This work presents a minute single-chip piezoelectric micromachined ultrasonic transducers (PMUTs)-on-complementary metal-oxide-semiconductor (CMOS)-based hydrophone with high receiving sensitivities ...and low noise. The system is based on three different Sc9.5%Al90.5%N PMUTs geometries: (a) square with an <inline-formula> <tex-math notation="LaTeX">80 \, \mu </tex-math></inline-formula>m side, (b) rectangular with a dimension of <inline-formula> <tex-math notation="LaTeX">60 \times 40 \, \mu </tex-math></inline-formula>m, and (c) annular with an outer diameter of <inline-formula> <tex-math notation="LaTeX">80 \, \mu </tex-math></inline-formula>m which allows to carry out acoustic measurements at very close distances from the transducer under test. Each device is monolithically integrated with a CMOS low noise amplifier (LNA) amplifier with a gain of 25 dB. The first hydrophone prototype was validated in water where two commercial hydrophones from ONDA (HGL-0085 and HNC-0200) were used as references. The experimental results give mean receiving sensitivities of -234 dB re 1 V/<inline-formula> <tex-math notation="LaTeX">\mu </tex-math></inline-formula>Pa (equivalent to 1.9 V/MPa), -234.6 dB re 1 V/<inline-formula> <tex-math notation="LaTeX">\mu </tex-math></inline-formula>Pa (equivalent to 1.86 V/MPa), and -238.3 dB re 1 V/<inline-formula> <tex-math notation="LaTeX">\mu </tex-math></inline-formula>Pa (equivalent to 1.22 V/MPa) for (a)-(c), respectively. These results demonstrate the high performance of the presented PMUTs-on-CMOS to be used in a miniaturized hydrophone for characterizing high-frequency ultrasound transducers.
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This paper presents a comprehensive review of hydrophones, their design considerations, physical aspects, and structures by reviewing many publications that have been published over ...the last two decades. The investigation of the fundamental aspects and essential considerations of hydrophones in the literature are distributed in different papers and have not been brought together in a conclusive manner. This paper has collected and classified all the information about hydrophones including the parameters that affect their performance as well as their features. We have categorized the hydrophones according to their mechanism of operation, structure design, frequency response, and application. The literature has been summarized in a way that enables the readers' easy referral to appropriate designs for their desired application scenarios.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Purpose:
Accurate and efficient guidance of needles to procedural targets is critically important during percutaneous interventional procedures. Ultrasound imaging is widely used for real‐time image ...guidance in a variety of clinical contexts, but with this modality, uncertainties about the location of the needle tip within the image plane lead to significant complications. Whilst several methods have been proposed to improve the visibility of the needle, achieving accuracy and compatibility with current clinical practice is an ongoing challenge. In this paper, the authors present a method for directly visualizing the needle tip using an integrated fiber‐optic ultrasound receiver in conjunction with the imaging probe used to acquire B‐mode ultrasound images.
Methods:
Needle visualization and ultrasound imaging were performed with a clinical ultrasound imaging system. A miniature fiber‐optic ultrasound hydrophone was integrated into a 20 gauge injection needle tip to receive transmissions from individual transducer elements of the ultrasound imaging probe. The received signals were reconstructed to create an image of the needle tip. Ultrasound B‐mode imaging was interleaved with needle tip imaging. A first set of measurements was acquired in water and tissue ex vivo with a wide range of insertion angles (15°–68°) to study the accuracy and sensitivity of the tracking method. A second set was acquired in an in vivo swine model, with needle insertions to the brachial plexus. A third set was acquired in an in vivo ovine model for fetal interventions, with insertions to different locations within the uterine cavity. Two linear ultrasound imaging probes were used: a 14–5 MHz probe for the first and second sets, and a 9–4 MHz probe for the third.
Results:
During insertions in tissue ex vivo and in vivo, the imaged needle tip had submillimeter axial and lateral dimensions. The signal‐to‐noise (SNR) of the needle tip was found to depend on the insertion angle. With the needle tip in water, the SNR of the needle tip varied with insertion angle, attaining values of 284 at 27° and 501 at 68°. In swine tissue ex vivo, the SNR decreased from 80 at 15° to 16 at 61°. In swine tissue in vivo, the SNR varied with depth, from 200 at 17.5 mm to 48 at 26 mm, with a constant insertion angle of 40°. In ovine tissue in vivo, within the uterine cavity, the SNR varied from 46.4 at 25 mm depth to 18.4 at 32 mm depth, with insertion angles in the range of 26°–65°.
