Serial architecture and energy saving method for ultrasonic and thermoacoustic systems

Abstract

Electronic architecture and power saving methods for use in dual mode USTA instruments including component placement and switch usage are disclosed. In embodiments, the instrument architecture includes US and TA analog components including transducers, TA pre-amps, pulse generators, switches, and AFEs (or ADCs with programmable amplifiers) arranged in a manner that allows efficient use of the same transducer elements, electronic components, wiring, and AFE channels in both US and TA modalities. Operation of fast power control to TA pre-amps is described that allows the TA pre-amp power to be turned off between TA measurement cycles regardless of whether there are US measurements between TA measurements. TA pre-amp power saving allows such designs to reduce TA pre-amp power consumption by many orders of magnitude, enabling the TA pre-amps to be integrated within the transducer housing or probe housing, and / or enabling the use of TA pre-amps in battery operated portable or handheld devices.

Description

[0001] This application includes copyrighted material. The copyright holder does not object to any reproduction of this patent disclosure by any person as if it appeared in a Patent and Trademark Office document or record, but otherwise reserves all copyright. Technical Field

[0002] This invention generally relates to the fields of biomedical (including biological, preclinical, and medical) imaging, sensing, and monitoring. Specifically, this invention relates to apparatus and methods for providing images and information on internal structures, molecular compositions, and functional processes within a living organism based on intrinsic or induced thermoacoustic (TA) and ultrasound (US) imaging. Background Technology

[0003] Thermoacoustics in Biology and Medicine

[0004] Thermoacoustics is a physical phenomenon characterized by the conversion of electromagnetic energy absorbed by a substance into broadband US waves (TA waves). These TA waves can be measured at a single point or multiple spatial locations using transducers with specialized low-noise, high-sensitivity electronics, and subsequently converted into parameters, signals, or images that indicate the spatial and temporal distribution of the electromagnetic energy absorbed within the substance. Preferably, these measurements should be performed by broadband devices capable of sensing TA waves anywhere between tens of kHz and tens of MHz. Some specific types of thermoacoustics used in biology and medicine include photoacoustics (or optoacoustics) (using visible and infrared light for excitation), microwave acoustics (using electromagnetic energy in the millimeter range of wavelengths), and X-ray acoustics. Biomedical thermoacoustics is frequently used due to the high efficiency of pulsed electromagnetic excitation with single pulse durations on the order of 1–1000 ns in generating measurable TA effects in biological tissues, as well as the availability of excitation sources. Biomedical thermoacoustics is a rapidly evolving field, and prototype and commercial TA technologies continue to demonstrate practicality and advantages in a wide range of applications, including diagnostic imaging and sensing, monitoring therapy and surgical interventions, drug development, basic biology, and medicine.

[0005] Ultrasound in Biology and Medicine

[0006] Ultrasound is widely used in clinical and biomedical sciences for applications requiring anatomical and functional imaging, sensing, and monitoring of tissues and organs, therapeutic procedures, and surgeries. Typically, ultrasound instruments are used both to irradiate tissues with ultrasound waves and to detect those waves after they have been scattered by the tissue or otherwise altered. The frequency bandwidth in US applications is typically much narrower than that in TA applications, while the generated and measured ultrasound signals are much larger.

[0007] Ultrasound and thermoacoustic imaging in biology and medicine USTA)

[0008] The combined dual-modal ultrasound and thermoacoustic imaging (USTA) has been proposed as a promising biomedical technology, offering the advantages of similar detection principles and instrumentation while enhancing each other with the benefits of one modality. For example, the superior imaging depth and mechanical tissue imaging provided by ultrasound can be enhanced by the functional and molecular imaging provided by multi-wavelength photoacoustics. To date, the main problem hindering the development of efficient, clinically acceptable, and compact USTA systems appears to lie in the significant differences in the technical requirements imposed by each individual modality on signal sensitivity, dynamic range, and frequency bandwidth, which are typically addressed by constructing two separate data acquisition units that communicate via external control electronics.

[0009] USTA Electronic Architecture

[0010] A dual-modal USTA system architecture can be based on parallel, shared US and TA electronic channels, either identically or differently. This approach has been used in the PhotoSound MoleculUS system and other USTA research and clinical systems. The energy and impedance requirements for USTA systems are considered.

