Method and system for estimating motion from overlapping multiline acquisitions of continuous ultrasound emission events

Abstract

The invention is entitled "Method and system for estimating motion from overlapping multiline acquisitions of consecutive ultrasound transmit events." A system and method for estimating motion from overlapping multiline acquisitions of consecutive transmit events is provided. The method includes receiving at a target a set of received data points for each transmit beam in a sequence of partially overlapping transmit beams transmitted from a transducer element in a plurality of directions. The set of received data points includes a plurality of received data point locations that overlap with received data point locations generated from other transmit beams in the sequence. The method includes compensating for different times of arrival for each received data point. The method includes determining a displacement of the target by comparing components of co-located received data points generated in response to different transmit beams. The method includes adding the co-located received data points into pixels of a B-mode image and presenting the B-mode image with velocity information at a display system based on the determined displacement of the target.

Description

Technical Field

[0001] Some implementations involve ultrasound imaging. More specifically, some implementations provide motion estimation from overlapping multi-line acquisitions of consecutive ultrasound emission events. Background Technology

[0002] Ultrasound imaging is a medical imaging technique used to image organs and soft tissues in the human body. Ultrasound imaging uses real-time, non-invasive high-frequency sound waves to produce two-dimensional (2D) and / or three-dimensional (3D) images.

[0003] Also known as retrospective transmit beamforming (RTB) or true confocal imaging, it is a beamforming technique that mitigates bidirectional focus reduction far from the transmit focus by using a large degree of transmit beam overlap in the imaging region. RTB processing may include aligning co-located received data by compensating for the different arrival times of the transmit wavefronts of different transmit events at the target image location. The aligned events are then summed along a specific output direction to generate a retrospective focus signal, where the aligned events acquired with wavefronts at different angles are summed using a weighting scheme.

[0004] The relevant technique for RTB is synthetic transmit beamforming (STB), in which the receive lines from adjacent transmit event pairs are combined with a set of weights without any alignment delay. If the transmit beam is in the position of the receive line, the phase of the weighted sum can be interpolated to the desired phase.

[0005] By comparing such systems with some aspects of this disclosure as set forth with reference to the accompanying drawings in the remainder of this application, the further limitations and disadvantages of conventional and traditional methods will become apparent to those skilled in the art. Summary of the Invention

[0006] A system and / or method for estimating motion from overlapping multiline acquisitions of continuous ultrasonic emission events is provided, the system and / or method being substantially as shown and / or described in conjunction with at least one figure, as set forth more fully in the claims.

[0007] These and other advantages, aspects and novel features of this disclosure, as well as details of its illustrative embodiments, will be more fully understood from the following description and accompanying drawings. Attached Figure Description

[0008] Figure 1 This is a block diagram of an exemplary ultrasound system operable to provide motion estimation from overlapping multiline acquisitions of continuous ultrasound emission events, based on various implementation schemes.

[0009] Figure 2It is an exemplary layout of a sequence of partially overlapping transmit beams and a corresponding set of receive data points at overlapping receive data point locations, according to various implementation schemes.

[0010] Figure 3 This is a flowchart illustrating exemplary steps for estimating motion from overlapping multiline acquisitions of continuous ultrasonic emission events, according to various implementation schemes. Detailed Implementation

[0011] Certain implementations can be found in methods and systems for estimating motion from overlapping multi-line acquisitions of continuous ultrasound emission events. More specifically, in retrospective transmit beamforming (RTB), multiple overlapping / co-located receive data points from a continuous transmit beam during an ultrasound scan can be recorded and combined into the output grid of a synthetic retrospectively focused transmit beam. In each direction, the RTB delay-corrected receive data point components can also provide an estimate of the tissue's local velocity by calculating the correlated phase of the aligned receive data points over the direction of the continuous transmit beam. RTB delay alignment compensates for registration discrepancies due to the position of the transmit wavefront.

[0012] Various aspects of this disclosure provide an estimation technique for correlating co-located, RTB-delay-corrected multi-line acquisition and reception data points from different transmit beams with equivalent transmit-receive geometries. Various embodiments offer the technical advantage of using co-located reception data points with RTB delay compensation from multiple consecutive partially overlapping transmit beams to calculate tissue velocity and / or flow velocity across the entire B-mode image using normal acquisition and RTB from a single transmit B-mode acquisition in each direction. Some embodiments have the technical advantage of performing estimation based on reception data points with transmit wavefront correction and a significantly larger “group size” because more co-located MLAs from a greater number of transmit events exist at a distance from the focal point. Various aspects of this disclosure provide the technical advantage of generating tissue or flow velocity estimates as a byproduct of performing conventional B-mode imaging using prior art retrospective transmit beamforming. Velocity information can be used for tissue velocity imaging (TVI) as input to assist subsequent speckle tracking, etc.

[0013] The foregoing summary of the invention and the following detailed description of certain embodiments will be better understood when read in conjunction with the accompanying drawings. For the purposes of the figures illustrating the functional blocks of various embodiments, these functional blocks do not necessarily represent a division between hardware circuits. Thus, for example, one or more functional blocks (e.g., a processor or memory) may be implemented in a single piece of hardware (e.g., a general-purpose signal processor or a block of random access memory, a hard disk, etc.) or in multiple pieces of hardware. Similarly, a program may be a standalone program, may be included as a subroutine in an operating system, may be a function in an installed software package, etc. It should be understood that the various embodiments are not limited to the arrangements and tools shown in the drawings. It should also be understood that embodiments may be combined, or other embodiments may be utilized, and structural, logical, and electrical changes may be made without departing from the scope of the various embodiments. Therefore, the following detailed description should not be considered limiting, and the scope of this disclosure is defined by the appended claims and their equivalents.

