A method for near-field effect elimination in ultrasound imaging

Abstract

This application provides a method for eliminating near-field interference in ultrasound imaging. The method includes acquiring a target echo signal with near-field interference and a static standard near-field echo signal generated when there is no imaging target. The target echo signal and the static standard near-field echo signal are then sequentially subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering to obtain the target echo signal after near-field interference removal. This application requires no changes to the transmitting and receiving circuits or the transmission frequency of the ultrasound transducer. It can effectively reduce or eliminate near-field interference in B-mode ultrasound imaging, significantly improving the imaging quality of B-mode ultrasound. It is applicable to any type and size of ultrasound transducer and to B-mode ultrasound imaging in any scenario, demonstrating broad applicability.

Description

Technical Field

[0001] This application relates to the field of ultrasound imaging technology, specifically to a method for eliminating near-field effects in ultrasound imaging. Background Technology

[0002] The near field refers to the region near the wave source, which is a region of sound pressure maxima and minima caused by wave interference; it is also known as the Fresnel zone. Near-field interference in the Fresnel zone of the sound field is mainly caused by the edge effect of the transducer. The presence of near-field influence results in higher amplitude ultrasound echo signals in the near-field region closer to the ultrasound transducer during B-mode ultrasound imaging, which appears as bright areas on the B-mode ultrasound image.

[0003] In B-mode ultrasound imaging, if the target is also within the near-field region, the echo signal intensity generated by the target may be negligible compared to the near-field signal intensity. Furthermore, the near-field signal superimposed on the useful image information creates background interference. A common method to eliminate near-field interference is to design digital filters to filter the acquired ultrasound echo signal. The filter design primarily removes frequency components other than the transmission center frequency from the echo signal. However, digital filters are not very effective at eliminating near-field interference because the main frequency components of the near-field interference signal are similar to those of the imaging echo signal, thus failing to effectively filter out near-field interference. Another method to eliminate near-field interference in ultrasound imaging is to use multi-frequency pulse transmission. This method requires alternating and cyclical transmission at multiple frequencies, and continuous adjustment of the transmission interval between each frequency to achieve a significant near-field interference reduction effect. This undoubtedly greatly increases the complexity of the transmitter circuitry.

[0004] Therefore, there is an urgent need for an efficient and effective method to eliminate near-field effects during B-mode ultrasound imaging. Summary of the Invention

[0005] This application provides a method for eliminating near-field interference in ultrasound imaging. It can effectively reduce or eliminate near-field interference in B-mode ultrasound imaging without changing the transmission frequency of the transmitting and receiving circuit or the ultrasound transducer. The technical solution is as follows.

[0006] On the one hand, a method for eliminating near-field effects in ultrasound imaging is provided, the method comprising:

[0007] Acquire the target echo signal; the target echo signal is the echo signal with near-field influence received by the ultrasonic transducer when an imaging target is present;

[0008] Acquire static standard near-field echo signal; the static standard near-field echo signal is the echo signal received by the ultrasonic transducer when there is no imaging target under static standard conditions;

[0009] The target echo signal and the static standard near-field echo signal are sequentially subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering to obtain the echo signal of the target echo signal after filtering out near-field influences.

[0010] In another aspect, a near-field effect cancellation device for ultrasound imaging is provided, the device comprising:

[0011] The target echo signal acquisition module is used to acquire the target echo signal; the target echo signal is the echo signal with near-field influence received by the ultrasonic transducer when an imaging target is present.

[0012] A static standard near-field echo signal acquisition module is used to acquire static standard near-field echo signals; the static standard near-field echo signal is the echo signal received by the ultrasonic transducer when there is no imaging target under static standard conditions;

[0013] The near-field influence filtering module is used to sequentially perform amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering on the target echo signal and the static standard near-field echo signal to obtain the echo signal of the target echo signal after near-field influence filtering.

[0014] In one possible implementation, the near-field influence filtering module is further configured to:

[0015] The target echo signal and the static standard near-field echo signal are subjected to amplitude normalization processing, and the amplitude normalization processing result is obtained.

[0016] The target echo signal after amplitude normalization and the static standard near-field echo signal after amplitude normalization are subjected to cross-correlation alignment calibration processing, and the cross-correlation alignment calibration processing results are obtained.

[0017] Based on the amplitude normalization processing result and the cross-correlation alignment calibration processing result, the target echo signal is subjected to near-field signal filtering processing to obtain the echo signal after filtering out near-field influences.

[0018] In one possible implementation, the device is further configured to:

[0019] The target echo signal is subjected to bandpass filter noise reduction processing after filtering out near-field effects to obtain the noise-reduced echo signal after filtering out near-field effects.