[0011] TA imaging applications require transducer arrays with a large number of elements used in Rx-only mode. Electrical transducer elements are represented by capacitive sensors with element capacitance ranging from less than 1 pF to several nF. The low end of this range can be exemplified by transducers used in photoacoustic and low-frequency (≤1 MHz) X-ray acoustic applications. The high end of this range is a narrowband high-frequency ultrasonic transducer array with performance limitations in TA mode. In TA mode, each capacitive transducer channel generates a low-level and wideband electrical signal. Parasitic capacitance in the transmission line between the transducer element and the preamplifier input causes charge redistribution through parasitic capacitance and voltage signal loss. The low-level transducer capacitance necessitates a short and low-capacitance transmission line between the transducer and the first amplification stage. The combination of a capacitive sensor with capacitance C and the input resistance R of the first amplification stage forms a high-pass RC filter for an input signal with a angular frequency of 1 / (2πRC). Wideband analog signals require a low corner frequency and correspondingly a high input impedance R for the first preamplifier stage. This high input impedance R creates an impedance mismatch at the transmission line termination. Another mismatch is at the capacitive transducer at the other end of the transmission line. For a two-meter transmission line (transducer cable), this impedance mismatch creates a quarter-wavelength resonance with a first harmonic frequency as low as 25 MHz. Suppressing this quarter-wavelength resonance in TA applications often requires shorter cable lengths. Ideally, the first preamplifier stage should be located within the transducer array housing, close to the transducer elements. The TA preamplifier has a low output impedance (typically 50 Ω) and is capable of driving a transmission line with a matched impedance terminated at an impedance-matching resistor at the device that converts the analog signal to a digital signal. Such devices may or may not include analog stages, such as amplification stages, analog bandwidth filters, or ADC drivers. Such devices may be referred to as data acquisition systems (DAQ), analog-to-digital converters (ADCs), or analog front-ends (AFEs). In the following text, this device will be referred to as an AFE following the Texas Instruments ultrasonic AFE series (e.g., AFE5832, AFE5816, etc.). The length of the impedance matching transmission line between the TA preamplifier output and the AFE input can be customized as needed, for example, 2 meters.

[0012] TA imaging applications require a large number of channels equipped with TA preamplifiers, resulting in relatively high power consumption. For example, the PhotoSound Legion series of multi-channel preamplifier designs using discrete components consumes 30mW per channel. A preamplifier with 256 channels consumes 8W excluding power losses, and a preamplifier with 1024 channels consumes approximately 32W. This level of power consumption does not allow for the integration of TA preamplifiers within the transducer array housing because the heat generated by the preamplifier cannot be effectively dissipated within a small hermetically sealed volume. Power consumption is also a limiting factor for battery-powered portable and handheld devices. The power consumption of existing commercial TA preamplifiers and prototypes cannot be significantly reduced without degrading the input noise level and signal-to-noise ratio. Summary of the Invention

[0013] In the embodiments, the disclosed serial architecture and method allow for the provision of an instrument with dual US and TA imaging modes, which operates using only a single mode at any given time. This instrument (1) incorporates and shares components required for both modes, (2) at each specific operating time point, is capable of efficiently engaging those components required only for operation of the active single mode, and (3) at each specific operating time point, is capable of efficiently excluding (bypassing) components unnecessary for operation of the active single mode. The disclosed method also allows for a fast power-saving mode (standby mode) when no mode-specific components are used, thereby reducing heat dissipation in space-constrained areas of the instrument and enabling rapid activation / deactivation cycles multiple times per second for each specific mode. Attached Figure Description

[0014] The foregoing and other objects, features, and advantages of the invention will become apparent from the following more detailed description of the preferred embodiments illustrated in the accompanying drawings, in which reference numerals refer to the same parts throughout the various views. The drawings are not necessarily drawn to scale, but rather focus on illustrating the principles of the invention. In the drawings, the disclosed embodiments are illustrated by way of example rather than limitation, and similar reference numerals indicate similar elements.

[0015] Figure 1 shows an analog signal chain for a serial USTA system architecture. Figures 1A-1E Different embodiments of the TA preamplifier and its position in the analog signal chain are shown. The analog signal chain components are shown as geometric figures labeled from 101 to 110.

[0016] The pulse generator (102) operates as follows in TA and US Rx modes: Figure 1A As shown in (111). The pulse generator operation in US Tx mode is as follows. Figure 1A It is described in (112).

[0017] exist Figure 1A In –1E, the top panel describes Rx-only operation in TA mode. In TA mode, the TA preamp module (104) is fully powered and plugged into the Rx analog signal chain.

[0018] exist Figure 1A-1E The bottom panel describes the Tx and Rx operations in US mode. In US mode, the TA preamplifier output is disconnected from the analog signal chain. In US mode, the TA preamplifier (104) operates in a fast power-saving mode indicated by a shaded triangle (104). A power-saving mode is fast if the preamplifier can enter and exit power-saving mode on a μs timescale. For example, a fast power-saving mode can be implemented in Analog Devices' ADA4895 operational amplifier IC family. According to the device datasheet, the ADA4895 can be disabled to enter power-saving state within 0.25 μs and re-enabled to return to normal operation within 6 μs.