[0014] As used herein, elements or steps listed in the singular and beginning with the word "a" or "an" should be understood to not exclude multiple said elements or steps unless such exclusion is explicitly stated. Furthermore, references to "exemplary embodiments," "various embodiments," "certain embodiments," "representative embodiments," etc., are not intended to be construed as excluding the existence of additional embodiments that also incorporate the described features. Moreover, unless explicitly stated to the contrary, embodiments that "comprise," "include," or "have" one or more elements having a particular property may include additional elements that do not have that property.

[0015] Additionally, as used herein, the term "image" broadly refers to both a visual image and the data representing that image. However, many implementations generate (or are configured to generate) at least one visual image. Furthermore, as used herein, the phrase "image" is used to refer to ultrasound modes such as B-mode (2D mode), M-mode, three-dimensional (3D) mode, CF mode, BSI mode, 3DCF mode, PW Doppler, MGD, and / or submodes of B-mode and / or CF such as volumetric composite imaging (VCI), shear wave elastography (SWEI), TVI, Angio, B-flow, BMI, BMI_Angio, and in some cases also MM, CM, TVD, CW, where "image" and / or "plane" includes a single beam or multiple beams.

[0016] Furthermore, as used herein, the term processor or processing unit refers to any type of processing unit capable of performing the required computations required for various implementation schemes, such as single-core or multi-core: CPU, Accelerated Processing Unit (APU), graphics board, DSP, FPGA, ASIC, or combinations thereof.

[0017] It should be noted that the various embodiments of generating or forming images described herein may include processing for forming the image, which in some embodiments includes beamforming, while in others does not. For example, an image may be formed without beamforming, such as by multiplying a matrix of demodulated data by a coefficient matrix such that the product is an image, and wherein the process does not form any “beams.” Alternatively, image formation may be performed using a combination of channels that may originate from more than one transmission event (e.g., synthetic aperture technology).

[0018] In various implementations, ultrasound processing to form an image is performed, for example, in software, firmware, hardware, or a combination thereof, including ultrasound beamforming, such as receive beamforming. One specific implementation of an ultrasound system having a software beamformer architecture formed according to various implementations is... Figure 1 As shown in the image.

[0019] Figure 1 This is a block diagram of an exemplary ultrasound system 100 operable according to various implementations for providing motion estimation from overlapping multiline acquisitions of continuous ultrasound emission events. See also Figure 1 An ultrasound system 100 is shown. The ultrasound system 100 includes a transmitter 102, an ultrasound probe 104, a transmit beamformer 110, a receiver 118, a receive beamformer 120, an RF processor 124, an RF / IQ buffer 126, a user input device 130, a signal processor 132, an image buffer 136, a display system 134, and a file 138.

[0020] Transmitter 102 may include suitable logic, circuitry, interfaces, and / or code operable to drive ultrasound probe 104. Ultrasound probe 104 may include a two-dimensional (2D) array of piezoelectric elements, or may be a one-dimensional (1D) mechanical array, etc. Ultrasound probe 104 may include a set of transmitting transducer elements 106 and a set of receiving transducer elements 108 that generally constitute the same components. In some embodiments, ultrasound probe 104 may be used to acquire ultrasound image data covering at least a majority of anatomical structures, such as the heart, fetus, or any suitable anatomical structure.

[0021] The transmitting beamformer 110 may include suitable logic, circuitry, interfaces, and / or code operable to control a transmitter 102, which optionally drives the set of transmitting transducer elements 106 via a transmitting sub-aperture beamformer 114 to transmit ultrasonic signals to a target (e.g., a person, animal, underground cavity, physical structure, etc.). In various embodiments, the set of transmitting transducer elements 106 is operable to transmit partially overlapping sequences of transmitting beams at the target in multiple directions. The transmitted ultrasonic signals may be backscattered from the target (e.g., blood cells or tissue) to generate echoes. The echoes are received by receiving transducer elements 108.

[0022] The set of receiving transducer elements 108 in the ultrasonic probe 104 is operable to convert the received echo into an analog signal, perform sub-aperture beamforming via an optional receiving sub-aperture beamformer 116, and / or then transmit it to a receiver 118. The receiver 118 may include suitable logic, circuitry, interfaces, and / or code operable to receive the signal from the receiving sub-aperture beamformer 116. The analog signal can be transmitted to one or more of a plurality of A / D converters 122.

[0023] Multiple A / D converters 122 may include suitable logic, circuitry, interfaces, and / or code operable to convert analog signals from receiver 118 into corresponding digital signals. The multiple A / D converters 122 are disposed between receiver 118 and RF processor 124. However, this disclosure is not limited in this respect. Therefore, in some embodiments, multiple A / D converters 122 may be integrated within receiver 118.

[0024] RF processor 124 may include suitable logic, circuitry, interfaces, and / or code operable to demodulate digital signals output from a plurality of A / D converters 122. According to one embodiment, RF processor 124 may include a demodulator (not shown) operable to demodulate digital signals to form I / Q data pairs representing corresponding echo signals. The RF or I / Q signal data can then be transmitted to an RF / IQ buffer 126. RF / IQ buffer 126 may include suitable logic, circuitry, interfaces, and / or code operable to provide temporary storage of the RF or I / Q signal data generated by RF processor 124.

[0025] Receiver beamformer 120 may include suitable logic, circuitry, interfaces, and / or code operable to sum co-located received data points into pixels of a mode B image. In various embodiments, receiver beamformer 120 applies beamforming techniques that leverage the high coherence of delay-corrected signal data to enhance points in space. Receiver beamformer 120 may be configured to substitute, mix, or multiply a metric of phase coherence for beam summation to balance off-axis scattering and sidelobe energy. The beamforming techniques provided by receiver beamformer 120 may be configured to recapitulate the spatial specificity of the signal data. In various embodiments, signal data beamforming can be performed as multi-line acquisition (MLA) for multiple receive directions or for a single transmit direction. The receiver beamformer 120 may include suitable logic, circuitry, interfaces, and / or code that can be used to weight the delay and summation beamforming by selecting a coherence factor prior to IQ data summation, in order to enhance energy from the main beam direction of the reflector and attenuate sidelobe energy from the off-axis scatterer. Alternative processing, such as minimum variance beamforming, can also be implemented, which can be combined with the output from linear beamforming to add spatial specificity.

