change between consecutive forward echo signal segments is also a continuous change, and the difference is not very large, in the process of obtaining the phase adjustment filters corresponding to other forward echo signal segments except the first forward echo signal segment, the filter coefficient of the phase adjustment filter corresponding to the previous forward echo signal segment may be used as the initial filter coefficient of the adaptive filter to be currently adjusted. For example, assume a forward echo signal segment Y1The coefficient of the corresponding phase adjusting filter is W1-GThen, the forward echo signal segment Y can be segmented2The initial value of the filter coefficient of the corresponding adaptive filter is set to W1-G. By this processing, the adjustment speed of the adaptive filter can be increased.
Step 304: and superposing the forward echo signal segment after the phase adjustment and the corresponding reverse echo signal segment to offset the fundamental wave signal to obtain a harmonic signal segment.
In this embodiment of the present application, since the above step 304 is performed, so that the phases of the forward echo signal segment and the backward echo signal segment are completely opposite, and thus, the forward echo signal segment after the phase adjustment and the corresponding backward echo signal segment are superimposed, the fundamental wave can be completely cancelled out due to the opposite phases, and thus the harmonic signal segment is obtained.
Step 305: and combining the harmonic signal sections to obtain the harmonic signal of the scanning line.
In the embodiment of the application, all the obtained harmonic signal sections are combined finally, and then the complete harmonic signal can be obtained.
In addition, in order to eliminate the extra noise caused by the data combination, the harmonic signal obtained in step 305 may be filtered by a high-pass filter.
The cutoff frequency of the high-pass filter is the harmonic frequency 2F0, and in practical applications, the cutoff frequency may not be the strict 2F0, and may be varied up and down in the range around 2F 0.
It is thus clear that by above-mentioned embodiment, through segmenting to forward echo signal and reverse echo signal, obtain forward echo signal section and reverse echo signal section, carry out phase adjustment with forward echo signal section and the reverse echo signal section that corresponds as the unit, make each forward echo signal section completely opposite with the phase place of the reverse echo signal section that corresponds, after in order to realize follow-up stack, make fundamental wave signal accomplish the elimination because of the phase place is opposite, obtain high-quality harmonic signal section, merge the harmonic signal section that obtains at last again, can obtain complete high-quality harmonic signal, it is thus visible, this application can realize extracting high-quality harmonic signal from the echo signal that ultrasonic probe received.
As follows, fig. 6 illustrates a system architecture for implementing the fundamental harmonic separation method provided in the embodiment of the present application, so as to further describe the fundamental harmonic separation method provided in the embodiment of the present application in conjunction with the system architecture illustrated in fig. 6.
First, it can be found by comparing fig. 1 that the number of the beam forming modules and the number of the memories are increased in the system illustrated in fig. 6, wherein the specific number of the beam forming modules and the memories may be determined according to the number of the echo signals received at one time in practical application, and fig. 6 only takes 3 beam forming modules and 3 memories as an example, which is not limited in this application; the system illustrated in fig. 6 further includes a phase calculation module 654 and a phase adjustment module 655, which together perform a phase adjustment process of the echo signal, and the specific adjustment process is not described in detail herein; the system illustrated in fig. 6 further increases the number of the superposition modules, wherein the superposition module 656 and the superposition module 657 are respectively configured to superpose two sets of echo signals with opposite phases, and the superposition module 658 is configured to superpose the echo signals output by the superposition module 356 and the superposition module 657.
Next, with reference to the example shown in fig. 2, the fundamental harmonic separation of the echo signal on the a +1 line will be described as an example.
