Ultrasonic imaging method and system with double working modes

Abstract

The invention discloses a double-working-mode ultrasonic imaging method and system, and relates to the field of medical instruments.The method comprises the steps that under the condition that a handheld terminal and a trolley are in wired connection, a performance signal is generated; the handheld terminal performs front-end preprocessing on the radio-frequency signal to generate a first complex baseband signal, and transmits the first complex baseband signal to the trolley in a wired manner; the trolley performs beam forming based on adaptive delay calculation to generate a second complex baseband signal; a first amplitude signal is generated through envelope detection, and then image display is carried out; under the condition that the handheld terminal and the trolley are in wireless connection, a portable signal is generated; the handheld terminal performs parallel beam forming through a preset delay lookup table to generate a beam forming signal; generating a second amplitude signal through envelope detection and down-sampling, and wirelessly transmitting the second amplitude signal to the trolley; and the trolley displays an image according to the second amplitude signal. By implementing the invention, the problem that the existing ultrasonic imaging equipment cannot give consideration to high performance and high portability at the same time can be solved, and the practicability of the equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to an ultrasound imaging method and system with dual working modes. Background Technology

[0002] Medical ultrasound imaging equipment, as a non-invasive and radiation-free medical diagnostic tool, has been widely used in clinical diagnosis. Traditional ultrasound equipment is mainly divided into two categories based on its form and performance: one is large desktop machines, which have multi-channel (such as 64 channels, 128 channels or even more), high-performance beam combiners and computing units, and can provide extremely high image quality, but are bulky, expensive, and immobile; the other is portable or handheld ultrasound equipment, which are small and lightweight, but usually have fewer channels (8-32 channels) and use lower-performance fixed hardware for beam combining, and their image quality, functionality, and processing flexibility are far inferior to large desktop equipment.

[0003] With the development of semiconductor and computing technologies, soft beamforming technology has emerged. This technology uses general-purpose high-performance processors (such as CPUs and GPUs) to replace traditional dedicated hardware beamformers with software algorithms, improving flexibility and algorithm iteration capabilities. However, the huge data throughput and computational demands of this technology have created new bottlenecks. Ultimately, existing single-form ultrasound imaging equipment still cannot balance the needs of high performance and high portability. Users either use high-performance but bulky desktop computers at the diagnostic site, or sacrifice image quality and functional experience for portability. Summary of the Invention

[0004] This invention provides an ultrasound imaging method and system with dual working modes, which can solve the problem that existing ultrasound imaging equipment cannot simultaneously achieve high performance and high portability, thereby improving the practicality of the equipment.

[0005] An embodiment of the present invention provides a dual-mode ultrasound imaging method, applicable to the mode selection module of an ultrasound imaging system; the ultrasound imaging system further includes: a handheld terminal and a trolley; Ultrasound imaging methods include: When the handheld terminal and the trolley are connected by a wire, a performance signal is generated; The performance signal is sent to the handheld terminal, which then performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal, and transmits it to the trolley via wired connection. The radio frequency signal is obtained by the handheld terminal after acquiring the echo signal and then amplifying it through the analog front-end and converting it to digital. The echo signal is obtained by the handheld terminal exciting the array element position of the built-in probe according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and is then acquired. The performance signal is sent to the trolley, which then performs beamforming on the first complex baseband signal of all channels based on adaptive delay calculation to generate a second complex baseband signal; envelope detection is performed on the second complex baseband signal to generate a first amplitude signal; and image display is performed based on the first amplitude signal. When the handheld terminal and the trolley are wirelessly connected, a portable signal is generated. The portable signal is sent to the handheld terminal, which then performs parallel beamforming on the radio frequency signal of each channel using a preset delay lookup table to generate a beamformed signal. The beamformed signal is then envelope-detected and downsampled to generate a second amplitude signal, which is then wirelessly transmitted to the trolley. The portable signal is sent to the trolley so that the trolley can display an image based on the second amplitude signal.

[0006] Furthermore, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal, including: The radio frequency signal of each channel is quadrature demodulated to obtain the corresponding first demodulated signal; The first compensation gain is determined based on the first demodulated signal; The first demodulated signal is compensated according to the first compensation gain to obtain the compensated complex baseband signal; The compensated complex baseband signal is filtered and enhanced using a preset frequency band filter to obtain the corresponding first complex baseband signal.

[0007] Furthermore, the trolley, based on adaptive delay calculation, performs beamforming on the first complex baseband signal of all channels to generate a second complex baseband signal, including: Set the imaging parameters; the imaging parameters include: depth range and number of scan lines; The pixel grid of the image to be displayed is determined based on the imaging parameters; the pixel grid includes several pixel positions. For each pixel position, the first delay of the corresponding channel is calculated based on the path difference between the straight-line propagation distance from the element position to the pixel position and the propagation distance along the depth direction. Based on the first delay of each channel, the first complex baseband signal value under the first delay is interpolated to obtain the first delay alignment signal value of the corresponding channel. Based on the first preset weight, the first delay alignment signal values ​​of all channels are weighted and summed to obtain the second complex baseband signal value; The second complex baseband signal is constructed based on the second complex baseband signal values ​​at all pixel locations.

[0008] Furthermore, the handheld terminal performs parallel beamforming on the radio frequency signals of each channel using a preset delay lookup table to generate a beamformed signal, including: Based on the preset delay lookup table, look up the second delay corresponding to each pixel position in each channel; For each pixel position, the radio frequency signal value under the second delay is interpolated according to the second delay of each channel to obtain the second delay alignment signal value of the corresponding channel; According to the second preset weight, the second delay alignment signal values ​​of all channels are weighted and summed to obtain the beamforming signal value; The beamforming signal is constructed based on the beamforming signal values ​​at all pixel locations.

[0009] Furthermore, the handheld terminal performs parallel beamforming on the radio frequency signals of each channel using a preset delay lookup table to generate a beamformed signal, including: The radio frequency signal of each channel is quadrature demodulated to obtain the corresponding second demodulated signal; The second compensation gain is determined based on the second demodulated signal; The second demodulated signal is compensated according to the second compensation gain to obtain the corresponding third complex baseband signal; Based on the preset delay lookup table, look up the second delay corresponding to each pixel position in each channel; For each pixel position, based on the second delay of each channel, the third complex baseband signal value under the second delay is interpolated to obtain the third delay alignment signal value of the corresponding channel. Based on the third preset weight, the third delay alignment signal values ​​of all channels are weighted and summed to obtain the beamforming signal value; The beamforming signal is constructed based on the beamforming signal values ​​at all pixel locations.

[0010] Furthermore, the first preset weight is determined in the following way: For each pixel position, construct the first covariance matrix based on the first delay alignment signal values ​​of all channels; Construct a steering vector based on the first delay of all channels; The first preset weights are determined based on the first covariance matrix and the steering vector.