[0026] The receiver beamformer 120 can employ various techniques to perform beamforming. For example, the receiver beamformer 120 can apply a coherence factor C, which measures coherence as the ratio of the coherent to the incoherent sum of the delayed-aligned signal data, as described below:

[0027]

[0028] Where x is the delayed alignment signal data, i is the channel number, and N is the number of channels in the beamformer. The coherence factor C is multiplied as a factor by the receiving beamformer 120 in the beamformer output, where an adjustable adjustment factor can determine the degree to which the coherence with the conventional beamformer output is traded off. For the purposes of this disclosure, the term "coherence" is not limited to the factor C, but includes any suitable method that substantially depends on the amount of computation of coherence, see, for example, J. Camacho et al., "Adaptive Beamforming by Phase Coherence Processing," *Ultrasound Imaging*, Mr. Masayuki Tanabe (ed.), ISBN: 978-953-307-239-5, InTech, 2011, the full text of which is incorporated herein by reference. In various embodiments, coherence factor beamforming can be mixed with conventional beamforming. The use of phase coherence is provided to distinguish and attenuate off-axis scatterers and sidelobe energy from the actual in-beam reflector.

[0029] In various embodiments, the resulting processed information may be co-located receive data points whose beams are summed to pixels in a B-mode image output from receive beamformer 120 and transmitted to signal processor 132. According to some embodiments, receiver 118, multiple A / D converters 122, RF processor 124, and beamformer 120 may be integrated into a single beamformer, which may be digital. In some embodiments, receive beamformer 120 may be a multi-line ultrasonic beamformer configured to generate multiple receive lines in response to each single transmit beam. Multi-line receive beamformer 120 may apply different delays and combine signal data to generate steered receive data points. In some embodiments, the above beamforming techniques may be combined with other reconstruction types of methods to reduce sidelobe energy, such as synthetic transmit beamforming or retrospective synthetic focusing techniques utilizing the overlap between two or more adjacent transmit beams. For example, the receive beamformer 120 can be configured to apply retrospective transmit beamforming (RTB) to provide dynamic transmit focusing and use a time delay calculated from the probe geometry to align the transmit line with the corresponding receive data point to correct the acquired ultrasound data.

[0030] User input device 130 can be used to input patient data, scan parameters, settings, select protocols and / or templates, select imaging modes, etc. In an exemplary embodiment, user input device 130 can be operated to configure, manage, and / or control the operation of one or more components and / or modules in ultrasound system 100. In this regard, user input device 130 can be used to configure, manage, and / or control the operation of transmitter 102, ultrasound probe 104, transmit beamformer 110, receiver 118, receive beamformer 120, RF processor 124, RF / IQ buffer 126, user input device 130, signal processor 132, image buffer 136, display system 134, and / or file 138. User input device 130 may include one or more buttons, one or more rotary encoders, a touch screen, motion tracking, voice recognition, a mouse device, a keyboard, a camera, and / or any other device capable of receiving user commands. In some embodiments, for example, one or more of user input devices 130 may be integrated into other components such as display system 134. For example, user input device 130 may include a touch screen display.

[0031] Signal processor 132 may include suitable logic, circuitry, interfaces, and / or code operable to process ultrasound scan data (i.e., summed IQ signals) to generate an ultrasound image for presentation on display system 134. Signal processor 132 is operable to perform one or more processing operations based on multiple selectable ultrasound modalities on the acquired ultrasound scan data. In an exemplary embodiment, signal processor 132 is operable to perform tissue velocity image processing, speckle tracking, etc. Acquired ultrasound scan data can be processed in real time during a scanning session as echo signals are received. Alternatively or concurrently, ultrasound scan data may be temporarily stored in RF / IQ buffer 126 during a scanning session and processed in a less real-time manner during online or offline operation. In various embodiments, the processed image data may be presented at display system 134 and / or stored at archive 138. Archive 138 may be a local archive, a Picture Archiving and Communication System (PACS), or any suitable device for storing images and related information. In a representative embodiment, signal processor 132 may include measurement processor 140.

[0032] Signal processor 132 may include suitable logic, circuitry, interfaces, and / or code operable to process ultrasound scan data (i.e., summed IQ signals) to generate an ultrasound image for presentation on display system 134. Signal processor 132 is operable to perform one or more processing operations based on multiple selectable ultrasound modalities on the acquired ultrasound scan data. In exemplary embodiments, signal processor 132 may be used to perform display processing and / or control processing, etc. In various embodiments, signal processor 132 is operable to perform tissue velocity image processing, speckle tracking, etc. Acquired ultrasound scan data can be processed in real time during a scanning session as echo signals are received. Alternatively or concurrently, ultrasound scan data may be temporarily stored in RF / IQ buffer 126 during a scanning session and processed in a less real-time manner during online or offline operation. In various embodiments, processed image data may be presented at display system 134 and / or stored at archive 138. File 138 can be a local file, a Picture Archiving and Communication System (PACS), or any suitable device for storing images and related information.

[0033] Signal processor 132 may be one or more central processing units, graphics processing units, microprocessors, microcontrollers, etc. For example, signal processor 132 may be an integrated component or may be distributed in various locations. In an exemplary embodiment, signal processor 132 may include a delay compensation processor 140, a displacement determination processor 150, and a speed information processor 160, which are capable of receiving input information from user input device 130 and / or file 138, generating output that can be displayed by display system 134, and manipulating the output in response to input information from user input device 130, etc. For example, signal processor 132, delay compensation processor 140, displacement determination processor 150, and speed information processor 160 may perform any of the methods and / or instruction sets discussed herein according to various embodiments.