As shown in fig. 2, 3 sets of echo signals, including two sets of forward echo signals and one set of backward echo signals, are received on the a +1 line, and the 3 sets of echo signals can be stored in the memories 651, 652 and 653 illustrated in fig. 6, respectively, and the backward echo signals are stored in the memory 652 and the two sets of forward echo signals are stored in the memories 651 and 653, respectively, for example, the memories 651 and 652 can be divided into one set, designated as 1/2 set, the memories 652 and 653 can be divided into another set, designated as 2/3 set, and then the forward echo signals (or the backward echo signals) in the 1/2 and 2/3 sets can be phase-adjusted by the phase calculation module 654 and the phase adjustment module 655, respectively, so that the phases of the forward echo signals and the backward echo signals in each set are completely opposite, subsequently, the superposition module 656 is used to superpose the forward echo signal and the backward echo signal in the 1/2 group, the superposition module 657 is used to superpose the forward echo signal and the backward echo signal in the 2/3 group, so as to obtain two harmonic signals, and finally, the superposition module 658 is used to superpose the two harmonic signals, so as to obtain a final complete harmonic signal of the a +1 line.
It should be noted that, in the system illustrated in fig. 6, two phase adjustment modules may be further provided to perform phase adjustment on the forward echo signal and the backward echo signal in 1/2 groups and 2/3 groups simultaneously, and the system architecture illustrated in fig. 6 is only an example and should not be construed as limiting the application.
Corresponding to the embodiments of the fundamental harmonic separation method, the application also provides embodiments of a fundamental harmonic separation device.
Referring to fig. 6, a block diagram of an embodiment of a fundamental harmonic separation apparatus according to the present application is shown, the apparatus including: a first segmentation module 71, a second segmentation module 72, a phase adjustment module 73, a signal superposition module 74, and a signal combination module 75.
Wherein the first segmentation module 71 is used for determining the focal position O according to the forward echo signal1Dividing the forward echo signal into N forward echo signal segments, wherein N is a natural number not less than 2;
a second segmentation module 72 for determining a focal position O based on the backward echo signal2Dividing the backward echo signal into N backward echo signal segments, wherein the forward echo signal and the backward echo signal correspond to the same scanning line;
a phase adjusting module 73, configured to adjust the phase of the forward echo signal segment by using a phase adjusting filter, so that the phase of the phase-adjusted forward echo signal segment is completely opposite to the phase of the corresponding backward echo signal segment;
a signal superposition module 74, configured to superpose the phase-adjusted forward echo signal segment and the corresponding reverse echo signal segment to cancel a fundamental wave signal, so as to obtain a harmonic signal segment;
and a signal combining module 75, configured to combine the harmonic signal segments to obtain a harmonic signal of the scan line.
In an embodiment, the first segmentation module 71 may specifically be configured to: locating the forward echo signal at the focal position O1The previous part is divided into A segments of forward echo signals, and the forward echo signals are positioned at the focus position O1Dividing the subsequent part into B segments of forward echo signals, wherein A and B are both natural numbers greater than 1;
the second segmentation module 72 may be specifically configured to: locating the back echo signal at the focal position O2The previous part is divided into a segment of a backward echo signal and the backward echo signal is located at the focal position O2The latter part is divided into B segments of the reverse echo signal.
In an embodiment, the apparatus may further comprise (not shown in fig. 7):
the negation module is used for negating the forward echo signal segment;
the filtering module is used for filtering the inverted forward echo signal section by adopting a set self-adaptive filter for phase adjustment to obtain a first forward filtering signal;
and the modifying module is used for modifying the filter coefficient of the adaptive filter if the phases of the first forward filtering signal and the corresponding backward echo signal segment are inconsistent.
In one embodiment, the modification module comprises (not shown in fig. 7):
a coefficient modification submodule, configured to modify a filter coefficient of the adaptive filter according to a set algorithm if the phase of the first forward filtered signal is inconsistent with the phase of the corresponding backward echo signal segment;
the first filtering submodule is used for filtering the inverted forward echo signal section by adopting a set low-pass filter and a modified self-adaptive filter to obtain a second forward filtering signal;
the second filtering submodule is used for filtering the corresponding reverse echo signal section by adopting the low-pass filter to obtain a reverse filtering signal;
an error determination submodule, configured to obtain an error signal according to the backward filtered signal and the second forward filtered signal;
and the processing submodule is used for continuously modifying the filter coefficient of the self-adaptive filter according to the set algorithm if the modulus of the error signal exceeds a set error value until the modulus of the error signal does not exceed the set error value.