[0019] Analog wiring is shown using wires that connect individual signal chain components. Analog wiring can be implemented via rigid or flexible PCB traces, internal wiring within the IC, connectors, and cables (including miniature coaxial cable bundles).

[0020] The analog signal path in a specific operating mode is represented by lines of increasing thickness. Arrows marked with Tx and Rx signals indicate the direction of signal propagation from the source to the receiver. TA mode is Rx only. US mode can operate as US Tx and USRx. The direction of the arrow leaving the transducer corresponds to the Rx signal, while the direction of the arrow entering the transducer corresponds to the Tx signal.

[0021] The analog signal chain is shown for a single channel of the USTA system. Digital control and components are present in addition to the analog components, but are not shown except for the AFE (110). The system can have multiple channels (e.g., 32, 96, 256 channels or more). Serial architectures can be used with or without channel multiplexing. Channel multiplexing including the ADC, pulse generator, and other components is not shown in Figure 1.

[0022] Figure 2AA timing diagram and an example of an energy-saving protocol for a USTA system with a 40Hz US component and a 10Hz TA component are shown. (207) – Control US / USTA signal; (201) – 10Hz trigger signal for TA excitation; (202) – 10Hz TA acquisition triggered with a 99.99ms delay relative to (201); (208) – 10Hz TA switch activation signal with a 99.8ms delay relative to (201); (209) – 40Hz US acquisition signal; (203)-(205) are segments of the high (204) and standby (203) and (205) power modes of the TA preamplifier; (206) – Time axis in milliseconds.

[0023] Figure 2B An example of a USTA imaging operation sequence with interleaved US and TA image frames is shown. Detailed Implementation

[0024] The following description and accompanying drawings are illustrative and should not be construed as limiting. Numerous specific details are described to provide a thorough understanding. However, in some instances, well-known or conventional details have not been described to avoid obscuring the description. References to one embodiment or embodiments in this disclosure are not necessarily references to the same embodiment, and such references indicate at least one.

[0025] In this specification, references to "embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of this disclosure. The phrase "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. Furthermore, various features that may be demonstrated by some embodiments but not by others are described. Similarly, various requirements that may be required for some embodiments but not for others are described.

[0026] The invention is described below with reference to block diagrams and operational instructions providing methods and apparatus for ultrasound and thermoacoustic imaging or data generation. It should be understood that each block in the block diagrams or operational instructions, as well as combinations of blocks in the block diagrams or operational instructions, can be implemented by analog or digital hardware and computer program instructions. The computer program instructions can be stored on a computer-readable medium and provided to a hard or soft core processor of a general-purpose computer, special-purpose computer, field-programmable gate array (FPGA), ASIC, or other programmable data processing device, such that the instructions, executed via the processor of the computer or other programmable data processing device, implement the functions / actions specified in the block diagrams or one or more operational blocks. In some alternative embodiments, the functions / actions marked in the blocks may not occur in the order indicated in the operational instructions. For example, depending on the functionality / action involved, two blocks shown successively may actually be executed substantially simultaneously, or these blocks may sometimes be executed in reverse order.

[0027] As used herein, the following terms and phrases shall have the meanings set forth below. Unless otherwise defined, all technical and scientific terms used herein shall have the same meanings as commonly understood by one of ordinary skill in the art.

[0028] As used herein, the terms “a” or “an” may mean one or more. As used herein, “another” or “other” may mean at least a second or more identical or different elements or components thereof. The terms “comprise” and “comprising” are used in an inclusive, open sense, meaning that additional elements may be included. As used herein, the term “or” means “and / or” unless explicitly indicated to refer only to alternatives or that the alternatives are mutually exclusive.

[0029] As used herein, the term "about" refers to a numerical value, including, for example, integers, fractions, and percentages, whether explicitly stated or not. The term "about" generally refers to a range of numerical values ​​that a person skilled in the art would consider approximately equal to the value (e.g., having the same function or result) (e.g., ±25% of the value, unless otherwise explicitly stated). In many instances, the term "about" may include a numerical value rounded to the nearest significant digit.

[0030] As used in this document, the following terms and abbreviations have the following meanings:

[0031] •ADC—Analog-to-Digital Converter.

[0032] •AFE—Analog Front End, integrated US amplifier and ADC or separate US amplifier and ADC.

[0033] Analog signals are electrical signals whose values ​​change continuously. In modern US and TA instruments with digital algorithms for image reconstruction, the amplified Rx analog signal from the transducer is digitized using an ADC device.

