An ultrasonic imaging system including an adjustable transducer probe

Abstract

Receiving echo signals with transducer elements reflected in the near and far fields of the medium, outputting a first set of digitally multiplexed echo signals corresponding to a first set of a plurality of transducer elements defining a small aperture for receiving echo signals reflected in the near field, group multiplexing the transducer elements of a second set of transducer elements into sub-arrays providing a second set of digitally multiplexed echo signals, summing the digitally multiplexed echo signals from the second set of transducer elements within each sub-array, summing the digitally multiplexed echo signals from the second set of transducer elements, and outputting an echo data stream including the first set and / or the second set of digitally multiplexed echo signals to a host system via a communication interface having a fixed maximum bandwidth.

Description

Technical Field

[0001] Ultrasonic images are essential for many medical imaging applications. An ultrasonic imaging system typically includes an ultrasonic probe and a processing system. The probe can include an array of ultrasonic transducer elements configured to transmit sound waves through a patient's body and receive echo signals when the sound waves are reflected from tissues, organs, and other structures. The timing and intensity of the echo signals generally correspond to the size, shape, and mass of the structures within the patient's body, and the image is displayed to the user of the ultrasonic imaging system.

Background Art

[0002] Up-to-date ultrasonic imaging systems can include a digital probe that digitizes echo signals from transducer elements within the probe itself. Since analog processing channels are not required in the base system connected to the digital probe, the image quality is not restricted by the ultrasonic imaging system. However, the digital probe has a fixed digital bandwidth that limits the performance of the ultrasonic imaging system. That is, the maximum data rate achievable in the digital probe is limited by power (heat), transistor technology speed (a trade-off in terms of cost and reliability), and the number of lines in the cable assembly that connects the digital probe to the host system. When these metrics are defined by project requirements, various methods must be used to reduce the resulting data rate in order to accommodate the desired number of channels or dynamic range.

Summary of the Invention

Problems to be Solved by the Invention

[0003] What is needed is an ultrasonic imaging system with a digital probe that efficiently reduces the data rate of the received echo signal, thereby effectively increasing the bandwidth. Reducing the data rate enables more channels to be recorded without affecting the final image quality while avoiding using more power, implementing faster / more expensive technology, and / or adding more conductors.

[0004] WO 2022 / 069264 A1 describes an ultrasonic imaging system including an ultrasonic probe. The ultrasonic probe includes a housing and a transducer array having first, second, and third acoustic elements.

[0005] U.S. Patent Application Publication No. 2008 / 114248 (A1) describes a method for ultrasonic interrogation of a medium, including transmitting non-beamforming or beamformed ultrasonic waves into the medium.

Means for Solving the Problem

[0006] According to an exemplary embodiment, a transducer probe of an ultrasonic imaging system includes a transducer array, a plurality of analog-to-digital converters (ADCs), a combiner, a switch, a digital processing unit, and a communication interface. The transducer array includes a plurality of transducer elements configured to transmit ultrasonic signals into a medium, receive echo signals in response to the ultrasonic signals being reflected in the near field and far field of the medium, and output corresponding electrical echo signals. The ADCs are configured to digitize the electrical echo signals and provide digitized echo signals. The combiner includes a multiplexer and a beamformer. The multiplexer is configured to multiplex the digitized echo signals and output a first set of digitized echo signals corresponding to a first set of transducer elements of the plurality of transducer elements that define a small aperture for receiving echo signals reflected in the near field. The beamformer groups transducer elements of a second set of transducer elements into subarrays that provide a second set of digitized echo signals, and includes a plurality of adders configured to sum the digitized echo signals from the second set of transducer elements within each subarray to receive echo signals reflected in the far field, where the second set of transducer elements includes more transducer elements than the first set of transducer elements. The switch is operable to select the multiplexer for near-field ultrasonic imaging and the beamformer for far-field ultrasonic imaging. The digital processing unit is configured to receive the first set of digitized echo signals and the second set of digitized echo signals and output corresponding digital echo streams. The communication interface is configured to communicate the echo data stream to an ultrasonic imaging system host, and the communication interface has a fixed maximum bandwidth. The small aperture defined by the first set of transducer elements provides a digital bandwidth of the echo data stream that is less than the maximum bandwidth of the communication interface.

[0007] In some embodiments, the combiner may further comprise a sampling rate switch configured to selectively connect a plurality of ADCs to the first signal generator or the second signal generator, the first signal generator providing a first signal for controlling the plurality of ADCs to sample the electrical echo signal at a first sampling rate for short-range imaging, and configured to provide a second signal for controlling the plurality of ADCs to sample the electrical echo signal at a second sampling rate for long-range field imaging, the first sampling rate being greater than the second sampling rate.

[0008] According to another exemplary embodiment, a method for controlling an ultrasonic transducer probe including a transducer array having a plurality of transducer elements is provided. The method includes receiving echo signals with a plurality of transducer elements in response to ultrasonic signals radiated by at least some of the plurality of transducer elements, where the echo signals are reflected in the near-field and far-field of the medium and output corresponding electrical echo signals; digitizing the digitized echo signals to provide digitized echo signals; multiplexing the digitized echo signals to output a first set of digitized echo signals corresponding to a first set of a plurality of transducer elements that define a small aperture for receiving echo signals reflected in the near-field; grouping transducer elements of a second set of transducer elements to provide a second set of digitized echo signals; summing digitized echo signals from the second set of transducer elements in each sub-array to receive echo signals reflected in the far-field, where the second set of transducer elements includes more transducer elements than the first set of transducer elements; and outputting an echo data stream including the first set and the second set. The digitized echo signals are sent to a host system via a communication interface having a fixed maximum bandwidth, and the small aperture defined by the first set of transducer elements provides a digital bandwidth of the echo data stream that is smaller than the maximum bandwidth of the communication interface.

[0009] According to another aspect of the present invention, a transducer probe of an ultrasonic imaging system includes a transducer array, a plurality of analog-to-digital converters (ADCs), a combiner, a digital processing unit, and a communication interface. The transducer array is configured to transmit ultrasonic signals into a medium, receive echo signals in response to the ultrasonic signals being reflected in the near-field and / or far-field of the medium, and output corresponding electrical echo signals, and includes a plurality of transducer elements. The ADCs are configured to digitize the electrical echo signals and provide digitized echo signals. The combiner is configured to process a first set of digitized echo signals corresponding to a first set of transducer elements of the plurality of transducer elements differently from a second set of digitized echo signals corresponding to a second set of transducer elements of the plurality of transducer elements. The first set of transducer elements includes fewer transducer elements than the plurality of transducer elements for receiving echo signals reflected at a short distance, thereby defining a small aperture, and the second set of transducer elements includes more transducer elements than the first set of transducer elements for receiving echo signals reflected in the far-field, thereby defining a large aperture. The digital processing unit is configured to receive the first set of digitized echo signals and / or the second set of digitized echo signals and output corresponding digital echo streams. The communication interface is configured to communicate the echo data stream to an ultrasonic imaging system host, and the communication interface has a fixed maximum bandwidth. The small aperture defined by the first set of transducer elements provides a digital bandwidth of the echo data stream that is less than the maximum bandwidth of the communication interface.

[0010] In some embodiments, it may include a multiplexer configured to multiplex the digitized echo signals in order for the combiner to output a first set of digitized echo signals corresponding to the first set of transducer elements that define the small aperture.

[0011] In some embodiments, the electrical echo signal can be digitized at a first sampling rate to provide a first set of digitized echo signals, the electrical echo signal is digitized at a second sampling rate to provide a second set of digitized echo signals, the first sampling rate is different from the second sampling rate, and preferably the first sampling rate is at least 25 percent greater than the second sampling rate.

