ULTRASOUND TRANSDUCER PROBE BASED ANALOG-TO-DIGITAL CONVERSION FOR CONTINUOUS WAVE DOPPLER METHOD AND ASSOCIATED DEVICES, SYSTEMS AND METHODS - Patent application

Abstract

The ultrasound system includes a transducer array configured to generate analog ultrasound signals. The ultrasound system includes one or more analog-to-digital converters (ADCs) in communication with the transducer array. The ADCs are configured to convert the analog ultrasound signals into digital ultrasound signals. The ultrasound system includes a processor circuit in communication with the ADCs. The processor circuit includes a digital in-phase / quadrature (I / Q) mixer configured to generate digital continuous wave (CW) Doppler signals based on the digital ultrasound signals. The processor circuit is configured to process the digital CW Doppler signals to generate a visual representation of a distribution of blood flow velocity over multiple cardiac cycles and output the visual representation to a display in communication with the processor circuit.

Description

[Technical field]

[0001]

[0001] This disclosure relates generally to ultrasound imaging, such as continuous wave (CW) Doppler imaging. In particular, analog CW Doppler signals are converted to digital signals in a transducer probe and transmitted to a host system over a low-cost, high-speed digital multi-lane communication link. [Background technology]

[0002]

[0002] Ultrasound is widely used in medical imaging. Ultrasound imaging systems typically include a transducer probe separate from a main processing system. The ultrasound probe has an array of ultrasound transducer elements. The ultrasound transducer elements send sound waves through a patient's body and generate signals that are reflected by tissues and / or organs in the patient's body. In conventional ultrasound applications, the timing and / or intensity of the echo signals correspond to the size, shape, and mass of the patient's tissues, organs, or other features, and images depicting the measured tissues, organs, or other features are displayed to a user of the ultrasound system. In some ultrasound applications, continuous wave (CW) Doppler imaging methods are additionally used to measure velocities within the patient's body, such as fluid motion (e.g., blood flow). Typically, raw analog ultrasound echo signals corresponding to each transducer element are passed from the transducer probe through a cable to a main processing system for processing. In B-mode applications, the processing system first digitizes the analog ultrasound signal with an analog-to-digital converter and then further processes the signal using digital techniques to generate an ultrasound image depicting tissues and / or organs within the patient. In CW Doppler applications, the processing system processes the analog ultrasound signal using analog mixers and filters to combine the element data prior to digitization. The digitized signal is further processed to generate a visual representation of velocities within the patient over time. Summary of the Invention [Problem to be solved by the invention]

[0003]

[0003] To transmit raw analog ultrasonic echo signals from the probe to the main processing system, the connecting cable usually has many conductors, and in some cases, a conductor or set of conductors is required for each receiving ultrasonic transducer element, making the cable thick, complex, unwieldy, and bulky. Since the cable needs to transmit the echo signal received from each ultrasonic transducer element to the main processing system, the cable size or diameter is also large. Therefore, in terms of cable cost, it can be the most expensive component of an ultrasound imaging system. Also, cables have a high failure rate.

[0004]

[0004] One approach to overcome the limitations of analog processing is to include a low-power analog-to-digital converter (ADC) in the transducer probe, perform full or partial beamforming digitally in the transducer probe, and transmit the digital signal to the main processing system with fewer conductors. When used in a conventional ultrasound imaging system, this approach significantly reduces the cost, diameter, and overall operability of the cable connecting the ultrasound imaging probe to the main processing system. However, such an approach is not suitable for CW Doppler imaging because the CW Doppler ultrasound signal has a wide dynamic range. In particular, the dynamic range of the low-power ADC used to convert raw analog signals to digital signals in the ultrasound imaging probe is not sufficient to properly receive and convert the analog signals associated with CW Doppler imaging. As a result, in an ultrasound imaging system with both a B-mode ultrasound imaging path and a CW Doppler path, the ultrasound imaging signal for B-mode imaging is converted to a digital signal in the probe, but the signal for the CW Doppler signal cannot be converted. While digital signals for B-mode imaging can be transmitted to the main processing system over fewer conductors, transmitting analog signals for CW Doppler imaging over a cable requires a separate set of conductors, with one or more conductors corresponding to each receiving transducer element, resulting in undesirable size and cost, similar to the transmission of analog signals. [Means for solving the problem]

[0005]

[0005] An embodiment of the present disclosure is a system, device, and method for continuous wave (CW) Doppler ultrasound imaging. The ultrasound system includes a host, a probe, and a connecting cable between the host and the probe. The ultrasound imaging probe includes an array of ultrasound transducers that transmit ultrasound signals toward an anatomical structure and receive waves reflected from the anatomical structure. The received ultrasound waves are used for CW Doppler imaging of velocities in the patient's anatomy. An example of such velocities is blood flow velocity between the chambers of the heart (e.g., between the atria and ventricles). Analog CW Doppler signals are converted to digital signals in the ultrasound imaging probe. These digital CW Doppler signals are combined in the probe before being transmitted to the ultrasound host via a connecting cable. By converting the analog signals to digital signals in the probe, the number of conductors required to transmit the CW Doppler data is significantly reduced, since digital data is more easily combined. Similarly, the cost of the cable is also significantly reduced. Also, the cable and probe are more manageable and easier for the sonographer to operate. Thus, aspects of the present disclosure advantageously address shortcomings of existing ultrasound imaging systems.

[0006]

[0006] Additional embodiments of the present disclosure include additional circuitry within the probe that converts the analog CW Doppler signal to a digital signal. Due to the limited dynamic range of the analog-to-digital converter (ADC), the large dynamic range of the analog CW Doppler signal overdrives the ADC. This results in poor data quality. A large signal slew rate results in large signal differences between samples. Small position movements of the tissue and transducer can shift the samples where large signal transitions occur, resulting in bright white spike artifacts in the Doppler display. To reduce the dynamic range and slew rate of the analog CW Doppler signal, a soft limiter and low pass filter are placed in the signal processing path within the probe before the ADC. A switch also engages unused ADCs associated with the transmitting transducer in parallel communication with the ADCs associated with the receiving transducer. This parallel configuration doubles the ADCs used to convert the analog CW Doppler signal, increasing the total dynamic range of the ADCs in the probe by at least 3 dB. This increase prevents the ADCs from being overdriven and maintains good signal and data quality. By reducing the dynamic range of the analog CW Doppler signal, increasing the dynamic range of the ADC in the probe, and / or converting the analog CW Doppler signal to digital in the probe, advantageously eliminating the need for an analog signal path for CW Doppler imaging between the probe and the host in the ultrasound imaging system.

[0007]

[0007] In an exemplary aspect of the present disclosure, an ultrasound system is provided. The ultrasound system includes a transducer array configured to generate an analog ultrasound signal, a first analog-to-digital converter (ADC) in communication with the transducer array, the first ADC configured to convert the analog ultrasound signal into a digital ultrasound signal, and a processor circuit in communication with the first ADC, the processor circuit including a digital in-phase / quadrature (I / Q) mixer configured to generate a digital continuous wave (CW) Doppler signal based on the digital ultrasound signal, the processor circuit configured to process the digital CW Doppler signal to generate a visual representation of a distribution of blood flow velocity over multiple cardiac cycles, and output the visual representation on a display in communication with the processor circuit.

[0008] In some aspects, the ultrasound system further comprises analog limiter circuitry communicatively disposed between the transducer array and the first ADC. In some aspects, the analog limiter circuitry includes soft limiter circuitry. In some aspects, the ultrasound system further comprises a low pass filter communicatively disposed between the analog limiter circuitry and the first ADC. In some aspects, the ultrasound system further comprises analog gain compression circuitry communicatively disposed between the transducer array and the first ADC. In some aspects, the ultrasound system further comprises a second ADC, the transducer array comprises a first acoustic element and a second acoustic element, the first ADC associated with the first acoustic element, and the second ADC associated with the second acoustic element. In some aspects, the ultrasound system further comprises a switch configured to selectively establish communication between the second ADC and the first acoustic element or the second acoustic element, where the switch establishes communication between the second ADC and the first acoustic element when the second acoustic element is a transmit element and the first acoustic element is a receive element. In some aspects, the processor circuit further comprises a digital low pass filter communicatively disposed between the digital I / Q mixer and the display, and a digital high pass filter communicatively disposed between the digital low pass filter and the display. In some aspects, the ultrasound system further comprises an ultrasound probe having a housing and a cable configured to transmit digital ultrasound signals, and a host system in communication with the ultrasound probe via the cable, where the transducer array is coupled to the housing of the ultrasound probe, the first ADC is disposed within the housing, and the processor circuit is disposed within the host system. In some aspects, the ultrasound system further comprises a preamplifier disposed between the transducer array and the first ADC disposed within the housing of the ultrasound probe. In some aspects, the ultrasound system further comprises circuitry for combining digital ultrasound signals. hi some aspects, the circuitry for combining digital ultrasound signals is disposed within a housing of the ultrasound probe.In some aspects, circuitry for synthesizing the digital ultrasound signal is located within the host system, hi some aspects, processor circuitry is configured to process the digital ultrasound signal to generate an ultrasound image of the heart, and output the ultrasound image to a display.

[0009]

[0009] In an exemplary aspect of the present disclosure, a method is provided, the method including generating an analog ultrasound signal, converting the analog ultrasound signal to a digital ultrasound signal, generating a digital continuous wave (CW) Doppler signal based on the digital ultrasound signal, processing the digital CW Doppler signal, generating a visual representation of a distribution of blood flow velocity over multiple cardiac cycles, and outputting the visual representation on a display in communication with a processor circuit.

[0010]

[0010] Additional aspects, features, and advantages of the present disclosure will become apparent from the following detailed description.

[0011]

[0011] Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1]

[0012] FIG. 1 is a schematic diagram of an ultrasound imaging system according to an aspect of the present disclosure. [Diagram 2]

[0013] FIG. 2 is a schematic diagram illustrating an exemplary circuit configuration of an ultrasound imaging system according to aspects of the present disclosure. [Diagram 3]

[0014] FIG. 2 is a schematic diagram illustrating an exemplary circuit configuration of an ultrasound imaging system according to aspects of the present disclosure. [Figure 4]

[0015] 1 is a visual representation of a CW Doppler spectrum measured with an ultrasound imaging system according to an embodiment of the present disclosure. [Diagram 5]

[0016] FIG. 2 is a schematic diagram illustrating an exemplary circuit configuration of an ultrasound imaging probe according to aspects of the present disclosure. [Figure 6]

[0017] 1 is a visual representation of a CW Doppler spectrum measured with an ultrasound imaging system according to an embodiment of the present disclosure. [Figure 7]

[0018] FIG. 2 is a schematic diagram of a processor circuit according to an aspect of the present disclosure. [Figure 8]

[0019] FIG. 1 is a flow diagram of an ultrasound imaging method according to an aspect of the present disclosure. [Figure 9A]

[0020] FIG. 1 is a schematic diagram illustrating an exemplary ultrasound transducer array according to aspects of the present disclosure. [Figure 9B]

[0021] FIG. 2 is a schematic diagram illustrating an example circuit configuration of an analog beamformer in accordance with aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013]

[0022] For the purposes of facilitating an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings and specific terms will be used to describe these embodiments. It will be understood, however, that no limitation of the scope of the present disclosure is intended. Any changes and further modifications to the described apparatus, systems, and methods, and any further applications of the principles of the present disclosure, as would normally occur to one skilled in the art to which the present disclosure pertains, are fully contemplated and encompassed within the present disclosure. In particular, it is fully contemplated that features, components, and / or steps described with respect to one embodiment may be combined with features, components, and / or steps described with respect to other embodiments of the present disclosure. However, for the sake of brevity, these combinations will not be repeatedly and individually described. FIG. 1 is a schematic diagram of an ultrasound imaging system 100 according to an aspect of the present disclosure. The system 100 is used to scan a region, area, or volume of a patient's body. The system 100 includes an ultrasound imaging probe 110 that communicates with a host 130 via a communication interface or link 150. At a high level, the probe 110 directs ultrasound waves toward an anatomical object 105 (e.g., a patient's body) and receives ultrasound echoes reflected from the object 105. The probe 110 transmits electrical signals representative of the received echoes via link 150 to the host 130 for processing and image display. The probe 110 is of any suitable form for placement inside or outside the patient's body to image various parts of the patient's body. For example, the probe 110 may be in the form of a handheld ultrasound scanner or a patch ultrasound device. In some embodiments, the probe 110 may be an intracorporeal probe, such as a transesophageal echocardiogram (TEE) probe, a catheter, or an intracavity probe. The probe 110 may include a transducer array 112, various circuitry 114, and a communication interface 122.

[0014]

[0023] The transducer array 112 emits ultrasonic signals toward the object 105 and receives echo signals that reflect off the object 105 and return to the transducer array 112. The transducer array 112 includes acoustic elements arranged in a one-dimensional (1D) array, a 1.X-dimensional array, or a two-dimensional (2D) array. The acoustic elements may also be referred to as transducer elements. Each transducer element may emit ultrasonic waves toward the object 105 and receive echoes that reflect back from the object 105. For example, the transducer array 112 may include M transducer elements that generate M analog ultrasonic echo signals 160. In some embodiments, M may be about 2, 16, 64, 128, 192, 1000, 5000, 9000, and / or other suitable values ​​both larger and smaller.

[0015]

[0024] The circuitry 114 disposed within the probe 110 may be of any suitable type and perform a number of functions. For example, the circuitry 114 may include resistors, capacitors, transistors, inductors, relays, clocks, timers, or any other suitable electrical components that may be incorporated into an integrated circuit. Additionally, the circuitry 114 is configured to support analog and / or digital signals transmitted to or from the transducer array 112 and / or the probe 110. In some embodiments, the circuitry 114 includes an analog front end (AFE), an analog-to-digital switch (ADC), a multiplexer (MUX), and an encoder, among various other components. In some embodiments, the circuitry 114 may include hardware components, software components, and / or a combination of hardware and software components.

[0016]

[0025] The communication interface 122 is coupled to the circuitry 114 via L signal lines. In some embodiments, the circuitry 114 may reduce the number of lines required from M signal lines to L signal lines. This is accomplished in any suitable manner using any suitable components. For example, a MUX, beamformer, or other components are used to reduce the M signal lines from the transducer array 112 to L signal lines 166. In the embodiment of FIG. 1, L is less than M. The communication interface 122 is configured to transmit the L signals 166 to the host 130 via the communication link 150. The communication link 150 includes L data lanes for transmitting digital signals 168 to the host 130, as described in more detail herein. The communication interface 122 includes hardware components, software components, or a combination of hardware and software components. The circuitry 114 and / or the communication interface 122 are configured to generate a signal 168 conveying information from the L signals 166 for transmission via the communication link 150. Signal 168 may be a digital signal, an analog signal, or a combination of digital and analog signals.

[0017]

[0026] The host 130 may be any suitable computing and display device, such as a workstation, a personal computer (PC), a laptop, a tablet, a mobile phone, or a patient monitor. In some embodiments, the host 130 is located on a mobile cart. In the host 130, a communication interface 140 receives a digital signal 168 from a communication link 150. The communication interface 140 includes hardware components, software components, or a combination of hardware and software components. The communication interface is substantially similar to the communication interface 122 of the probe 110.

[0018]

[0027] The circuitry 134 disposed within the host 130 may be of any suitable type and perform any suitable function. For example, the circuitry 134 may include resistors, capacitors, transistors, inductors, relays, clocks, timers, processing components, memory components, or any other suitable electrical components that may be incorporated into an integrated circuit. Additionally, the circuitry 134 is configured to support analog and / or digital signals transmitted to or from the probe 110. The circuitry 134 is configured to process signals 168 received from the probe 110. For example, the circuitry 134 unfolds L signal lines received from the probe 110 back into M signal lines corresponding to specific transducer elements or groups / patches of transducer elements in the transducer array 112. The circuitry 134 may be configured to generate image signals 174 for display to a user and / or perform image processing and analysis for various diagnostic modalities or ultrasound types (B-mode, CW Doppler, etc.).

[0019]

[0028] The circuitry 114 and / or circuitry 134 may additionally include a central processing unit (CPU), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA), another hardware device, a firmware device, or any combination thereof. The circuitry 114 and / or circuitry 134 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a combination of a GPU and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0020]

[0029] The display unit 132 is coupled to the circuitry 134. The display unit 132 may include a monitor, a touch panel, or any suitable display. The display unit 132 is configured to display images and / or diagnostic results processed by the circuitry 134. The host 130 may further include a keyboard, a mouse, a touch panel, or any suitable user input component configured to receive user input for controlling the system 100.

[0021]

[0030] 1 is described in the context of transmitting digital ultrasound echo signals from the probe 110 to the host 130 for display, the host 130 may also generate signals for transmission to the probe 110. For example, power signals, signals to control the probe 110 (e.g., to excite transducer elements in the transducer array 112 to emit energy) may be transmitted by the host 130 to the probe 110 over the communications link 150.

[0022]

[0031] 2 is a schematic diagram illustrating an example circuit configuration of an ultrasound imaging system according to an embodiment of the present disclosure. FIG 2 is a more detailed diagram of the system 100 including a transmission path from the probe 110 to the host 130 and from the host 130 to the probe 110.

[0023]

[0032] As shown in FIG. 2, the probe 110 further includes an optional analog beamformer 214, as well as L transmit / receive switches (T / R switches) 216, L preamplifiers 219, L analog-to-digital converters (ADCs) 220, and L transmit pulsers 218. The probe 110 also includes a clock 224 and a combiner 222. FIG. 2 also shows the host 130. The host 130 includes an integrated circuit 230. The integrated circuit 230 includes an in-phase mixer 234 / quadrature mixer 236, and a low-pass filter (LPF) 238. The host 130 additionally includes a controller 252, a power supply 254, a plurality of wall filters 255 (including an LPF 256 and an op-amp 258), and a window function 260. The host 130 also includes a component 262 configured to perform a fast Fourier transform (FFT), a component 264 configured to perform various conditioning functions, and a display 266, among other components configured to perform various functions or operations. The host 130 additionally includes hardware components, software components, or a combination of hardware and software components. As shown in FIG. 2, the probe 110 and the host 130 are connected and establish signal communication with a number of conductors of a connecting cable 290. These conductors include a number of signal lines including conductors, twisted pairs, and / or any other suitable means of transmitting data. For example, the connecting cable 290 may include a power conductor 294 for transmitting power from the host 130 to the probe 110. The cable 290 may also include a control signal line 292 for transmitting control and clock signals from the host 130 to the probe. The cable 290 may also include K signal lines 296 for transmitting signals from the probe 110 to the host 130.

[0024]

[0033] The signal path from the probe 110 to the host 130 begins with the transducer array 112 shown in FIG. 2. The transducer array 112 includes M transducer elements. As previously mentioned, in some embodiments, M can be any suitable number and the transducer elements are of any suitable type and in any suitable arrangement. The transducer array 112 generates analog electrical signals representative of ultrasound echoes received at one or more transducer elements for any suitable imaging type (e.g., B-mode imaging, CW Doppler imaging, etc.). For CW Doppler imaging, one or more elements of the transducer array 112 are continuously emitting ultrasound energy at the same time that one or more other elements of the transducer array 112 are continuously receiving ultrasound echoes (based on the emitted ultrasound energy). For example, half of the acoustic elements of the transducer array 112 can be for transmitting and half of the acoustic elements of the transducer array 112 can be for receiving. The transducer array 112 generates analog electrical CW Doppler data based on the ultrasonic echoes received by the transducer elements in a receive mode. In some embodiments, for CW Doppler imaging, equal portions of the transducer array 112 operate in transmit and receive modes, respectively.

[0025]

[0034] The transducer array 112 communicates with the analog beamformer 214 via M signal lines. In some embodiments, the transducer array 112 includes many transducer elements. The analog beamformer 214 is used to reduce the amount of signal lines from the transducer array 112. For example, in some embodiments, the analog beamformer 214 delays and sums signals received from the transducer array 112 to create smaller subsets. The analog beamformer 214 can be a receive beamformer and / or a transmit beamformer. In embodiments where the analog beamformer is a transmit beamformer, the analog beamformer 214 includes or communicates with high-voltage pulse generation circuitry. In other embodiments, such as those where the transducer array 112 is a one-dimensional array of transducer elements or where the number of transducer elements is otherwise reduced, the analog beamformer 214 may not be necessary or may not be included within the probe 110. In some embodiments in which the transducer array 112 is a one-dimensional array, or in which the number of transducer elements is otherwise reduced, the analog beamformer 214 is still included within the probe 110 .

[0026]

[0035] The analog beamformer 214 communicates with a number of T / R switches 216 via a smaller number of signal lines (e.g., L signal lines). The probe 110 may include one T / R switch 216 for each transducer element of the array 112 or for each group / patch of transducer elements. The T / R switch 216 is configured to switch positions between different transmit and receive signal paths. For example, in the transmit path position, the T / R switch 216 transmits a high-voltage activation signal from the pulser 218 to one or more elements of the transducer array 112 to activate the one or more transducer elements 112 to emit ultrasonic energy. In the receive mode, the T / R switch 216 transmits a receive signal corresponding to the reflected wave received by the one or more transducer elements of the transducer array 112 to the preamplifier 219. The T / R switch 216 is in communication with the host 130 via data lines 292, through which it receives instructions regarding switching between transmit and receive signal paths. The T / R switch 216 may also be in communication with the host 130 via any other suitable conductors or methods.

[0027]

[0036] The probe 110 additionally includes a transmit pulser 218. The transmit pulser 218 receives command signals generated by the host 130. In response to the command signals, the transmit pulser 218 generates electrical excitation pulses timed to cause the transducer array 112 to create an acoustic transmit wavefront with any desired or specified focal characteristics.

[0028]

[0037] The probe 110 includes L preamplifiers 219. The preamplifiers 219 amplify signals received from the transducer array 112 via the T / R switches 216 to improve the quality of the received signals, for example by reducing the noise floor. In some embodiments, the number of transmit pulsers 218 is equal to the number of preamplifiers 219 and the number of T / R switches 216. For example, each T / R switch 216 is configured to receive data from one pulser 218 and transmit data from the transducer array 112 to one preamplifier 219.

[0029]

[0038] The receive signal path can be the same for CW Doppler imaging data and other imaging data (e.g., B-mode imaging data) from the transducer array to the preamplifier 319. At the preamplifier 319, the receive signal path branches within the probe 110 to include different parallel paths for CW Doppler imaging data and other imaging data. In the signal path for other imaging data, such as B-mode imaging data, each preamplifier 219 communicates with an ADC 220. The ADC 220 is configured to convert analog ultrasound echo signals into digital ultrasound echo signals. For example, the ADC 220 receives analog ultrasound echo signals generated by the transducer array 112, transmitted to the preamplifier 219 via the T / R switch 216, and amplified by the preamplifier 219, and converts them into digital ultrasound echo signals. The digital ultrasound echo signals include digital samples indicative of the waveform of the corresponding analog ultrasound echo signal. The ADC 220 employs a successive approximation ADC architecture that achieves high performance and low power consumption, thereby keeping the total power dissipation of the probe 110 within the thermal budget of the probe 110. However, any suitable ADC architecture may be used for the ADC 220.

[0030]

[0039] The clock 224 functions as a master clock within the probe 110. The clock 224 provides a clock signal to the ADC 220 and other components within the probe 110.

[0031]

[0040] Each ADC 220 is in communication with a combiner 222. The combiner 222 is representative of a circuit configuration that can reduce the total number of signal lines received from the ADCs 220 and reduce the number of signal lines required to transmit data to the host 130. The combiner 222 reduces the number of signal lines in any suitable manner. In some embodiments, the combiner 222 includes a summing node. The combiner 222, and any other suitable components or circuitry within the system 100, may include features similar to those described in U.S. Patent Application No. 16 / 329,433, filed February 28, 2019, entitled "ULTRASOUND PROBE WITH MULTILINE DIGITAL MICROBEAMFORMER," and / or U.S. Provisional Patent Application No. 62 / 631,549, filed February 16, 2018, entitled "DIGITAL ULTRASOUND CABLE AND ASSOCIATED DEVICES, SYSTEMS, AND METHODS," both of which are incorporated herein by reference in their entireties. In some embodiments, the combiner 222 multiplexes data received from the ADC 220 onto a high-speed serial link, which is then transmitted to the host 130 for processing. In some embodiments, the combiner 222 is a digital beamformer that performs a second stage of beamforming (delaying and summing signals) after the first stage of beamforming by the analog beamformer 214 is completed.

[0032]

[0041] FIG. 2 additionally depicts a connecting cable 290 disposed between the probe 110 and the host 130. The cable 290 includes multiple signal lines, including conductors, twisted pairs, or any other suitable means for transmitting data. For example, the cable 290 includes a data line 292, a power line 294, and K signal lines 296. The data line 292 communicates with a controller 252 in the host 130. The controller 252 transmits control signals over the data line 292 to control the clock 224, the ADC 220, the T / R switch 216, the pulser 218, the analog beamformer 214, the transducer array 112, the combiner 222, or any other components in the probe 110. In some embodiments, the data line 292 is a twisted pair of conductors. In other embodiments, the data line 292 may be a single conductor or any other suitable signal communication conductor. In various embodiments, the command signals transmitted over the data line 292 are analog or digital signals. When the digital command signals are transmitted, data is transmitted over data line 292 at any suitable bit rate, such as between 400 Mbit / s and 8 Gbit / s, including values ​​such as 2.4 Gbit / s, and / or other suitable greater and lesser values.

[0033]

[0042] The power line 294 communicates with a power source 254 in the host 130 or any other suitable location. The power line 294 provides power to various components in the probe 110. In some embodiments, the power source 254 can provide direct current (DC) power to the probe 110 via the power line 294. In some embodiments, the power source 254 additionally provides power to components in the host 130.

[0034]

[0043] The K signal lines 296 correspond to a reduced number of signal lines output from the combiner 222. The signal lines 296 carry digital ultrasound data for CW Doppler imaging and B-mode imaging. In some embodiments, the signal lines 296 include only a single signal line. In other embodiments, the signal lines 296 include two or more signal lines. The cable 290 and any corresponding conductors enclosed within the cable 290 for the data line 292, the signal line 296, and / or the power line 294 are of any suitable length. For example, the cable 290 and all associated conductors are 1 meter, 2 meters, 3 meters, or more in length, or any suitable length therebetween. The cable 290 may be referred to as a flexible elongated member. In some embodiments, the cable may be replaced with an optical or wireless interface.

[0035]

[0044] The host 130 includes an integrated circuit 230. The integrated circuit 230 comprises any suitable circuit configuration. In some embodiments, the integrated circuit 230 is implemented in the form of an FPGA, an application specific integrated circuit (ASIC), or any other suitable type of circuit. In other embodiments, the integrated circuit 230 may be a configurable processor, an NPU, an accelerator card, an SoC, or any other component. The integrated circuit 230 comprises an in-phase (I) mixer 234 / quadrature (Q) mixer 236 and a low pass filter (LPF) 238. The I mixer 234 / Q mixer 236 and the LPF 238 are digital components in that they are implemented as part of the integrated circuit 230 and operate on digital signals.

[0036]

[0045] Signal line 296 transmits digital signal data from combiner 222 to integrated circuit 230. In integrated circuit 230, the signal is transmitted to two paths corresponding to the I component of the signal associated with mixer 234 and the Q component of the signal associated with mixer 236. I mixer 234 and Q mixer 236 create two signals with offset phases. For example, I mixer 234 defines a sequence corresponding to a digital square wave (e.g., a sequence of +1s and -1s, or a sequence of +1s and 0s) and multiplies the sequence with the received signal. Q mixer 236 defines a similar sequence, but delayed by 1 / 4 period (90 degrees) with respect to the I sequence, and multiplies the sequence with the received signal. I mixer 234 and Q mixer 236 multiply their respective sequences in such a way as to create a phase offset between the two signal paths. For example, in some embodiments, the phase offset is 90°. The digital square wave sequence is a square wave of any suitable frequency. The frequency of the generated digital square wave corresponds to the sample rate of the signal received by the I mixer 234 and the Q mixer 236, for example, but not limited to, in the range of 1 Mhz to 10 Mhz. The signal transmitted from the probe 110 to the host 130 via the K signal lines 296 is at any suitable sample rate. For example, but not limited to, in some embodiments, the signal transmitted and mixed via the I mixer 234 and the Q mixer 236 may be in the range of 4 Mhz to 40 Mhz. In some embodiments, the sample rate is at least four times the Doppler frequency. The sample rate of the sequence generated by the I mixer 234 and the Q mixer 236 is consequently some frequency lower than the sample rate of the received signal.

[0037]

[0046] After the signal is received at the host 130 and mixed by the I mixer 234 and the Q mixer 236, the signal is then filtered through the LPF 238. The LPF 238 filters any high frequency content in the received signal so that the signal corresponds primarily to content in the audible range. In some embodiments, the LPF 238 may be a box car filter. For example, the LPF 238 sums or averages a set number of samples in the received signal into sets. The LPF 238 groups and sums sets of 1680 samples. In other embodiments, the LPF 238 sums sets in the range of, but not limited to, 100 to 6000. In embodiments in which the LPF 238 includes a box car filter, the resulting sample rate is reduced by the number of samples included in a particular set. Thus, in some embodiments, the sample rate of the data signal after passing through the LPF 238 corresponds to the audible frequency range and can be processed using standard processing components. In other embodiments, LPF 238 may be any suitable low pass filter, such as an FIR digital filter or an IR digital filter, or any other suitable low pass filter.

[0038]

[0047] The host 130 may additionally include one or more wall filters 255. The wall filter 255 is a digital filter that operates on the digital signal data. For example, the wall filter 255 may be a circuit configuration in the host 130. The wall filter 255 further includes an LPF 256. The wall filter 255 is configured to filter low or high frequency Doppler signals corresponding to arterial walls or any other static tissue in the patient. The wall filter 255 may additionally filter high amplitude low frequency content from, for example, heartbeat, general patient or probe motion, or motion in the patient from other sources. In some embodiments, the wall filter 255 is an aggressive filter. In some embodiments, the wall filter 255 may be a 40 point, 4 term Blackman-Harris filter or any other suitable filter. The wall filter 255 also comprises a high pass filter.

[0039]

[0048] After the signal is processed through wall filter 255, a window function 260 is applied. Window function 260 is applied by a digital multiplier or any other suitable electronic component. Window function 260 applies various weights to the signal before further processing occurs. A fast Fourier transform (FFT) 262 is applied to the signal data to create a Doppler spectrum associated with the velocity of motion (e.g., blood flow) within the patient. Following FFT 262, conditioning 264 conditions the data. A visual representation of the CW Doppler data is then output for display to a user via display 266. It is fully contemplated that any suitable form of data processing may be applied to the signal data at this stage, or any stage, in the circuitry of the present invention. For example, host 130 may apply additional data processing techniques to improve the quality of the signal data, identify or highlight various characteristics or aspects of the signal data, etc. One or more of the signal processing components within host 130 and / or probe 110 may be implemented as hardware, software, or a combination of hardware and software.

[0040]

[0049] The signal path of Figure 2 in the probe 110 is shared for B-mode data and CW Doppler data. Figure 2 shows the path of the CW Doppler signal in the host 130. Some components of the CW Doppler signal path (e.g., conditioning 264, display 266) are shared with the B-mode signal path, while other components (e.g., integrated circuit 230, wall filter 255, FFT 262) are dedicated to CW Doppler processing. The host 130 can include signal processing circuitry for generating and displaying B-mode images based on the ultrasound data acquired by the probe 110.

[0041]

[0050] FIG. 3 is a schematic diagram illustrating an exemplary circuit configuration of an ultrasound imaging system according to aspects of the disclosure. FIG. 3 specifically illustrates an embodiment in which the combiner 222 is located in the host 130 (instead of the probe 110). In some embodiments, a serializer block 233 is included in the probe 110 to stream ADC data to the host 130 via a high-speed serial link. In such an embodiment, the combiner 222 is a digital beamformer that performs a second stage of beamforming after the first stage of beamforming by the analog beamformer 214 is completed. This embodiment may be advantageously implemented to simplify the signal processing circuitry in the probe 110. In this way, the probe 110 may better meet weight and / or thermal constraints (e.g., maximum weight and / or maximum temperature of the probe 110) and may better increase efficiency and reduce costs associated with manufacturing the probe 110. The serializer block 233 may additionally include a current mode logic (CML) block. The serializer block 233 converts signals received from the ADC 220 or any other components in the probe 110 into a bit stream for transmission to the host 130. It should also be noted that the system 100 shown in Figure 3 and / or the probe 510 shown in Figure 5 may additionally include a serializer block substantially similar to the serializer block 233 shown in Figure 3.

[0042]

[0051] The serializer / CML 233 reconfigures the lines communicating with the combiner 232 and / or ADC 220 into a high-rate serial data stream. In some embodiments, the serializer / CML 233 operates at a higher data rate than the other circuitry in the probe 110. For example, the serial data stream operates at 160 MHz, while the other circuitry in the ultrasound signal path operates at 20 MHz. The serializer / CML 233 may operate in a manner similar to the serializer disclosed in PCT patent application PCT / EP2017 / 070804, entitled "ULTRASOUND PROBE WITH MULTILINE DIGITAL MICROBEAMFORMER," which is incorporated by reference in its entirety. Thus, one of the signal paths of the probe 110 can transmit digital ultrasound data (e.g., B-mode data) from the probe 110 to the host 130 via conductor 296. The conductor 296 is a twisted pair of conductors. It will be appreciated that embodiments of the probe may include a combiner 222, a serializer 233, and / or both a combiner 222 and a serializer 233.

[0043]

[0052] FIG. 4 is a visual display of a Doppler spectrum measured by an ultrasound imaging system according to aspects of the disclosure. Display 266 (FIG. 2) displays to a user a Doppler spectrum similar to Doppler spectrum 400. Doppler spectrum 400 depicts the velocity of fluids and / or other objects within a patient. A direction 450 axis along Doppler spectrum 400 indicates a time dimension. The time dimension depicted by direction 450 in FIG. 4 is in any suitable units. For example, direction 450 is measured in seconds, milliseconds, or any other suitable units. A direction 460 along Doppler spectrum 400 indicates a velocity. In some embodiments, this velocity corresponds to the velocity of blood in the patient's heart or blood vessels. In some embodiments, the Doppler spectrum velocity corresponds to blood flow through the mitral valve in the heart. The velocity depicted along direction 460 is measured in m / s, cm / s, mm / s, or any other suitable units. The values ​​410 depicted in the Doppler spectrum 400 indicate the velocity of fluid at a defined location within the patient at a given time. For example, the values ​​410 correspond to the velocity of blood in or around the mitral valve in the heart as it beats. The peaks 430 correspond to moments of high blood flow velocity. The Doppler spectrum 400 additionally depicts one or more sampling errors 420. The sampling errors 420 may be caused by full-scale signal transitions seen at the output of the preamplifier 219 resulting from motion by or within the patient or from thermal noise. The sampling errors 420 may be caused by a high slew rate acoustic signal associated with the transmit energy coupling into the receive aperture overdriving the preamplifier 219. Such motions causing full-scale signal transitions include heartbeats, general patient motion, probe motion, or any other abrupt motion during a patient ultrasound examination. These motions cause abrupt changes in the output of the I-mixer 234 and / or Q-mixer 236 (FIG. 2) causing mismatches between samples resulting in large changes in the output signal. Sampling error 420 may result from jitter on the timing of the edges of the square waves at I mixer 234 and Q mixer 236 .For example, sampling in ADC 220 may result in capturing the signal level before an edge or after an edge, depending on the momentary jitter. This uncertainty results in a full-scale sampling error 420, which after downstream processing results in artifacts or large white spikes in the Doppler spectrum 400. As described below, aspects of the present disclosure are intended to minimize and / or eliminate sampling error 420 in the Doppler spectrum 400.

[0044]

[0053] The Doppler spectrum 400 may be presented or depicted to the user in any suitable form. For example, the display 266 may additionally display to the user a number of metrics associated with the patient's anatomy. In some embodiments, the display 266 includes scales along any suitable direction of the Doppler spectrum 400. The display 266 may further include calculated metrics, such as averages, trends, forecasts, or any other suitable metrics. In some embodiments, the Doppler spectrum 400 may be referred to as a trace or a spectral trace.

[0045]

[0054] FIG. 5 is a schematic diagram illustrating an exemplary circuit configuration of an ultrasound imaging probe according to an aspect of the disclosure. The probe 510 illustrated in FIG. 5 is substantially similar to the probe 110. Also, the transducer array 112 includes two sets of transducer elements / acoustic elements, one set of receive transducers 112a and one set of transmit transducers 112b. In some embodiments, the transducer elements may be referred to as acoustic elements. The probe 510 includes two circuit configuration blocks or signal paths, namely, a circuit configuration 520a that communicates with the receive transducer set 112a and a circuit configuration 520b that communicates with the transmit transducer set 112b. The circuit configuration 520a includes a limiter 511, a low pass filter 512, and an ADC 220a. The circuit configuration 520b includes an ADC 220b. The circuit configuration 520a communicates with the circuit configuration 520b via a connecting conductor 522 and a switch 520. The ultrasound imaging system 100 capable of performing CW Doppler imaging includes a plurality of transducer elements in the transducer array 112 and includes a plurality of circuit configuration blocks 520a and 520b. In some embodiments, each of the ADCs 220a and 220b corresponds to one circuit configuration block 520a and one circuit configuration block 520b, respectively.

[0046]

[0055] In CW Doppler mode, set 112b of transducer elements (e.g., half of the transducer elements) is used to transmit acoustic waves, indicated by arrows 552 in FIG. 5, and set 112a is used to receive reflected waves, indicated by arrows 562.

[0047]

[0056] In some embodiments, ultrasound imaging system 100 is capable of performing various ultrasound imaging functions in addition to CW Doppler imaging. For example, ultrasound imaging system 100 performs B-mode, C-mode, M-mode, power Doppler, color Doppler, shear wave, pulse inversion, and / or other imaging types. When performing ultrasound imaging functions other than CW Doppler, the host controls one or more of the transducer elements in transducer array 112 to selectively transmit acoustic waves as indicated by arrow 552 and receive reflected waves as indicated by arrow 562.

[0048]

[0057] Each transducer element communicates with an ADC. For example, each transducer element in the receive set 112a communicates with the ADC 220a. In some embodiments, multiple transducer elements communicate with a single ADC 220a (e.g., when an analog beamformer is provided in the probe 510 between the ADC 220 and the transducer array 112). In such embodiments, any suitable number of transducer elements communicate with one ADC 220a. For example, 2, 4, 6, 8, or more transducer elements, or any suitable value of greater and lesser transducer elements, communicate with the ADC 220a. Similarly, each transducer element in the transmit set 112b also communicates with the ADC 220b, or multiple transducer elements, including any number of the foregoing, communicate with a single ADC 220b. ADC 220a is substantially similar to ADC 220b, and both ADC 220a and ADC 220b are substantially similar to ADC 220 described herein.

[0049]

[0058] Circuitry 520a includes limiter 511. Limiter 511 is a filter configured to limit the dynamic range of signals received by transducer elements in receive set 112a while maintaining good signal behavior. In some embodiments, limiter 511 allows signals below a certain input power or input level to pass unaffected while attenuating stronger signal peaks above a threshold. In some embodiments, limiter 511 is a clipper, soft clipper, hard limiter, or any other type of suitable limiter. Limiter 511 includes analog limiter circuitry. In some embodiments, the analog limiter circuitry of limiter 511 includes soft limiter circuitry.

[0050]

[0059] The circuit configuration 520a additionally includes a low pass filter 512 disposed in communication with the limiter 511. The low pass filter 512 can admit signals with frequencies lower than a selected cutoff frequency and attenuate signals having frequencies higher than the cutoff frequency. The low pass filter 512 may further be referred to as a high cut filter in some applications. The low pass filter 512 may be of any suitable type. For example, the low pass filter 512 may be a Butterworth filter, a Chebyshev filter, an elliptic filter, a Bessel filter, a Gaussian filter, an RC filter, a RL filter, an RLC filter, or a high order passive filter. Furthermore, the low pass filter 512 may include any suitable active filter and may be integrated within an integrated circuit. In some embodiments, one limiter 511 communicates with one low pass filter 512 as shown in FIG. 5. In other embodiments, any suitable number of limiters 511 may be in communication with one low pass filter 512 or vice versa. The combination of limiter 511 and low pass filter 512 provides ADC 220 with a slower edge that results in smaller errors in the presence of jitter or motion, as previously described.

[0051]

[0060] Both the limiter 511 and the low pass filter 512, together and / or individually, serve to reduce the dynamic range of the signal received by the transducer elements in the receive set of transducer elements 112a. The limiter 511 and the low pass filter 512 also serve to reduce the effect of any full-scale signal transitions similar to sampling errors 420 (FIG. 4) resulting from motion in the patient. This advantageously results in a more accurate and visible Doppler spectrum. In some embodiments, the parameters and / or specifications of the limiter 511 and / or the low pass filter 512 reduce power consumption and heat loss in the probe 510. Additionally, the parameters and / or specifications of the limiter 511 and / or the low pass filter 512 are selected and / or configured to preserve the overall signal integrity of the signal received from the transducer elements in the receive set of transducer elements 112a while sufficiently reducing the dynamic range of the signal so as not to overdrive the ADC 220a.

[0052]

[0061] In some embodiments, limiter 511 and / or low pass filter 512 are replaced with any suitable non-linear circuit. For example, a non-linear circuit having a compressive transfer function is used without or in combination with either limiter 511 or low pass filter 512. Additionally, the circuitry includes analog gain compression circuitry. In some embodiments, this circuitry is implemented via hardware. In other embodiments, this circuitry is a software implementation.

[0053]

[0062] To increase the overall dynamic range of the analog-to-digital conversion process in the probe 510, the probe 510 additionally includes conductors 522 and switches 520. The conductors 522 are of any suitable material, shape, or size. The conductors 522 extend from the signal paths 564 of the circuitry 520a to the switch 520 that communicates with the signal paths 554 of the circuitry 520b. In some embodiments, each signal path 564 and / or the circuitry 520a corresponds to one receiving transducer element, and each signal path 554 and / or the circuitry 520b corresponds to one transmitting transducer element. In such embodiments, the number of signal paths 564 is equal to the number of signal paths 554, such that a single conductor 522 communicates with one signal path 564 and one signal path 554. Conductor 522 is positioned within probe 510 such that one end of conductor 522 is placed in communication with signal path 564 between ADC 220a and low pass filter 512. Additionally, the location of limiter 511 and / or low pass filter 512 need not be in the order shown in FIG. 5 and may be in any suitable order. The other end of conductor 522 is in communication with signal path 554 and is positioned at any suitable location along signal path 554. In other embodiments, signal path 554 additionally includes limiter 511 and / or low pass filter 512 similar to signal path 564. Although only one signal path 564 and one signal path 554 are depicted and shown in FIG. 5, it is understood that any suitable number of signal paths 554 and / or signal paths 564 may be included within probe 510 such that there are L / 2 conductors 522 within probe 510.

[0054]

[0063] As shown in FIG. 5, one end of conductor 522 communicates with switch 520. In some embodiments, while ultrasound imaging system 100 is performing imaging other than CW Doppler, switch 520 is set to a position that engages signal path 554 such that ADC 220b is in communication with preamplifier 219 and set of transducer elements 112b and is not in communication with signal path 564 or conductor 522. When ultrasound imaging system 100 is to image a region of interest within a patient using CW Doppler imaging, switch 520 is actuated to establish communication with conductor 522 and signal path 564 as shown in FIG. 5. That is, switch 520 establishes communication between circuitry 520a and circuitry 520b when system 100 is performing CW Doppler imaging. While performing CW Doppler imaging, ultrasound imaging system 100 uses transmit set of transducer elements 112b to transmit sound waves as indicated by arrow 552. In such a configuration, if switch 520 or conductor 522 is not present, ADC 220b is not used. Switch 520 effectively combines signal path 564 with signal path 554 after preamplifier 219. For example, switch 520 parallels ADCs 220a and 220b such that signals received by receive set 112a are converted from digital to analog using both ADCs 220a and 220b. Combining the signal paths in this manner increases the dynamic range of the ADCs by at least 3 dB. Additional switches and conductors similar to switch 520 and conductor 522 may be present in probe 510 and / or host 130 to recombine signal paths.

[0055]

[0064] In some embodiments, circuitry 520 operates on the analog signal from the receive portion of the array 112a to limit the slew rate. In function, the slew rate limiting circuitry may be an op-amp clipping against a power rail (e.g., power signal line 294) followed by an active low pass filter. This circuitry (and / or other circuitry in block 520) may be integrated within the probe 510 as an integrated circuit.

[0056]

[0065] FIG. 6 is a visual representation of a Doppler spectrum measured by an ultrasound imaging system according to an embodiment of the disclosure. Display 266 (FIG. 2) displays to a user a Doppler spectrum similar to Doppler spectrum 600. Specifically, Doppler spectrum 600 is a depiction of data measured and processed using ultrasound imaging system 100 with a probe similar to probe 510 (FIG. 5) including limiter 511, low pass filter 512, switch 520, and conductor 522. As a result, Doppler spectrum 600 is similar to Doppler spectrum 400 (FIG. 4), but there are also differences in Doppler spectrum 600. Specifically, Doppler spectrum 600 may depict the velocities of fluids and other objects, but with less sampling error 420 due to the increased dynamic range. As with the visual representation of FIG. 4, the axis of direction 650 along Doppler spectrum 600 indicates the time dimension. The direction 660 along the Doppler spectrum 600 indicates velocity, which corresponds to the velocity of blood in the patient's heart or blood vessels. In some embodiments, the Doppler spectrum velocity corresponds to blood flow through the mitral valve in the heart. The values ​​610 depicted in the Doppler spectrum 600 indicate the velocity of fluid at a given location in the patient at a given time. However, the Doppler spectrum 600 differs from the Doppler spectrum 400 in that it does not include or includes less of the sampling error 420 of FIG. 4. The limiter 511 and the low pass filter 512 have the effect of reducing the dynamic range of the received signal, so that the sampling error 420 may be significantly reduced or absent in parts in the Doppler spectrum 600. Furthermore, the switch 520 and the conductor 522 expand the overall dynamic range of the ADC in the probe 510, so that the Doppler spectrum 600 does not include or includes less of the sampling error 420.

[0057]

[0066] Similar to Doppler spectrum 400, Doppler spectrum 600 may be presented or depicted to a user in any suitable manner. For example, display 266 may additionally display a number of metrics associated with Doppler spectrum 600 or corresponding to the patient's anatomy.

[0058]

[0067] The Doppler spectrum 600 of FIG. 6 additionally includes several regions 615, which correspond to high velocities that are recorded and displayed to the user. Such high velocities correspond to leaks of various valves in the patient's heart, or leaks at any other suitable location in the patient's vascular system. For example, the mitral valve in the patient's heart may not close completely and leak, resulting in blood being ejected at a very high velocity through the mitral valve when it should be closed while the heart is pumping. Thus, the present invention is useful in diagnosing such or similar conditions in the patient's heart or vascular system.

[0059]

[0068] FIG. 7 is a schematic diagram of a processor circuit according to an embodiment of the disclosure. The processor circuit 710 may be implemented in the host 130, the probe 110 of FIG. 1, or any other suitable location. The one or more processor circuits 710 are configured to perform the operations described herein. The processor circuit 710 may include additional circuitry or electronic components, such as those described herein. As an example, the processor circuit 710 communicates with the transducer array 112, the circuitry 114, the communication interface 122, the communication interface 140, the circuitry 134, and / or the display 132 in the probe 110, as well as any other suitable components or circuits in the ultrasound system 100 (FIG. 1). As shown, the processor circuit 710 includes a processor 760, a memory 764, and a communication module 768. These elements communicate with each other directly or indirectly, for example, via one or more buses.

[0060]

[0069] Processor 760 may include a CPU, GPU, DSP, application specific integrated circuit (ASIC), controller, FPGA, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein. Processor 760 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0061]

[0070] The memory 764 may include cache memory (e.g., cache memory of the processor 760), random access memory (RAM), magnetoresistive RAM (MRAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory devices, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, the memory 764 includes a non-transitory computer readable medium. The memory 764 stores instructions 766. The instructions 766 include instructions that, when executed by the processor 760, cause the processor 760 to perform operations described herein with reference to the probe 110 and / or the host 130 (FIG. 1). The instructions 766 may also be referred to as code. The terms "instructions" and "code" should be interpreted broadly to include any type of computer readable statements. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, procedures, etc. "Instructions" and "code" may include a single computer readable statement or multiple computer readable statements.

[0062]

[0071] The communications module 768 may include any electronic and / or logical circuitry for facilitating direct or indirect communication of data between the processor circuit 710, the probe 110, and / or the display. In this regard, the communications module 768 may be an input / output (I / O) device. In some implementations, the communications module 768 facilitates direct or indirect communication between various elements of the processor circuit 710, the probe 110 (FIG. 1), and / or the host 130 (FIG. 1).

[0063]

[0072] 8 is a flow diagram of an ultrasound imaging method 800 according to aspects of the present disclosure. One or more steps of method 800 may be performed by a processor circuit of ultrasound imaging system 100, including, for example, processor 760 (FIG. 7). As shown, method 800 includes several enumerated steps, although embodiments of method 800 may include additional steps before, after, or between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted, performed in a different order, or performed simultaneously. The steps of method 800 may be performed by any suitable component within ultrasound imaging system 100, and all steps need not be performed by the same component.

[0064]

[0073] At step 805, the method 800 includes generating an analog ultrasound signal. A command signal is generated in the host 130 and transmitted to the probe 110 via signal line 292. The pulser 218 generates a signal that in turn excites the transmit set 112b of transducer elements to generate ultrasound waves (FIG. 5). The transducers of the receive set 112a then receive echo signals reflected off of features of the patient's anatomy and generate analog electrical signals representative of the ultrasound echoes. The generated analog ultrasound signal is then transmitted to circuitry 520a (FIG. 5).

[0065]

[0074] In step 810, method 800 includes limiting the slew rate of the analog signal so as not to overdrive the analog-to-digital converter to eliminate artifacts associated with motion and jitter. In some embodiments, the slew rate of the analog signal is limited within the probe to match or not exceed a slew rate that can be processed by ADC 220 (FIG. 5) or by probe 510 or any other component within system 100, to advantageously prevent artifacts in the visual display of blood flow velocity over the cardiac cycle.

[0066]

[0075] At step 815, the method 800 includes converting the analog ultrasound signal to a digital ultrasound signal. As previously described, reflected ultrasound energy is optionally reduced via the analog beamformer 214. The analog signal corresponding to the reflected wave is then sent to the ADC 220, ADC 220a, or ADC 220b for conversion from an analog ultrasound signal to a digital ultrasound signal. The digital signal is then further beamformed, multiplexed, or otherwise combined via the combiner 222 of FIG. 2 or any other suitable component before being sent to the host 130 via the cable 290. In some embodiments, the digital ultrasound signal is beamformed and / or otherwise combined via the combiner 222 located within the host 130, as shown in FIG. 3.

[0067]

[0076] At step 820, the method 800 includes generating a digital CW Doppler signal based on the digital ultrasound signal. The CW Doppler signal may be generated in any suitable manner based on the received digital ultrasound. For example, a digital I / Q mixer may receive the digital ultrasound signal and generate the digital CW Doppler signal within the host 130.

[0068]

[0077] At step 825, method 800 includes processing the digital CW Doppler signal. Processing the digital CW Doppler signal includes any suitable data processing components or procedures, including filtering via a low pass filter, a high pass filter, or any suitable type of filter. Data processing may further include windowing, summing, averaging, smoothing, conversion from one domain to another such as a fast Fourier transform, and any other suitable conditioning to improve overall data quality, clarity, or presentation. Additionally, the digital signal processing may be performed via a processor, in software form, or in hardware such as physical circuitry within host 130, or via any other suitable method or form.

[0069]

[0078] At step 830, the method 800 includes generating a visual display of blood flow velocity over the cardiac cycle. The visual display includes any suitable means of data presentation. For example, the visual display includes a list of data including data related to time, velocity, size, or location of the imaged object within the patient's anatomy. The visual display may additionally include a Doppler spectrum similar to those depicted in FIG. 4 and / or FIG. 6. The visual display may also include any suitable drawing, photograph, or depiction that conveys information to a user regarding the patient's health or physical condition. The visual display may also include any of the previously described metrics of the patient's anatomy, or a CW Doppler graph.

[0070]

[0079] At step 835, the method 800 includes outputting a visual representation of the blood flow velocity over the cardiac cycle to the display. Any of the foregoing visual representations may be output to the display 132. Such visual representations may be displayed in real time as the sonographer performs the ultrasound examination or may be displayed at a later time. The visual representations generated by the ultrasound imaging system 100 may be stored in a memory 764 connected to the processor circuit 710, or may be stored on a cloud-based server or similar device. Any suitable metrics associated with the patient's health or physical condition, based on data collected by the ultrasound imaging system 100, or obtained with other devices or procedures, or derived from various different examinations at different times, may also be displayed to the user along with any visual representation.

[0071]

[0080] 9A is a schematic diagram illustrating an example ultrasonic transducer array 912 according to an embodiment of the present disclosure. The ultrasonic transducer array 912 includes a plurality of ultrasonic transducers 910 arranged in a subarray 920.

[0072]

[0081] The transducer array 912 shown in FIG. 9A is a 1.X-dimensional or two-dimensional matrix of ultrasonic elements 910. The transducer array 912 is substantially similar to the transducer array 112 of FIG. 1 and / or FIG. 2. In other embodiments, the transducer array 912 may be a one-dimensional linear array, or any other suitable type of array. As previously described with respect to the transducer array 112, the transducer array 912 includes any suitable number of transducer elements 910. The transducer elements 910 are arranged in a number of subarrays 920 within the transducer array 912. The subarrays 920 may further be referred to as groups or patches, among other suitable terms. Each subarray 920 includes four transducer elements 910, or any other suitable number of transducer elements 910. For example, a subarray 920 may comprise 2, 4, 6, 8, 10, 12, or more transducer elements 910, and any suitable number of transducer elements 910 therebetween. Additionally, in some embodiments, each subarray 920 need not include the same number of transducer elements 910, and each may vary according to any suitable arrangement or pattern. Note that the spacing between subarrays 920 shown in FIG. 9A does not necessarily indicate a physical spacing or separation within the array. For example, each of the transducer elements within an array may have the same spacing as each adjacent element (whether or not the elements are part of the same subarray). Rather, the spacing shown in FIG. 9A may illustrate a grouping of subarrays.

[0073]

[0082] FIG. 9B is a schematic diagram illustrating an example circuit configuration of an analog beamformer 930 according to an embodiment of the present disclosure. The analog beamformer 930 is substantially similar to the analog beamformer 214 of FIG. 2. FIG. 9B provides a more detailed view of the analog beamformer 930 implemented in an ultrasound probe. The analog beamformer 930 includes a number of transmit pulsers 932, a preamplifier 934, a delay circuit 940, a summing component 950, and conductors 990 that provide power, clock, and / or control signals to any of these components. FIG. 9B further depicts a subarray 920 that includes a number of ultrasound transducer elements 910. The subarray 920 shown in FIG. 9B may be one of the subarrays 920 shown in FIG. 9A or may be a different subarray.

[0074]

[0083] The transmit pulser 932 is substantially similar to the pulser 218 of Figure 2. In particular, the transmit pulser 932 receives command signals from the host and, in response to these command signals, transmits high voltage pulses to activate the ultrasonic elements 910 to emit ultrasonic energy that propagates into the patient's anatomy. Thus, each ultrasonic element 910 corresponds to and / or communicates with a transmit pulser 932.

[0075]

[0084] Further depicted in Figure 9B are a number of preamplifiers 934. The preamplifiers 934 are substantially similar to the preamplifiers 219 of Figure 2. The preamplifiers 934 amplify the signals received from the ultrasonic elements 910 to improve the quality of the received signals, for example, by reducing the noise floor.

[0076]

[0085] A number of delay circuits 940 communicate with the preamplifiers 934 in the analog beamformer 930. The delay circuits 940 may be of any suitable type. For example, the delay circuits 940 may include analog delay circuitry for the analog beamformer 930. The delay circuits 940 apply a delay profile to signals received from the ultrasound transducer 910 to perform beamforming or partial beamforming associated with all elements in the subarray 920. Such a delay profile may be provided to the delay circuits 940 via any suitable method. For example, in some embodiments, a conductor corresponding to control data or clock data in conductors 990 may communicate with the delay circuits 940 and dictate a delay profile for the delay circuits 940.

[0077]

[0086] 9B further depicts summing component 950. Summing component 950 is an analog summing circuit, summing mixer, or any suitable electronic component for summing signals. Summing component 950 communicates with the outputs of each of delay circuits 940. In such a configuration, the signals output from each delay circuit 940 are summed in an analog manner. In other embodiments, summing component 950 comprises any suitable circuit configuration or arrangement for combining signals from the outputs of delay circuits 940 in other ways. The outputs of summing component 950 then communicate with one or more T / R switches 216 of FIG. 2, and the signals combined by analog beamformer 930 are further processed and / or combined within probe 110 and / or host 130 as described or in any other suitable manner.

[0078]

[0087] Those skilled in the art will recognize that the above-described devices, systems, and methods can be modified in various ways. Thus, those skilled in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the specific exemplary embodiments described above. In this regard, while exemplary embodiments have been shown and described, a wide range of modifications, changes, and substitutions are contemplated in the above disclosure. It is understood that such variations can be made above without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be broadly construed in a manner consistent with the present disclosure.

Claims

1. A transducer array for generating a continuous analog ultrasonic signal, the transducer array comprising at least a first acoustic element and a second acoustic element; a first analog-to-digital converter (ADC) in communication with the first acoustic element of the transducer array, the first ADC converting the continuous analog ultrasound signal to a digital ultrasound signal; a second ADC in communication with the second acoustic element of the transducer array, the second ADC converting the continuous analog ultrasound signal to a digital ultrasound signal; and a switch for selectively establishing communication between the second ADC and the first acoustic element or the second acoustic element, the switch establishing communication between the second ADC and the first acoustic element when the second acoustic element is a transmit element and the first acoustic element is a receive element; a processor circuit in communication with the first and second ADCs, the processor circuit comprises a digital in-phase / quadrature (I / Q) mixer that generates a digital continuous wave (CW) Doppler signal based on the digital ultrasound signal, the processor circuit comprising: processing the digital CW Doppler signal; generating a visual representation of the distribution of blood flow velocities; An ultrasound system that outputs the visual representation on a display in communication with the processor circuit.

2. 10. The ultrasound system of claim 1, further comprising analog limiter circuitry communicatively disposed between the transducer array and the first ADC.

3. 3. The ultrasound system of claim 2, wherein the analog limiter circuitry comprises soft limiter circuitry.

4. 3. The ultrasound system of claim 2, further comprising a low pass filter communicatively disposed between the analog limiter circuitry and the first ADC.

5. 10. The ultrasound system of claim 1, further comprising analog gain compression circuitry communicatively disposed between the transducer array and the first ADC.

6. The processor circuitry comprises: a digital low pass filter communicatively disposed between the digital I / Q mixer and the display; a digital high-pass filter communicatively disposed between the digital low-pass filter and the display; 10. The ultrasound system of claim 1, further comprising:

7. an ultrasound probe having a housing and a cable for transmitting the digital ultrasound signal; a host system that communicates with the ultrasound probe via the cable; Further equipped with the transducer array is coupled to the housing of the ultrasonic probe; the first ADC is disposed within the housing; The ultrasound system of claim 1 , wherein the processor circuitry is disposed within the host system.

8. 8. The ultrasound system of claim 7, further comprising a preamplifier disposed between the transducer array and the first ADC disposed within the housing of the ultrasound probe.

9. 10. The ultrasound system of claim 7, further comprising circuitry for synthesizing digital ultrasound signals.

10. 10. The ultrasound system of claim 9, wherein the circuitry for synthesizing digital ultrasound signals is located within the housing of the ultrasound probe.

11. 10. The ultrasound system of claim 9, wherein the circuitry for synthesizing digital ultrasound signals is located within the host system.

12. The processor circuitry comprises: processing the digital ultrasound signal; Producing an ultrasound image of the heart; The ultrasound system of claim 1 , wherein the ultrasound image is output to the display.

13. A method for producing a continuous analog ultrasound signal using a transducer array having at least a first acoustic element and a second acoustic element; converting the continuous analog ultrasound signal to a digital ultrasound signal using at least a first ADC in communication with the first acoustic element and a second ADC in communication with the second acoustic element; using a switch to selectively establish communication between the second ADC and the first acoustic element or the second acoustic element, where communication between the second ADC and the first acoustic element is established when the second acoustic element is a transmit element and the first acoustic element is a receive element; generating a digital continuous wave (CW) Doppler signal based on the digital ultrasound signal using a digital in-phase / quadrature (I / Q) mixer; processing the digital CW Doppler signal; generating a visual representation of the distribution of blood flow velocities; outputting said visual representation on a display in communication with the processor circuit; The method comprising:

Images