[0020] In one possible implementation, the near-field influence filtering module is further configured to:

[0021] The maximum amplitude value in the target echo signal and the maximum amplitude value in the static standard near-field echo signal are both normalized to one.

[0022] The amplitude values ​​of the target echo signal (excluding the maximum amplitude) and the amplitude values ​​of the static standard near-field echo signal (excluding the maximum amplitude) are normalized to values ​​less than one according to the target ratio to obtain the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence.

[0023] In one possible implementation, the near-field influence filtering module is further configured to:

[0024] Construct the cross-correlation function between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence;

[0025] Based on the cross-correlation function, obtain the displacement when the correlation between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence is maximized;

[0026] Based on the displacement, the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence are aligned to obtain cross-correlation alignment calibration results.

[0027] In one possible implementation, the near-field influence filtering module is further configured to:

[0028] Based on the subtraction result between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence after cross-correlation alignment calibration, the echo signal after filtering out near-field influences of the target echo signal is obtained.

[0029] In one possible implementation, the static standard near-field echo signal acquisition module is further configured to:

[0030] Acquire multiple sets of static echo signals generated when there is no imaging target;

[0031] The multiple sets of echo signals are subjected to amplitude normalization and cross-correlation alignment calibration to obtain multiple sets of normalized and aligned static echo signals.

[0032] The average of the multiple sets of normalized and aligned static echo signals is taken to obtain the static standard near-field echo signal.

[0033] In another aspect, a near-field effect cancellation system for ultrasound imaging is provided. The system includes: an imaging target, a central control system, a motor controller, a motor, an ultrasonic transducer, and an ultrasonic transmission and reception system. The central control system is connected to both the motor controller and the ultrasonic transmission and reception system. The motor controller is connected to the motor. The ultrasonic transmission and reception system is connected to the ultrasonic transducer. The motor is connected to the ultrasonic transducer.

[0034] The motor is used to drive the ultrasonic transducer to rotate;

[0035] The motor controller is used to control the motor to run at a target rotational speed;

[0036] The imaging target is used to reflect the ultrasonic pulse signal to form an ultrasonic echo signal;

[0037] The ultrasonic transducer is used to convert the electrical pulse signal generated by the ultrasonic transmitting and receiving system into an ultrasonic pulse signal for transmission and to convert the received ultrasonic echo signal into an electrical echo signal.

[0038] The ultrasonic transmitting and receiving system is used to transmit the electrical pulse signal and acquire the electrical echo signal;

[0039] The central control system is used to control the ultrasonic transmitting and receiving system to send electrical pulse signals to the ultrasonic transducer, control the ultrasonic transmitting and receiving system to collect the electrical echo signals generated by the ultrasonic transducer, and execute a near-field effect cancellation method in ultrasonic imaging as described above.

[0040] In another aspect, a computer device is provided, the computer device including a processor and a memory, the memory storing at least one instruction, the at least one instruction being loaded and executed by the processor to implement the above-described method for eliminating near-field effects in ultrasound imaging.

[0041] In another aspect, a computer-readable storage medium is provided, wherein at least one instruction is stored therein, the at least one instruction being loaded and executed by a processor to implement the above-described method for eliminating near-field effects in ultrasound imaging.

[0042] In another aspect, a computer product or computer is provided, the computer product or computer including computer instructions stored in a computer-readable storage medium. A processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the aforementioned near-field effect cancellation method in ultrasound imaging.

[0043] The technical solution provided in this application may include the following beneficial effects:

[0044] This method acquires the target echo signal with near-field interference and the static standard near-field echo signal generated when there is no imaging target. The target echo signal and the static standard near-field echo signal are then subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering, respectively, to obtain the target echo signal after near-field interference is removed. This application requires no changes to the transmitting and receiving circuits or the transmission frequency of the ultrasonic transducer, effectively reducing or eliminating near-field interference in B-mode ultrasound imaging, significantly improving the imaging quality of B-mode ultrasound, and is applicable to any type and size of ultrasonic transducer, and suitable for B-mode ultrasound imaging in any scenario, demonstrating broad applicability.

[0045] Furthermore, the method proposed in this application only involves signal processing, without adding additional hardware circuits or other components, without changing the transmission circuit, and without altering the original ultrasound B-mode imaging hardware system, thus saving costs and reducing complexity. It is applicable to ultrasound signals of any frequency and suitable for B-mode ultrasound imaging in any scenario. The implementation steps involved include normalization, cross-correlation calculation, and averaging, with low algorithm complexity, fast processing speed, and significant effects, exhibiting the characteristics of simplicity and efficiency. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram illustrating the structure of a near-field effect cancellation system in ultrasound imaging according to an exemplary embodiment.

[0048] Figure 2 This is a flowchart illustrating a method for eliminating near-field effects in ultrasound imaging according to an exemplary embodiment.

[0049] Figure 3 This is a flowchart illustrating a method for eliminating near-field effects in ultrasound imaging according to an exemplary embodiment.

[0050] Figure 4 This is a flowchart illustrating a method for eliminating near-field effects in ultrasound imaging according to an exemplary embodiment.

[0051] Figure 5This is a schematic diagram illustrating the extraction process of a static standard near-field echo signal according to an exemplary embodiment.

[0052] Figure 6 This is a structural block diagram illustrating a near-field effect cancellation device in ultrasound imaging according to an exemplary embodiment.

[0053] Figure 7 A structural block diagram of a computer device illustrated in an exemplary embodiment of this application is shown. Detailed Implementation

[0054] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0055] It should be understood that the term "instruction" mentioned in the embodiments of this application can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0056] In the description of the embodiments of this application, the term "correspondence" may indicate that there is a direct or indirect correspondence between two things, or that there is an association between two things, or that there is a relationship of instruction and being instructed, configuration and being configured, etc.

[0057] In the embodiments of this application, "predefined" can be achieved by pre-storing corresponding codes, tables or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices). This application does not limit the specific implementation method.

[0058] Figure 1 This is a schematic diagram illustrating the structure of a near-field effect cancellation system in ultrasound imaging according to an exemplary embodiment. Figure 1 As shown, the system includes: an imaging target, a central control system, a motor controller, a motor, an ultrasonic transducer, and an ultrasonic transmission and reception system (i.e., Figure 1 The central control system is connected to the motor controller and the ultrasonic transmitting and receiving system respectively; the motor controller is connected to the motor; the ultrasonic transmitting and receiving system is connected to the ultrasonic transducer; and the motor is connected to the ultrasonic transducer.

[0059] The motor is used to drive the ultrasonic transducer to rotate;

[0060] The motor controller is used to control the motor to run at a target rotational speed;

[0061] This imaging target is used to reflect ultrasonic pulse signals to form ultrasonic echo signals;

[0062] The ultrasonic transducer is used to convert the electrical pulse signal generated by the ultrasonic transmitting and receiving system into an ultrasonic pulse signal for transmission and to convert the received ultrasonic echo signal into an electrical echo signal.

[0063] The ultrasonic transmitting and receiving system is used to transmit the electrical pulse signal and acquire the electrical echo signal;

[0064] The central control system is used to control the ultrasonic transmitting and receiving system to send electrical pulse signals to the ultrasonic transducer, control the ultrasonic transmitting and receiving system to collect the electrical echo signals generated by the ultrasonic transducer, and perform actions such as... Figure 2 This paper illustrates a method for eliminating near-field effects in ultrasound imaging.

[0065] Optionally, the motor controller (Zolix, SC300-2B, Beijing, China) rotates the ultrasonic transducer at 1800 revolutions per minute via a rotary motor (i.e., the motor described above). The transmission of electrical pulse signals and the reception of electrical echo signals are performed using the Vantage 64LE system (Verasonics Inc., Redmond, WA, USA), i.e., the ultrasonic transmission and reception system described above, which can record 720 scan lines per revolution. The central control system is used to control the transmission and reception of electrical signals.

[0066] Optionally, the motor controller sends a trigger signal (Triger signal) to the rotary motor to control the rotation of the ultrasonic transducer.

[0067] Optionally, the center frequency of the ultrasonic transducer is 2.5 MHz.

[0068] Optionally, the imaging target can be a piece of cortical bone, placed 5 mm away from the ultrasound transducer and set on a displacement platform.

[0069] Figure 2 This is a flowchart illustrating a method for near-field effect cancellation in ultrasound imaging according to an exemplary embodiment. The method is executed by a computer device, which may be, for example... Figure 1 The central control system is shown in the image. Figure 2 As shown, the near-field effect elimination method may include the following steps:

[0070] Step S201: Acquire the target echo signal; the target echo signal is the echo signal with near-field influence received by the ultrasonic transducer when the imaging target is present.

[0071] In one possible implementation, when it is necessary to eliminate near-field effects in the target echo signal, the echo signal returned after the ultrasonic pulse signal emitted by the ultrasonic transducer is first obtained by the ultrasonic transmitting and receiving system after being reflected by the imaging target. The target echo signal contains near-field effects.

[0072] Furthermore, the target echo signal is... Figure 1 The signal obtained is obtained by the central control system controlling the ultrasonic transmitting and receiving system to collect the electrical echo signal generated by the ultrasonic transducer.

[0073] Step S202: Obtain the static standard near-field echo signal; the static standard near-field echo signal is the echo signal received by the ultrasonic transducer when there is no imaging target under static standard conditions.

[0074] In one possible implementation, after acquiring the target echo signal, it is necessary to acquire the echo signal generated by the ultrasonic pulse signal emitted by the ultrasonic transducer under standard static conditions when there is no imaging target. "Static" refers to the ultrasonic transducer transmitting and receiving signals in deionized water at a temperature of 20 degrees Celsius when there is no imaging target. This static standard near-field echo signal can be used as a reference signal for near-field signal cancellation during near-field influence cancellation operations.

[0075] Step S203: Perform amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering on the target echo signal and the static standard near-field echo signal in sequence to obtain the echo signal of the target echo signal after filtering out near-field influences.

[0076] In one possible implementation, this application uses the near-field echo signal of an ultrasonic transducer in a static standard liquid without an imaging target as a reference near-field interference signal. When imaging the target, the target echo signal and the static standard near-field echo signal are sequentially subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering. During operation, subtracting the reference near-field interference signal from the target echo signal in the near-field region yields the effectively filtered-out near-field interference target echo signal. This method effectively reduces or eliminates near-field interference in B-mode ultrasound imaging without requiring changes to the transmitter and receiver circuits or the ultrasonic transducer's transmission frequency. It is applicable to any type and size of ultrasonic transducer and suitable for B-mode ultrasound imaging in any scenario. Furthermore, the amplitude normalization process is a dimensionless processing method that can transform the absolute values ​​of different values ​​into relative values. This amplitude normalization process can make the target echo signal and the static standard near-field echo signal have the same dimensions. The cross-correlation alignment calibration process can characterize the correlation between two signal sequences. The near-field signal filtering process can achieve the near-field signal filtering effect.

[0077] In summary, this method acquires the target echo signal with near-field interference and the static standard near-field echo signal generated when there is no imaging target. The target echo signal and the static standard near-field echo signal are then subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering processes sequentially to obtain the target echo signal after near-field interference is removed. This application requires no changes to the transmitting and receiving circuits or the transmission frequency of the ultrasonic transducer, effectively reducing or eliminating near-field interference in B-mode ultrasound imaging, significantly improving the imaging quality of B-mode ultrasound, and is applicable to any type and size of ultrasonic transducer, as well as B-mode ultrasound imaging in any scenario, demonstrating broad applicability.

[0078] Furthermore, the method proposed in this application only involves signal processing, without adding additional hardware circuits or other components, without changing the transmission circuit, and without altering the original ultrasound B-mode imaging hardware system, thus saving costs and reducing complexity. It is applicable to ultrasound signals of any frequency and suitable for B-mode ultrasound imaging in any scenario. The implementation steps involved include normalization, cross-correlation calculation, and averaging, with low algorithm complexity, fast processing speed, and significant effects, exhibiting the characteristics of simplicity and efficiency.

[0079] Figure 3 This is a flowchart illustrating a method for near-field effect cancellation in ultrasound imaging according to an exemplary embodiment. The method is executed by a computer device, which may be, for example... Figure 1 The central control system is shown in the image. Figure 3As shown, the near-field effect elimination method may include the following steps:

[0080] Step S301: Acquire the target echo signal; the target echo signal is the echo signal with near-field influence received by the ultrasonic transducer when the imaging target is present.

[0081] In one possible implementation, please refer to Figure 4 The diagram illustrates a method for eliminating near-field interference in ultrasound imaging. The near-field interference elimination includes an ultrasound echo signal acquisition unit 10, a near-field signal processing unit 20, and an imaging target signal unit 30. First, the ultrasound echo signal acquisition unit 10 acquires the target echo signal, which includes a target echo signal 16 and a static standard near-field echo signal 17. Based on the propagation characteristics of ultrasound, the ultrasound pulse signal emitted by the ultrasound transducer 11 is reflected back to the receiver, forming the target echo signal 16. The target echo signal 16 further includes a near-field echo signal 13 and a far-field echo signal 15. When the imaging target 12 is within the near-field signal region, the ultrasound echo signal containing imaging target information is superimposed on the near-field echo signal, forming an interference-laden imaging echo signal 14. In other words, the target echo signal 16 is an echo signal with near-field interference generated when an imaging target is present. Subsequently, the static standard near-field echo signal 17, the target echo signal 16, and the static standard near-field echo signal 17 are acquired and fed into the near-field signal processing unit 20 for signal processing.

[0082] Step S302: Obtain the static standard near-field echo signal; the static standard near-field echo signal is the echo signal received by the ultrasonic transducer when there is no imaging target.

[0083] In one possible implementation, multiple sets of static echo signals generated when there is no imaging target are acquired;

[0084] Amplitude normalization and cross-correlation alignment calibration were performed on the multiple sets of echo signals to obtain multiple sets of normalized and aligned static echo signals.

[0085] The average of the multiple sets of normalized and aligned static echo signals is taken to obtain the static standard near-field echo signal.

[0086] Furthermore, Figure 5 The extraction process of the static standard near-field echo signal 17 is shown. For example... Figure 5 As shown, under static conditions, multiple sets of static echo signals, such as 41s(n)1 and 42s(n)2, are acquired, and then amplitude normalization processing is performed on the multiple sets of echo signals (i.e., ...). Figure 5 Signal amplitude normalization processing 21) and cross-correlation alignment calibration processing (i.e. Figure 5The cross-correlation alignment process 22) yields multiple sets of normalized aligned static echo signals s(n)′. k For multiple sets of normalized and aligned static echo signals s(n)′ k The average value is calculated using the following formula: 25.

[0087]

[0088] Where s(n) represents the static standard near-field echo signal, and the static echo signal s(n)′ k The number of groups is k to l. This embodiment can effectively filter out interference and noise in the system and obtain a more accurate static standard near-field echo signal 17.

[0089] Step S303: Perform amplitude normalization processing on the target echo signal and the static standard near-field echo signal, and obtain the amplitude normalization processing result.

[0090] In one possible implementation, the maximum amplitude value in the target echo signal and the maximum amplitude value in the static standard near-field echo signal are both normalized to one.

[0091] The amplitude values ​​of the target echo signal (excluding the maximum amplitude) and the amplitude values ​​of the static standard near-field echo signal (excluding the maximum amplitude) are normalized to values ​​less than one according to the target ratio to obtain the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence.

[0092] Furthermore, such as Figure 4 As shown, the target echo signal 16 and the static standard near-field echo signal 17 are fed into the near-field signal processing unit 20 for signal processing. The near-field signal processing unit 20 includes: signal amplitude normalization processing 21, mutual alignment processing 22, near-field signal filtering processing 23, and bandpass filter noise reduction processing 24. The signal amplitude normalization processing 21 first performs amplitude normalization processing on the target echo signal 16 and the static standard near-field echo signal 17. Normalization is a dimensionless processing method that transforms the absolute values ​​of different values ​​into relative values. Linear normalization simplifies calculations and is an effective way to reduce the magnitude. Linear normalization of the original data can map the values ​​to the range of zero to one. This process can be expressed by the following formula:

[0093]

[0094] Where, x(n) nor Let x(n) represent the normalized discrete sequence, x(n) be the original discrete data sequence, and max and min represent finding the maximum and minimum values ​​of the sequence.

[0095] The maximum amplitude of the target echo signal 16 and the static standard near-field echo signal 17 is normalized to one, and the other amplitudes are proportionally normalized to values ​​less than one, finally yielding the normalized target echo signal r(n). nor And the normalized static standard near-field echo signal s(n) nor Normalization can give the target echo signal 16 and the static standard near-field echo signal 17 the same dimensions.

[0096] Step S304: Perform cross-correlation alignment calibration on the target echo signal after amplitude normalization and the static standard near-field echo signal after amplitude normalization, and obtain the cross-correlation alignment calibration result.

[0097] In one possible implementation, a cross-correlation function is constructed between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence;

[0098] Based on the cross-correlation function, obtain the displacement when the correlation between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence is maximized;

[0099] Based on the displacement, the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence are aligned to obtain the cross-correlation alignment calibration result.

[0100] Furthermore, after performing signal amplitude normalization processing 21, the target echo signal 16 and the static standard near-field echo signal 17 are subjected to cross-correlation alignment processing 22. The result can characterize the correlation between the two signal sequences. In the field of digital signal processing, cross-correlation can represent the similarity between two signals. For two discrete real signal sequences f(n) and g(n), the cross-correlation function can be defined as...

[0101]

[0102] in, The cross-correlation function of two signals over time, also known as the "sliding dot product," is used to calculate the cross-correlation function. turn up Taking the maximum value of m, this value represents the time difference when the correlation between signal sequences f(n) and g(n) is at its maximum. Finally, alignment with sequence f(n) can be achieved by shifting the sequence signal g(n) by m. Based on this cross-correlation function principle, the normalized target echo signal 16r(n) is then analyzed. nor The normalized static standard near-field echo signal 17s(n) nor Perform cross-correlation calculations:

[0103]

[0104] in, This represents the correlation between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence. Finding the point with the largest value in the calculated result sequence indicates the maximum correlation between the two sequences. The displacement m. Record this position m, and then normalize the static standard near-field echo signal sequence s(n). nor Moving to this position yields s(n)′ nor This leads to the normalized static standard near-field echo signal sequence s(n). nor The normalized target echo signal sequence r(n) nor Alignment.