[0034] Bypassing—Bypassing analog devices connected in series in an analog signal chain involves connecting one or more short-matched inputs and one or more outputs together. Active device outputs must be disconnected from the signal chain. In some cases, device inputs must be disconnected, for example, in… Figures 1C-1E The input of the TA preamplifier is disconnected in US mode to protect the TA preamplifier input from the high voltage of US Tx.

[0035] • DAQ – Data Acquisition Device, typically based on an ADC plus a PC interface and a (preamp) amplifier or AFE.

[0036] EMI – Electromagnetic Interference.

[0037] FPGA—Field Programmable Gate Array IC.

[0038] A hard-core processor is a processor implemented at the hardware level, such as a microprocessor or a programmable microcontroller.

[0039] HV – High voltage.

[0040] HV switch – High voltage switch.

[0041] • IC – An integrated circuit that contains one or more chips within a package.

[0042] The serial USTA system architecture is a system architecture in which the Rx US and TA analog signals share signal path components and include the same ADC channels arranged in series for both US and TA modes. The shared Rx path excludes components required in one mode but not in the other; for example, the TA preamplifier is typically bypassed in US mode.

[0043] LV – Low Voltage.

[0044] The parallel USTA system architecture is a system architecture in which the US and TA Rx analog signals are split or completely separated into US and TA analog signal chains, and separate ADC devices are used for the US and TA signals.

[0045] PC – Personal Computer.

[0046] PCB – Printed Circuit Board.

[0047] The preamplifier is the first stage of the amplifier circuit.

[0048] • Rx — Receive mode.

[0049] A soft-core processor is a processor implemented at the firmware code level, such as MicroBlaze, which is implemented as FPGA firmware code. TM Soft-core processors are available from Xilinx, a company located in San Jose, California. Soft-core processors offer functionality similar to hard-core processors.

[0050] • SPST – Single Pole Single Throw. An electrical switch with two terminals and an ON position, which can be implemented electronically or mechanically.

[0051] • SPDT – Single Pole Double Throw. An electrical switch with three terminals and two ON positions, which can be implemented electronically or mechanically.

[0052] ·TA—Thermoacoustics, which includes photoacoustics, microwave acoustics, X-ray acoustics, and other thermoacoustic phenomena.

[0053] • TA Mode – Thermal Mode. TA mode is an Rx-only analog circuit operation mode used for TA.

[0054] A TA preamplifier is a preamplifier specifically designed for TA applications and typically offers additional gain and a high input impedance value for broadband applications compared to a US preamplifier. The TA preamplifier is the only preamplifier discussed in this patent and may be referred to simply as a preamplifier.

[0055] A transmission line is a single-ended electrical connection used for AC (alternating current) signals with a specific impedance.

[0056] • Tx — Transmission mode.

[0057] US – Ultrasound.

[0058] • US mode – an ultrasound mode with US Tx and US Rx systems.

[0059] USTA – Ultrasonic and Thermoacoustic.

[0060] Commonly used units of measurement:

[0061] ·Hz — Hertz

[0062] kHz — kilohertz

[0063] MHz — megahertz

[0064] μs — microsecond

[0065] In the embodiments, the currently disclosed systems and methods provide a novel serial architecture for USTA systems. Essentially the same analog and digital signal paths are used for both US and TA modes. All design modules are arranged in series along the signal path starting from the transducer array cable connector, as shown in Figure 1. Modules not used in a particular operating mode are bypassed, i.e., excluded from the analog signal path. The HV pulse generator is bypassed by its internal switch in both TA and US Rx modes. The TA preamplifier is disabled and bypassed in US mode. The serial architecture allows the instrument to maintain optimal performance for each mode of the USTA system while reducing component count, system size, and cost. The performance of the serial USTA system in US mode is equivalent to that of a US system without a TA mode. The performance of the serial USTA system in TA mode is equivalent to that of a TA system without a US mode, but in some cases, the input impedance may be limited by the high-voltage leakage resistance value. In the embodiments, the component size and number of the serial USTA system with a custom TA preamplifier and switching IC are only slightly larger than those of the equivalent US system without dedicated TA capability. The beamformer and HV circuitry system, including the pulse generator and HV power, are used only in US mode. In this embodiment, the TA preamplifier is used only in TA mode. All other components (including the transducer array, AFE (ADC), FPGA, PC interface, and software) are used in both modes. This reduced number of components allows for an increase in the number of parallel channels per DAQ PCB.