[0034] The ultrasound system 100 is operable to continuously acquire ultrasound scan data at a frame rate suitable for the imaging situation under consideration. Typical frame rates are in the range of 20 to 120, but can be lower or higher. The acquired ultrasound scan data can be displayed on the display system 134 at the same, slower, or faster display rate as the frame rate. An image buffer 136 is included for storing frames of the acquired ultrasound scan data that are not scheduled for immediate display. Preferably, the image buffer 136 has sufficient capacity to store frames of ultrasound scan data for at least several minutes. The frames of ultrasound scan data are stored in a manner that facilitates retrieval based on their acquisition order or time. The image buffer 136 can be embodied in any known data storage medium.

[0035] Signal processor 132 may include delay compensation processor 140, which includes suitable logic, circuitry, interfaces, and / or code operable to compensate for time-of-arrival differences for each received data point from a set of received data points. For example, delay compensation processor 140 may be operable to delay received data points to compensate for distances between transducer elements 106, 108 and a target. Delay alignment compensation performed by delay compensation processor 140 is due to registration differences caused by the position of the transmit wavefront. Delay-compensated received data points may be provided to receive beamformer 120 and / or stored in archive 138 or any suitable data storage medium.

[0036] Figure 2 This is an exemplary layout 200 of a partially overlapping sequence of transmit beams 210 and a corresponding set of receive data points 220 at overlapping receive data point locations, according to various implementation schemes. (See reference...) Figure 2The layout 200 may include a vertical axis corresponding to time, a horizontal axis corresponding to position / steering angle, and receive data points 220 (specified by "x") for a specific transmit beam 210 (specified by "T"). As indicated, the overlapping transmit beam sequences 210 are spaced apart along separate transmit axes. Receive data points 220 may include co-located receive data point pairs generated from different transmit events 210 (e.g., 220-1, 220-2, 220-3, 220-4, 220-5 and / or any suitable co-located receive data point pairs). The identified co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, and 220-5 are examples of receive data point pairs suitable for calculating the correlated phase as a displacement estimate because the identified pairs 220-1, 220-2, 220-3, 220-4, and 220-5 are located at the receive data point positions relative to completely opposite transmission axes, causing residual geometric errors to cancel each other out. The combination of co-located receive data point pairs 220-1 provides a displacement estimate with a pulse repetition time (PRT) difference. The combination of co-located receive data point pairs 220-2 provides a displacement estimate with a 3*PRT difference. The combination of co-located receive data point pairs 220-3 provides a displacement estimate with a 5*PRT difference. The combination of co-located receive data point pairs 220-4 provides a displacement estimate with a 7*PRT difference. The combination of co-located receive data point pairs 220-5 provides a displacement estimate with a 9*PRT difference. Different combinations of co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, and 220-5 each provide estimates at different speed ratios (e.g., for faster movement speeds, co-located receive data point pairs 220-1 and 220-2 are more accurate, while for slower movement speeds, co-located receive data point pairs 220-4 and 220-5 are more accurate). For example, exemplary layout 200 can represent harmonic or fundamental wavebands 210 emitted in different directions. For example, layout 200 can be generated using a high number of overlapping multi-line acquisition (MLA) receive data point locations due to RTB processing. Delay compensation processor 140 can compensate for the different arrival times of the emitted wavefront at each receive pixel location for each receive data point. Therefore, events are aligned relative to the emitted wavefront but have different wavefront tilts, such as... Figure 2 As shown.

[0037] Refer again Figure 1 ,refer to Figure 2The signal processor 132 may include a displacement determination processor 150, which includes suitable logic, circuitry, interfaces, and / or code operable to determine the displacement of a target between transmissions by comparing components of co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, and 220-5, which are generated in response to different transmit beams 210 in a partially overlapping transmit beam sequence 210. For example, the displacement determination processor 150 may calculate the correlated phase between the co-located receive data points 210 after delay compensation and perform spatial filtering using a median filter of the estimated values ​​to increase the signal-to-noise ratio (SNR) since the target organization is a rigid body where adjacent pixels move with a degree of uniformity. As an example, if r x,tx If the data is received at position x and beam tx, then from the obtained angle...

[0038]

[0039] Then, the displacement of the tissue is estimated by obtaining the displacement from the angle.

[0040] In various embodiments, the displacement determination processor 150 may be configured to combine co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, 220-5 with mirror geometry to reduce residual biases not compensated by the delay compensation processor 140. For example, the displacement determination processor 150 may be configured to combine co-located receive data point pairs 220-1 (i.e., from the innermost right MLA of one transmission to the innermost left MLA of the next transmission) to provide a displacement estimate after 1*PRT time. Alternatively, the displacement determination processor 150 may be configured to combine co-located receive data point pairs 220-2, 220-3, 220-4, 220-5, etc., to provide displacement estimates after 3*PRT, 5*PRT, 7*PRT, 9*PRT, etc. In various embodiments, one or two of these estimates may be feasible near the focal point, while other combinations / estimates may be used further away from the focal point. In exemplary embodiments, a large number of pairs can be combined across most or the entire image for divergent, planar, or high f-value (i.e., high ratio of imaging depth to aperture size) emission settings.

[0041] In some implementations, the displacement determination processor 150 can be configured to estimate several velocities individually at different scales by individually estimating the displacement of the proximal co-located receive data point pair 220-1 and the displacement between the more distant co-located receive data point pairs 220-2, 220-3, 220-4, and 220-5, which independently correspond to slow tissue movement, valve movement, very rapid valve tilting, etc. In a representative implementation, the displacement determination processor 150 can be configured to combine all relevant estimates into a total average to reduce the SNR by having a larger effective group size as described below:

[0042]

[0043] Here, R indicates the correlation between the data from tx1 and tx2, while dividing by a number (tx2-tx1) assumes txN indicates the sequence number, such that if tx2 = tx1 + 3, then dividing by tx2-tx1 considers a displacement that is 3 times the PRT. The availability of longer time intervals between correlated events, such as 3*PRT or 5*PRT, provides a more accurate determination of the velocity of slower movement events, and combining multiple measurements reduces the SNR.