In an embodiment, the initial value of the filter coefficient of the adaptive filter is the filter coefficient of the optimal phase adjustment filter corresponding to the previous forward echo signal segment.
The implementation process of the functions and actions of each unit in the above device is specifically described in the implementation process of the corresponding step in the above method, and is not described herein again.
For the device embodiments, since they substantially correspond to the method embodiments, reference may be made to the partial description of the method embodiments for relevant points. The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of the application. One of ordinary skill in the art can understand and implement it without inventive effort.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.
Claims (8)
1. A fundamental harmonic separation method, the method comprising:
focal position O based on forward echo signal1Dividing the forward echo signal into N forward echo signal segments, wherein N is a natural number not less than 2;
focal position O based on a backward echo signal2Dividing the backward echo signal into N backward echo signal segments, wherein the forward echo signal and the backward echo signal correspond to the same scanning line;
adjusting the phase of the forward echo signal segment by adopting a phase adjusting filter so as to ensure that the phase of the forward echo signal segment after phase adjustment is completely opposite to that of the corresponding reverse echo signal segment;
superposing the forward echo signal segment after the phase adjustment and the corresponding reverse echo signal segment to offset a fundamental wave signal to obtain a harmonic signal segment;
combining the harmonic signal sections to obtain a harmonic signal of the scanning line;
the focal position O according to the forward echo signal1Dividing the forward echo signal into N forward echo signal segments, including:
will be described inThe forward echo signal is at the focal position O1The previous part is divided into A segments of forward echo signals, and the forward echo signals are positioned at the focus position O1Dividing the subsequent part into B segments of forward echo signals, wherein A and B are both natural numbers not less than 1;
accordingly, the focal position O based on the backward echo signal2Dividing the backward echo signal into N backward echo signal segments, including:
locating the back echo signal at the focal position O2The previous part is divided into a segment of a backward echo signal and the backward echo signal is located at the focal position O2The latter part is divided into B segments of the reverse echo signal.
2. The method of claim 1, further comprising, prior to said adjusting the phase of said forward echo signal segment with a phase adjustment filter:
inverting the forward echo signal segment;
filtering the inverted forward echo signal segment by adopting a set self-adaptive filter for phase adjustment to obtain a first forward filtering signal;
and if the phases of the first forward filtering signal and the corresponding backward echo signal segment are inconsistent, modifying the filtering coefficient of the self-adaptive filter.
3. The method of claim 2, wherein said modifying filter coefficients of said adaptive filter comprises:
modifying the filter coefficient of the self-adaptive filter according to a set algorithm;
filtering the inverted forward echo signal section by adopting a set low-pass filter and a modified adaptive filter to obtain a second forward filtering signal;
filtering the corresponding reverse echo signal section by adopting the low-pass filter to obtain a reverse filtering signal;
obtaining an error signal according to the backward filtering signal and the second forward filtering signal;
and if the modulus of the error signal exceeds a set error value, continuously modifying the filter coefficient of the self-adaptive filter according to the set algorithm until the modulus of the error signal does not exceed the set error value.
4. The method of claim 3, wherein the initial value of the filter coefficient of the adaptive filter is the filter coefficient of the phase adjustment filter corresponding to the previous forward echo signal segment.