[0105] Step S305: Based on the amplitude normalization processing result and the cross-correlation alignment calibration processing result, perform near-field signal filtering processing on the target echo signal to obtain the echo signal after filtering out near-field influences.

[0106] In one possible implementation, the echo signal after filtering out near-field effects of the target echo signal is obtained by subtracting the normalized target echo signal sequence from the normalized static standard near-field echo signal sequence after cross-correlation alignment calibration.

[0107] Furthermore, after performing cross-correlation calibration and alignment processing 22 on the normalized echo signal sequence and the normalized static standard near-field echo signal sequence, near-field signal filtering processing 23 is performed. The normalized echo signal sequence is subtracted from the cross-correlation aligned normalized static standard near-field echo signal sequence:

[0108] r(n)′=r(n) nor -s(n)′ nor ;

[0109] At this point, the echo signal r(n)′ after filtering out the near-field influence of the target echo signal can be obtained, thus achieving the near-field signal filtering effect.

[0110] Step S306: Perform bandpass filter noise reduction on the echo signal of the target echo signal after filtering out near-field effects to obtain the noise-reduced echo signal after filtering out near-field effects.

[0111] Furthermore, by applying a bandpass filter to the echo signal r(n)′ after filtering out near-field effects, noise reduction can be achieved. Since a small amount of noise is introduced during the near-field signal filtering process 23, a digital bandpass filter can be designed to remove this introduced noise as well as the noise components in the ultrasonic transmitting and receiving system. The digital bandpass filter can be designed with the center frequency of the ultrasonic transducer as the center frequency, and the upper and lower cutoff frequencies, as well as the filter type and order, can be designed according to actual requirements. Figure 4 In the imaging target signal unit 30, after processing by the near-field signal processing unit 20, a noise-reduced echo signal 34 with near-field effects filtered out can be obtained. The noise-reduced echo signal 34 contains only useful imaging information of the imaging target 12, which can be used for B-mode ultrasound imaging.

[0112] In summary, this method acquires the target echo signal with near-field interference and the static standard near-field echo signal received when there is no imaging target. The target echo signal and the static standard near-field echo signal are then subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering processes sequentially to obtain the target echo signal after near-field interference removal. This application requires no changes to the transmitting and receiving circuits or the transmission frequency of the ultrasonic transducer, effectively reducing or eliminating near-field interference in B-mode ultrasound imaging, significantly improving the imaging quality of B-mode ultrasound, and is applicable to any type and size of ultrasonic transducer, as well as B-mode ultrasound imaging in any scenario, demonstrating broad applicability.

[0113] Furthermore, the method proposed in this application only involves signal processing, without adding additional hardware circuits or other components, without changing the transmission circuit, and without altering the original ultrasound B-mode imaging hardware system, thus saving costs and reducing complexity. It is applicable to ultrasound signals of any frequency and suitable for B-mode ultrasound imaging in any scenario. The implementation steps involved include normalization, cross-correlation calculation, and averaging, with low algorithm complexity, fast processing speed, and significant effects, exhibiting the characteristics of simplicity and efficiency.

[0114] Figure 6 This is a structural block diagram illustrating a near-field effect cancellation device in ultrasound imaging according to an exemplary embodiment. The device includes:

[0115] The target echo signal acquisition module 601 is used to acquire the target echo signal; the target echo signal is the echo signal with near-field influence received by the ultrasonic transducer when the imaging target is present.

[0116] The static standard near-field echo signal acquisition module 602 is used to acquire the static standard near-field echo signal; the static standard near-field echo signal is the echo signal received by the ultrasonic transducer when there is no imaging target;

[0117] The near-field influence filtering module 603 is used to perform amplitude normalization, cross-correlation alignment calibration and near-field signal filtering on the target echo signal and the static standard near-field echo signal in sequence, so as to obtain the echo signal of the target echo signal after filtering out the near-field influence.

[0118] In one possible implementation, the near-field influence filtering module 603 is also used for:

[0119] The amplitude of the target echo signal and the static standard near-field echo signal are normalized, and the amplitude normalization result is obtained.

[0120] Cross-correlation alignment calibration is performed on the target echo signal after amplitude normalization and the static standard near-field echo signal after amplitude normalization, and the cross-correlation alignment calibration results are obtained.

[0121] Based on the amplitude normalization processing result and the cross-correlation alignment calibration processing result, near-field signal filtering processing is performed on the target echo signal to obtain the echo signal after filtering out near-field influences.

[0122] In one possible implementation, the device is also used for:

[0123] The echo signal of the target after filtering out near-field effects is subjected to bandpass filter noise reduction processing to obtain the noise-reduced echo signal after filtering out near-field effects.

[0124] In one possible implementation, the near-field influence filtering module 603 is also used for:

[0125] The maximum amplitude of the target echo signal and the maximum amplitude of the static standard near-field echo signal are both normalized to one.