[0044] Signal processor 132 may include speed information processor 160, which includes suitable logic, circuitry, interfaces, and / or code operable to generate speed information based on a displacement determined by displacement determination processor 150. For example, speed information processor 160 may present speed information superimposed on a B-mode image, such as color flow information or any suitable speed information.

[0045] File 138 may be one or more computer-readable storage devices integrated with and / or communicatively coupled (e.g., via a network) to ultrasound system 100, such as Image Archiving and Communication System (PACS), server, hard disk, floppy disk, CD, CD-ROM, DVD, compact memory, flash memory, random access memory, read-only memory, electrically erasable and programmable read-only memory, and / or any suitable memory. File 138 may include, for example, a database, library, information set, or other memory accessed by and / or combined with signal processor 132. For example, file 138 may be able to temporarily or permanently store data. File 138 may be able to store medical image data, data generated by signal processor 132, and / or instructions readable by signal processor 132, etc. In various embodiments, for example, file 138 stores medical image data, delay compensation processing instructions, displacement determination processing instructions, target displacement estimation, velocity information processing instructions, velocity information, and beamforming instructions.

[0046] Display system 134 can be any device capable of transmitting visual information to a user. For example, display system 134 may include a liquid crystal display, a light-emitting diode display, and / or any suitable one or more displays. Display system 134 can be used to display information from signal processor 132 and / or archive 138, such as a B-mode image with speed information and / or any suitable information. In various embodiments, display system 134 is operable to present speed information overlaid on a B-mode image.

[0047] The components of the ultrasound system 100 can be implemented in software, hardware, firmware, etc. The various components of the ultrasound system 100 can be communicatively connected. The components of the ultrasound system 100 can be implemented individually and / or integrated in various forms. For example, the display system 134 and the user input device 130 can be integrated into a touchscreen display.

[0048] Figure 3 This is flowchart 300, illustrating exemplary steps 302-314 for estimating motion from overlapping multiline acquisitions of continuous ultrasonic emission events, according to various implementations. See also... Figure 3 The diagram illustrates flowchart 300, which includes exemplary steps 302 to 314. Some embodiments may omit one or more steps, and / or perform the steps in a different order than listed, and / or combine certain steps discussed below. For example, some steps may not be performed in some embodiments. Also, some steps may be performed in a different chronological order than listed below, including simultaneous execution.

[0049] At step 302, a sequence of partially overlapping transmit beams 210 is emitted from the first plurality of transducer elements 106 in multiple directions at the target location. For example, an ultrasound probe 104 having a set of transmitting transducer elements 106 is positioned to acquire ultrasound data in a region of interest. The ultrasound probe emits a sequence of transmit beams in a certain direction from each of the transducer elements 106. For example, each transducer element 106 may sequentially emit ten (10) or any suitable number of transmit beams.

[0050] At step 304, in response to each of the transmit beams 210, multiple echo signals are received at a receive data point location at each of the second plurality of transducer elements 108. For example, an ultrasound probe 104 having a group of receive transducer elements 108 receives echo signals from a target at a receive data point location, which typically constitutes the same element as the group of transmit transducer elements 106. In various embodiments, one or more receive data point locations of multiple echo signals received in response to one of the transmit beams 210 overlap with one or more receive data point locations of multiple echo signals received in response to one or more other transmit beams 210 in a partially overlapping sequence of transmit beams 210.

[0051] At step 306, the ultrasound system 100 generates a set of receive data points 220 from each of the receive data point locations of a plurality of echo signals received from each of the transmit beams 210. For example, the RF processor 124 of the ultrasound system 100 may generate receive data points 220 corresponding to RF signal data representing the corresponding echo signal. As another example, the RF processor 124 may include a demodulator that can be used to demodulate digital signals to form receive data points 220 corresponding to I / Q data representing the corresponding echo signal. The receive data points 220 may then be transmitted to an RF / IQ buffer 126. The RF / IQ buffer 126 may include suitable logic, circuitry, interfaces, and / or code operable to provide temporary storage for the receive data points 220 generated by the RF processor 124.

[0052] At step 308, the signal processor 132 of the ultrasound system 100 compensates for the time difference of arrival of each received data point 220 from the set of received data points 220. For example, the delay compensation processor 140 may be configured to delay the received data points 220 to compensate for the distance between the transducer elements 106, 108 and the target. The delay alignment compensation performed by the delay compensation processor 140 is due to registration differences caused by the position of the transmitted wavefront.

[0053] At step 310, the signal processor 132 of the ultrasound system 100 determines the displacement of the target between transmissions 210 by comparing the components of co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, and 220-5, which are generated in response to different transmission beams 210 in a partially overlapping sequence of transmission beams 210. For example, the displacement determination processor 150 of the signal processor 132 of the ultrasound system may be configured to calculate the correlated phase between the co-located receive data points 210 after delay compensation at step 308 and perform spatial filtering with a median filter of the estimated values ​​to increase the signal-to-noise ratio (SNR) since the target tissue is a rigid body in which adjacent pixels move with a degree of uniformity. As another example, the displacement determination processor 150 may be configured to combine co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, and 220-5 with mirror geometry to reduce residual biases not compensated by the delay compensation processor 140. In some implementations, the displacement determination processor 150 can be configured to estimate several velocities individually at different scales by separately estimating the displacement of the proximal co-located receive data point pair 220-1 and the displacement between the more distant co-located receive data point pairs 220-2, 220-3, 220-4, and 220-5, which independently correspond to slow tissue movement, valve movement, very rapid valve tilting, etc. In a representative implementation, the displacement determination processor 150 can be configured to combine all relevant estimates into a total average to reduce SNR through a larger effective packet size.