5. A fundamental harmonic separation apparatus, comprising:
a first segmentation module for determining a focus position O according to the forward echo signal1Dividing the forward echo signal into N forward echo signal segments, wherein N is a natural number not less than 2;
a second segmentation module for determining a focus position O according to the backward echo signal2Dividing the backward echo signal into N backward echo signal segments, wherein the forward echo signal and the backward echo signal correspond to the same scanning line;
the phase adjusting module is used for adjusting the phase of the forward echo signal segment by adopting a phase adjusting filter so as to ensure that the phase of the forward echo signal segment after phase adjustment is completely opposite to that of the corresponding reverse echo signal segment;
the signal superposition module is used for superposing the forward echo signal segment after the phase adjustment and the corresponding reverse echo signal segment so as to offset a fundamental wave signal and obtain a harmonic signal segment;
the signal merging module is used for merging the harmonic signal sections to obtain harmonic signals of the scanning lines;
the first segmentation module is specifically configured to: locating the forward echo signal at the focal position O1The previous part is divided into A segments of forward echo signals, and the forward echo signals are positioned at the focus position O1The latter part is divided into B-segment forward echoesA signal segment, wherein A and B are both natural numbers not less than 1;
the second segmentation module is specifically configured to:
locating the back echo signal at the focal position O2The previous part is divided into a segment of a backward echo signal and the backward echo signal is located at the focal position O2The latter part is divided into B segments of the reverse echo signal.
6. The apparatus of claim 5, further comprising:
the negation module is used for negating the forward echo signal segment;
the filtering module is used for filtering the inverted forward echo signal section by adopting a set self-adaptive filter for phase adjustment to obtain a first forward filtering signal;
and the modifying module is used for modifying the filter coefficient of the adaptive filter if the phases of the first forward filtering signal and the corresponding backward echo signal segment are inconsistent.
7. The apparatus of claim 6, wherein the modification module comprises:
a coefficient modification submodule, configured to modify a filter coefficient of the adaptive filter according to a set algorithm if the phase of the first forward filtered signal is inconsistent with the phase of the corresponding backward echo signal segment;
the first filtering submodule is used for filtering the inverted forward echo signal section by adopting a set low-pass filter and a modified self-adaptive filter to obtain a second forward filtering signal;
the second filtering submodule is used for filtering the corresponding reverse echo signal section by adopting the low-pass filter to obtain a reverse filtering signal;
an error determination submodule, configured to obtain an error signal according to the backward filtered signal and the second forward filtered signal;
and the processing submodule is used for continuously modifying the filter coefficient of the self-adaptive filter according to the set algorithm if the modulus of the error signal exceeds a set error value until the modulus of the error signal does not exceed the set error value.
8. The apparatus of claim 7, wherein the initial value of the filter coefficient of the adaptive filter is the filter coefficient of the phase adjustment filter corresponding to the previous forward echo signal segment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710717595.6A CN107320131B (en) | 2017-08-21 | 2017-08-21 | Fundamental harmonic separation method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710717595.6A CN107320131B (en) | 2017-08-21 | 2017-08-21 | Fundamental harmonic separation method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107320131A CN107320131A (en) | 2017-11-07 |
| CN107320131B true CN107320131B (en) | 2020-06-26 |
Family