[0066] Please note that some US systems have a so-called Rx-only mode and reuse the AFE / ADC, FPGA, and PC interface for both modes. An example of such a system is the Vantage, available from Verasonics in Kirkland, Washington. TM However, such systems cannot be considered dual-mode USTA systems with a serial design because they lack a dedicated TA preamplifier with the high input impedance and additional gain necessary to achieve wide signal bandwidth, high sensitivity, and low signal-to-noise ratio in TA mode. The TA mode of such systems provides poor image quality and is generally equivalent to US Rx mode. US systems with only Rx mode can be upgraded for TA applications using an external TA preamplifier (e.g., the Legion preamplifier available from Opto-Acoustic Technologies in Houston, Texas), but such upgrades lack HV switches, such as... Figure 1C – Figure 1E The HV switches shown are examples of those. Ultrasound systems with such external TA preamplifiers cannot be used in US mode without physically removing the TA preamplifier.

[0067] The serial dual-mode USTA architecture uses the same transducer array element (101) and the same analog signal path from the transducer element to the AFE chip (110). Switching between US and TA modes is performed using the switch described in Figure 1. Digital control of the switch states is not shown, but the control sequence and timing diagram are described in Figure 2.

[0068] Figure 1: The US mode employs an HV pulse generator, beamformer, and HV protection switch, which can be integrated into a single pulse generator-beamformer IC (e.g., Texas Instruments' TX7332 or TX7316). Figure 1A-1E The part is labeled (102). The internal structure of the pulse generator block (102) is not shown. The HV circuit system is disabled in TA and US Rx modes.

[0069] TA mode operates with a much weaker signal and a much wider BW than US Rx mode. TA mode requires an additional amplification stage implemented as the TA preamplifier (104), which may have high-impedance inputs, programmable frequency filters, and other features not required in US mode. In US mode, the TA preamplifier output should be disconnected and the TA preamplifier bypassed; that is, the preamplifier input should be directly connected to the next stage of the analog signal chain, not the TA preamplifier output. The bypass connection and output connection can be achieved by two SPST switches (105), (106) for each analog channel. Figure 1A ) or an SPDT switch (107)( Figure 1B The control selects either TA or US mode. The state of the TA preamplifier (103) switch is... Figure 1A – Figure 1E It is shown in the diagram for TA(Rx) mode and US(Rx and Tx) mode. Figure 1C – Figure 1E All TA preamplifier switches must be HV tolerant to operate in US Rx mode.

[0070] The TA preamplifier can be implemented using discrete components or as an IC. The TA preamplifier may have a single analog channel or multiple analog channels. The TA preamplifier IC may integrate switches (105)–(109), or the switches (105)–(109) may be implemented as separate components.

[0071] In TA and US Rx modes, the pulse generator HV signal is disconnected from the analog signal chain, and the pulse generator allows the signal to pass through, as shown in (111).

[0072] The Tx signal is an HV signal that exists only in US mode. In US mode, the Tx signal is time-separated from the Rx signal. The HV Tx signal propagates from the pulse generator (102) into the transducer and is not present on the low-voltage analog output from the pulse generator to the AFE side, as shown in (112).

[0073] Signal acquisition in TA applications has a low duty cycle, that is, the preamplifier operates at a low duty cycle relative to the time when the TA preamplifier is not required to operate (202)(). Figure 2A This represents a fraction of the operation time. Rapidly disabling and enabling DAQ electronics, including the TA preamplifier, second-stage amplifier, and ADC, can significantly save power and reduce average power consumption. Figure 2A In the diagram, the time when the TA preamplifier is enabled (full power mode) is shown as (204), and the time when the TA preamplifier is disabled is shown as (203) and (205).

[0074] Figure 1A and 1B An application with a TA preamplifier located in the LV section of a circuit is described. The TA preamplifier in the LV section of the circuit can be equipped with an LV switch. Figure 1A and Figure 1B It has a TA preamplifier, in which Figure 1A Each channel has two SPST switches, and correspondingly... Figure 1B Each channel has an SPDT switch.

[0075] Figure 1A An analog signal path implementation with two SPST switches per channel is shown. Each SPST switch has an open and closed position. One switch is a bypass switch (105), and the other is an output switch (106). In TA mode, the output switch (106) is closed to deliver the preamplifier output signal to the AFE (110); the bypass switch (105) is open. In US mode, the output switch (106) is open and used to exclude the TA preamplifier from the signal path; the bypass switch (105) is closed and used to pass the analog signal to the AFE (110).

[0076] Figure 1B The analog signal path implementation with one SPDT switch per channel is shown. The SPDT switch (107) has a preamplifier output position (for TA mode) and a preamplifier bypass position (for US mode).

[0077] If the TA preamplifier (104) is equipped with an HV switch, it can be placed immediately after the transducer (101) in the analog signal chain, such as Figure 1C – Figure 1E As shown. This placement of the TA preamplifier allows for integration into the transducer array housing, thereby improving TA signal sensitivity, EMI suppression, and quality, especially in the case of low-capacitance or high-frequency TA transducers. It allows the drive transmission line to exit directly from the transducer array housing. This architecture allows for the use of long transducer array cables without sacrificing TA mode performance for any cable length. The pulse generator and subsequent components can be housed at the other end of a micro-coaxial cable bundle within the USTA equipment housing.

[0078] An additional HV protection switch (108) is required. Figure 1C , 1D ) or (109)( Figure 1E This is to protect the preamplifier input from HV in US Tx mode. The HV switch can be arranged as follows: Figure 1C The three SPST switches (105), (106) and (108) in the middle or Figure 1D , 1E One SPDT switch and one SPST switch. The single SPST can be used as the input switch for the TA preamplifier (108). Figure 1D ) or output switch (106)( Figure 1E ).

[0079] Figure 1C – Figure 1E The configuration of a TA preamplifier with an HV section located in the circuit is described. The TA preamplifier located in the HV section of the circuit must be equipped with an HV switch for HV protection. In US Tx mode, the TA preamplifier inputs and outputs must be disconnected from the analog signal chain, which requires additional switches for the preamplifier inputs. Figure 1C A TA preamplifier with an HV SPST switch is described. Figure 1D and Figure 1E A TA preamplifier with HV SPST and SPDT switches is described.

[0080] Figure 1CAn analog signal path implementation with three HV-tolerant SPST switches per channel is shown. One switch is a bypass switch (105), another is an output switch (106), and the third switch is an input protection switch (108). In TA mode, the input switch (108) is closed to allow signal transmission from the transducer to the preamplifier input; the output switch (106) is closed to allow signal transmission from the preamplifier output to the AFE (110) via the pulse generator (102); the bypass switch (105) is open. In US mode, the input and output switches (108) and (106) are respectively opened to exclude the TA preamplifier from the analog signal path and protect the preamplifier from HV US Tx signals; the bypass switch (105) is closed and used to transmit the analog Rx signal to the AFE (110) via the pulse generator state (111) or to transmit the Tx signal from the pulse generator to the transducer.

[0081] Figure 1D and Figure 1E The diagram illustrates an analog signal path implementation with one HV-tolerant SPST switch and one HV-tolerant SPDT switch per channel.

[0082] exist Figure 1D In this circuit, SPDT switch (107) replaces two SPST switches (105) and (106). Figure 1C ).

[0083] exist Figure 1E In this circuit, the SPDT switch (109) replaces the two SPST switches (105) and (108). Figure 1C ).

[0084] Figure 1F The system with TA-only mode is described. The top panel describes Rx TA operation. The bottom panel describes the power-saving state with TA preamplifier (104) in standby mode. The switch is not in... Figure 1F The switches are shown, but may exist. If they exist, they must operate in TA mode, as shown below. Figure 1A – Figure 1E As described in the top panel.

[0085] Figure 2A A timing diagram of a USTA system with implemented fast energy-saving technology is shown. The dual-modal USTA mode is activated for a limited time, corresponding to the high USTA_on signal on timeline (207). The TA_ex_in signal on timeline (201) indicates TA excitation events, such as the emission of an excitation laser in the case of photoacoustic imaging.

[0086] The TA_aq signal (202) indicates a TA data acquisition event, which typically lasts no more than 100-200 μs and has a fixed delay offset from the previous TA excitation signal.

[0087] The time intervals (203)–(205) indicate the TA preamplifier power mode. Before and after the activation of the USTA mode (see timeline (207)) (as indicated by the time interval (203)) and during the pause between TA data acquisition events (202) (as indicated by the time interval (205)), the TA preamplifier power can be disabled and can be used for the acquisition of US frames (209).

[0088] The time intervals (203) and (205) indicate the fast power saving mode of the TA preamplifier.

[0089] When the TA preamplifier is turned on or off, the time interval (204) indicates the full-power mode of the TA preamplifier, which includes two transient phases, each <100μs. Figure 2A In the example shown, considering a typical 10Hz TA excitation rate, the TA preamplifier remains in power-saving mode for ≥99% of the time and remains active for only ≤1% of the time.

[0090] Timeline (208) shows a high value for the TA_sw signal, which is used to enable the cascade connection of the TA preamplifier for TA mode. A low value for TA_sw is used to enable the bypass connection of the TA preamplifier for US mode.