[0011] Furthermore, the handheld terminal excites the array element positions of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and acquires the data, including: The array element position of the built-in probe is excited once according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and the data is collected; or the array element position of the built-in probe is excited multiple times according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and the data is collected. When the array element positions of the built-in probe are excited multiple times, the handheld terminal performs front-end preprocessing on the RF signal of each channel to generate the corresponding first complex baseband signal; the handheld terminal performs parallel beamforming on the RF signal of each channel through a preset delay lookup table to generate a beamformed signal; the beamformed signal is then envelope-detected and downsampled to generate a second amplitude signal, including: For each excitation, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal; for each excitation, the handheld terminal performs parallel beamforming on the radio frequency signal of each channel through a preset delay lookup table to generate a beamforming signal; after weighted summation of the beamforming signals of each excitation, envelope detection and downsampling are performed to generate a second amplitude signal. With multiple excitations of the array element positions of the built-in probe, the trolley, based on adaptive delay calculation, performs beamforming on the first complex baseband signals of all channels to generate a second complex baseband signal; and performs envelope detection on the second complex baseband signal to generate a first amplitude signal, including: For each excitation, the trolley performs beamforming on the first complex baseband signal of all channels based on adaptive delay calculation to generate the second complex baseband signal; after weighted summation of the second complex baseband signal for each excitation, envelope detection is performed to generate the first amplitude signal.

[0012] Furthermore, the trolley displays an image based on the first amplitude signal, including: Extract the first harmonic component of the first amplitude signal; the first harmonic component includes the second harmonic or the third harmonic; The image is displayed based on the first harmonic component.

[0013] Based on the above method embodiments, the present invention provides corresponding device embodiments, including: a mode selection module, a handheld terminal, and a trolley; The mode selection module is used to generate a performance signal when the handheld terminal and the trolley are connected by a wire; and to send the performance signal to the handheld terminal and the trolley respectively; when the handheld terminal and the trolley are connected by a wireless connection, it generates a portable signal; and to send the portable signal to the handheld terminal and the trolley respectively. The handheld terminal is used to excite the array element positions of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and collects the echo signal; the echo signal is amplified by analog front-end and converted from analog to digital to obtain radio frequency (RF) signal; when the performance signal is received, the RF signal of each channel is preprocessed by front-end to generate the corresponding first complex baseband signal, and transmitted to the trolley via wire; when the portable signal is received, the RF signal of each channel is parallel beamformed by using a preset delay lookup table to generate beamformed signal; the beamformed signal is envelope detected and downsampled to generate a second amplitude signal, and transmitted wirelessly to the trolley. The trolley is used to receive the first complex baseband signal of each channel sent by the handheld terminal; upon receiving the performance signal, it performs beamforming on the first complex baseband signals of all channels based on adaptive delay calculation to generate a second complex baseband signal; it performs envelope detection on the second complex baseband signal to generate a first amplitude signal; it performs image display based on the first amplitude signal; it receives the second amplitude signal sent by the handheld terminal; and it performs image display based on the second amplitude signal.

[0014] Furthermore, the trolley displays an image based on the first amplitude signal, including: Extract the first harmonic component of the first amplitude signal; the first harmonic component includes the second harmonic or the third harmonic; The image is displayed based on the first harmonic component.

[0015] Compared with the prior art, the beneficial effects of this embodiment are as follows: This invention switches the working modes of the handheld terminal and the trolley via a mode selection module. When the handheld terminal and the trolley are wired, the mode selection module generates a performance signal. The handheld terminal only handles the front-end preprocessing of the radio frequency signal and transmits the preprocessed first complex baseband signal to the trolley via a wired connection. The trolley, with its stronger computing power, performs adaptive delay calculation to complete beamforming, generating a second complex baseband signal. After envelope detection, the first amplitude signal is obtained and then displayed as an image. In this process, the handheld terminal only handles lightweight preprocessing, while the trolley undertakes complex calculations, achieving high-resolution, low-artifact high-performance imaging. When the two are wirelessly connected, the mode selection module generates a portable signal. The handheld terminal completes parallel beamforming through a preset delay lookup table, eliminating the need for real-time delay calculation and significantly reducing power consumption. The beamformed signal is then subjected to envelope detection and downsampling to compress the data volume, and the second amplitude signal is wirelessly transmitted to the trolley for display. This process, by simplifying calculations and data compression, adapts to the low-power and low-bandwidth requirements of wireless scenarios, achieving highly portable operation of the device. This invention employs a dual-mode design that switches between connection methods, precisely matching the complex computations required for high performance with the lightweight processes needed for portability. This solves the technical problem that existing ultrasound imaging devices cannot simultaneously achieve both high performance and high portability, thus improving the practicality of the device. Attached Figure Description

[0016] Figure 1 This is a schematic flowchart of a dual-working-mode ultrasound imaging method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a dual-working-mode ultrasound imaging system provided in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0019] like Figure 1 As shown, to address the issue that existing ultrasound imaging equipment cannot simultaneously achieve high performance and high portability, one embodiment of the present invention provides a dual-working-mode ultrasound imaging method, applicable to the mode selection module of an ultrasound imaging system; as shown... Figure 2As shown, the ultrasound imaging system also includes: a handheld terminal and a trolley; Specifically, the hardware of the handheld terminal includes: an ultrasonic transducer, a data acquisition module, and a transmission module; The ultrasonic transducer contains an ultrasonic probe with 64 physical array elements, supporting probe types such as convex array, linear array, and phased array, and is responsible for transmitting ultrasonic waves and receiving echo signals. The acquisition module includes a high-voltage transmitting circuit, a 64-channel analog front-end (AFE), a 64-channel analog-to-digital converter (ADC), and a front-end preprocessing unit (FPGA). The high-voltage transmitting circuit excites the probe to emit ultrasonic waves. The 64-channel analog front-end integrates a low-noise amplifier (LNA) and a variable gain amplifier (VGA) to amplify the echo signal. The 64-channel ADC converts the echo signal into a digital radio frequency (RF) signal with 12-14 bit precision and a 40-60MHz sampling rate. The front-end preprocessing unit, as the core of data processing, performs digital down-conversion (DDC) in performance mode, converting the high-frequency RF signal into a baseband in-phase / quadrature (I / Q) signal, and performs digital time gain compensation (TGC). It then performs enhancement filtering through specific frequency bands, packages the 64-channel I / Q data, and prepares it for transmission via a high-speed interface. In portable mode, a simplified real-time beam combiner is loaded. Using a built-in delay lookup table, it performs delay summation (DAS) calculations on the 64 channels to generate the beam-combined signal, which is then used for envelope detection. Detection, ultimately generating low-volume envelope data (EnvelopedData); The transmission module is equipped with a high-speed wired interface and a high-speed wireless interface. In this invention, the high-speed wired interface adopts a Thunderbolt 5 interface, which can provide a bidirectional bandwidth of up to 120Gbps for transmitting high-speed raw I / Q data streams in performance mode; the high-speed wireless interface adopts a Wi-Fi 6E / 7 module, supports the 6GHz band, and provides high-bandwidth, low-latency wireless connectivity for transmitting envelope data in portable mode.

[0020] The trolley, also known as a mobile computing trolley, includes hardware such as a high-performance computing module, a display control module, and an internal high-speed interconnect module. Among them, the high-performance computing module adopts a GPU-based parallel computing architecture and can be equipped with a built-in NVIDIA discrete graphics card (such as the RTX series), NVIDIA Jetson AGX Orin module, or similar high-performance parallel processor. As the computing engine in performance mode, this module is responsible for receiving the raw I / Q data transmitted by the handheld terminal, running soft beamforming algorithms including adaptive beamforming and synthetic aperture, and completing subsequent image processing tasks such as filtering, logarithmic compression, and scan conversion. The display control module can be a PC, tablet computer, or high-end ARM development board. It runs the main control software and provides a user interface (UI). It can receive image data processed by the high-performance computing module, or directly receive image data transmitted from the handheld terminal for display. It also undertakes the function of issuing control commands, such as mode switching, imaging depth adjustment, gain adjustment and other operations. The internal high-speed interconnection is achieved through high-bandwidth buses such as PCIe or USB4, enabling high-speed, low-latency data transmission between the high-performance computing module and the display control module, ensuring the coordinated and efficient operation of high-performance computing and real-time image display.

[0021] The handheld terminal and the trolley can be connected via Thunderbolt 5 cable or Wi-Fi. Note that when using Wi-Fi, the trolley must be connected to the same Wi-Fi network as the handheld terminal.

[0022] The ultrasound imaging method of the present invention includes at least the following steps: Step S101: When the handheld terminal and the trolley are connected by a wire, generate a performance signal; In step S101, the mode selection module monitors the connection status between the handheld terminal and the trolley in real time. If a wired connection is detected between the handheld terminal and the trolley, the performance mode is automatically activated, and the mode selection module generates a performance signal. In this mode, the goal is to maximize image quality and fully utilize the GPU computing power of the trolley.

[0023] It should be noted that if the handheld terminal and the trolley are detected to be connected in both wired and wireless modes at the same time, the performance mode will be started automatically by default. On this basis, users can also manually start the portable mode to flexibly switch to the corresponding working mode according to the user's actual needs. Furthermore, manual start has higher priority than automatic start, meaning that manual operation will override the current automatic mode state.

[0024] Furthermore, assuming no connection failures or other anomalies are detected, if the handheld terminal and the trolley are not connected via wire, they must be connected wirelessly. In this case, proceed to step S201 to automatically activate portable mode. The execution order of steps S101 and S201 is not important.

[0025] Step S102: The performance signal is sent to the handheld terminal so that the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal, and transmits it to the trolley via wired connection; wherein, the radio frequency signal is obtained by the handheld terminal after collecting the echo signal and then amplifying it through the analog front-end and converting it from analog to digital; the echo signal is obtained by the handheld terminal exciting the array element position of the built-in probe according to the preset excitation pulse so that the built-in probe emits ultrasonic waves and then collects them; In a preferred embodiment, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate a corresponding first complex baseband signal, including: The radio frequency signal of each channel is quadrature demodulated to obtain the corresponding first demodulated signal; The first compensation gain is determined based on the first demodulated signal; The first demodulated signal is compensated according to the first compensation gain to obtain the compensated complex baseband signal; The compensated complex baseband signal is filtered and enhanced using a preset frequency band filter to obtain the corresponding first complex baseband signal.

[0026] For step S102, the mode selection module sends the performance signal generated in step S101 to the handheld terminal.

[0027] Upon receiving the performance signal, the handheld terminal first works with the trolley to complete ultrasonic transmission and echo acquisition. Specifically, the user sets scanning parameters, such as depth, frequency, and focus, through the software interface on the trolley. These scanning parameters are sent to the FPGA of the handheld terminal via a Thunderbolt interface. The FPGA controls the high-voltage transmission circuit to generate specific excitation pulses, which excite the array elements of the probe to emit ultrasonic waves. Subsequently, 64 array elements receive the echo signals, which are then amplified by an analog front-end and converted to digital signals (ADC) to obtain 64 channels of digital radio frequency (RF) signals.

[0028] The FPGA in the handheld terminal performs front-end preprocessing on the RF signal of each channel. Specifically, it performs quadrature demodulation on the RF signal of each channel through digital downconversion (DDC), converting it into baseband I / Q signals to obtain the corresponding first demodulated signal. The specific formula is as follows: ; ; in, Indicates radio frequency signal, Indicates the center frequency of the radio frequency signal. This represents the in-phase signal of the first demodulated signal. This represents the quadrature signal of the first demodulated signal.

[0029] This invention significantly reduces the data rate through the quadrature demodulation process of digital downconversion (DDC), typically reducing it to 1 / 4 of the original RF signal data rate. Taking a 50MHz RF signal as an example, the complex sampling rate of the I / Q signal can be reduced to 12.5MSps, which effectively reduces the real-time data processing load of the handheld terminal FPGA and also reduces the bandwidth occupation of subsequent transmission links.

[0030] Next, the FPGA in the handheld terminal determines the first compensation gain based on the depth-time information in the first demodulated signal, thereby performing digital time gain compensation (TGC) on the I / Q signals to compensate for the attenuation of ultrasound with increasing depth. Specifically: The corresponding tissue attenuation coefficient is selected according to the clinical application scenario of the present invention. With transmission frequency Taking abdominal ultrasound imaging as an example, the corresponding tissue attenuation coefficient is selected. Transmission frequency Depth calculated based on depth attenuation model The signal attenuation at depth is obtained using the following formula. The signal attenuation value in decibels is as follows: ; in, Indicates depth The signal attenuation value in decibels at that location. This represents the initial signal amplitude before the ultrasonic wave attenuates after emission. Indicates depth The actual signal amplitude at that location.

[0031] To ensure that the amplitude of the compensated signal remains constant, the gain curve must satisfy the following relationship: ; in, Represents the base gain curve. This represents a fixed compensation coefficient used to adjust the overall brightness of the image.

[0032] Based on the above relationship, combined with the fixed compensation coefficient Generate the basic gain curve This is to counteract the attenuation of ultrasound waves with increasing depth, as specifically shown below: ; Then, the 64 channels were calibrated by inputting a standard sine wave of the same amplitude into all channels, acquiring the I / Q data of the first demodulated signal of each channel, and calculating its amplitude. The baseline amplitude is the amplitude of channel 1 or the average amplitude of all channels. The calibration factor is obtained using the following formula: ; in, Indicates each channel The calibration factor is used to correct amplitude differences between different channels. If a certain channel... actual range Less than the reference amplitude The corresponding calibration factor The value will be greater than 1, at which point the calibration factor can perform additional gain compensation for that channel; if a channel actual range Greater than the reference amplitude The corresponding calibration factor It will be less than 1, at which point the calibration factor can attenuate the gain of the channel.

[0033] Finally, the base gain curve Calibration factor of the corresponding channel Multiply to get each channel In depth First compensation gain at the location : ; and the first compensation gain Applied to the original I / Q signal, i.e. , The compensated I / Q data can be obtained using the following formula: ; ; in, and This represents the compensated I / Q data. After compensation, a specific frequency band filter H(z) is designed to filter the designated frequency bands that need enhancement, typically the second and third harmonic bands. The enhanced I / Q data is obtained after filtering. ; ; in, and This represents the enhanced I / Q data, with the corresponding signal serving as the in-phase component of the first complex baseband signal. and orthogonal components .

[0034] This invention calculates a base gain curve based on a depth attenuation model to compensate for the attenuation of ultrasound waves with increasing depth. Then, calibration factors are obtained through channel calibration to correct amplitude differences between different channels. The base gain curve is combined with the corresponding channel calibration factors to generate a final gain curve applied to the I / Q signals. This achieves both attenuation compensation for ultrasound waves with increasing depth and elimination of amplitude deviations between channels, ensuring amplitude stability of signals at different depths and in different channels. Furthermore, in ultrasound applications, harmonic signals typically correspond to richer tissue or target features. Enhancement allows the in-phase and quadrature components of the first complex baseband signal to more clearly represent these features, helping to improve the contrast and resolution of subsequent ultrasound imaging and making the signal features of different channels easier to identify.

[0035] The handheld terminal organizes the first complex baseband signal of each channel into a specific data packet structure, adds header information such as timestamps and channel numbers, and directly writes the packaged data into the high-speed buffer of the Thunderbolt 5 controller via direct memory access (DMA), ready for transmission. This method eliminates the need for CPU resources for data relay, thus improving data processing efficiency.

[0036] Finally, the Thunderbolt 5 interface operates in full-duplex mode, continuously and stably transmitting I / Q data streams of up to 1.5GB / s from the handheld terminal to the trolley. The Thunderbolt protocol has a built-in high-priority isochronous transmission channel, which can ensure the real-time and deterministic nature of data transmission and effectively avoid data loss.

[0037] Step S103: Send the performance signal to the trolley so that the trolley performs beamforming on the first complex baseband signal of all channels based on adaptive delay calculation to generate a second complex baseband signal; perform envelope detection on the second complex baseband signal to generate a first amplitude signal; and display the image based on the first amplitude signal. In a preferred embodiment, the trolley, based on adaptive delay calculation, performs beamforming on the first complex baseband signals of all channels to generate a second complex baseband signal, including: Set the imaging parameters; the imaging parameters include: depth range and number of scan lines; The pixel grid of the image to be displayed is determined based on the imaging parameters; the pixel grid includes several pixel positions. For each pixel position, the first delay of the corresponding channel is calculated based on the path difference between the straight-line propagation distance from the element position to the pixel position and the propagation distance along the depth direction. Based on the first delay of each channel, the first complex baseband signal value under the first delay is interpolated to obtain the first delay alignment signal value of the corresponding channel. Based on the first preset weight, the first delay alignment signal values ​​of all channels are weighted and summed to obtain the second complex baseband signal value; The second complex baseband signal is constructed based on the second complex baseband signal values ​​at all pixel locations.

[0038] In step S103, the mode selection module sends the performance signal generated in step S101 to the trolley. Upon receiving the performance signal, the trolley receives the data packet sent by the handheld terminal, unpacks the data packet using the GPU driver to obtain the first complex baseband signal of each channel, and reassembles the 64-channel I / Q data into a three-dimensional array Data[Channel][Sample][I / Q] in the GPU memory, where Channel represents the channel number and Sample represents the sampling point position.

[0039] Next, the trolley completes beamforming based on adaptive delay calculation. Specifically, it first sets imaging parameters including depth range and number of scan lines, and then determines the pixel grid of the image to be displayed based on these imaging parameters. The pixel grid consists of several pixel positions.

[0040] This invention takes a linear array as an example, targeting each pixel position. Based on the path difference between the linear propagation distance from the element position to the pixel position and the propagation distance along the depth direction for each channel, the first delay of the corresponding channel is calculated using the following formula. : ; in, Indicates pixel position, Indicates the scan line position. Indicates depth position. Indicates the pixel position Upper The first delay of each channel, Indicates the speed of sound in the medium. Indicates the first The position of the array element in each channel. This represents the arithmetic square root operation.

[0041] Since the first delay typically does not correspond to a discrete sampling time point, the first complex baseband signal value under this delay needs to be interpolated, such as by sinc interpolation or linear interpolation, to obtain the first delay-aligned signal value for the corresponding channel. It should be noted that this step is performed in parallel by thousands of threads on the GPU, with each thread responsible for calculating a sampling point or a portion of a pixel for one channel. This significantly reduces the processing time of this step and adapts to the computational needs of multi-channel, large-scale pixel grids.

[0042] Then, for each pixel position According to the first preset weight The second complex baseband signal value at the pixel location is obtained by weighted summing of the first delay alignment signal values ​​of all channels. ; ; in, Indicates pixel position The in-phase signal value of the second complex baseband signal. Indicates the first Each channel during the first delay The in-phase signal value of the first delayed aligned signal obtained after interpolation processing. Indicates pixel position The orthogonal signal values ​​of the second complex baseband signal, Indicates the first Each channel during the first delay The orthogonal signal values ​​of the first delayed aligned signal obtained after interpolation processing. This represents the first preset weight, i.e., the aperture weighting coefficient, such as the Hamming window.

[0043] Integrate the second complex baseband signal values ​​of all pixel locations, and combine the values ​​of each pixel location. The corresponding in-phase and quadrature components of the second complex baseband signal are aggregated according to the pixel grid spatial distribution of the imaging area, thereby forming a complete second complex baseband signal that covers the entire imaging range and contains the position, amplitude and phase information of all pixels.

[0044] Envelope detection is performed on the second complex baseband signal. For the in-phase and quadrature components at each pixel location in the second complex baseband signal, their magnitudes are calculated using the following formula. The magnitudes of all pixel locations are then summed to obtain the first amplitude signal. : ; The trolley, through its display control module, performs logarithmic compression on the amplitude data in the first amplitude signal, compressing its dynamic range to a range that the display can accommodate (e.g., 0-255). Subsequently, a scan conversion is performed. The polar coordinate data acquired by the phased array / convex array probe is converted into image data in a Cartesian coordinate system. Following the spatial distribution of the pixel grid, each amplitude value is precisely matched to its corresponding pixel coordinate position. Different amplitudes will exhibit different brightness or color levels, ultimately rendering a visualized ultrasound image that allows clinical users to intuitively observe the tissue structure of the imaging area.

[0045] After completing the basic Delayed Summation (DAS), in order to further improve image quality, in a preferred embodiment, the first preset weight is determined in the following way: For each pixel position, construct the first covariance matrix based on the first delay alignment signal values ​​of all channels; Construct a steering vector based on the first delay of all channels; The first preset weights are determined based on the first covariance matrix and the steering vector.

[0046] In one embodiment of the present invention, for each pixel position First, the first delay alignment signal values ​​of all channels are aggregated to form a data vector. Then, based on the data vector, the first covariance matrix is ​​constructed. ; in, Let the first covariance matrix be denoted as . Represents a data vector. This represents the mathematical expectation operation. This indicates the conjugate transpose operation.

[0047] Based on the first delay of all channels, a steering vector is formed. The first preset weights are calculated by combining the first covariance matrix and the steering vector: ; in, The guide vector represents the theoretical phase delay in the main lobe direction. In this embodiment, the contribution of each channel is adaptively adjusted based on the signal statistical characteristics of the current pixel, thereby reducing beamside lobe interference.

[0048] In a preferred embodiment, the trolley displays an image based on a first amplitude signal, including: Extract the first harmonic component of the first amplitude signal; the first harmonic component includes the second harmonic or the third harmonic; The image is displayed based on the first harmonic component.

[0049] In one embodiment of the present invention, in order to further enhance the detail rendering capability and tissue differentiation of ultrasound images, and make the imaging results more in line with the high image quality requirements of clinical diagnosis, harmonic imaging is introduced. Specifically, the trolley extracts the first harmonic component of the first amplitude signal, which can be achieved in the following three ways: First, by using a bandpass filter, the second harmonic component with a center frequency of 2f (f is the frequency of the emitted ultrasound) or the third harmonic component with a center frequency of 3f (f is the frequency of the emitted ultrasound) is extracted from the I / Q data using a digital bandpass filter; Second, by using a demodulation method, the original RF signal is directly demodulated synchronously twice, and the corresponding second / third harmonic components are extracted by designing a demodulator containing 4πft (the phase term corresponding to the 2f frequency); Third, by using quadrature demodulation and digital downconversion (DDC), the RF signal is first digitally downconverted on the FPGA or GPU to lock the 2f frequency to obtain the I / Q component corresponding to the second harmonic or the 3f frequency to obtain the I / Q component corresponding to the third harmonic.

[0050] After extracting the second / third harmonic components, their corresponding amplitude values ​​are mapped to the corresponding grayscale or color visual parameters according to the spatial distribution of the pixel grid, and finally rendered as an ultrasound image.

[0051] In this embodiment, the imaging method based on second / third harmonics can effectively reduce the background noise caused by the scattering of the fundamental wave of human tissue, highlight the echo signal of specific tissues (such as diseased tissues and microvessels), greatly improve the tissue contrast and detail of the image, and make it easier for clinical users to identify subtle anatomical structures and abnormal lesion areas, thereby improving the accuracy of diagnosis.

[0052] Step S201: When the handheld terminal and the trolley are wirelessly connected, generate a portable signal; For step S201, the mode selection module monitors the connection status between the handheld terminal and the trolley in real time. If it detects that the handheld terminal and the trolley are wirelessly connected, it automatically starts the portable mode and the mode selection module generates a portable signal.

[0053] In this mode, the core focus is on ensuring the mobility and flexibility of the equipment. It adapts to the bandwidth limitations of wireless transmission and moves some signal processing tasks to the handheld terminal to reduce the amount of data transmitted. While balancing portability and basic imaging requirements, it meets the usage needs of scenarios such as bedside mobile examinations.

[0054] Step S202: Send the portable signal to the handheld terminal so that the handheld terminal performs parallel beamforming on the radio frequency signal of each channel through a preset delay lookup table to generate a beamformed signal; perform envelope detection and downsampling on the beamformed signal to generate a second amplitude signal, and wirelessly transmit it to the trolley. In step S202, the mode selection module sends the portable signal generated in step S201 to the handheld terminal.

[0055] When the handheld terminal receives a portable signal, it loads a pre-designed and highly optimized beam synthesizer IP core inside the handheld terminal FPGA. The IP core adopts a fully parallel pipeline architecture and contains a pre-computed delay lookup table (LUT) that stores the delay values ​​of all channels, all scan lines, and all depth points, which can save the computing power consumption of real-time delay calculation.

[0056] By performing parallel beamforming on the RF signals of each channel using a delay lookup table, a beamformed signal integrating multiple channels can be quickly generated. This invention addresses the signal processing needs of FPGAs in portable mode by designing two processing procedures adapted to different computational logics, corresponding to the following two embodiments: In a preferred embodiment, the handheld terminal performs parallel beamforming on the radio frequency signals of each channel using a preset delay lookup table to generate a beamformed signal, including: Based on the preset delay lookup table, look up the second delay corresponding to each pixel position in each channel; For each pixel position, the radio frequency signal value under the second delay is interpolated according to the second delay of each channel to obtain the second delay alignment signal value of the corresponding channel; According to the second preset weight, the second delay alignment signal values ​​of all channels are weighted and summed to obtain the beamforming signal value; The beamforming signal is constructed based on the beamforming signal values ​​at all pixel locations.

[0057] In one embodiment of the present invention, the FPGA directly processes radio frequency (RF) data. First, by using the delay lookup table pre-stored in the IP core, the second delay corresponding to each pixel position under each channel is directly retrieved, saving the computational power consumption of real-time delay calculation.

[0058] Subsequently, for each pixel position, the interpolator configured for each channel by the IP core (such as a fractional delay filter with a Farrow structure) is used to interpolate the RF signal value corresponding to the second delay, thus solving the problem of misalignment between the delay and the discrete sampling point and obtaining the second delay aligned signal value of the corresponding channel.

[0059] The beamforming signal value at the pixel location is obtained by weighting and summing the second delay alignment signal values ​​of all channels according to the second preset weight using the multiply-accumulate (MAC) within the IP core.

[0060] Finally, the entire process follows the fully parallel pipeline architecture of the IP core. After the RF data stream enters the IP core, it flows forward like a pipeline in each clock cycle. At the end of the pipeline, 64 channels of weighting, delay, interpolation, and summation operations are completed. The result of a single depth point for a single scan line is output in real time at a high clock frequency of 100-200MHz. Finally, the beamforming signal values ​​of all pixel positions are integrated according to the spatial distribution of the imaging area to form a complete beamforming signal. In this embodiment, although the computational load of directly processing RF data is relatively large, the demodulation stage is eliminated, and the insufficient number of FPGA computing units is compensated for by hardware parallelism, ensuring the high efficiency of beamforming in portable mode.