ID=60228128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710717595.6A Active CN107320131B (en) | 2017-08-21 | 2017-08-21 | Fundamental harmonic separation method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107320131B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110731795B (en) * | 2018-07-19 | 2022-04-29 | 青岛海信医疗设备股份有限公司 | Processing method and device for spatial compound imaging |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6095980A (en) * | 1997-10-02 | 2000-08-01 | Sunnybrook Health Science Centre | Pulse inversion doppler ultrasonic diagnostic imaging |
| US6186950B1 (en) * | 1999-11-04 | 2001-02-13 | Atl Ultrasound | Ultrasonic pulse inversion harmonic separation with reduced motional effects |
| US6454714B1 (en) * | 2000-10-20 | 2002-09-24 | Koninklijke Philips Electronics N.V. | Ultrasonic harmonic flash suppression |
| CN1903132A (en) * | 2005-07-28 | 2007-01-31 | 美国西门子医疗解决公司 | Medical diagnostic ultrasound transducer system for harmonics |
| CN101623204A (en) * | 2008-07-11 | 2010-01-13 | 株式会社东芝 | Ultrasound diagnosis apparatus |
| CN107205722A (en) * | 2015-01-29 | 2017-09-26 | 皇家飞利浦有限公司 | The fundamental wave harmonic frequency ultrasound diagnosing image of broadband mixing |
-
2017
- 2017-08-21 CN CN201710717595.6A patent/CN107320131B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6095980A (en) * | 1997-10-02 | 2000-08-01 | Sunnybrook Health Science Centre | Pulse inversion doppler ultrasonic diagnostic imaging |
| US6186950B1 (en) * | 1999-11-04 | 2001-02-13 | Atl Ultrasound | Ultrasonic pulse inversion harmonic separation with reduced motional effects |
| US6454714B1 (en) * | 2000-10-20 | 2002-09-24 | Koninklijke Philips Electronics N.V. | Ultrasonic harmonic flash suppression |
| CN1903132A (en) * | 2005-07-28 | 2007-01-31 | 美国西门子医疗解决公司 | Medical diagnostic ultrasound transducer system for harmonics |
| CN101623204A (en) * | 2008-07-11 | 2010-01-13 | 株式会社东芝 | Ultrasound diagnosis apparatus |
| CN107205722A (en) * | 2015-01-29 | 2017-09-26 | 皇家飞利浦有限公司 | The fundamental wave harmonic frequency ultrasound diagnosing image of broadband mixing |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107320131A (en) | 2017-11-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102727255B (en) | Method and device for ultrasonic image space compound imaging | |
| CN110680380B (en) | Ultrasonic imaging apparatus and image processing apparatus | |
| US8840554B2 (en) | Ultrasonic 3-dimensional image reconstruction method and ultrasonic wave system thereof | |
| JP2004283490A (en) | Ultrasonic transmitter-receiver | |
| JP5931195B2 (en) | Ultrasonic diagnostic apparatus and method of operating ultrasonic diagnostic apparatus | |
| JP2003164451A (en) | Method and system for combining beam | |
| KR20150112057A (en) | Module for Processing Ultrasonic Signal Based on Spatial Coherence and Method for Processing Ultrasonic Signal | |
| CN104160423A (en) | Filtering systems and methods for suppression of non-stationary reverberation in ultrasound images | |
| WO2018097989A1 (en) | Deep tissue super-resolution ultrasound imaging method and system | |
| CN107320131B (en) | Fundamental harmonic separation method and device | |
| KR101627821B1 (en) | Method for synthetic focusing ultrasound field based on virtual source and ultrasonic apparatus using the method | |
| KR20210022056A (en) | Synthetic and non-rigid image matching for ultrasonic speckle reduction | |
| CN110536647A (en) | For handling system, method and computer-readable medium with composite ultraphonic image in the presence of motion | |
| JP6998477B2 (en) | Methods and systems for color Doppler ultrasound imaging | |
| US11151697B2 (en) | Ultrasonic diagnosis device and program | |
| CN103654868B (en) | The formation method of ultrasonic diagnostic equipment and system | |
| CN111012379B (en) | Method and system for performing ultrasound imaging | |
| CN115060354A (en) | Full-focusing imaging method and device for piezoelectric micro-mechanical ultrasonic transducer | |
| JP2015033569A (en) | Ultrasonic diagnostic device, medical image processor and medical image processing method | |
| CN115390078A (en) | Frequency domain beam synthesis method of double-pulse wave synthetic aperture of focused wave transmission | |
| JP2016198119A (en) | Ultrasonic imaging apparatus | |
| KR101551469B1 (en) | Ultrasonics wave transmission receive focusing method and system using plane wave | |
| JP6863817B2 (en) | Ultrasound imaging device | |
| JP2019025247A (en) | Ultrasonic imaging apparatus and image processing apparatus | |
| KR102175923B1 (en) | Speckle pattern reduction system for ultrasound diagnostic image |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |