KR20170076024A - Ultrasound system and method for adaptively compensating spectral downshift of signals - Google Patents

Ultrasound system and method for adaptively compensating spectral downshift of signals Download PDF

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KR20170076024A
KR20170076024A KR1020150185721A KR20150185721A KR20170076024A KR 20170076024 A KR20170076024 A KR 20170076024A KR 1020150185721 A KR1020150185721 A KR 1020150185721A KR 20150185721 A KR20150185721 A KR 20150185721A KR 20170076024 A KR20170076024 A KR 20170076024A
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phase
phase shift
denotes
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최동영
이동준
이유화
이상신
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지멘스 메디컬 솔루션즈 유에스에이, 인크.
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    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
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Abstract

An ultrasound system and method for adaptively compensating for a spectral downshift of a signal is disclosed. The ultrasound system includes an ultrasonic probe and a processor. The ultrasonic probe transmits an ultrasonic signal to the object and receives an ultrasonic echo signal from the object. The processor forms a complex baseband signal including an in-phase component signal and a quadrature component signal based on an ultrasonic echo signal, determines a phase shift and a phase dispersion based on the complex baseband signal, And filters the demodulated baseband signal by a dynamic filter to adaptively compensate for the spectral downshift of the ultrasonic echo signal.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an ultrasound system and method for adaptively compensating for a spectral downshift of a signal,

The present disclosure relates to an ultrasound system, and more particularly to an ultrasound system and method for adaptively compensating for a spectral downshift of a signal.

BACKGROUND OF THE INVENTION Ultrasonic systems are widely used in the medical field to obtain information about objects of interest within an object. The ultrasound system can provide a high-resolution image of a target object in real time using a high-frequency sound wave without the need for a surgical operation to directly cut the target object. Ultrasonic systems have non-invasive and non-destructive properties and are widely used in the medical field.

The ultrasound system transmits an ultrasound signal to a target object and receives an ultrasound signal (i.e., an ultrasound echo signal) reflected from the target object. In addition, the ultrasound system forms a receive focusing signal by performing a beam forming process on an ultrasonic echo signal, performs a quadrature demodulation on the receive focusing signal to form a complex baseband signal, And forms an ultrasound image of the object based on the band signal.

Generally, when the ultrasonic signal propagates to the object, the ultrasonic signal is attenuated by the medium of the object. This attenuation of the ultrasonic signal causes a spectral (frequency) downshift to the ultrasonic echo signal reflected from the medium of the object. The spectral downshift of the ultrasonic echo signal deteriorates the performance of the orthogonal demodulation and deteriorates the image quality of the ultrasound image.

Dynamic quadrature demodulation is used to dynamically adjust the demodulation frequency and the cutoff frequency of the filter to compensate for the spectral downshift of such an ultrasonic echo signal. However, the dynamic quadrature demodulation compensates the spectral downshift of the ultrasonic echo signal, assuming that the medium in the object is uniform and the attenuation coefficient of the ultrasonic echo signal is the same. Therefore, the dynamic quadrature demodulation equally compensates for the spectral downshift even for the ultrasonic echo signal of the medium having the damping coefficient which is not constant, thereby deteriorating the image quality of the ultrasound image.

The present disclosure provides an ultrasound system and method for forming a complex baseband signal based on an ultrasound echo signal from a subject and adaptively compensating for a spectral downshift of the ultrasound echo signal based on the complex baseband signal.

In one embodiment, the ultrasound system includes an ultrasound probe and a processor. The ultrasonic probe is configured to transmit the ultrasonic signal to the object and receive the ultrasonic echo signal from the object. The processor forms a complex baseband signal including an in-phase component signal and a quadrature component signal based on an ultrasonic echo signal, determines a phase shift and a phase dispersion based on the complex baseband signal, And to filter the complex baseband signal by a dynamic filter to adaptively compensate for the spectral downshift of the ultrasound echo signal based on the received signal.

In another embodiment, a method of adaptively compensating for a spectral downshift comprises the steps of: transmitting an ultrasound signal to a target and receiving an ultrasound echo signal from the target; Comprising: forming a complex baseband signal comprising a phase component signal; determining phase shift and phase variance based on a complex baseband signal; and performing spectral down-conversion of the ultrasound echo signal based on phase shift and phase variance. And filtering the complex baseband signal by a dynamic filter to adaptively compensate for the shift.

According to the present disclosure, the phase shift and phase dispersion can be determined (predicted) based on the ultrasonic echo signal of the object, and the spectral downshift of the ultrasonic echo signal can be adaptively compensated based on the determined phase shift and phase dispersion . Therefore, the image quality of the ultrasound image can be prevented from varying according to the attenuation coefficient of the medium in the target body.

1 is a block diagram schematically showing a configuration of an ultrasound system according to an embodiment of the present disclosure;
2 is a block diagram schematically illustrating a configuration of a processor according to an embodiment of the present disclosure;
3 is a block diagram schematically showing a configuration of a signal processing unit according to the first embodiment of the present disclosure;
4 is a block diagram schematically showing a configuration of a complex baseband signal forming unit according to a first embodiment of the present disclosure;
5 illustrates an example of phase shift, phase distribution, smoothed phase shift, and smoothed phase shift according to the first embodiment of the present disclosure;
6 is a block diagram schematically showing a configuration of a signal processing unit according to a second embodiment of the present disclosure;
7 is a block diagram schematically showing a configuration of an upmixing processor according to a second embodiment of the present disclosure;

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The term "part " used in this embodiment means software or hardware components such as software, field-programmable gate array (FPGA), application specific integrated circuit (ASIC) However, "part" is not limited to hardware and software. "Part" may be configured to reside on an addressable storage medium, and may be configured to play back one or more processors. Thus, by way of example, and not limitation, "part, " as used herein, is intended to be broadly interpreted as referring to components such as software components, object-oriented software components, class components and task components, Firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided within the component and the "part " can be combined into a smaller number of components and" part " or further separated into additional components and "part ".

1 is a block diagram schematically showing a configuration of an ultrasound system 100 according to an embodiment of the present disclosure. The ultrasound system 100 includes a control panel 110, an ultrasound probe 120, a processor 130, a storage unit 140, and a display unit 150. In one embodiment, the processor 130 controls the control panel 110, the ultrasonic probe 120, the storage unit 140, and the display unit 150.

The control panel 110 receives the input information from the user and transmits the received input information to the processor 130. The control panel 110 may include an input device (not shown) that enables an interface between the user and the ultrasound system 100 and allows the user to manipulate the ultrasound system 100. The input device may include an input unit, for example a trackball, a keyboard, a button, etc., suitable for performing operations such as selection of a diagnostic mode, control of a diagnostic operation, input of appropriate commands necessary for diagnosis, signal operation, output control and the like.

The ultrasonic probe 120 includes an ultrasonic transducer (not shown) configured to mutually convert an electric signal and an ultrasonic signal. The ultrasonic probe 120 transmits an ultrasonic signal to a target object (not shown). The object includes an object of interest (e.g., liver, heart, etc.). The ultrasonic probe 120 receives an ultrasonic signal (that is, an ultrasonic echo signal) reflected from the object and converts the ultrasonic echo signal into an electrical signal (hereinafter referred to as a "reception signal").

In response to the input information received through the control panel 110, the processor 130 controls the ultrasonic probe 120 to transmit the ultrasonic signal to the object and receive the ultrasonic echo signal reflected from the object. In addition, the processor 130 forms ultrasonic data based on a received signal provided from the ultrasonic probe 120. [ In addition, the processor 130 forms an ultrasound image (e.g., a brightness mode image or the like) of the object based on the ultrasound data.

The storage unit 140 sequentially stores the reception signals formed by the ultrasonic probe 120 on a frame-by-frame basis. In addition, the storage unit 140 sequentially stores the ultrasound data formed by the processor 130. In addition, the storage unit 140 stores one or more ultrasound images formed by the processor 130. In addition, the storage unit 140 may store instructions for operating the ultrasound system 100.

The display unit 150 displays one or more ultrasound images formed by the processor 130. In addition, the display unit 150 may display appropriate information regarding the ultrasound image or the ultrasound system 100.

2 is a block diagram schematically illustrating the configuration of a processor 130 according to an embodiment of the present disclosure. The processor 130 includes a transmitter 210. The transmitting unit 210 forms an electrical signal (hereinafter referred to as " transmitting signal ") for obtaining an ultrasound image of a target object. For example, the transmission signal has a predetermined frequency. The transmission signal is provided to the ultrasonic probe 120. The ultrasonic probe 120 converts a transmission signal into an ultrasonic signal, and transmits the ultrasonic signal to the object. Further, the ultrasonic probe 120 receives the ultrasonic echo signal reflected from the object and forms a reception signal.

The processor 130 further includes a transmission / reception switch 220 and a reception unit 230. The transmission / reception switch 220 serves as a duplexer for switching between the transmission unit 210 and the reception unit 230. For example, when the ultrasonic probe 120 alternately performs transmission and reception, the transmission / reception switch 220 appropriately transmits the transmission unit 210 or the reception unit 230 to the ultrasonic probe 120 (i.e., the ultrasonic transducer) Switching or electrical connection.

The receiving unit 230 amplifies the reception signal provided from the ultrasonic probe 120 through the transmission / reception switch 230, and converts the amplified reception signal into a digital signal. The receiver 230 includes a time gain compensation (TGC) unit (not shown) for compensating for the attenuation that occurs when the ultrasonic signal passes through the object, an analog-to-digital conversion (analog to digital conversion) unit (not shown), and the like.

The processor 130 further includes a signal forming unit 240. The signal forming unit 240 performs a beamforming process on the digital signal provided from the receiving unit 230 to form a receive focusing signal. The receive focus signal may be an RF (radio frequency) signal, but is not limited thereto.

The processor 130 further includes a signal processor 250. The signal processing unit 250 forms complex baseband signals based on a receive focusing signal provided from the signal forming unit 240. Further, the signal processing unit 250 determines the phase shift and phase dispersion based on the complex baseband signal, and adapts the spectral downshift of the reception focusing signal (i.e., the ultrasonic echo signal) based on the determined phase shift and phase dispersion To form a dynamic filter for compensation. In addition, the signal processing unit 250 filters the complex baseband signal by the formed dynamic filter.

The processor 130 further includes an image forming unit 260. The image forming unit 260 forms an ultrasound image of a target object based on the complex baseband signal filtered by the signal processing unit 250.

3 is a block diagram schematically showing the configuration of the signal processing unit 250 according to the first embodiment of the present disclosure. The signal processing unit 250 includes a complex baseband signal forming unit 310. The complex baseband signal forming unit 310 forms a complex baseband signal based on a receive focusing signal provided from the signal forming unit 240. For example, the complex baseband signal includes an in-phase component signal (I signal) and a quadrature phase component signal (Q signal).

4 is a block diagram schematically showing the configuration of the complex baseband signal forming unit 310 according to the first embodiment of the present disclosure. The complex baseband signal forming unit 310 includes an orthogonal demodulator 410.

The quadrature demodulator 410 performs quadrature demodulation on the reception convergence signal provided from the signal generator 240 to form an in-phase component signal and a quadrature component signal. In one embodiment, the quadrature demodulator 410 includes a cosine function multiplier 411 and a sine function multiplier 412. The cosine function multiplier 411 multiplies the reception focusing signal by a cosine function (cos 2? F T n) to form an in-phase component signal. For example, the frequency f T of the cosine function (cos 2 pi f T n) may be the frequency of the transmission signal formed by the transmission unit 210. The sine function multiplier 412 multiplies the receive focusing signal by a sinusoidal function sin < 2 > f T < n > to form a quadrature component signal. For example, the frequency f T of the sinusoidal function sin 2 pi f T n may be a frequency of a transmission signal formed by the transmission unit 210.

The complex baseband signal forming unit 310 further includes a low pass filtering unit 420. The low-pass filtering unit 420 is connected to the quadrature demodulation unit 410 and filters the same-phase component signal and the quadrature-phase component signal provided from the quadrature demodulation unit 410. In one embodiment, the low pass filtering unit 420 includes a first low pass filter 421 and a second low pass filter 422. The first low pass filter 421 is connected to a cosine function multiplier 411 to filter the in-phase component signals provided from the cosine function multiplier 411. For example, the cut-off frequency f c of the first low-pass filter 421 may be the frequency f T of the transmit signal formed by the transmitter 210. The second low-pass filter 422 is connected to a sine function multiplier 412 to filter the orthogonally transformed signal provided from the sine function multiplier 412. For example, the cut-off frequency f c of the second low-pass filter 422 may be the frequency f T of the transmit signal formed by the transmitter 210.

The complex baseband signal forming unit 310 further includes a decimation unit 430. The decimation unit 430 is connected to the low-pass filtering unit 420 and decimates the same-phase component signal and the quadrature-phase component signal filtered by the low-pass filtering unit 420 based on the predetermined sampling frequency. ) Processing. In one embodiment, the decimation unit 430 includes a first decimation unit 431 and a second decimation unit 432. The first decimation unit 431 is connected to the first low-pass filter 421 and performs decimation on the same-phase component signal filtered by the first low-pass filter 421. The second decimation unit 432 is connected to the second low-pass filter 422 and performs a decimation process on the quadrature-phase component signal filtered by the second low-pass filter 422.

Referring again to FIG. 3, the signal processing unit 250 further includes a signal transforming unit 320. The signal converting unit 320 performs Fourier transform on the complex baseband signal provided from the complex baseband signal forming unit 310. [ For example, the Fourier transform includes a short-time Fourier transform (STFT). In one embodiment, the signal transforming unit 320 divides the complex baseband signal into a plurality of regions by applying a window having a predetermined size to the complex baseband signal provided from the complex baseband signal forming unit 310 . The signal converting unit 320 performs Fourier transform on the complex baseband signal corresponding to each region to form a Fourier transform signal.

The signal processing unit 250 further includes a phase information determination unit 330. The phase information determination unit 330 determines the phase information based on the Fourier transform signal provided from the signal conversion unit 320. [ For example, the phase information includes phase shift and phase variance.

In one embodiment, the phase information determination section 330 as shown in Figure 5 (a), a plurality of regions (m × n), the phase shift based on the Fourier transform signal corresponding to each (Δφ i, j (1? i? m, 1? j? n)). For example, the phase shift can be determined by the following equation.

Figure pat00001

Denotes a real part of a signal (e.g., a Fourier transform signal), R (1) denotes a phase shift, Im {} denotes an imaginary part of a signal ) Represents one-lag autocorrelation.

5 (a), the phase information determination unit 330 determines the phase variance (? 2 i, j (1) based on the Fourier transform signals corresponding to the plurality of regions 1 ≤ m ≤ n). For example, the phase variance can be determined by the following equation.

Figure pat00002

Here, σ 2 represents the dispersion phase, R (0) denotes the zero-lag autocorrelation (zero-lag autocorrelation), R (1) is a circle represents the auto-correlation lag.

The signal processing unit 250 further includes a spatial filtering unit 340. The spatial filtering unit 340 performs a smoothing process on the phase information determined by the phase information determination unit 330 (i.e., phase shift and phase dispersion). For example, the spatial filtering unit 340 includes a spatial filter (not shown) for performing a smoothing process.

In one embodiment, the spatial filtering unit 340 performs phase shifting (? I, j (1? I? M, 1? J? N) by a spatial filter as shown in FIG. To perform a smoothing processing on the smoothed phase shift (

Figure pat00003
(1? I? M, 1? J? N)). 5 (b), the spatial filtering unit 340 performs smoothing on the phase variance (? 2 i, j (1? I ? M, 1? J ? N) To obtain a smoothed phase dispersion (
Figure pat00004
(1? I? M, 1? J? N).

The signal processing unit 250 further includes a dynamic filtering unit 350. The dynamic filtering unit 350 filters the Fourier transform signal provided from the signal transforming unit 320 based on the phase information determined by the spatial filtering unit 340 (i.e., smoothed phase shift and phase variance). For example, the dynamic filtering unit 350 includes a dynamic filter (i.e., a band pass filter, not shown) for adaptively compensating for the spectral downshift of the receive focusing signal (i.e., the ultrasonic echo signal).

In one embodiment, the dynamic filtering unit 350 includes a smoothed phase variance (< RTI ID = 0.0 >

Figure pat00005
(1? I? M, 1? J? N)) to determine the bandwidth of the dynamic filter (i.e., band pass filter). For example, the bandwidth of the band-pass filter may be determined according to the following equation.

Figure pat00006

Here, B represents the bandwidth of the band-pass filter,

Figure pat00007
Represents a smoothed phase dispersion.

In addition, the dynamic filtering unit 350 may use the determined bandwidth (B) and the smoothed phase shift

Figure pat00008
(1? I? M, 1? J? N)). For example, the cut-off frequency of the band-pass filter can be determined according to the following equation.

Figure pat00009

Here,? C represents the cut-off frequency of the band-pass filter, B represents the bandwidth of the band-pass filter,

Figure pat00010
Represents a smoothed phase shift,
Figure pat00011
Represents a smoothed phase dispersion.

The dynamic filtering unit 350 forms a dynamic filter (that is, a band-pass filter) based on the determined bandwidth B and the cut-off frequency c , Filter the converted signal.

The signal processing unit 250 further includes a signal inverse transform unit 360. The signal inverse transform unit 360 performs an inverse Fourier transform on the Fourier transform signal filtered by the dynamic filtering unit 350 to form a complex baseband signal in the time domain (i.e., a co-phase component signal and a quadrature component) do.

6 is a block diagram schematically showing the configuration of the signal processing unit 250 according to the second embodiment of the present disclosure. The signal processing unit 250 includes a complex baseband signal forming unit 610. Since the complex baseband signal forming unit 510 in this embodiment is the same as the complex baseband signal forming unit 310 in the first embodiment, the description of the complex baseband signal forming unit 610 is omitted.

The signal processing unit 250 further includes a phase information determination unit 620. The phase information determination unit 620 determines the phase information based on the complex baseband signal provided from the complex baseband signal forming unit 610. For example, the phase information includes phase shift and phase variance.

In one embodiment, the phase information determination unit 620 applies a window having a predetermined size to the complex baseband signal to divide the complex baseband signal into a plurality of regions (for example, mxn). 5 (a), the phase information determination unit 620 determines the phase shift (? I, j (1? I? M, 1? J ? n). For example, the phase shift can be determined according to the above-described equation (1).

5 (b), the phase information determining unit 620 determines the phase variance (? 2 i, j (1? I ? M, 1 ? J? N). For example, the phase variance can be determined according to Equation (2) described above.

The signal processing unit 250 further includes a spatial filtering unit 630. Since the spatial filtering unit 630 in this embodiment is the same as the spatial filtering unit 340 in the first embodiment, the description of the spatial filtering unit 630 is omitted.

The signal processing unit 250 further includes an upmixing unit 640. The upmixing unit 640 receives the phase shift ("

Figure pat00012
(1? I? M, 1? J? N)), the complex baseband signal provided from the complex baseband signal forming unit 610 is subjected to the upmixing process.

7 is a block diagram schematically showing the configuration of the upmixing unit 540 according to the second embodiment of the present disclosure. The upmixing unit 640 includes a first upmixing cosine function multiplier 710. The first upmixing cosine function multiplier 610 is connected to the complex baseband signal forming unit 510. The first upmixing cosine function multiplier 710 multiplies the complex baseband signal (i.e., the in-phase component signal (I signal)) provided from the complex baseband signal generator 610 by a cosine function

Figure pat00013
) To form a first upmixing signal. Here, the cosine function (
Figure pat00014
) F S represents the sampling frequency (sampling frequency) in the decimation unit (not shown) of the complex baseband signal forming section 610 in.

The upmixing unit 640 further includes a first upmixing sine function multiplier 720. [ The first upmix sine function multiplier 720 is connected to the complex baseband signal forming unit 610. The first upmix sine function multiplier 720 multiplies the complex baseband signal (i.e., the in-phase component signal (I signal)) provided from the complex baseband signal generator 610 by a sine function

Figure pat00015
) To form a second upmixing signal.

The upmixing unit 640 further includes a second upmixing cosine function multiplier 730. The second upmixing cosine function multiplier 730 is connected to the complex baseband signal forming unit 610. 2 upmixing cosine function multiplier 730 multiplies the complex baseband signal (i.e., the quadrature component signal (Q signal)) provided from the complex baseband signal forming unit 610 by a cosine function

Figure pat00016
) To form a third upmixing signal.

The upmixing unit 640 further includes a second upmixing sine function multiplier 740. The second upmix sine function multiplier 740 is connected to the complex baseband signal forming unit 610. The second upmix sine function multiplier 740 multiplies the complex baseband signal (i.e., the quadrature component signal (Q signal)) provided from the complex baseband signal generator 610 by a sine function

Figure pat00017
) To form a fourth upmixing signal.

The upmixing unit 640 further includes a first adder 750. The first adder 750 is connected to a first upmixing cosine function multiplier 710 and a second upmixing sine function multiplier 740. The first adder 750 adds the first upmixing signal provided from the first upmixing cosine function multiplier 710 and the fourth upmixing signal provided from the second upmixing sine function multiplier 740, Component signal.

The upmixing unit 640 further includes a second adder 760. The second adder 760 is connected to the first upmix sine function multiplier 720 and the second upmixing cosine function multiplier 730. The second adder 760 adds the second upmixing signal provided from the first upmixing sine function multiplier 720 and the third upmixing signal provided from the second upmixing cosine function multiplier 730 to generate a quadrature phase Component signal.

Referring again to FIG. 6, the signal processing unit 250 further includes a dynamic filtering unit 650. The dynamic filtering unit 650 receives the signal up-processed by the upmixing unit 640 based on the phase variance determined (i.e., smoothed) by the spatial filtering unit 630 I signal) and a quadrature-phase component signal (Q signal). For example, the dynamic filtering unit 650 may include a dynamic filter (for example, a linear time varying (LTV) low-pass filter for adaptively compensating for the spectral downshift of a receive focusing signal (i.e., an ultrasonic echo signal) (Not shown).

In one embodiment, the dynamic filtering unit 650 includes a first LTV low pass filter (not shown) coupled to a first adder 750 of the upmixing unit 640 and a second LTV low pass filter And a second LTV low pass filter (not shown) coupled to an adder 760.

In one embodiment, the dynamic filtering unit 650 may include a smoothed phase-

Figure pat00018
(That is, the LTV low-pass filter) based on the following equation (1? I? M, 1? J? N) For example, the bandwidth of a dynamic filter (i.e., LTV low-pass filter) can be determined by Equation 3 above.

In addition, the dynamic filtering unit 650 determines the cutoff frequency of the dynamic filter (i.e., the LTV low-pass filter) based on the determined bandwidth. For example, the cut-off frequency of the dynamic filter may be determined according to the following equation.

Figure pat00019

Here,? C, LPF represents the cut-off frequency of the LTV low-pass filter, B represents the bandwidth of the LTV low-pass filter,

Figure pat00020
Represents a smoothed phase dispersion.

The dynamic filtering unit 350 forms a dynamic filter (that is, an LTV low-pass filter) based on the determined bandwidth B and the cut-off frequency? C, LPF , (The in-phase component signal (I signal) and the quadrature component signal (Q signal).

While specific embodiments have been described, these embodiments are provided by way of illustration and should not be construed as limiting the scope of the present disclosure. The novel methods and apparatus of the present disclosure can be implemented in various other forms, and it is possible to variously omit, substitute, and alter the embodiments disclosed herein without departing from the spirit of the present disclosure. It is intended that the appended claims and their equivalents be interpreted as embracing all such forms and modifications as fall within the scope and spirit of this disclosure.

100: Ultrasonic system 110: Control panel
120: Ultrasonic probe 130: Processor
140: storage unit 150: display unit
210: transmitting unit 220: transmitting / receiving switch
230: Receiving unit 240: Signal forming unit
250: Signal processing unit 260: Image forming unit
310, and 610 complex baseband signal forming units
320:
330, and 620:
340, 630: Space filtering unit
350, 650: Dynamic filtering unit
360: signal inverse transform unit
410: orthogonal demodulator
411: cosine function multiplier 412: sine function multiplier
420: low-pass filtering unit 421: first low-pass filter
420: second low-pass filter 430: decimation unit
431: first decimation unit 432: second decimation unit
640: upmixing unit
710: first upmixing cosine function multiplier
720: first upmix sine function multiplier
730: second upmixing cosine function multiplier
740: second upmix sine function multiplier
750: first adder 760: second adder

Claims (35)