[0012] In some embodiments, the combiner may comprise a plurality of adders configured to group transducer elements of a second set of transducer elements into sub-arrays and sum the digitized echo signals from the transducer elements within each sub-array.

[0013] In some embodiments, each sub-array may include two of the transducer elements of the second set of transducer elements.

[0014] In some embodiments, the combiner is disposed in front of the plurality of adders and may further comprise a plurality of delay elements configured to delay the digitized echo signals by respective amounts of delay to focus the digitized echo signals on each pixel being imaged.

[0015] According to another aspect of the present invention, there is provided a method of controlling an ultrasonic transducer probe including a transducer array having a plurality of transducer elements. The method includes receiving echo signals with a plurality of transducer elements in response to ultrasonic signals radiated by at least some of the plurality of transducer elements, the echo signals being reflected in a near-field and / or a far-field of a medium and outputting corresponding electrical echo signals, digitizing the electrical echo signals to provide digitized echo signals, selecting a first set of digitized echo signals corresponding to a first set of the plurality of transducer elements, the first set of transducer elements including fewer transducer elements than the plurality of transducer elements for receiving echo signals reflected in the near-field, thereby defining a small aperture, selecting a second set of digitized echo signals corresponding to a second set of the plurality of transducer elements, the second set of transducer elements including more transducer elements than the first set of transducer elements for receiving echo signals reflected in the far-field, thereby defining a large aperture, and the first and / or the second set of digitized echo signals being sent to a host system via a communication interface having a fixed maximum bandwidth, wherein the small aperture defined by the first set of transducer elements provides a digital bandwidth of an echo data stream smaller than the maximum bandwidth of the communication interface.

[0016] In some embodiments, the electrical echo signals may be digitized at a first sampling rate to provide a first set of digitized echo signals, the electrical echo signals are digitized at a second sampling rate to provide a second set of digitized echo signals, the first sampling rate is different from the second sampling rate, preferably the first sampling rate is at least 25 percent greater than the second sampling rate.

[0017] In some embodiments, selecting the first set of digitized echo signals may include multiplexing the digitized echo signals to output a first set of digitized echo signals corresponding to the first set of transducer elements.

[0018] In some embodiments, selecting the second set of digitized echo signals includes grouping transducer elements of the second set of transducer elements into sub-arrays and summing the digitized echo signals from the transducer elements within each sub-array to reduce the digital bandwidth of the second set of digitized echo signals.

[0019] In some embodiments, each sub-array may include two of the transducer elements of the second set of transducer elements.

[0020] In some embodiments, selecting the first set of digitized echo signals may further include delaying the digitized echo signals by respective delay amounts before summing the digitized echo signals from the transducer elements within each sub-array to focus the digitized echo signals on respective pixels being imaged.

[0021] Exemplary embodiments are best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that the various features are not necessarily drawn to scale. In fact, the dimensions may be arbitrarily increased or decreased for clarity of discussion. Where applicable and practical, like reference numerals refer to like elements.

Brief Description of the Drawings

[0022]

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DETAILED DESCRIPTION OF THE INVENTION

[0023] In the following detailed description, for purposes of explanation and not limitation, exemplary embodiments are described that disclose specific details in order to provide a thorough understanding of the embodiments according to the present teachings. Descriptions of known systems, devices, materials, methods of operation, and methods of manufacture may be omitted to avoid obscuring the description of the exemplary embodiments. Nevertheless, systems, devices, materials, and methods within the scope of those skilled in the art are within the scope of the present teachings and may be used in accordance with the exemplary embodiments. It should be understood that the terms used herein are for the purpose of describing only specific embodiments and are not intended to be limiting. The defined terms are in addition to the technical and scientific meanings of the defined terms as commonly understood and accepted in the technical field of the present teachings.

[0024] In this specification, terms such as first, second, third, etc. may be used to describe various components or constituent components, but it should be understood that these components or constituent components should not be limited by these terms. These terms are only used to distinguish one component or constituent component from another. Thus, the first element or component described below can be referred to as the second element or component without departing from the teachings of the concept of the present invention.

[0025] The terms used in this specification are for the sole purpose of describing particular embodiments and are not intended to be limiting. When used in this specification and the appended claims, the singular forms of the terms "a", "an", and "the" are intended to include both the singular and plural forms unless the context clearly dictates otherwise. In addition, the terms "comprise", "comprising", and / or similar terms specify the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0026] When used in this specification and the appended claims, and in addition to their ordinary meanings, the term "about" means having an acceptable limit or degree. For example, one of ordinary skill in the art would consider that a signal is at 20 GHz within a reasonable measure in the sense of "about 20 GHz".

[0027] When used in this specification and the appended claims, the term "substantially" means within an acceptable limit or degree in addition to its ordinary meaning. For example, "a plurality of transducer ports are substantially the same" means that one of ordinary skill in the art would consider that the plurality of transducer ports should be the same. FIG. 1 is a simplified schematic diagram of an ultrasonic imaging system including an ultrasonic probe and a host according to a representative embodiment. The system is used to scan a region, area, or volume of a patient's body. A portion of the system is described, for example, in U.S. Patent Application No. 2021 / 0007717, titled "Digital Ultrasonic Cable and Related Devices, Systems, and Methods," filed on January 31, 2019, which is hereby incorporated by reference in its entirety.

[0028] Referring to FIG. 1, ultrasonic imaging system 100 includes a digital ultrasonic probe 110 that communicates with an ultrasonic host system 130 via a communication link 150. At a high level, probe 110 emits ultrasonic waves toward an object 105 (e.g., a patient's body or an anatomical structure) and receives ultrasonic echoes reflected from object 105. Probe 110 digitizes the received echoes into an electrical echo signal representing the echoes and transmits them as a digital echo data stream via communication link 150 to host system 130 for processing and image display. Communication link 150 can communicate data in an analog-digital format and / or in both analog and digital formats. Probe 110 can be in any suitable form for imaging various body parts of the patient while being placed inside or outside the patient's body. For example, probe 110 can be a handheld ultrasonic scanner such as a transthoracic echocardiogram (TTE) probe, or in the form of a patch-based ultrasonic device. In some embodiments, probe 110 is not handheld and is held in place via a strap, mechanical holder, and / or adhesive. In some embodiments, probe 110 can be a catheter, a transesophageal echocardiogram (TEE) probe, or other cavity or cavity probe. Probe 110 can include any of the components shown in FIG. 1. Any of the components of probe 110 can be placed or stored within housing 111. If probe 110 is a handheld probe, housing 111 is configured to be gripped by a user's hand (e.g., a sonographer).

[0029] In the illustrated configuration, the probe 110 includes a transducer array 112, a circuit 114, and a communication interface 140 within a housing 111. The transducer array 112 radiates ultrasonic signals (waves) toward the object 105 and receives echo signals (waves) that are reflected from within the object 105 and return to the transducer array 112. The transducer array 112 can include an array of acoustic elements. The transducer array 112 can be coupled to a microbeamformer (not shown) to control the reception of signals by the acoustic elements. In an exemplary embodiment, the transducer array 112 is a l.X - dimensional array such as, for example, a 1.25D array or a 1.5D array. In other embodiments, the transducer array may be arranged in a one - dimensional (1D) array or a two - dimensional (2D) array.