[0091] Figure 2B The operating sequence of a USTA imaging system with implemented fast energy-saving technology is shown. The USTA imaging system is typically operated in US mode (210), very similar to its analogue—clinical ultrasound. When there is a need to enable USTA imaging, the system is initialized to a specific TA excitation frequency FexTA (211), for example, with a high USTA_on signal (timeline (207)). Figure 2A The start corresponds to this. Subsequently, the system continues US imaging and waits for the first TA_ex_in signal (timeline (201)). Figure 2A The controller turns on the power in the TA preamplifier and enables a timeline (208) slightly shorter than 1 / FexTA. Figure 2A ) time delay TA acquisition event ( Figure 2A (202)). Subsequently, the system reactivates US imaging (214) until the next TA_sw signal is received (line (208)). Figure 2ASuch a sequence of intertwined TA and US imaging events continues until the USTA mode termination command, for example, in the form of a low-level USTA_on signal at which the system returns to its default US imaging mode (timeline (207)). Figure 2A )arrive.

[0092] The ability to switch to a low-power mode when not performing thermoacoustic receiving operations allows for a significant reduction in power requirements. One advantage of this reduction is the ability to include the TA preamplifier, DAQ, analog-to-digital converter, or ultrasonic analog front end within the housing of the probe or transducer array.

[0093] At least some of the disclosed aspects can be instantiated at least partially in software. That is, the technology can be executed in a dedicated or general-purpose computer system or other data processing system to execute sequences of instructions contained in memory (such as ROM, volatile RAM, non-volatile memory, cache, or remote storage devices) in response to its hard-core or soft-core processor (such as a microprocessor). The functions expressed in the claims can be executed by a processor in conjunction with memory storing the code and should not be construed as a means-plus-function limitation.

[0094] The routines executed to implement the embodiments may be implemented as part of an application, operating system, firmware, ROM, middleware, service delivery platform, SDK (Software Development Kit) component, network service, or other specific application, component, program, object, module, or sequence of instructions referred to as a "computer program." The calling interface of these routines may be exposed to the software development community as an API (Application Programming Interface). A computer program typically comprises one or more sets of instructions residing at different times in various memories and storage devices within a computer, and when read and executed by one or more processors in the computer, causes the computer to perform the operations necessary to perform elements involving various aspects.

[0095] Machine-readable media can be used to store software and data that enable a data processing system to perform various methods when executed. Executable software and data can be stored in various locations, including, for example, ROM, volatile RAM, non-volatile memory, and / or cache. A portion of the software and / or data can be stored in any of these storage devices. Furthermore, data and instructions can be obtained from a central server or a peer-to-peer network. Different portions of the data and instructions can be obtained at different times, in different communication sessions, or in the same communication session from different central servers and / or peer-to-peer networks. Data and instructions can be obtained completely before the application is executed. Alternatively, portions of the data and instructions can be obtained dynamically in a timely manner when needed for execution. Thus, it is not necessary for data and instructions to be completely present on the machine-readable medium at a specific time.

[0096] Examples of computer-readable media include, but are not limited to, media of recordable and non-recordable types, such as volatile and non-volatile storage devices, read-only memory (ROM), random access memory (RAM), flash memory devices, floppy disks and other removable disks, magnetic disk storage media, optical storage media (e.g., compact disk read-only memory (CD ROM), digital versatile disk (DVD), etc.).

[0097] Generally speaking, machine-readable media includes any mechanism that provides (e.g., stores) information in a form accessible to a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device having one or more processor sets, etc.).

[0098] In various embodiments, hardwired circuitry systems can be used in conjunction with software instructions to implement the technology. Thus, the technology is neither limited to any particular combination of hardware circuitry systems and software, nor to any particular source of instructions executed by the data processing system.

Claims

1. An instrument for thermoacoustic data acquisition and / or imaging, comprising: A transducer or transducer array for receiving thermoacoustic signals from the object being questioned; A thermoacoustic data acquisition unit, including a thermoacoustic preamplifier and an analog front end for providing an analog-to-digital conversion of an input signal, wherein one or more components of the data acquisition unit or each of the acquisition units have a fast low-power mode disabled and a fast full-power mode enabled, each mode being activated multiple times per second between and during measurement cycles. The thermoacoustic data acquisition unit is configured to amplify and digitize the signal received by the transducer or the transducer array. Circuitry that provides digital processing and / or digital control in the instrument; The instrument is configured to switch one or more components of the thermoacoustic data acquisition unit or its components between a low-power mode and a full-power mode according to a preset protocol. The instrument is configured to reduce the power consumption of the thermal preamplifier multiple times by keeping the thermal preamplifier in the fast disable low-power mode for ≥99% of the time during the thermal measurement cycle.

2. The instrument according to claim 1, wherein, The circuit that provides digital processing and / or digital control is a field-programmable gate array (FPGA).

3. The instrument according to claim 1, wherein, The instrument is configured to switch one or more components of the thermoacoustic data acquisition unit or its components to the full-power mode when the instrument acquires a thermoacoustic signal, and to switch one or more components of the thermoacoustic data acquisition unit or its components to the low-power mode when the instrument is not acquiring a thermoacoustic signal.

4. The instrument according to claim 1, wherein, The thermoacoustic preamplifier of the thermoacoustic data acquisition unit is placed inside a housing containing the transducer or the transducer array.

5. The instrument according to claim 1, wherein, One or more components of the instrument are integrated into a portable device and / or a battery-operated device.

6. The instrument according to claim 1, wherein, One or more components of the instrument are integrated into the handheld device.

7. An instrument for dual-modal ultrasound and thermoacoustic data acquisition and / or imaging, comprising: A transducer or transducer array for applying mechanical energy to a subject being questioned and for receiving signals from the subject being questioned; A pulse generator / beamformer is used to apply non-static electromagnetic energy to the transducer or the transducer array, thereby enabling the instrument to operate in ultrasonic emission mode. A thermoacoustic preamplifier configured to provide a fast disable low-power mode and a fast enable full-power mode, each mode being activated multiple times per second between and during measurement cycles; An analog front end is used to provide analog-to-digital conversion of signals received by the transducer or the transducer array; Circuitry that provides digital processing and / or digital control in the instrument; The instrument is equipped with multiple electronic switches for bypassing the thermoacoustic preamplifier in ultrasonic mode and for enabling the thermoacoustic preamplifier in thermoacoustic mode. The instrument is configured to reduce the power consumption of the thermal preamplifier multiple times by keeping the thermal preamplifier in the fast disable low-power mode for ≥99% of the time during the thermal measurement cycle.

8. The instrument according to claim 7, wherein, The circuit that provides digital processing and / or digital control is a field-programmable gate array (FPGA).

9. The instrument of claim 7, configured such that the same transducer elements and analog front-end channels are used for both ultrasonic and thermoacoustic modes.

10. The instrument according to claim 7, wherein, The instrument is configured to switch the thermoacoustic preamplifier between low-power and full-power modes according to a preset protocol.

11. The instrument according to claim 10, wherein, The instrument is configured to switch the thermoacoustic preamplifier to the full-power mode when the instrument acquires a thermoacoustic signal, and to switch the thermoacoustic preamplifier to the low-power mode when the instrument does not acquire a thermoacoustic signal.

12. The instrument according to claim 10, wherein, The pulse generator and / or the thermoacoustic preamplifier are housed within a housing containing the transducer or the transducer array.

13. The instrument according to claim 10, wherein, One or more components of the instrument are integrated into a portable device and / or a battery-operated device.

14. The instrument according to claim 10, wherein, All or some of the components of the instrument are integrated into the handheld device.

15. The instrument according to claim 7, wherein, The instrument is configured to use multiple HV protection and bypass switches.

16. The instrument according to claim 15, wherein, The multiple HV protection and bypass switches are integrated within the pulse generator / beamformer circuit.

17. The instrument according to claim 7, wherein, The instrument is configured such that when the instrument is operating in ultrasonic receiving mode or thermoacoustic mode, the pulse generator / beamformer is idle, allowing the received signal to pass through while the HV circuitry of the pulse generator / beamformer is disconnected; When the instrument is operating in ultrasonic emission mode, the pulse generator / beamformer is connected to the HV circuit system to actively apply electromagnetic energy to the transducer or the transducer array, and is disconnected from the thermoacoustic preamplifier and the analog front end.

18. A thermoacoustic preamplifier having a fast disable low-power mode and a fast enable full-power mode, each mode being activated multiple times per second between and during measurement cycles, the thermoacoustic preamplifier being configured to reduce power consumption of the thermoacoustic preamplifier multiple times by being held in the fast disable low-power mode for ≥99% of the time during a thermoacoustic measurement cycle.

19. A thermoacoustic data acquisition unit, comprising a thermoacoustic preamplifier and an analog front-end for providing an input signal, wherein the data acquisition unit or some of its components have a fast-disable low-power mode and a fast-enable full-power mode, each mode being activating multiple times per second between and during measurement cycles, the thermoacoustic preamplifier being configured to reduce power consumption of the thermoacoustic preamplifier multiple times by being held in the fast-disable low-power mode for ≥99% of the time during a thermoacoustic measurement cycle.

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