[0061] In another preferred embodiment, the handheld terminal performs parallel beamforming on the radio frequency signals of each channel using a preset delay lookup table to generate a beamformed signal, including: The radio frequency signal of each channel is quadrature demodulated to obtain the corresponding second demodulated signal; The second compensation gain is determined based on the second demodulated signal; The second demodulated signal is compensated according to the second compensation gain to obtain the corresponding third complex baseband signal; Based on the preset delay lookup table, look up the second delay corresponding to each pixel position in each channel; For each pixel position, based on the second delay of each channel, the third complex baseband signal value under the second delay is interpolated to obtain the third delay alignment signal value of the corresponding channel. Based on the third preset weight, the third delay alignment signal values ​​of all channels are weighted and summed to obtain the beamforming signal value; The beamforming signal is constructed based on the beamforming signal values ​​at all pixel locations.

[0062] In another embodiment of the present invention, the FPGA performs basic quadrature demodulation (DDC) and gain compensation (TGC) processing. First, quadrature demodulation is performed on the RF signal of each channel to convert the RF signal into a baseband signal and obtain the corresponding second demodulated signal. This completes the conversion of the signal from the RF domain to the baseband domain, which facilitates the subsequent gain compensation processing.

[0063] Subsequently, a second compensation gain is determined based on the characteristics of the second demodulated signal. This gain is then used to perform gain compensation (TGC) on the second demodulated signal to offset the signal attenuation problem caused by the increase of propagation depth, thereby obtaining the corresponding third complex baseband signal.

[0064] By utilizing a pre-defined delay lookup table, the second delay corresponding to each pixel position under each channel is directly retrieved, eliminating the computational overhead of real-time delay calculation. For each pixel position, the interpolator configured for each channel in the IP core (such as a fractional delay filter with a Farrow structure) is used to interpolate the third complex baseband signal value corresponding to the second delay, resolving the misalignment issue between the delay and discrete sampling points, and obtaining the third delay aligned signal value for the corresponding channel. The multiplier-accumulator (MAC) within the IP core is then used to perform a weighted summation of the third delay aligned signal values ​​for all channels according to a third pre-defined weight, yielding the beamforming signal value for that pixel position.

[0065] Finally, the entire process also follows the fully parallel pipeline architecture of the IP core. After the third complex baseband data stream enters the IP core, it flows forward like a pipeline in each clock cycle. At the end of the pipeline, the 64 channels are weighted, delayed, interpolated, and summed to complete the results of a single depth point for a single scan line in real time at a high clock frequency. Finally, the beamforming signal values ​​of all pixel positions are integrated according to the spatial distribution of the imaging area to form a complete beamforming signal. Although this embodiment adds the steps of quadrature demodulation and gain compensation, it can optimize the signal quality in advance and is more suitable for portable mode scenarios with high requirements for signal preprocessing.

[0066] The beam-synthesized signal is either a radio frequency (RF) signal or a complex baseband signal. Envelope detection is performed on the beam-synthesized signal. If the beam-synthesized signal is a complex baseband signal, the amplitude information is extracted by calculating the magnitudes of its in-phase component (I) and quadrature component (Q). If the beam-synthesized signal is an RF signal, the amplitude information is extracted by envelope detection processing in the digital domain.

[0067] Subsequently, the extracted amplitude signal is downsampled to reduce the number of sampling points and lower the signal sampling rate while retaining valid amplitude information. After envelope detection and downsampling, a second amplitude signal is finally generated. This data is single-channel amplitude information, and the data rate is reduced by several orders of magnitude compared to the original RF data. This significantly reduces the bandwidth usage of wireless transmission, avoids transmission delay and data packet loss, and also reduces the transmission power consumption of the handheld terminal, thus effectively adapting to the needs of mobile use scenarios in portable mode.

[0068] The handheld FPGA packages the second amplitude signal into data, standardizes the signal transmission format to adapt to the wireless communication protocol, and wirelessly transmits the second amplitude signal to the trolley via the Wi-Fi module. In this embodiment, due to the very low data rate of only about 20MB / s, which is far below the bandwidth capacity of Wi-Fi 6E, stable and low-latency transmission is possible, and power consumption is extremely low.

[0069] Step S203: Send the portable signal to the trolley so that the trolley can display an image based on the second amplitude signal.

[0070] In step S203, the mode selection module sends the portable signal generated in step S201 to the trolley. Upon receiving the portable signal, the trolley receives the second amplitude signal sent by the handheld terminal. Subsequently, the trolley maps the values ​​corresponding to the second amplitude signal to the corresponding grayscale or color visual parameters according to the spatial distribution of the pixel grid, and finally renders it into a visualized ultrasound image. This ensures that clinical users can observe the tissue structure of the imaging area in real time and clearly in mobile scenarios in portable mode, while relying on the low data rate advantage of the second amplitude signal to achieve stable and low-latency image display.

[0071] It should be noted that, in order to further improve image quality, the adaptive calculation of preset weights and the implementation method of harmonic imaging in the embodiments of the present invention can be used. Only the adaptability adjustment needs to be made to suit the signal data characteristics in portable mode. The specific implementation process and effect will not be described in detail.

[0072] In a preferred embodiment, the handheld terminal excites the array element positions of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and acquires the data, including: The array element position of the built-in probe is excited once according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and the data is collected; or the array element position of the built-in probe is excited multiple times according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and the data is collected. When the array element positions of the built-in probe are excited multiple times, the handheld terminal performs front-end preprocessing on the RF signal of each channel to generate the corresponding first complex baseband signal; the handheld terminal performs parallel beamforming on the RF signal of each channel through a preset delay lookup table to generate a beamformed signal; the beamformed signal is then envelope-detected and downsampled to generate a second amplitude signal, including: For each excitation, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal; for each excitation, the handheld terminal performs parallel beamforming on the radio frequency signal of each channel through a preset delay lookup table to generate a beamforming signal; after weighted summation of the beamforming signals of each excitation, envelope detection and downsampling are performed to generate a second amplitude signal. With multiple excitations of the array element positions of the built-in probe, the trolley, based on adaptive delay calculation, performs beamforming on the first complex baseband signals of all channels to generate a second complex baseband signal; and performs envelope detection on the second complex baseband signal to generate a first amplitude signal, including: For each excitation, the trolley performs beamforming on the first complex baseband signal of all channels based on adaptive delay calculation to generate the second complex baseband signal; after weighted summation of the second complex baseband signal for each excitation, envelope detection is performed to generate the first amplitude signal.

[0073] In one embodiment of the present invention, the handheld terminal excites the probe array elements in two ways: single excitation and multiple excitation, to adapt to different imaging requirements. If single excitation is used, the handheld terminal will excite the probe array element positions once according to a preset excitation pulse, causing the probe to emit ultrasonic waves and collect echo signals. Subsequently, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal. Then, it performs parallel beamforming on the signals of each channel through a preset delay lookup table to obtain a beamformed signal. Finally, it generates a second amplitude signal through envelope detection and downsampling. Meanwhile, the trolley performs beamforming on the first complex baseband signals of all channels based on adaptive delay calculation to obtain a second complex baseband signal, and then generates a first amplitude signal through envelope detection, thereby completing rapid imaging under single excitation.

[0074] If multiple excitations (i.e., synthetic aperture imaging) are used, the handheld terminal will apply excitations to different array elements (or small array elements) of the probe multiple times, with each excitation stimulating a different array element and the echo signal being received by all array elements. For each excitation, the handheld terminal will perform front-end preprocessing on the RF signals of each channel to generate the first complex baseband signal, and then use a delay lookup table to complete parallel beamforming to obtain the beamforming signal corresponding to this excitation. Finally, the beamforming signals obtained from all excitations will be weighted and summed. ; ; in, This represents the in-phase component of the beamforming signal obtained from all excitations, after weighted summation. This represents the orthogonal components of the beamforming signals obtained from all excitations, after weighted summation. Indicates the number of launch stimuli. Indicates the number of receive channels. Indicates the first Secondary incentive The weighting coefficients corresponding to each receiving channel.

[0075] Similarly, for each excitation, the trolley performs beamforming of the first complex baseband signal of each channel based on adaptive delay calculation to obtain the second complex baseband signal corresponding to this excitation. Then, the second complex baseband signals of multiple excitations are weighted and summed before envelope detection to generate the first amplitude signal.

[0076] In this embodiment, by using multiple excitation methods and fusing data from multiple transmission paths, the probe aperture is effectively increased, which can significantly improve the lateral resolution and penetration of ultrasound images, making the imaging details clearer; while a single excitation can meet the needs of rapid imaging scenarios. The two excitation methods together cover the imaging requirements of different clinical scenarios.

[0077] This invention monitors the connection status between the handheld terminal and the trolley in real time through a mode selection module, enabling switching between performance mode and portable mode. It also adapts the signal processing of the corresponding mode according to the different computing power of the trolley and the handheld terminal. By using dual working modes, it takes into account both high-quality diagnosis and treatment and the needs of mobile scenarios, and solves the contradiction between high-performance computing and portability. This allows clinicians to obtain the optimal diagnostic experience in multiple scenarios on a single device. Table 1 shows a comparison of the characteristics of performance mode and portable mode.

[0078] Table 1 Comparison of Features between Performance Mode and Portable Mode The following is an example of a specific application: Take, for example, a scenario where a cardiologist needs to move between the catheterization lab and patient rooms: In the catheterization lab (performance mode required), the doctor connects the handheld terminal to the trolley host via a Thunderbolt 5 cable. The system automatically recognizes and enters performance mode. After the doctor scans the patient's heart using a phased array probe, 64 channels of I / Q data are transmitted to the trolley at high speed via cable. The internal NVIDIA RTX 5000 GPU performs real-time high-precision delay calculation, adaptive beamforming, and harmonic imaging. The display then presents a dynamic image of the heart with extremely high resolution and excellent tissue contrast, which can be directly used for precise preoperative diagnosis and intraoperative guidance. When traveling to the ward for a consultation (requiring portable mode), the doctor simply unplugs the Thunderbolt 5 cable. The system seamlessly switches to portable mode within seconds. The doctor then carries the probe and tablet to the ward. At this time, the FPGA in the handheld terminal performs beamforming and envelope detection in real time and sends the data to the tablet app via Wi-Fi. After receiving the data, the app completes the image display. Although the image quality is slightly lower than in performance mode, it far exceeds that of traditional portable devices and is sufficient to meet the needs of bedside rapid assessment, fluid examination, etc., helping doctors to make an immediate diagnosis. After the consultation ends and the doctor returns to the catheterization lab, the doctor plugs the cable back in, and the system automatically switches back to performance mode, restoring imaging performance and seamlessly connecting to subsequent diagnostic and treatment operations.

[0079] Based on the above method embodiments, corresponding system embodiments are provided; An embodiment of the present invention provides an ultrasound imaging system with dual working modes, including: a mode selection module, a handheld terminal, and a trolley; The mode selection module is used to generate a performance signal when the handheld terminal and the trolley are connected by a wire; and to send the performance signal to the handheld terminal and the trolley respectively; when the handheld terminal and the trolley are connected by a wireless connection, it generates a portable signal; and to send the portable signal to the handheld terminal and the trolley respectively. The handheld terminal is used to excite the array element positions of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and collects the echo signal; the echo signal is amplified by analog front-end and converted from analog to digital to obtain radio frequency (RF) signal; when the performance signal is received, the RF signal of each channel is preprocessed by front-end to generate the corresponding first complex baseband signal, and transmitted to the trolley via wire; when the portable signal is received, the RF signal of each channel is parallel beamformed by using a preset delay lookup table to generate beamformed signal; the beamformed signal is envelope detected and downsampled to generate a second amplitude signal, and transmitted wirelessly to the trolley. The trolley is used to receive the first complex baseband signal of each channel sent by the handheld terminal; upon receiving the performance signal, it performs beamforming on the first complex baseband signals of all channels based on adaptive delay calculation to generate a second complex baseband signal; it performs envelope detection on the second complex baseband signal to generate a first amplitude signal; it performs image display based on the first amplitude signal; it receives the second amplitude signal sent by the handheld terminal; and it performs image display based on the second amplitude signal.

[0080] In a preferred embodiment, the trolley displays an image based on a first amplitude signal, including: Extract the first harmonic component of the first amplitude signal; the first harmonic component includes the second harmonic or the third harmonic; The image is displayed based on the first harmonic component.

[0081] It is understood that the above system embodiments correspond to the method embodiments of the present invention, and can implement the dual-working-mode ultrasound imaging method provided by any of the above method embodiments of the present invention.

[0082] It should be noted that the system embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the system embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0083] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A dual-mode ultrasound imaging method, characterized in that, A mode selection module suitable for ultrasound imaging systems; The ultrasound imaging system also includes: a handheld terminal and a trolley; The ultrasound imaging method includes: When the handheld terminal and the trolley are connected by a wire, a performance signal is generated; The performance signal is sent to the handheld terminal, which then performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal, and transmits it to the trolley via wired connection. The radio frequency signal is obtained by the handheld terminal acquiring the echo signal and then amplifying it through an analog front-end and performing analog-to-digital conversion. The echo signal is obtained by the handheld terminal exciting the array element position of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and the signal is acquired. The performance signal is sent to the trolley, which then performs beamforming on the first complex baseband signal of all channels based on adaptive delay calculation to generate a second complex baseband signal; envelope detection is performed on the second complex baseband signal to generate a first amplitude signal; and image display is performed based on the first amplitude signal. When the handheld terminal and the trolley are wirelessly connected, a portable signal is generated. The portable signal is sent to the handheld terminal, which then performs parallel beamforming on the radio frequency signal of each channel using a preset delay lookup table to generate a beamformed signal. The beamformed signal is then envelope-detected and downsampled to generate a second amplitude signal, which is then wirelessly transmitted to the trolley. The portable signal is sent to the trolley so that the trolley can display an image based on the second amplitude signal.