[0054] At step 312, the ultrasound system 100 sums each of the co-located receive data points 220 into pixels of the B-mode image. For example, the receive beamformer 120 of the ultrasound system 100 is operable to combine the co-located receive data points 220 into pixels of the B-mode image. In various embodiments, the receive beamformer 120 applies beamforming techniques that utilize the high coherence of delay-corrected signal data to enhance points in space. The receive beamformer 120 can be configured to substitute, mix, or multiply a metric of phase coherence for beam summation to balance off-axis scattered signal and sidelobe energy. The beamforming techniques provided by the receive beamformer 120 can be configured to reacquire the spatial specificity of the signal data. In various embodiments, the signal data beamforming can be performed as multiple receive directions or as multi-line acquisition (MLA) for a single transmit direction. The receive beamformer 120 may include suitable logic, circuitry, interfaces, and / or code that can be used to weight the delay and summation beamforming by selecting a coherence factor before IQ data summation, in order to enhance energy from the main beam direction of the reflector and attenuate sidelobe energy from the off-axis scatterer. Alternative processing, such as minimum variance beamforming, can also be implemented, which can be combined with the output from linear beamforming to add spatial specificity. In a representative embodiment, the resulting processed information may be co-located receive data points that are beam-summed into pixels of a B-mode image output from the receive beamformer 120 and transmitted to the signal processor 132. In some embodiments, the receive beamformer 120 may be a multi-line ultrasonic beamformer configured to generate multiple receive lines in response to each single transmit beam. The multi-line receive beamformer 120 may apply different delays and combine signal data to produce steered receive data points. In exemplary embodiments, the beamforming technique described above can be combined with other reconstruction-type methods to reduce sidelobe energy, such as synthetic transmit beamforming or retrospective synthetic focusing techniques utilizing the overlap between two or more adjacent transmit beams. For example, the receive beamformer 120 can be configured to apply retrospective transmit beamforming (RTB) to provide dynamic transmit focusing and use a time delay calculated from the probe geometry to align the transmit beam 210 with the corresponding receive data point 220 to correct the acquired ultrasound data.

[0055] At step 314, the signal processor 132 of the ultrasound system 100 can present a B-mode image with velocity information at the display system 134 based on the determined displacement of the target. For example, the velocity information processor 160 of the signal processor 132 can generate velocity information based on the displacement of the target determined by the displacement determination processor 150 at step 310. As an example, the velocity information processor 160 can present velocity information overlaid on the B-mode image, such as color flow information or any suitable velocity information.

[0056] This disclosure provides a method 300 and a system 100 for estimating motion from overlapping multi-line acquisition of consecutive transmission events. According to various embodiments, method 300 may include transmitting 302 a sequence of partially overlapping transmit beams 210 from a first plurality of transducer elements 106 in multiple directions at a target. Method 300 may include receiving 304 a plurality of echo signals at receive data point locations at each of the second plurality of transducer elements 108 in response to each transmit beam 210. One or more receive data point locations receiving the plurality of echo signals in response to one of the transmit beams may overlap with one or more receive data point locations receiving the plurality of echo signals in response to one or more other transmit beams 210 in the partially overlapping transmit beam 210 sequence. Method 300 may include generating 306 a set of receive data points 220 from each receive data point location in response to the plurality of echo signals received from each of the transmit beams 210. Method 300 may include compensating for arrival time differences of each received data point 220 from a set of received data points 220 by at least one processor 132, 140. Method 300 may include determining, by at least one processor 132, 150, the displacement of a target between transmissions 310 by comparing components of a co-located received data point pair 220-1, 220-2, 220-3, 220-4, 220-5, which is generated in response to different transmitted beams 210 in a partially overlapping sequence of transmitted beams 210. Method 300 may include adding 312 of each received data point in the co-located received data points 220 to pixels of a B-mode image by at least one beamformer 120. Method 300 may include causing at least one processor 132, 160 to display a B-mode image with velocity information based on the determined displacement of the target.

[0057] In an exemplary embodiment, each transmit beam in the partially overlapping transmit beam 210 sequence is a focused transmit beam. In a representative embodiment, method 300 may include receiving data point pairs 220-1, 220-2, 220-3, 220-4, 220-5 co-located by at least one processor 132, 150, which exhibit mirror geometry relative to corresponding positions of the different transmit beams 210 from the partially overlapping transmit beam 210 sequence. In some embodiments, method 300 may include combining components of the receiving data point pairs 220-1, 220-2, 220-3, 220-4, 220-5 co-located by at least one processor 132, 150, which exhibit mirror geometry from the partially overlapping transmit beam 310 sequence. In various implementations, the displacement of target 310 is determined by calculating the correlated phase between the components of co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, and 220-5. In an exemplary implementation, method 300 may include compensating each of the co-located receive data points 220 of target 310 based on the determined displacement of the target using at least one processor 132, 150. In some implementations, velocity information is overlaid on the B-mode image.

[0058] Various embodiments provide an ultrasonic system 100 for estimating motion from overlapping multi-line acquisitions of consecutive transmission events. The ultrasonic system 100 may include a plurality of transducer elements 106, 108, at least one processor 132, 140, 150, 160, at least one receive beamformer 120, and a display system 134. Each of the plurality of transducer elements 106, 108 is operable to transmit a partially overlapping sequence of transmit beams 210 in multiple directions at a target and to receive a set of receive data points 220 for each transmit beam in the sequence of transmit beams 210. The set of receive data points 220 may include a plurality of receive data point locations that overlap with receive data point locations from other transmit beams 210 in the partially overlapping sequence of transmit beams 210. At least one processor 132, 140 may be configured to compensate for different arrival times from each receive data point 220 in the set of receive data points 220. At least one processor 132, 150 may be configured to determine the displacement of a target by comparing components within a co-located pair of received data points 220-1, 220-2, 220-3, 220-4, 220-5, which are generated in response to different transmitted beams 210 in a partially overlapping sequence of transmitted beams 210. At least one received beamformer 120 is operable to add each of the co-located received data points 220 to a pixel of a B-mode image. A display system 134 may be configured to present a B-mode image with velocity information based on the determined displacement of the target.

[0059] In a representative embodiment, each transmit beam in the partially overlapping transmit beam 210 sequence is a focused transmit beam. In various embodiments, at least one processor 132, 150 may be configured to select a co-located pair of receive data points 220-1, 220-2, 220-3, 220-4, 220-5 that exhibit mirror geometry relative to corresponding positions of the different transmit beams 210 from the partially overlapping transmit beam 210 sequence. In some embodiments, at least one processor 132, 150 may be configured to combine components of the co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, 220-5 that exhibit mirror geometry relative to corresponding positions of the different transmit beams 210 from the partially overlapping transmit beam 210 sequence. In an exemplary embodiment, at least one processor 132, 150 may be configured to calculate the correlated phase between the components of co-located received data point pairs 220-1, 220-2, 220-3, 220-4, 220-5 to determine the displacement of the target. In a representative embodiment, at least one processor 132, 150 may be configured to compensate each of the co-located received data points 220 based on the determined displacement of the target. In various embodiments, velocity information may be overlaid on the B-mode image.

[0060] Some embodiments provide a non-transitory computer-readable medium on which a computer program is stored, the computer program having at least one code segment. This at least one code segment is machine-executable to cause the ultrasound system 100 to perform step 300. Step 300 may include receiving, at a target location, a set of received data points 220 from each of a partially overlapping sequence of transmitted beams 210 emitted 302 from each of a plurality of transducer elements 106 in multiple directions, 304, 306. The set of received data points 220 may include multiple received data point locations that overlap with received data point locations generated by other transmitted beams 210 in the partially overlapping sequence of transmitted beams 210. Step 300 may include compensating 308 for the different arrival times of each received data point 220 in the set of received data points 220. Step 300 may include determining the displacement of target 310 by comparing components of a co-located pair of received data points 220-1, 220-2, 220-3, 220-4, 220-5, which are generated in response to different transmitted beams 210 in a partially overlapping sequence of transmitted beams 210. Step 300 may include adding 312 of each of the co-located received data points 220 to a pixel of a B-mode image. Method 300 may include causing display system 134 314 to present a B-mode image with velocity information based on the determined displacement of the target.

[0061] In various embodiments, each transmit beam in the partially overlapping transmit beam 210 sequence is a focused transmit beam. In some embodiments, step 300 may include selecting a pair of receive data points 220-1, 220-2, 220-3, 220-4, 220-5 that are co-located by 310, which exhibit mirror geometry relative to corresponding positions of different transmit beams 210 from the partially overlapping transmit beam 210 sequence. In an exemplary embodiment, step 300 may include combining components of the co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, 220-5 that exhibit mirror geometry relative to corresponding positions of different transmit beams 210 from the partially overlapping transmit beam 210 sequence. In a preferred embodiment, the displacement of the target 310 is determined by calculating the correlated phase between the components of the co-located receive data point pairs 220-1, 220-2, 220-3, 220-4, 220-5. In various implementations, step 300 may include determining each of the received data points 220 in the target-based displacement compensation 310 co-located received data points.

[0062] As used herein, the term "circuit" refers to physical electronic components (i.e., hardware) and any software and / or firmware ("code") that is configurable hardware, executed by the hardware, and / or otherwise associated with the hardware. For example, as used herein, a particular processor and memory may include a first "circuit" when executing one or more lines of first code, and a particular processor and memory may include a second "circuit" when executing one or more lines of second code. As used herein, "and / or" means any one or more items in a list linked by "and / or". For example, "x and / or y" means any element in the three-element set {(x),(y),(x,y)}. As another example, "x, y and / or z" means any element in the seven-element set {(x),(y),(z),(x,y),(x,z),(y,z),(x,y,z)}. As used herein, the term "exemplary" means used as a non-limiting example, instance, or illustration. As used herein, the terms “eg” and “for example” refer to a list of one or more non-limiting examples, instances, or illustrations. As used herein, a circuit is “usable” to perform a function whenever the circuit includes the necessary hardware and code to perform the function, if needed, regardless of whether the execution of the function is disabled or not enabled by some user-configurable settings.

[0063] Other embodiments may provide a computer-readable device and / or a non-transitory computer-readable medium, and / or a machine-readable device and / or a non-transitory machine-readable medium, wherein the computer-readable device and / or the non-transitory computer-readable medium and / or the machine-readable device and / or the non-transitory machine-readable medium stores machine code and / or a computer program having at least one code segment executable by a machine and / or a computer, thereby enabling the machine and / or the computer to perform the steps described herein for estimating motion from overlapping multi-line acquisition of successive emission events.

[0064] Therefore, this disclosure can be implemented in hardware, software, or a combination of hardware and software. This disclosure may be implemented centrally in at least one computer system or distributed, wherein different elements are distributed across several interconnected computer systems. Any kind of computer system or other apparatus suitable for performing the methods described herein is appropriate.

[0065] Various implementation schemes may also be embedded in a computer program product that includes all the features of the methods described herein and is capable of executing those methods when loaded into a computer system. As used herein, a computer program means any expression of a set of instructions represented in any language, code, or notation, which is intended to cause a system with information processing capabilities to perform a particular function directly or after being: a) translated into another language, code, or notation; or b) reproduced in a different material form.

[0066] While this disclosure has been described with reference to certain embodiments, those skilled in the art will understand that various changes and substitutions can be made without departing from the scope of this disclosure. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the specific embodiments disclosed, but rather to include all embodiments falling within the scope of the appended claims.