[0126] The amplitude values ​​of the target echo signal (excluding the maximum amplitude) and the amplitude values ​​of the static standard near-field echo signal (excluding the maximum amplitude) are normalized to values ​​less than one according to the target ratio to obtain the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence.

[0127] In one possible implementation, the near-field influence filtering module 603 is also used for:

[0128] Construct the cross-correlation function between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence;

[0129] Based on the cross-correlation function, obtain the displacement when the correlation between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence is maximized;

[0130] Based on the displacement, the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence are aligned to obtain the cross-correlation alignment calibration result.

[0131] In one possible implementation, the near-field influence filtering module 603 is also used for:

[0132] Based on the subtraction result between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence after cross-correlation alignment calibration, the echo signal of the target echo signal after filtering out near-field influences is obtained.

[0133] In one possible implementation, the static standard near-field echo signal acquisition module 603 is also used for:

[0134] Acquire multiple sets of static echo signals generated when there is no imaging target;

[0135] Amplitude normalization and cross-correlation alignment calibration were performed on the multiple sets of echo signals to obtain multiple sets of normalized and aligned static echo signals.

[0136] The average of the multiple sets of normalized and aligned static echo signals is taken to obtain the static standard near-field echo signal.

[0137] In summary, this method acquires the target echo signal with near-field interference and the static standard near-field echo signal generated when there is no imaging target. The target echo signal and the static standard near-field echo signal are then subjected to amplitude normalization, cross-correlation alignment calibration, and near-field signal filtering processes sequentially to obtain the target echo signal after near-field interference is removed. This application requires no changes to the transmitting and receiving circuits or the transmission frequency of the ultrasonic transducer, effectively reducing or eliminating near-field interference in B-mode ultrasound imaging, significantly improving the imaging quality of B-mode ultrasound, and is applicable to any type and size of ultrasonic transducer, as well as B-mode ultrasound imaging in any scenario, demonstrating broad applicability.

[0138] Furthermore, the method proposed in this application only involves signal processing, without adding additional hardware circuits or other components, without changing the transmission circuit, and without altering the original ultrasound B-mode imaging hardware system, thus saving costs and reducing complexity. It is applicable to ultrasound signals of any frequency and suitable for B-mode ultrasound imaging in any scenario. The implementation steps involved include normalization, cross-correlation calculation, and averaging, with low algorithm complexity, fast processing speed, and significant effects, exhibiting the characteristics of simplicity and efficiency.

[0139] Please see Figure 7 This is a schematic diagram of a computer device provided according to an exemplary embodiment of the present application. The computer device includes a memory and a processor. The memory is used to store a computer program. When the computer program is executed by the processor, it implements the above-described method for eliminating near-field effects in ultrasound imaging.

[0140] The processor can be a central processing unit (CPU). It can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations thereof.

[0141] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the embodiments of this application. The processor executes various functional applications and data processing by running the non-transitory software programs, instructions, and modules stored in the memory, thereby implementing the methods in the above-described embodiments.

[0142] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0143] In one exemplary embodiment, a computer-readable storage medium is also provided for storing at least one computer program, which is loaded and executed by a processor to implement all or part of the steps in the above-described method. For example, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, or optical data storage device, etc.

[0144] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0145] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for near-field effect cancellation in ultrasonic imaging, characterized in that, The method comprises: acquiring a target echo signal; the target echo signal is an echo signal with near-field influence received by an ultrasonic transducer when an imaging target exists; acquiring a static standard near-field echo signal; the static standard near-field echo signal is an echo signal received by an ultrasonic transducer when there is no imaging target under static standard conditions; sequentially performing amplitude normalization processing, cross-correlation alignment calibration processing and near-field signal filtering processing on the target echo signal and the static standard near-field echo signal to acquire an echo signal of the target echo signal after filtering out the near-field influence; the acquiring of the static standard near-field echo signal comprises: acquiring a plurality of groups of static echo signals generated when there is no imaging target; performing amplitude normalization processing and cross-correlation alignment calibration processing on the plurality of groups of static echo signals to acquire a plurality of groups of normalized and aligned static echo signals; performing average processing on the plurality of groups of normalized and aligned static echo signals to acquire the static standard near-field echo signal.

2. The method of claim 1, wherein, the sequentially performing of the amplitude normalization processing, the cross-correlation alignment calibration processing and the near-field signal filtering processing on the target echo signal and the static standard near-field echo signal to acquire the echo signal of the target echo signal after filtering out the near-field influence comprises: performing amplitude normalization processing on the target echo signal and the static standard near-field echo signal, and acquiring an amplitude normalization processing result; performing cross-correlation alignment calibration processing on the target echo signal after the amplitude normalization processing and the static standard near-field echo signal after the amplitude normalization processing, and acquiring a cross-correlation alignment calibration processing result; performing near-field signal filtering processing on the target echo signal according to the amplitude normalization processing result and the cross-correlation alignment calibration processing result to acquire the echo signal of the target echo signal after filtering out the near-field influence.