[0030] The acoustic elements are hereinafter referred to as transducer elements and may be, for example, capacitive micromachined ultrasonic transducers (CMUTs) or piezoelectric transducers formed of materials such as PZT or PVDF. Each transducer element can transmit ultrasonic signals into the object 105 and can receive echo signals when the ultrasonic signals are reflected from within the object 105. Each transducer element generates an analog electrical signal representative of the received ultrasonic echo signal. The transducer array 112 can include M transducer elements arranged in rows and columns that generate M analog ultrasonic echo signals.

[0031] The circuit 114 disposed within the probe 110 may be any suitable type of circuit and may perform several functions. For example, the circuit 114 may include resistors, capacitors, transistors, inductors, relays, clocks, timers, or any other suitable electrical components that may be integrated into an integrated circuit. Further, the circuit 114 may be configured to support analog and / or digital signals transmitted between the transducer array 112 and / or the probe 110. In some embodiments, the circuit 114 may include, among other various other components, an analog front end (AFE), an analog-to-digital converter (ADC), a multiplexer (MUX), and an encoder. In some embodiments, the circuit 114 may include hardware components, software components, and / or a combination of hardware components and software components. Examples of the circuit 114 are described below with reference to FIGS. 4 and 5.

[0032] The communication interface 122 is coupled to the circuit 114 via L signal lines. In some embodiments, the circuit 114 can reduce the number of lines required from M signal lines to L signal lines. This can be achieved by any suitable method using any suitable component. For example, a MUX, beamformer, or other component can be used to reduce the M signal lines to L signal lines from the transducer array 112 to the L signal lines 166 as described below. In the embodiment of FIG. 1, L is less than M. The communication interface 122 is configured to transmit L signals to the host system 130 via the communication link 150. In one embodiment, the communication interface 122 and / or the communication link 150 have a fixed maximum bandwidth. The communication interface 122 can include a combination of hardware components and software components configured to generate a signal 168 that carries information from the L signals transmitted via the communication link 150. In an exemplary embodiment, the signal 168 is a digital signal such that digital ultrasound data is transmitted from the probe 110 to the host system 130 as described below. The communication link 150 can include L data lanes for transferring the signal 168 to the host system 130.

[0033] The host system 130 can be any suitable computing and display device such as a workstation, personal computer (PC), laptop, tablet, mobile phone, or patient monitor. In some embodiments, the host system 130 may be disposed on a mobile cart. The host system 130 includes a communication interface 140 configured to receive the signal 168 from the communication link 150. The communication interface 140 can include a hardware component, a software component, or a combination of a hardware component and a software component. The communication interface can be substantially similar to the communication interface 122 within the probe 110.

[0034] The circuit 134 disposed within the host system 130 may be of any suitable type and may perform any suitable function. For example, the circuit 134 may include resistors, capacitors, transistors, inductors, relays, clocks, timers, processing components, memory components, or any other suitable electrical components that may be integrated into an integrated circuit. Further, the circuit 134 may be configured to support analog and / or digital signals transmitted between the circuit 134 and the probe 110. The circuit 134 may be configured to process the digital signal 168 received from the probe 110. For example, the circuit 134 may expand the L signal lines received from the probe 110 to the original M signal lines corresponding to specific transducer elements or groups or patches of transducer elements within the transducer array 112. The circuit 134 may be configured to generate an image signal 174 for display to the user and / or to perform image processing and image analysis for various diagnostic modalities or ultrasound types (such as B-mode, CW Doppler, etc.). The circuit 134 may further include one or more processing circuits described below with reference to FIG. 2. For example, the circuit 134 may include a general-purpose computer, a computer processor, a microprocessor, a graphics processing unit (GPU), a central processing unit (CPU), a digital signal processor (DSP), a microcontroller, a state machine, a programmable logic device, a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SOC), or a combination thereof. The circuit 134 may be configured to generate an image signal 174 for display to the user and / or to perform image processing and image analysis for various diagnostic modalities.

[0035] The display 132 is coupled to the circuit 134. The display 132 may include, for example, a monitor, a touch screen, a television, a liquid crystal display (LCD), a light emitting diode (LED) display, a flat panel display, a solid state display, a cathode ray tube (liquid) display, or any suitable display. The display 132 is configured to display the images and / or diagnostic results processed by the circuit 134.

[0036] The host system 130 may further include a user interface (not shown) for providing the information and data output by the circuit 134 to the user and / or receiving the information and data input by the user. The user interface may include, for example, a mouse, a keyboard, a mouse, a trackball, a joystick, a microphone, a video camera, a touch pad, a touch screen, a microphone or voice or gesture recognition captured by a video camera. All or part of the interface may be incorporated into the display 132 as a graphical user interface (GUI) for displaying and receiving information from the user.

[0037] Although FIG. 1 is described in the context of transferring detected ultrasonic echo signal data from the probe 110 to the host system 130 for display, the host system 130 can also generate and transmit control signals for controlling the operation of the probe 110, for example, the excitation of the transducer elements in the transducer array 112.

[0038] FIG. 2 is a simplified schematic diagram of a processor circuit implemented by an ultrasonic imaging system 100 according to an exemplary embodiment. For example, the processor circuit 210 may be implemented at the probe 110, the host system 130 of FIG. 1, and / or any other suitable location. One or more processor circuits 210 may be configured to perform the operations described herein. The processor circuit 210 may be part of the circuit 114 and / or the circuit 134, or may be a separate circuit. In one example, the processor circuit 210 may communicate with the transducer array 112, the circuit 114, the communication interface 122, the communication interface 140, the circuit 134, and / or the display 132, as well as any other suitable component or circuit within the ultrasonic imaging system 100.

[0039] Referring to FIG. 2, the processor circuit 210 includes a processor 260, a memory 264, and a communication module 268. These elements can communicate directly or indirectly with each other, for example, via one or more buses.

[0040] The processor 260 may be implemented by a general-purpose computer, a computer processor, a microprocessor, a GPU, a CPU, a DSP, a microcontroller, a state machine, a programmable logic device, an FPGA, an ASIC, an SOC, or a combination thereof, using any combination of hardware, software, firmware, hardwired logic circuitry, or combinations thereof. Further, any processing unit or processor herein may include multiple processors, parallel processors, or both. The multiple processors may be included in a single device or multiple devices, or may be coupled.

[0041] As used herein, the term "processor" encompasses an electronic component capable of executing programs or machine-executable instructions. References to a computing device having a "processor" should be construed to include two or more processors or processing cores, such as in a multi-core processor. A processor may also refer to a collection of processors that are within a single computer system or distributed among multiple computer systems, such as in a cloud-based or other multi-site application. The term "computing device" should also be construed to include a collection or network of computing devices, each including one or more processors. A program has software instructions that are executed by one or more processors and may be within the same computing device or distributed across multiple computing devices.

[0042] Memory 264 stores instructions executable by processor 260. Memory 264 can include main memory and / or static memory, and such memory can communicate with each other and with processor 260 via one or more buses. Memory 264 stores instructions for implementing some or all aspects of the methods and processes described herein. Memory 264 can include cache memory (e.g., the cache memory of processor 260), random access memory (RAM), magnetoresistive RAM (MRAM), read only memory (ROM), field programmable gate array read only memory (PROM), erasable field programmable gate array read only memory (EPROM), electrically erasable field programmable gate array read only memory (EEPROM), flash memory, solid state memory devices, hard disk drives, other forms of volatile and non-volatile memory, or combinations of different types of memory.

[0043] Memory 264 includes a non-transitory computer-readable medium that stores instructions 266. When executed by processor 260, instructions 266 can include instructions that cause processor 260 to perform operations described herein with respect to probe 110 and / or host system 130. Instructions 266 may also be referred to as code. The terms “instructions” and “code” should be broadly interpreted to include any type of computer-readable statement. For example, the terms “instructions” and “code” may refer to one or more programs, routines, subroutines, functions, procedures, etc., and “instructions” and “code” can include a single computer-readable statement or many computer-readable statements. As used herein, the term “non-transitory” should be interpreted as a property of a state that persists over a period of time, rather than as a property of a permanent state. The term “non-transitory” specifically negates fleeting properties such as the properties of a carrier wave or signal, or other forms that exist only temporarily at any time and any place. Memory 264 may be secure and / or encrypted, or non-secure and / or non-encrypted.

[0044] Communication module 268 can include any electronic circuit and / or logic circuit to facilitate direct or indirect communication of data between processor circuit 210, probe 110, and / or display 132. In this regard, communication module 268 can be an input / output (I / O) device. In some instances, communication module 268 facilitates direct or indirect communication between various elements of processor circuit 210 and / or probe 110 and / or host system 130.

[0045] FIG. 3 is a schematic diagram showing an exemplary circuit of an ultrasonic imaging system 100 having a transducer array, according to an exemplary embodiment. In particular, FIG. 3 provides a more detailed view of the circuit within probe 110 connected to host system 130, according to an exemplary embodiment. Any of the components of probe 110 can be disposed or disposed within a housing (e.g., housing 111).

[0046] Referring to FIG. 3, the circuit of probe 110 includes a transducer array 312 that can be substantially the same as the transducer array 112 described above. The transducer array 312 communicates with an analog front end (AFE) circuit 310 and a digitization circuit 320 via corresponding conductors. The conductors can include conductive paths or conductive traces disposed on a printed circuit board (PCB), a flexible or non-flexible substrate, or in any other suitable configuration. Axes 398 and 399 provide the orientation directions of the transducer array 312, axis 398 indicates the elevation angle or elevation direction, and axis 399 indicates the azimuth angle or transverse direction. For ease of explanation, it is assumed that the transducer array 312 is a 1.0-dimensional (D) array having a single row of N transducer elements in the azimuth direction, as described below. Without departing from the scope of the present teachings, any suitable number N of transducer elements can be included. For example, the transducer elements in row N can include 2, 8, 16, 50, 64, 80, 90, 100, etc. transducer elements. The N transducer elements have N associated channels (signal paths) for communicating analog and digital signals.

[0047] The transmitting portion of the transducer element is configured to send an ultrasonic signal into a medium (e.g., the object 105). The receiving portion of the N transducer elements is configured to receive an ultrasonic echo signal in response to the transmitted ultrasonic signal being reflected from the medium and output a corresponding electrical echo signal. Each of the transmitting portion and the receiving portion can include one or more (up to and including all N of the transducer elements) of the transducer elements of the transducer array 312 and can include the same or different transducers, as will be apparent to those skilled in the art, to provide advantages specific to any particular situation or to meet the application-specific design requirements of various implementations.

[0048] In various embodiments, the transducer array 312 is an appropriate type of 1.XD array, such as a 1.25D array, a 1.5D array, or a 1.75D array, or a 2.XD array. In some aspects, the 1.25D array may include circuitry for controlling the aperture size in the height direction. The 1.5D array can include additional circuitry configured to apply various delays to received signals from elements of the elevation dimension to focus these signals. In some embodiments, it can be assumed that the 1.25D and 1.5D arrays have symmetry where the gain and delay are symmetric with respect to the center of the elevation dimension. The 1.75D array can apply different delays to each of the outer transducer elements in elevation and can be configured to steer the acoustic beam. The 1.75D array may be symmetric or asymmetric with respect to the center column of elements.

[0049] The AFE circuit 310 is configured to perform signal processing on the electrical echo signals output by the transducer elements of the transducer array 312. For example, the AFE circuit 310 can include N gain controllers in N channels respectively corresponding to N transducer elements to adjust the gain of the electrical echo signals. The gain controller can be, for example, a time gain compensation (TGC) controller or an automatic gain control (AGC) controller. As will be apparent to those skilled in the art, the AFE circuit 310 can include additional analog signal conditioning circuitry such as filters, operational amplifiers, etc.

[0050] The digitization circuit 320 is configured to digitize the adjusted electrical echo signal output by the AFE circuit 310. The digitization circuit 320 may include N ADCs in channels respectively corresponding to N transducer elements to digitize the electrical echo signal output by N gain controllers. The ADCs each output N digital echo signals. The output of each of the ADCs may be, for example, a 12-bit digital signal, but the ADCs may have any suitable bit rate (e.g., 4 bits, 8 bits, 16 bits, 24 bits, 32 bits, 64 bits).

[0051] In one embodiment, the ADC of the digitization circuit 320 has an adjustable sampling rate, and the sampling rate (first sampling rate) for digitizing the electrical echo signal from the near field is higher than the sampling rate (second sampling rate) for digitizing the electrical echo signal from the far field. That is, the higher sampling rate is used for ultrasonic images at a smaller depth within the medium (e.g., the patient's anatomical structure), while the lower sampling rate is used for ultrasonic images at a greater depth within the medium. This is because the ultrasonic echo signal reflected from the near field has a higher frequency that has passed through less high-frequency attenuation tissue than the ultrasonic signal reflected from the far field. In some cases, the system uses a higher frequency transmission excitation in the near field to further emphasize the high-frequency nature of the near-field data. For example, the near-field sampling rate of the ADC can be twice the far-field sampling rate. Generally, the near-field sampling rate is at least 25 percent greater than the far-field sampling rate. The different sampling rates can be selected using a representative sampling rate switch 325, which can be controlled, for example, by the processor 260, to switch between the near-field signal generator 326 and the far-field signal generator 327. The near-field signal generator 326 provides a first signal that controls the ADC to sample the electrical echo signal at the first sampling rate for near-field imaging, and the far-field signal generator 327 provides a second signal that controls the ADC to sample the electrical echo signal at the second sampling rate for far-field imaging.

[0052] Probe 110 includes, for example, a coupler 330 and a near / far switch 340 operable by a processor 260 to select near or far operation. The coupler 330 is configured to reduce the total number of channels from the digitization circuit 320, thereby reducing the data rate and thus the digital bandwidth for transmitting data to the host system 130. In the illustrated embodiment, the coupler 330 includes a multiplexer 334 for selecting digitized echo signals for near-field ultrasonic imaging and a beamformer 336 for beamforming a sub-array of digitized echo signals for far-field ultrasonic imaging. The near / far switch 340 is operable to select either the multiplexer 334 or the beamformer 336, respectively, according to near or far ultrasonic imaging.

[0053] As further discussed below with reference to FIG. 4, multiplexer 334 is configured to multiplex digitized echo signals corresponding to echo signals reflected from the near field in order to reduce the number of digitized echo signals. For example, in the illustrated embodiment, multiplexer 334 is an N, N / 2 multiplexer and selects half of the digital echo signals from half of the transducer elements in the azimuthal direction respectively indicated by axis 399. Thus, coupler 330 reduces the number of channels from N channels to N / 2 channels. The transducer elements that provide the selected digital echo signals may be referred to as a first set of transducer elements, which includes a number less than all of the N transducer elements in transducer array 312. Thereby, the first set of transducer elements defines a small aperture for receiving echo signals. The first set of transducer elements may have various arrangements relative to each other to provide different apertures within transducer array 212. For example, the transducer elements may be adjacent to each other and grouped around the acquired image line to provide an aperture for receiving echo signals reflected from the near field. Other configurations of the first set of transducer elements may be implemented to provide advantages specific to any particular situation or to meet application-specific design requirements of various implementations, as will be apparent to those skilled in the art.

[0054] As further discussed below with reference to FIG. 5, beamformer 336 includes an adder configured to sum signals in the azimuth direction indicated by axis 399 from digitization circuit 320 to the subarray, such that there are fewer digitized echo signals present than are provided by all of the transducer elements within transducer array 316. The transducer elements that provide the digital echo signals to be combined may be referred to as a second set of transducer elements. For example, beamformer 336 may be an N, N / 2 beamformer that couples pairs of digital echo signals. In this case, each subarray includes two transducer elements of transducer array 316. Beamformer 336 may further include delay elements arranged in front of the adder to delay the signals by each delay amount in order to focus the signals to each pixel being imaged. Beamformer 336 may be regarded as a digital beamformer that performs the second stage (signal delay and summation) of beamforming after the first stage of beamforming has been completed by an optional analog beamformer (not shown). In the illustrated embodiment, combiner 330 reduces the number of channels from N channels to N / 2 channels. Subarrays that combine various numbers of digital echo signals may be implemented to provide advantages specific to any particular situation or to meet the application-specific design requirements of various implementations, as will be apparent to those skilled in the art.

[0055] Probe 110 further includes a digital processing unit 350 that can include a serializer and a high-speed current mode logic (CML) cable driver that communicates with coupler 330 via a near / far switch 340. The digital processing unit 350 can be implemented, for example, using one or more processor circuits 210. The digital processing unit 350 serializes the digitized echo signal output by the coupler 330 onto a high-speed serial link and can transmit the serialized data (e.g., B-mode data) to the host system 130 via a communication interface (not shown) and signal conductor 360. The digital processing unit 350 can also rearrange the lines received from the coupler 330 and / or the digitizing circuit 320 into a high data rate, serial, digital echo data stream. In some embodiments, the digital processing unit 350 can operate at a higher data rate than other circuits within the probe 110. For example, the echo data stream operates at 2.4 GHz, while other circuits within the ultrasonic channel operate at 20 MHz.

[0056] Probe 110 is connected to the host system 130 via connection conductors that include signal conductor 360 and power and control conductor 365. The signal conductor 360 and the power and control conductor 365 may together form a single cable or a plurality of separate cables, or may be arranged in any other suitable configuration. The signal conductor 360 and the power and control conductor 365 may be part of the communication link 150 described above with reference to FIG. 1.

[0057] The signal conductor 360 can accommodate a reduction in the number of signal lines output from the digital processing unit 350. In various embodiments, the signal conductor 360 may include only a single signal line or may include a plurality of signal lines. The signal conductor 360 can be a twisted pair, a single conductor, a coaxial conductor, or any other suitable communication path for transmitting data signals. Further, in some embodiments, the signal conductor 360 can carry only digital signals. In other embodiments, the signal conductor 360 can also carry analog signals. In some embodiments, the signals can be carried via an optical link. In some embodiments, the signals can be carried wirelessly.

[0058] The power and control conductor 365 can include one or more signal and / or power lines, including conductors, twisted pairs, or any other suitable means for transferring data, signals, or power. For example, the power and control conductor 365 can include dedicated conductors for providing control signals or other data from the host system 130 to the probe 110. The power and control conductor 365 can further include conductors for providing the necessary AC and / or DC power from the host system 130 (or other power source) to components within the probe 110. The conductors can communicate, for example, with a controller or any other suitable component within the host system 130 implemented by one or more processor circuits 210 and can provide signals for controlling a clock, a switch, a pulsar, a transducer array 312, an AFE circuit 310, an ADC circuit 320, a coupler 330, a digital processing unit 350, and / or any other component within the probe 110. In various embodiments, the power and control conductor 365 may include only a single signal line or may include a plurality of signal lines. The power and control conductor 365 can be a twisted pair, a single conductor, a coaxial conductor, or any other suitable communication path for transmitting data signals.

[0059] The signal conductor 360 and the power and control conductor 365 can form one connection cable similar to the communication link 150 described with reference to FIG. 1. Specifically, the signal conductor 360 and the power and control conductor 365 may be wound together with a cable shield. The signal conductor 360, the power and control conductor 365, and any corresponding conductors enclosed together may be of any suitable length and / or may be flexible elongated members. For example, the signal conductor 360, the power conductor and the control conductor 365, and all related conductors may be 1 meter, 2 meters, 3 meters in length, or other suitable values, both larger, smaller, or in between. In other embodiments, the control conductor 365 and the power and control conductor 365 can form separate connection cables of the same or various lengths.

[0060] During ultrasonic inspection, the ultrasonic imaging system 100 can specify a transmission set of transducer elements of the transducer array 316 to transmit ultrasonic signals so that the ultrasonic energy propagates into the patient's anatomical structure. The ultrasonic imaging system 100 can further specify a reception set of transducer elements (e.g., the first set or the second set of transducer elements) to receive the reflected ultrasonic echo signals. In some embodiments, the transducer selected to transmit the ultrasonic signal may be the same transducer used to receive the reflected echo signal. In other embodiments, the transducer elements used to transmit the ultrasonic signal may be different from the transducer elements used to receive the reflected echo signal. For example, as described above, the ultrasonic imaging system 100 can select half of the transducer elements of the transducer array 316 to receive the reflected echo signal from the patient's anatomical structure in the near field.

[0061] FIG. 4 is a simplified block diagram of a transducer probe in an ultrasonic imaging system for reducing digital bandwidth using a multiplexer, according to an exemplary embodiment. The transducer probe is shown configured to receive echo signals reflected in the near field of a medium (e.g., object 105).

[0062] Referring to FIG. 4, probe 110 includes a transducer array 312 having a plurality of transducer elements 405. For ease of explanation, transducer array 112 is shown as a 1.0D array having a single row of N transducer elements 405. In the illustrated arrangement, exemplary transducer elements are the first transducer element 4051, the second transducer element 4052, the third transducer element 4053, the fourth transducer element 4054, …, N−3 rd transducer element 405 N-3, N−2 nd transducer element 405 N-2 、N−1 st transducer element 405 N-1 、and N th transducer element 405. The transmit portion of transducer element 405 is configured to send an ultrasonic signal into a medium (e.g., object 105). The receive portion of transducer element 405 is configured to receive an echo from the transmitted ultrasonic signal reflected within the medium and output a corresponding electrical echo signal. Each of the transmit and receive portions can include one or more (up to and including all) of the transducer elements 405 of transducer array 412 and, as will be apparent to those skilled in the art, can include the same or different transducer elements 405 to provide advantages specific to any particular situation or to meet application-specific design requirements of various implementations.

[0063] The probe 110 further includes an AFE circuit 310 including at least a gain controller 415 which can be, for example, a TGC controller or an AGC controller. In the illustrated setting, a typical gain controller 415 includes a first gain controller 4151, a second gain controller 4152, a third gain controller 4153, a fourth gain controller 4154, …, N−3 rd gain controller 415 N-3 , N−2 nd gain controller 415 N-2 , N−1 st gain controller 415 N , and N th gain controller 415. The gain controller 415 is configured to adjust the gain of the electrical echo signal output by the transducer element 405 in each channel.

[0064] The probe 110 further includes a digitization circuit 320 including an ADC 425 having an adjustable sampling rate for sampling the analog echo signal. The lower the sampling rate, the smaller the digital bandwidth of the digitized echo signal. In the illustrated setting, a typical ADC 425 includes a first ADC 4251, a second ADC 4252, a third ADC 4253, a fourth ADC 4254, .., N−3 rd ADC 425 N-3 , N−2 nd ADC 425 N-2 , N−1 st ADC 425 N-1 , and N th ADC 425 N is included. The ADC 425 is configured to digitize the electrical echo signal received from the gain controller 415 in each channel. Each of the ADCs 425 can have an adjustable sampling rate, and the sampling rate in the near-field setting is greater than the sampling rate in the far-field setting described below.

[0065] Probe 110 further includes multiplexer 334 of combiner 330. Multiplexer 334 receives the digitized echo signals output by ADC 425 via respective channels, and is configured to select some of the digitized echo signals for further processing by digital processing unit 350. The fewer the digitized echo signals selected by multiplexer 334, the smaller the digital bandwidth of the digitized echo signals output by multiplexer 334. For example, in the illustrated embodiment, multiplexer 334 is configured as an N, N / 2 multiplexer, reducing the number of digitized echo signals by half. The selection of the digitized echo signals is performed between channels in the azimuth direction corresponding to the selected transducer elements 405, which forms, for example, a small aperture for near-field imaging. The selected transducer elements 405 may be referred to as a first set of transducer elements. The operation of multiplexer 334 for selecting channels can be performed automatically, for example, using processor circuit 210, or manually, for example, using a user interface or GUI.

[0066] Digital processing unit 350 receives the multiplexed digital echo signals from multiplexer 334, for example, via a near / far switch 340 (not shown), and is configured to output a corresponding digital echo data stream having a smaller digital bandwidth than would be present if digital echo signals from all of ADC 425 were processed. When multiplexer 334 is configured as an N, N / 2 multiplexer, the data rate of the echo data stream is N / 2 × f s samples per second, where f s is the frequency of the electrical echo signals output by transducer elements 405.

[0067] Probe 110 also includes a communication interface 355 configured to communicate an echo data stream from the digital processing unit 350 to the host system 130 via the signal conductor 360. The operation of the multiplexer 334 reduces the number of digital echo signals such that the digital processing unit 350 provides an echo data stream having a total digital bandwidth less than the fixed maximum bandwidth of the communication interface.

[0068] FIG. 5 is a simplified block diagram of a transducer probe in an ultrasonic imaging system for reducing digital bandwidth using a beamformer, according to another representative embodiment. The transducer probe is shown configured to receive echo signals reflected in the far field of a medium (e.g., object 105).

[0069] Referring to FIG. 5, probe 110 includes a transducer array 312 that includes the plurality of transducer elements 405 described above. The transducer elements 405 are configured to receive echo signals reflected in the far field, thereby defining a large aperture (e.g., larger than the small aperture formed by the transducer elements 405 for near-field imaging). The transducer elements 405 used to receive echo signals reflected in the far field may be referred to as a second set of transducer elements. For illustration purposes, probe 110 shows a second set of transducer elements consisting of all of the transducer elements 405 to form a large aperture for far-field imaging. Of course, the second set of transducer elements can include a number less than all of the transducer elements 405 without departing from the scope of the present teachings. Generally, the far-field imaging requirements determine the size of the large aperture for image reconstruction.

[0070] Probe 110 further includes an AFE circuit 310 having at least a gain controller 415 and a digitization circuit 320 having the above-described ADC 425. The gain controller 415 and the ADC 425 are each within a channel associated with the transducer element 405. In one embodiment, each of the ADCs 425 may have an adjustable sampling rate where the sampling rate for the far-field setting is greater than the sampling rate for the near-field setting. Generally, fewer transducer elements 405 can be used for near-field imaging because the signal attenuation of the echoes from the medium over a shorter distance is less, and thus can be used for near-field imaging without affecting the quality. Therefore, instead of receiving echo signals using all of the transducer elements 405, a smaller subset or “patch” of adjacent transducer elements 405 can be recorded while minimally affecting the resolution of the near-field image.

[0071] Probe 110 further includes a beamformer 336 including an adder 435 and (optionally) a delay circuit 438. In the illustrated arrangement, a typical adder 435 includes a first adder 4351, a second adder 4352, …, N / 2 - 1 th adder 435 N / 2-1 , and N / 2 th adder 435 N / 2It includes. The adder 435 is configured to sum the digitized echo signals in the azimuth direction received from the ADC 425 and group the digitized echo signals into respective sub-arrays, which may be referred to as beamforming. For example, the first adder 435 sums the digitized echo signals in the channels corresponding to the first transducer element 4051 and the first transducer element 4051 respectively, and the second adder 435 sums the digitized echo signals in the channels corresponding to the third transducer element 4053 and the fourth transducer element 4054 respectively, and so on. The grouping results in fewer digitized echo signals than those provided by all of the transducer elements 405 within the transducer array 312. The transducer elements 405 that provide the digital echo signals coupled to the sub-arrays may be referred to as a second set of transducer elements. In the illustrated embodiment, the beamformer 336 is an N, N / 2 beamformer and combines pairs of digital echo signals such that each transducer element 405 is arranged into two sub-arrays. This reduces the number of digitized echo signals output by the beamformer 336 by half. The operation of the beamformer 336 for combining channels may be performed automatically using, for example, the processor circuit 210 or manually using, for example, a user interface or GUI.

[0072] The digital processing unit 350 is configured to receive, for example, a sub-array of digitized echo signals from the beamformer 336 via a near / far switch 340 (not shown) and output a corresponding digital echo data stream having a smaller digital bandwidth than would be present if digitized echo signals from all of the ADCs 425 were processed. When the beamformer 336 is configured as an N, N / 2 beamformer, the data rate of the echo data stream is N / 2 x f s samples per second, where f sis the frequency of the electrical echo signal output by the transducer element 405. The echo data stream output by the digital processing unit 350 is communicated to the host system 130 via a communication interface (not shown) and a signal conductor 360, and the communication interface has a fixed maximum bandwidth. The operation of the beamformer 336 reduces the number of digital echo signals so that the digital processing unit 350 provides an echo data stream having a total digital bandwidth smaller than the fixed maximum bandwidth of the communication interface.

[0073] As described above, the beamformer 336 may further include a delay circuit 438 that can be implemented, for example, as a digital RAM or a first-in first-out (FIFO) buffer. In the illustrated arrangement, a typical delay circuit 438 includes a first delay circuit 4381, a second delay circuit 4382, a third delay circuit 4383, a fourth delay circuit 4384, ···, N−3 rd delay circuit 438 N-3 , N−2 nd delay circuit 438 N-2 , N−1 st delay circuit 438 N-1 , and N th delay circuit 438 N and includes N delay circuits 438. The delay circuit 438 is configured to delay the digitized echo signals by respective amounts of delay to focus the digitized signals on respective pixels being imaged. The amount of delay may be determined by a digital “focus engine” state machine (not shown), as will be apparent to those skilled in the art. The amount of delay may be the same as or different from the amount of the delay circuit 438.

[0074] Adding the digitized echo signals to the subarray reduces the digital bandwidth of the digitized echo signals by a factor of the number of digitized echo signals being added together. In the illustrated arrangement, for example, each subarray combines digitized second echo signals from pairs of transducer elements 405, and the two transducer elements 405 of each pair are adjacent to each other. Of course, other sizes of subarrays and the arrangement of transducer elements 405 combined in the subarray can be changed without departing from the scope of the present teachings.

[0075] Probe 110 also includes a communication interface 355 configured to communicate an echo data stream from digital processing unit 350 to host system 130 via signal conductor 360. Adder 335 reduces the digitized second echo signals to a number that provides an echo data stream having a total digital bandwidth less than the fixed maximum bandwidth of communication interface 355.

[0076] In various embodiments, the arrangements of probe 110 shown in FIGS. 4 and 5 may be combined to complement each other. For example, probe 110 may be configured to reduce the digital bandwidth of the echo data stream by utilizing different apertures to receive near-field and far-field echoes, where each aperture is defined by the number of transducer elements 405. For example, a small aperture including less than all of the transducer elements 405 (e.g., half (N / 2)) can be used for near-field imaging, and a large aperture including all of the transducer elements 405 (N) can be used for far-field imaging.

[0077] In this example, it includes a first set of transducer elements composed of half of the total number of transducer elements 405 configured to receive a first echo signal in response to an ultrasonic signal reflected at a short distance and output a corresponding first electrical echo signal. The first set of transducer elements includes a number less than all of the transducer elements 405, thereby defining a small aperture. The transducer element 405 further includes a second set of transducer elements composed of all of the total number of transducer elements 405 configured to receive a second echo signal in response to the ultrasonic signal being reflected in the far field and output a corresponding second electrical echo signal. The second set of transducer elements does not necessarily include all of the transducer elements 405 and includes more transducer elements 405 than the first set of transducer elements.

[0078] Furthermore, in one embodiment, the first electrical echo signal is digitized at a first sampling rate by an ADC 425 that receives the first electrical echo signal from the selected transducer elements 405 of the small aperture, and the second echo signal is digitized at a second sampling rate by an ADC 425 that receives the second electrical echo signal from the transducer elements 405 of the large aperture, and the first sampling rate is different from the second sampling rate. For example, the first sampling rate may be at least 25 percent higher than the second sampling rate. For example, the first sampling rate may be twice the second sampling rate. In this case, the lower sampling rate for the larger number of echo signals from the second set of transducer elements further reduces the digital bandwidth of the echo data stream.

[0079] In one embodiment, the functions of the multiplexer 334 and the beamformer 336 of the combiner 330 can be combined using a switch circuit. FIG. 6 is a simplified block diagram of a switch circuit for a transducer probe in an ultrasonic imaging system for reducing digital bandwidth according to another representative embodiment.

[0080] Referring to FIG. 6, the combiner 330' includes a switch circuit 630 that is repeated in parallel a plurality of times (e.g., 4 times in the exemplary configuration) to provide sufficient switching capabilities. The switch circuit 630 receives digitized echo signals via channels (signal paths) corresponding to the transducer elements 405 and is configured to provide echo signals reflected in the near field and / or far field, respectively. Each pair of channels is provided to a multiplexing switch and a beamforming switch, which are activated to select one of two channels for near-field imaging or to combine two channels for far-field imaging. The operation of the switch circuit 630 may be performed, for example, by the processor circuit 210.

[0081] In particular, the switch circuit 630 includes a first multiplexing switch 631, a first adder 635, and a first beamforming switch 641, and a second multiplexing switch 632, a second adder 645, and a second beamforming switch 642. The first multiplexing switch 631 is configured to select a digitized echo signal from one of the first channel Ch 1 corresponding to the first transducer element 4051 or N / 2 + 1 st N / 2 + 1 corresponding to a transducer element (not shown) st channels Ch N / 2 + 1 (N / 2 + 1 stThe transducer element is the first transducer element of the second half (latter half) of the N transducer elements. The first adder 635 is configured to sum the digitized echo signals from the first channel Ch 1 and the second channel Ch 2. The first beamforming switch 641 is configured to select either the multiplexed output of the first multiplexing switch 631 or the sum output of the first adder 635. When the first beamforming switch 641 selects the multiplexed output of the first multiplexing switch 631, the digitized echo signal corresponding to the channel selected by the first multiplexing switch 631 is output from the combiner 330'. When the first beamforming switch 641 selects the output of the first adder 635, the combined (beamformed) digitized echo signal from the first adder 635 is output from the combiner 330'. Similarly, the second multiplexing switch 632 is configured to select a digitized echo signal from either the second channel Ch 2 corresponding to the second transducer element 4052 or N / 2 + 2 nd N / 2 + 2 corresponding to a transducer element (not shown) nd of the channels Ch N / 2 + 2. The second adder 645 is configured to sum the digitized echo signals from N / 2 + 1 st channels Ch N / 2 + 1 and N / 2 + 2 nd channel Ch N / 2 + 2 nd The second beamforming switch 642 is configured to select either the multiplexed output of the second multiplexing switch 632 or the sum output of the second adder 645. When the second beamforming switch 642 selects the multiplexed output of the second multiplexing switch 632, the digitized echo signal corresponding to the channel selected by the second multiplexing switch 632 is output from the combiner 330'. When the second beamforming switch 642 selects the output of the second adder 645, the combined (beamformed) digitized echo signal from the second adder 645 is output from the combiner 330'.

[0082] FIG. 7 is a flowchart of a method for controlling an ultrasonic transducer probe including a transducer array having a plurality of transducer elements according to an exemplary embodiment. This method can be implemented, for example, using the probe 110 described above.

[0083] Referring to FIG. 7, in block S711, echo signals are received by a plurality of transducer elements of a transducer array (e.g., transducer array 312), and corresponding electrical echo signals are output by the transducer elements. The echo signals are in response to ultrasonic signals transmitted by at least some of the transducer elements, and the echo signals are reflected in a near field and / or a far field of a medium such as a patient's anatomical structure (e.g., object 105). The transducer elements can be arranged in a 1.X-dimensional transducer array.

[0084] In block S712, the electrical echo signals are digitized to provide corresponding digitized echo signals. The electrical echo signals can be digitized by an ADC (e.g., ADC 425) arranged in a channel corresponding to the transducer elements of the transducer array. In one embodiment, the ADC can digitize the electrical echo signals at different sampling rates depending on whether the electrical echo signals correspond to echo signals reflected in a near field or a far field. Generally, electrical echo signals corresponding to echo signals reflected in a near field are digitized at a first sampling rate, electrical echo signals corresponding to echo signals reflected in a far field are digitized at a second sampling rate, and the first sampling rate is higher than the second sampling rate. For example, the first sampling rate can be at least 25 percent greater than the second sampling rate, or the first sampling rate can be at least twice the second sampling rate.

[0085] In block S713, a first set of digitized echo signals is selected to receive echo signals reflected at a short distance, and the first set of digitized echo signals corresponds to a first set of transducer elements of a plurality of transducer elements. The first set of transducer elements includes fewer transducer elements than the total of all transducer elements. Thereby, the first set of transducer elements defines a small aperture.

[0086] In block S714, a second set of digitized echo signals is selected to receive echo signals reflected in a far field, and the second set of digitized echo signals corresponds to a second set of transducer elements of a plurality of transducer elements. The second set of transducer elements includes more transducer elements than the first set of transducer elements. For example, the second set of transducer elements can include all of the plurality of transducer elements. Thereby, the second set of transducer elements defines a large aperture. The first and second sets of digitized echo signals can be selected by manual or automatic operation of a switch (e.g., a near / far switch 340).

[0087] The small aperture and the large aperture are relative in the sense that the small aperture means fewer transducer elements than all of the transducer elements in the transducer array, and the large aperture means more transducer elements than the transducer elements that make up the small aperture. The larger number of transducer elements in the large aperture for the far-field image compensates for the increased attenuation of the echo signals from the medium over the greater distance of the far-field image compared to the small aperture for the near-distance image. The small aperture typically includes less than half of all of the transducer elements in the transducer array, and the large aperture typically includes all of the transducer elements in the transducer array, although other configurations of the small aperture and the large aperture may be provided without departing from the scope of the present teachings.