2. The dual-mode ultrasound imaging method according to claim 1, characterized in that, The handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal, including: The radio frequency signal of each channel is quadrature demodulated to obtain the corresponding first demodulated signal; The first compensation gain is determined based on the first demodulated signal; The first demodulated signal is compensated according to the first compensation gain to obtain the compensated complex baseband signal; The compensated complex baseband signal is filtered and enhanced using a preset frequency band filter to obtain the corresponding first complex baseband signal.

3. The dual-mode ultrasound imaging method according to claim 2, characterized in that, The trolley, based on adaptive delay calculation, performs beamforming on the first complex baseband signals of all channels to generate a second complex baseband signal, including: Set imaging parameters; the imaging parameters include: depth range and number of scan lines; The pixel grid of the image to be displayed is determined based on the imaging parameters; the pixel grid includes several pixel positions. For each pixel position, the first delay of the corresponding channel is calculated based on the path difference between the straight-line propagation distance from the element position to the pixel position and the propagation distance along the depth direction. Based on the first delay of each channel, the first complex baseband signal value under the first delay is interpolated to obtain the first delay alignment signal value of the corresponding channel. Based on the first preset weight, the first delay alignment signal values ​​of all channels are weighted and summed to obtain the second complex baseband signal value; The second complex baseband signal is constructed based on the second complex baseband signal values ​​at all pixel locations.

4. The dual-mode ultrasound imaging method according to claim 3, characterized in that, The handheld terminal performs parallel beamforming on the radio frequency signals of each channel using a preset delay lookup table to generate a beamformed signal, including: Based on the preset delay lookup table, look up the second delay corresponding to each pixel position in each channel; For each pixel position, the radio frequency signal value under the second delay is interpolated according to the second delay of each channel to obtain the second delay alignment signal value of the corresponding channel; According to the second preset weight, the second delay alignment signal values ​​of all channels are weighted and summed to obtain the beamforming signal value; The beamforming signal is constructed based on the beamforming signal values ​​at all pixel locations.

5. The dual-mode ultrasound imaging method according to claim 3, characterized in that, The handheld terminal performs parallel beamforming on the radio frequency signals of each channel using a preset delay lookup table to generate a beamformed signal, including: The radio frequency signal of each channel is quadrature demodulated to obtain the corresponding second demodulated signal; The second compensation gain is determined based on the second demodulated signal; The second demodulated signal is compensated according to the second compensation gain to obtain the corresponding third complex baseband signal; Based on the preset delay lookup table, look up the second delay corresponding to each pixel position in each channel; For each pixel position, based on the second delay of each channel, the third complex baseband signal value under the second delay is interpolated to obtain the third delay alignment signal value of the corresponding channel. Based on the third preset weight, the third delay alignment signal values ​​of all channels are weighted and summed to obtain the beamforming signal value; The beamforming signal is constructed based on the beamforming signal values ​​at all pixel locations.

6. The dual-mode ultrasound imaging method according to claim 3, characterized in that, The first preset weight is determined in the following way: For each pixel position, construct the first covariance matrix based on the first delay alignment signal values ​​of all channels; Construct a steering vector based on the first delay of all channels; The first preset weights are determined based on the first covariance matrix and the steering vector.

7. The dual-mode ultrasound imaging method according to claim 1, characterized in that, The handheld terminal excites the array element positions of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and acquires the data, including: The array element position of the built-in probe is excited once according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and the data is collected; or the array element position of the built-in probe is excited multiple times according to the preset excitation pulse, so that the built-in probe emits ultrasonic waves and the data is collected. When the array element positions of the built-in probe are excited multiple times, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate a corresponding first complex baseband signal; the handheld terminal performs parallel beamforming on the radio frequency signal of each channel through a preset delay lookup table to generate a beamformed signal; the process of envelope detection and downsampling of the beamformed signal to generate a second amplitude signal includes: For each excitation, the handheld terminal performs front-end preprocessing on the radio frequency signal of each channel to generate the corresponding first complex baseband signal; for each excitation, the handheld terminal performs parallel beamforming on the radio frequency signal of each channel through a preset delay lookup table to generate a beamforming signal; after weighted summation of the beamforming signals of each excitation, envelope detection and downsampling are performed to generate a second amplitude signal. When the array element positions of the built-in probe are excited multiple times, the trolley performs beamforming on the first complex baseband signals of all channels based on adaptive delay calculation to generate a second complex baseband signal; the envelope detection of the second complex baseband signal to generate a first amplitude signal includes: For each excitation, the trolley performs beamforming on the first complex baseband signal of all channels based on adaptive delay calculation to generate the second complex baseband signal; after weighted summation of the second complex baseband signal for each excitation, envelope detection is performed to generate the first amplitude signal.

8. The dual-mode ultrasound imaging method according to claim 1, characterized in that, The trolley displays an image based on the first amplitude signal, including: Extract the first harmonic component of the first amplitude signal; the first harmonic component includes the second harmonic or the third harmonic; The image is displayed based on the first harmonic component.

9. A dual-mode ultrasound imaging system, characterized in that, include: Mode selection module, handheld terminal and trolley; The mode selection module is used to generate performance signals when the handheld terminal and the trolley are connected by a wire. The performance signal is sent to the handheld terminal and the trolley respectively; when the handheld terminal and the trolley are wirelessly connected, a portable signal is generated. The portable signal is sent to the handheld terminal and the trolley respectively; The handheld terminal is used to excite the array element positions of the built-in probe according to a preset excitation pulse, so that the built-in probe emits ultrasonic waves and collects the echo signal; the echo signal is amplified by analog front-end and converted from analog to digital to obtain a radio frequency signal; when a performance signal is received, the radio frequency signal of each channel is preprocessed by front-end to generate the corresponding first complex baseband signal, and transmitted to the trolley via wire; when a portable signal is received, the radio frequency signal of each channel is parallel beamformed by a preset delay lookup table to generate a beamformed signal; the beamformed signal is envelope detected and downsampled to generate a second amplitude signal, and transmitted wirelessly to the trolley. The trolley is used to receive the first complex baseband signal of each channel sent by the handheld terminal; Upon receiving the performance signal, based on adaptive delay calculation, beamforming is performed on the first complex baseband signal of all channels to generate the second complex baseband signal. Envelope detection is performed on the second complex baseband signal to generate the first amplitude signal; Based on the first amplitude signal, an image is displayed; a second amplitude signal sent by the handheld terminal is received; and based on the second amplitude signal, an image is displayed.

10. The dual-mode ultrasound imaging system according to claim 9, characterized in that, The trolley displays an image based on the first amplitude signal, including: Extract the first harmonic component of the first amplitude signal; the first harmonic component includes the second harmonic or the third harmonic; The image is displayed based on the first harmonic component.

Images