Claims

1. A method comprising: A sequence of beams that are partially overlapped and emitted from multiple transducer elements at the target location in multiple directions; At each of the second plurality of transducer elements, in response to each of the transmit beams receiving a plurality of echo signals at a receive data point location, wherein one or more of the receive data point locations of the plurality of echo signals received in response to one of the transmit beams overlap with one or more of the receive data point locations of the plurality of echo signals received in response to one or more of the other transmit beams in the partially overlapping transmit beam sequence; A set of received data points from each of the received data point locations is generated from the plurality of echo signals received in response to each of the transmitted beams. The arrival time difference of each received data point from the set of received data points is compensated by at least one processor; The displacement of the target between transmissions is determined by the at least one processor by comparing the components of a pair of commonly located received data points, the pair of commonly located received data points being generated in response to different transmitted beams in the partially overlapping transmitted beam sequence; Each of the commonly located received data points is added to the pixels of the B-mode image by at least one beamformer. as well as The at least one processor causes the display system to present the B-mode image with velocity information based on the determined displacement of the target. The commonly positioned data point pair is a pair of points located at the data point position relative to completely opposite transmission axes.

2. The method according to claim 1, wherein each of the transmitted beams in the partially overlapping transmitted beam sequence is a focused transmitted beam.

3. The method of claim 1, further comprising selecting the co-located receive data point pair by the at least one processor, the co-located receive data point pair exhibiting mirror geometry relative to the corresponding positions of the different transmit beams from the partially overlapping transmit beam sequence.

4. The method of claim 1, further comprising the combination by the at least one processor of the components of the co-located received data point pairs exhibiting mirror geometry from the partially overlapping transmitted beam sequence.

5. The method of claim 1, wherein the displacement of the target is determined by calculating the correlation phase between the components of the co-located received data point pair.

6. The method of claim 1, further comprising the at least one processor compensating each of the co-located received data points based on the determined displacement of the target.

7. The method of claim 1, wherein the velocity information is overlaid on the B-mode image.

8. An ultrasound system, the ultrasound system comprising: A plurality of transducer elements, wherein each of the plurality of transducer elements can be used for: A sequence of partially overlapping transmitted beams is emitted from multiple directions at the target location; A set of received data points for each transmitted beam in the transmitted beam sequence, wherein the set of received data points includes multiple received data point positions that overlap with the received data point positions from other transmitted beams in the partially overlapping transmitted beam sequence; At least one processor, said at least one processor being configured to: Compensation is provided for the different arrival times of each received data point from the set of received data points. as well as The displacement of the target is determined by comparing the components within a pair of commonly located receive data points, which are generated in response to different transmit beams in the partially overlapping transmit beam sequence. At least one receive beamformer, the at least one receive beamformer being operable to add each of the co-located receive data points to a pixel of the B-mode image; and A display system configured to present a B-mode image with velocity information based on the determined displacement of the target. The commonly positioned data point pair is a pair of points located at the data point position relative to completely opposite transmission axes.

9. The system of claim 8, wherein each of the transmitted beams in the partially overlapping transmitted beam sequence is a focused transmitted beam.

10. The system of claim 8, wherein the at least one processor is configured to select the co-located receive data point pair, the co-located receive data point pair exhibiting mirror geometry relative to the corresponding positions of the different transmit beams from the partially overlapping transmit beam sequence.

11. The system of claim 8, wherein the at least one processor is configured to combine the components of the co-located receive data point pair, the co-located receive data point pair exhibiting mirror geometry relative to the corresponding positions of the different transmit beams from the partially overlapping transmit beam sequence.

12. The system of claim 8, wherein the at least one processor is configured to calculate the correlation phase between the components of the co-located received data point pair to determine the displacement of the target.

13. The system of claim 8, wherein the at least one processor is configured to compensate each of the co-located received data points based on the determined displacement of the target.

14. The system of claim 8, wherein the speed information is overlaid on the B-mode image.

15. A non-transitory computer-readable medium storing a computer program, the computer program having at least one code segment executable by a machine to cause an ultrasound system to perform steps including: At the target location, a set of received data points are received in multiple directions from each of the partially overlapping transmitted beams in a sequence of transmitted beams emitted from each of the multiple transducer elements, wherein the set of received data points includes multiple received data point positions that overlap with the received data point positions generated from other transmitted beams in the partially overlapping transmitted beam sequence. Compensation is provided for the different arrival times of each received data point from the group of received data points. The displacement of the target is determined by comparing the components of a pair of commonly located received data points, the pair of commonly located received data points being generated in response to different transmitted beams in the partially overlapping transmitted beam sequence. Each of the commonly located received data points is added to the pixels of the B-mode image; as well as Based on the determined displacement of the target, the display system presents the B-mode image with velocity information. The commonly positioned data point pair is a pair of points located at the data point position relative to completely opposite transmission axes.

16. The non-transitory computer-readable medium of claim 15, wherein each of the transmitted beams in the partially overlapping transmitted beam sequence is a focused transmitted beam.

17. The non-transitory computer-readable medium of claim 15, wherein the step includes selecting the co-located pair of received data points, the co-located pair of received data points exhibiting mirror geometry relative to corresponding positions of the different transmitted beams from the partially overlapping transmitted beam sequence.

18. The non-transitory computer-readable medium of claim 15, wherein the step comprises combining the components of the co-located receive data point pair, the co-located receive data point pair exhibiting mirror geometry relative to corresponding positions of the different transmit beams from the partially overlapping transmit beam sequence.

19. The non-transient computer-readable medium of claim 15, wherein the displacement of the target is determined by calculating the correlation phase between the components of the co-located pair of received data points.

20. The non-transient computer-readable medium of claim 15, wherein the step includes compensating each of the co-located received data points based on the determined displacement of the target.

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