[0088] In block S715, the echo data stream is output to the host via a communication interface having a fixed maximum bandwidth. The echo data stream includes a first set and / or a second set of digitized echo signals. The small aperture defined by the first set of transducer elements for near-field imaging provides a digital bandwidth of the echo data stream that is less than the maximum bandwidth of the communication interface. Similarly, beamforming of the digitized echo signals from the second set of transducer elements for far-field images provides a digital bandwidth of the echo data stream that is less than the maximum bandwidth of the communication interface.

[0089] Accordingly, according to various embodiments, during near-field imaging, the aperture is smaller compared to the full transmit aperture. Instead of receiving using all channels, a smaller subset (or "patch") of adjacent channels (signal paths) can be recorded while minimally affecting the resolution of the image. In this mode, each of the channels within the patch is configured to receive. The signal is digitized and transmitted from the chip. Compared to the full aperture required for the far field, near-field reconstruction requires only about half of the total number of channels and can reduce all required data rates. When imaging in the far field, the imaging requirements determine the size of the larger aperture for image reconstruction. To reduce data, a subarray (e.g., a pair) of azimuth channels can be beamformed during reception. Next, the beamformed pair is digitized and transmitted from the chip. Beamforming reduces the number of channels to be digitized by a factor of two and reduces all required data rates. By combining the near-field reception profile and the far-field reception profile, an improved profile can be created that mimics the quality of a larger aperture beam profile and all transducer elements are recorded. This combination effectively reduces the data rates required on ultrasonic imaging systems having any number of channels.

[0090] With reference to some exemplary embodiments, a method, system, and components for implementing an imaging protocol have been described, but it should be understood that the words used are not limiting words but words of explanation and illustration. The foregoing description of the disclosed embodiments is provided to enable those skilled in the art to implement the concepts described in this disclosure. Therefore, to the maximum extent permitted by law, the scope of this disclosure should be determined by the broadest permissible interpretation of the following claims and should not be limited or restricted by the foregoing detailed description.

[0091] The summary of the disclosure is provided in accordance with 37 C.F.R. §1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Further, in the foregoing detailed description, for purposes of simplifying the disclosure, various features may be grouped together or described in a single embodiment. The disclosure should not be construed as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, the subject matter of the invention can be directed to less than all of the features of any of the disclosed embodiments. Accordingly, the following claims are incorporated into the detailed description, and each claim stands on its own as defining a separately claimed subject matter.

Claims

1. A transducer probe for an ultrasonic imaging system, comprising: A transducer array comprising a plurality of transducer elements configured to transmit ultrasonic signals into a medium and receive echo signals in response to reflection of the ultrasonic signals in a near field and a far field of the medium, and output corresponding electrical echo signals; A plurality of analog-to-digital converters configured to digitize the electrical echo signals and provide digitized echo signals; A combiner, comprising: A multiplexer configured to multiplex the digitized echo signals and output a first set of the digitized echo signals corresponding to a first set of transducer elements among the plurality of transducer elements that define a small aperture for receiving echo signals reflected in the near field; A beamformer comprising a plurality of adders configured to group transducer elements of a second set of transducer elements into sub-arrays that provide a second set of digitized echo signals, and sum the digitized echo signals from the second set of transducer elements in each sub-array to receive echo signals reflected in the far field, wherein the second set of transducer elements includes more transducer elements than the first set of transducer elements; A combiner having the beamformer; A switch operable to select between the multiplexer for near-field ultrasonic imaging and the beamformer for far-field ultrasonic imaging; A digital processing unit configured to receive the first set of digitized echo signals and the second set of digitized echo signals and output corresponding digital echo streams; A communication interface configured to communicate the echo data streams to an ultrasonic imaging system host, the communication interface having a fixed maximum bandwidth; Having the communication interface; The small aperture defined by the first set of transducer elements provides a digital bandwidth of the echo data stream that is narrower than the fixed maximum bandwidth of the communication interface; A transducer probe.

2. The electrical echo signal is digitized at a first sampling rate to provide a first set of the digitized echo signals, the electrical echo signal is digitized at a second sampling rate to provide a second set of the digitized echo signals, the first sampling rate is different from the second sampling rate, and preferably the first sampling rate is at least 25 percent greater than the second sampling rate, the transducer probe according to claim 1.

3. The transducer probe according to claim 1 or 2, wherein each subarray includes two of the transducer elements of the second set of transducer elements.

4. The beamformer is a plurality of delay elements configured in front of a plurality of adders, the delay elements being configured to delay the digitized echo signals by respective amounts of delay in order to focus the digitized echo signals on each pixel to be imaged and further includes the transducer probe according to any one of claims 1 to 3.

5. The combiner further includes a sampling rate switch configured to selectively connect the plurality of analog-to-digital converters to a first signal generator or a second signal generator and has a first signal generator configured to provide a first signal for controlling the plurality of analog-to-digital converters to sample the electrical echo signal at a first sampling rate for near-distance imaging and a second signal for controlling the plurality of analog-to-digital converters to sample the electrical echo signal at a second sampling rate for far-distance field imaging, the first sampling rate being greater than the second sampling rate, the transducer probe according to any one of claims 1 to 4.

6. The transducer array includes 1. an X-dimension array, the transducer probe according to any one of claims 1 to 5.

7. The multiplexer includes an N:N / 2 multiplexer, the transducer probe according to any one of claims 1 to 6.

8. A handheld ultrasonic scanner having the transducer probe according to any one of claims 1 to 7.

9. A method of controlling an ultrasonic transducer probe having a transducer array with a plurality of transducer elements, the method comprising: Receiving echo signals at the plurality of transducer elements in response to ultrasonic signals transmitted by at least some of the plurality of transducer elements, the echo signals being reflected in a near field and a far field of a medium and outputting corresponding electrical echo signals; Digitizing the electrical echo signals to provide digitized echo signals; Multiplying the digitized echo signals to output a first set of the digitized echo signals corresponding to a first set of transducer elements of the plurality of transducer elements that define a small aperture for receiving echo signals reflected in the near field; Grouping transducer elements of a second set of transducer elements into subarrays that provide a second set of digitized echo signals; Summing digitized echo signals from a second set of transducer elements within each subarray for receiving echo signals reflected in the far field, the second set of transducer elements including more transducer elements than the first set of transducer elements; Outputting an echo data stream comprising the first set of digitized echo signals and the second set of digitized echo signals to a host system via a communication interface having a fixed maximum bandwidth; and The small aperture defined by the first set of transducer elements provides a digital bandwidth of the echo data stream that is narrower than the fixed maximum bandwidth of the communication interface. Method. Claim 10 The electrical echo signal is digitized at a first sampling rate to provide a first set of the digitized echo signals, and the electrical echo signal is digitized at a second sampling rate to provide a second set of the digitized echo signals, wherein the first sampling rate is different from the second sampling rate, and preferably the first sampling rate is at least 25 percent greater than the second sampling rate, the method according to claim 9.

11. The method according to claim 9 or 10, wherein each subarray includes two of the transducer elements of the second set of the transducer elements.

12. Before summing the digitized echo signals from the second set of the transducer elements, the method further includes delaying each of the digitized echo signals by a respective delay amount to focus the digitized echo signals on respective pixels being imaged. The method according to any one of claims 9 to 11.

13. The method according to any one of claims 9 to 12, wherein the transducer array has a 1.X-dimensional array.

14. The method according to any one of claims 9 to 13, wherein the step of multiplexing the digitized echo signals is performed using an N:N / 2 multiplexer.

Images