As an ultrasound system,
An ultrasonic probe configured to transmit an ultrasonic signal to a target object and receive an ultrasonic echo signal from the target object;
A complex baseband signal including an in-phase component signal and a quadrature component signal is formed based on the ultrasonic echo signal, a phase shift and a phase dispersion are determined based on the complex baseband signal, and the phase shift and the phase A processor configured to filter the complex baseband signal by a dynamic filter to adaptively compensate for the spectral downshift of the ultrasonic echo signal based on the variance;
. 2. The ultrasound system of claim 1, wherein the dynamic filter comprises a bandpass filter. 3. The apparatus of claim 2,
A signal converter configured to perform a Fourier transform on the complex baseband signal to form a Fourier transform signal;
A phase information determination unit configured to determine the phase shift and the phase dispersion based on the Fourier transform signal;
A spatial filtering unit configured to perform smoothing processing on the phase shift and the phase dispersion;
A dynamic filtering unit configured to form the band-pass filter based on the smoothed phase shift and the phase variance, and to filter the Fourier transform signal by the band-pass filter;
A signal inverse transform unit configured to perform an inverse Fourier transform on the Fourier transform signal filtered by the band pass filter,
. 4. The ultrasound system of claim 3, wherein the Fourier transform includes a short-time Fourier transform (STFT). 4. The method of claim 3,
Figure pat00021
(Equation)
Is calculated by the above equation,
(1) represents the phase shift, Im {} represents the imaginary part of the Fourier transform signal, Re {} represents the real part of the Fourier transform signal, and R (1) represents the one-lag autocorrelation Ultrasonic system that represents. The method of claim 3,
Figure pat00022
(Equation)
Is calculated by the above equation,
σ 2 denotes the phase variance, R (0) denotes zero-lag autocorrelation, and R (1) denotes raw lag autocorrelation. The apparatus of claim 3, wherein the dynamic filtering unit comprises:
Determining a bandwidth of the band-pass filter based on the smoothed phase variance,
Determine a cut-off frequency of the band-pass filter based on the bandwidth and the smoothed phase shift,
And to form the band-pass filter based on the bandwidth and the cut-off frequency. 8. The method of claim 7,
Figure pat00023
(Equation)
Is calculated by the above equation,
B represents the bandwidth,
Figure pat00024
Represents the smoothed phase dispersion. 8. The method of claim 7,
Figure pat00025
(Equation)
Is calculated by the above equation,
? c denotes the cut-off frequency, B denotes the bandwidth,
Figure pat00026
Represents the smoothed phase shift,
Figure pat00027
Represents the smoothed phase dispersion. 2. The ultrasound system of claim 1, wherein the dynamic filter comprises a linear time varying (LTV) low pass filter. 11. The apparatus of claim 10,
A phase information determination unit configured to determine the phase shift and the phase dispersion based on the complex baseband signal;
A spatial filtering unit configured to perform smoothing processing on the phase shift and the phase dispersion;
An upmixing unit configured to perform an upmixing process on the complex baseband signal based on the smoothed phase shift;
A dynamic filtering unit configured to form the low-pass filter based on the smoothed phase variance and to filter the complex baseband signal that has been upmixed by the low-pass filter;
. 12. The method of claim 11,
Figure pat00028
(Equation)
Is calculated by the above equation,
(1) represents a Lagrange autocorrelation; [Delta] [phi] denotes the phase shift; Im {} denotes an imaginary part of the complex baseband signal; Re {} denotes a real part of the complex baseband signal; 12. The method of claim 11,
Figure pat00029
(Equation)
Is calculated by the above equation,
σ 2 denotes the phase variance, R (0) denotes zero-lag autocorrelation, and R (1) denotes raw lag autocorrelation. 12. The apparatus of claim 11, wherein the up-
A first upmixing cosine function multiplier configured to multiply the co-phase component signal by a cosine function based on the smoothed phase shift to form a first upmixing signal;
A first upmix sine function multiplier configured to multiply a sinusoidal function by the in-phase sinusoidal signal based on the smoothed phase shift to form a second upmixed signal;
A second upmixing cosine function multiplier configured to multiply the quadrature component signal by a cosine function based on the smoothed phase shift to form a third upmixing signal;
A second upmix sine function multiplier configured to multiply the quadrature component signal by a sine function based on the smoothed phase shift to form a fourth upmix signal;
A first adder coupled to the first upmixing cosine function multiplier and the second upmixing sine function multiplier to add the first upmixing signal and the fourth upmixing signal;
A second upmixing sine function multiplier coupled to the first upmixing sine function multiplier and the second upmixing cosine function multiplier to add the second upmixing signal and the third upmixing signal;
. 12. The apparatus of claim 11, wherein the dynamic filtering unit comprises:
Determining a bandwidth of the low-pass filter based on the smoothed phase variance,
Determining a cut-off frequency of the low-pass filter based on the bandwidth,
And to form the low-pass filter based on the bandwidth and the cut-off frequency. 16. The method of claim 15,
(Equation)
Is calculated by the above equation,
B represents the bandwidth,
Figure pat00031
Represents the smoothed phase dispersion. 16. The method of claim 15,
Figure pat00032
(Equation)
Is calculated by the above equation,
? c, LPF denotes the cut-off frequency, B denotes the bandwidth,
Figure pat00033
Represents the smoothed phase dispersion. A method for adaptively compensating for a spectral downshift of a signal,
Transmitting an ultrasonic signal to a target object and receiving an ultrasonic echo signal from the target object,
Forming a complex baseband signal including an in-phase component signal and a quadrature component signal based on the ultrasonic echo signal;
Determining a phase shift and a phase dispersion based on the complex baseband signal;