3. The method of claim 2, wherein, after the performing of the near-field signal filtering processing on the target echo signal to acquire the echo signal of the target echo signal after filtering out the near-field influence, the method further comprises: performing band-pass filter noise reduction processing on the echo signal of the target echo signal after filtering out the near-field influence to acquire a noise reduction echo signal after filtering out the near-field influence.

4. The method of claim 2, wherein, the performing of the amplitude normalization processing on the target echo signal and the static standard near-field echo signal, and the acquiring of the amplitude normalization processing result, comprises: normalizing an amplitude maximum value in the target echo signal and an amplitude maximum value in the static standard near-field echo signal into one respectively; normalizing other amplitude values in the target echo signal except the amplitude maximum value and other amplitude values in the static standard near-field echo signal except the amplitude maximum value into values less than one according to a target ratio to acquire a normalized target echo signal sequence and a normalized static standard near-field echo signal sequence.

5. The method of claim 4, wherein, the performing of the cross-correlation alignment calibration processing on the target echo signal after the amplitude normalization processing and the static standard near-field echo signal after the amplitude normalization processing, and the acquiring of the cross-correlation alignment calibration processing result, comprises: constructing a cross-correlation function between the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence; According to the cross-correlation function, a displacement amount is obtained when the correlation degree of the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence is maximum; According to the displacement amount, the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence are aligned to obtain a cross-correlation alignment calibration processing result.

6. The method of claim 5, wherein, The near-field signal filtering processing of the target echo signal according to the amplitude normalization processing result and the cross-correlation alignment calibration processing result includes: The target echo signal filtering near-field influence echo signal is obtained according to the subtraction result of the normalized target echo signal sequence and the normalized static standard near-field echo signal sequence after cross-correlation alignment calibration processing.

7. An apparatus for near-field effect elimination in ultrasonic imaging, characterized by The device includes: A target echo signal acquisition module is configured to acquire a target echo signal; the target echo signal is an echo signal with near-field influence received by an ultrasonic transducer when an imaging target exists; A static standard near-field echo signal acquisition module is configured to acquire a static standard near-field echo signal; the static standard near-field echo signal is an echo signal received by an ultrasonic transducer when an imaging target does not exist under a static standard condition; A near-field influence filtering module is configured to sequentially perform amplitude normalization processing, cross-correlation alignment calibration processing, and near-field signal filtering processing on the target echo signal and the static standard near-field echo signal to obtain a target echo signal filtering near-field influence echo signal; The static standard near-field echo signal includes: A plurality of groups of static echo signals generated when an imaging target does not exist are acquired; The plurality of groups of static echo signals are subjected to amplitude normalization processing and cross-correlation alignment calibration processing to obtain a plurality of groups of normalized and aligned static echo signals; The plurality of groups of normalized and aligned static echo signals are subjected to average processing to obtain the static standard near-field echo signal.

8. A near-field effect cancellation system in ultrasonic imaging, characterized by, The system includes an imaging target, a central control system, a motor controller, a motor, an ultrasonic transducer, and an ultrasonic transmitting and receiving system; the central control system is connected with the motor controller and the ultrasonic transmitting and receiving system respectively; the motor controller is connected with the motor; the ultrasonic transmitting and receiving system is connected with the ultrasonic transducer; the motor is connected with the ultrasonic transducer; The motor is configured to drive the ultrasonic transducer to rotate; The motor controller is configured to control the motor to operate at a target rotation speed; The imaging target is configured to reflect an ultrasonic pulse signal to form an ultrasonic echo signal; The ultrasonic transducer is configured to convert an electric pulse signal generated by the ultrasonic transmitting and receiving system into an ultrasonic pulse signal for transmission and convert the received ultrasonic echo signal into an electric echo signal; The ultrasonic transmitting and receiving system is configured to transmit the electric pulse signal and collect the electric echo signal; The central control system is configured to control the ultrasonic transmitting and receiving system to send an electric pulse signal to the ultrasonic transducer, control the ultrasonic transmitting and receiving system to collect an electric echo signal generated by the ultrasonic transducer, and perform the near-field influence elimination method in the ultrasonic imaging according to any one of claims 1 to 6.

9. A computer device, comprising: The computer device comprises a processor and a memory, and the memory stores at least one instruction which is loaded and executed by the processor to implement the near-field influence elimination method in the ultrasonic imaging according to any one of claims 1 to 6.

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