Filtering the complex baseband signal by a dynamic filter to adaptively compensate for a spectral downshift of the ultrasonic echo signal based on the phase shift and the phase variance
≪ / RTI > 19. The method of claim 18, wherein the dynamic filter comprises a bandpass filter. 20. The method of claim 19, wherein determining the phase shift and the phase dispersion comprises:
Performing a Fourier transform on the complex baseband signal to form a Fourier transform signal,
Determining the phase shift and the phase dispersion based on the Fourier transform signal
≪ / RTI > 21. The method of claim 20, wherein the Fourier transform comprises a short-time Fourier transform (STFT). 21. The method of claim 20,
Figure pat00034
(Equation)
Is calculated by the above equation,
(1) represents the phase shift, Im {} represents the imaginary part of the Fourier transform signal, Re {} represents the real part of the Fourier transform signal, and R (1) represents the one-lag autocorrelation How to represent. 21. The method of claim 20,
Figure pat00035
(Equation)
Is calculated by the above equation,
σ 2 denotes the phase variance, R (0) denotes zero-lag autocorrelation, and R (1) denotes circular lag autocorrelation. 20. The method of claim 19, wherein filtering the complex baseband signal comprises:
Performing a smoothing process on the phase shift and the phase shift;
Forming the band-pass filter based on the smoothed phase shift and the phase variance;
Filtering the Fourier transform signal by the band pass filter;
Performing inverse Fourier transform on the Fourier transform signal filtered by the band pass filter
≪ / RTI > 25. The method of claim 24, wherein forming the band-
Determining a bandwidth of the band pass filter based on the smoothed phase variance,
Determining a cutoff frequency of the bandpass filter based on the bandwidth and the smoothed phase shift;
Forming the band-pass filter based on the bandwidth and the cut-off frequency
≪ / RTI > 26. The method of claim 25,
Figure pat00036
(Equation)
Is calculated by the above equation,
B represents the bandwidth,
Figure pat00037
Wherein the smoothed phase variance represents the smoothed phase variance. 26. The method of claim 25,
Figure pat00038
(Equation)
Is calculated by the above equation,
? c denotes the cut-off frequency, B denotes the bandwidth,
Figure pat00039
Represents the smoothed phase shift,
Figure pat00040
Wherein the smoothed phase variance represents the smoothed phase variance. 19. The method of claim 18, wherein the dynamic filter comprises a linear time varying (LTV) low pass filter. 29. The method of claim 28,
Figure pat00041
(Equation)
Is calculated by the above equation,
(1) represents a Lagrange autocorrelation; [Delta] [phi] denotes the phase shift; Im {} denotes an imaginary part of the complex baseband signal; Re {} denotes a real part of the complex baseband signal; 29. The method of claim 28,
Figure pat00042
(Equation)
Is calculated by the above equation,
σ 2 denotes the phase variance, R (0) denotes zero-lag autocorrelation, and R (1) denotes circular lag autocorrelation. 29. The method of claim 28, wherein filtering the complex baseband signal comprises:
Performing a smoothing process on the phase shift and the phase shift;
Performing an upmixing process on the complex baseband signal based on the smoothed phase shift;
Forming the low-pass filter based on the smoothed phase variance,
Filtering the complex baseband signal that has been upmixed by the low-pass filter
≪ / RTI > 32. The method of claim 31, wherein performing the upmixing process on the complex baseband signal comprises:
Multiplying the co-phase component signal by a cosine function based on the smoothed phase shift to form a first upmixed signal,
Multiplying the sinusoidal signal by the sinusoidal signal based on the smoothed phase shift to form a second upmixed signal;
Multiplying the quadrature component signal by a cosine function based on the smoothed phase shift to form a third upmixed signal,
Multiplying the quadrature component signal by a sine function based on the smoothed phase shift to form a fourth upmixed signal;
Mixing the first upmixed signal and the fourth upmixed signal,
Mixing the second upmixing signal and the third upmixing signal
≪ / RTI > 32. The method of claim 31, wherein forming the low-
Determining a bandwidth of the low-pass filter based on the smoothed phase variance,
Determining a cut-off frequency of the low-pass filter based on the bandwidth,
Forming the low-pass filter based on the bandwidth and the cut-off frequency
≪ / RTI > 34. The method of claim 33,
Figure pat00043
(Equation)
Is calculated by the above equation,
B represents the bandwidth,
Figure pat00044
Wherein the smoothed phase variance represents the smoothed phase variance. 34. The method of claim 33,
Figure pat00045
(Equation)
Is calculated by the above equation,
? c, LPF denotes the cut-off frequency, B denotes the bandwidth,
Figure pat00046
Wherein the smoothed phase variance represents the smoothed phase variance.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6110116A (en) * 1994-08-05 2000-08-29 Acuson Corporation Method and apparatus for receive beamformer system
US6248071B1 (en) * 2000-01-28 2001-06-19 U-Systems, Inc. Demodulating wide-band ultrasound signals
JP4646808B2 (en) * 2003-12-02 2011-03-09 株式会社日立メディコ Ultrasonic diagnostic equipment
US20150045666A1 (en) * 2013-08-09 2015-02-12 Sonowise, Inc. Systems and Methods for Processing Ultrasound Color Flow Mapping
JP5801956B2 (en) * 2012-05-21 2015-10-28 古野電気株式会社 Propagation velocity measuring device, propagation velocity measuring program, and propagation velocity measuring method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6110116A (en) * 1994-08-05 2000-08-29 Acuson Corporation Method and apparatus for receive beamformer system
US6248071B1 (en) * 2000-01-28 2001-06-19 U-Systems, Inc. Demodulating wide-band ultrasound signals
JP4646808B2 (en) * 2003-12-02 2011-03-09 株式会社日立メディコ Ultrasonic diagnostic equipment
JP5801956B2 (en) * 2012-05-21 2015-10-28 古野電気株式会社 Propagation velocity measuring device, propagation velocity measuring program, and propagation velocity measuring method
US20150045666A1 (en) * 2013-08-09 2015-02-12 Sonowise, Inc. Systems and Methods for Processing Ultrasound Color Flow Mapping

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