Conclusions:
A fiber‐optic ultrasound receiver integrated into the needle cannula in combination with single‐element transmissions from the imaging probe allows for direct visualization of the needle tip within the ultrasound imaging plane. Visualization of the needle tip was achieved at depths and insertion angles that are encountered during nerve blocks and fetal interventions. The method presented in this paper has strong potential to improve the safety and efficiency of ultrasound‐guided needle insertions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Piezoelectric composites, which consist of a piezoelectric material and a polymer, have been extensively studied for the applications of underwater sonar sensors and medical diagnostic ultrasonic ...transducers. Acoustic sensors utilizing piezoelectric composites can have a high sensitivity and wide bandwidth because of their high piezoelectric coefficient and low acoustic impedance compared to single-phase piezoelectric materials. In this study, a thickness-mode driving hydrophone utilizing a 2-2 piezoelectric single crystal composite was examined. From the theoretical and numerical analysis, material properties that determine the bandwidth and sensitivity of the thickness-mode piezoelectric plate were derived, and the voltage sensitivity of piezoelectric plates with various configurations was compared. It was shown that the 2-2 composite with 011 poled single crystals and epoxy polymers can provide high sensitivity and wide bandwidth when used for hydrophones with a thickness resonance mode. The hydrophone element was designed and fabricated to have a thickness mode at a frequency around 220 kHz by attaching a composite plate of quarter-wavelength thickness to a hard baffle. The fabricated hydrophone demonstrated an open circuit voltage sensitivity of more than -180 dB re 1 V/μPa at the resonance frequency and a -3 dB bandwidth of more than 55 kHz. The theoretical and experimental studies show that the 2-2 single crystal composite can have a high sensitivity and wide bandwidth compared to other configurations of piezoelectric elements when they are used for thickness-mode hydrophones.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper demonstrates the cost-effective development of a hydrophone that covers a spectrum range from 0.1 Hz to 100 kHz. The sensing element underwent characterization techniques, such as X-ray ...Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray (EDX) in order to examine the morphology, consistency, microstructure, and crystallography of traditional lead zirconate titanate (PZT) piezoelectric discs, which served as sensing components. Additionally, an electronic circuit with a microcontroller was designed for enhancing the hydrophone's performance and enabling further analysis on a personal computer. This circuit comprises stages for preamplification and filtering, Direct Current (DC) biasing, and Analog-to-Digital Conversion. The digitized signal is subsequently analyzed using specialized audio software. To calibrate the hydrophone, the substitution method was employed, comparing its acoustic response with that of a commercial hydrophone.
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•Design and development of hydrophone device consisting of piezoelectric sensing element (PZT) and the appropriate electronics.•The hydrophone has high sensitivity at the range of 0.1 Hz to 100 kHz.•The sensor can be used for underwater monitoring, being low-cost and fully portable.•The acoustic signals can be sent and analyzed via a personal computer.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, we present an experimental investigation of a water pipeline leak detection system based on a low-cost, tiny-sized hydrophone sensor fabricated using the microelectromechanical system ...(MEMS) technologies. A 10 × 10 element arrayed MEMS hydrophone device with chip size of 3.5 × 3.5 mm<inline-formula><tex-math notation="LaTeX">^2</tex-math></inline-formula> was used in the experiment. The hydrophone device is packaged with a customized on-board preamplification circuit using an acoustic transparent material. The overall package size of the MEMS hydrophone is <inline-formula><tex-math notation="LaTeX">\Phi</tex-math></inline-formula>1.2 × 2.5 cm. The packaged MEMS hydrophone achieves an acoustic sensitivity of −180 dB (re: 1 V/<inline-formula><tex-math notation="LaTeX">\mu</tex-math></inline-formula>Pa), a bandwidth from 10 Hz to 8 kHz, and a noise resolution of around 60 dB (re: 1 <inline-formula><tex-math notation="LaTeX">\mu \text{Pa/}\sqrt{\text{Hz}}</tex-math></inline-formula>) at 1 kHz. A section of ductile iron water pipeline with an internal diameter of 10 cm, wall thickness of 0.73 cm, and length of 30 m is constructed as the test bed for the water leak detection. Two different leak sizes with leak flow rates of about 30 and 180 L/min are designed along the pipe, which is pressurized at 3.2 bar. Analysis of the transient signals and spectrograms shows that the MEMS hydrophone can capture the key acoustic information of the water leak, i.e., identifying the leak and locating the leak position. The measurement results demonstrate the feasibility to construct an affordable, highly efficient, real-time, and permanent in-pipe pipeline health monitoring network based on the MEMS hydrophones due to their high performance, low cost, and tiny size.
Fiber-optic hydrophone (FOH) is a significant type of acoustic sensor, which can be used in both military and civilian fields such as underwater target detection, oil and natural gas prospecting, and ...earthquake inspection. The recent progress of FOH is introduced from five aspects, including large-scale FOH array, very-low-frequency detection, fiber-optic vector hydrophone (FOVH), towed linear array, and deep-sea and long-haul transmission. The above five aspects indicate the future development trends in the FOH research field, and they also provide a guideline for the practical applications of FOH as well as its array.
The article considers the problem that arises during the amplitude-phase calibration of hydrophones by the reciprocity method and consists in the violation of the consistency of the hydrophone ...characteristics specified by the manufacturer. Violation of the indicated consistency of characteristics is due to the need to determine the phase-frequency characteristic when calibrating the hydrophone. The manufacturer sets the dimensions of the hydrophone receiving part and the position of the acoustic center according to the drawing of the receiving part and thereby replaces the acoustic parameters with geometric ones. To restore the consistency of the characteristics, it is proposed to determine the position of the acoustic center and the equivalent size of the hydrophone receiving part from the results of acoustic measurements. It is shown that the displacement of the hydrophone acoustic center relative to its geometric center is a typical phenomenon, and the geometric and acoustically measured dimensions of the active element can differ. To ensure the unity of acoustic measurements, it is proposed to introduce the concept of an equivalent radius and to clarify the concept of the hydrophone acoustic center, as well as to standardize the methods of their experimental determining. The results obtained will be useful in monitoring the phase responses of elements of hydroacoustic antennas for various purposes, ensuring the identity of the phase-frequency characteristics of the vector receivers measuring channels, in solving problems related to restoring the acoustic signal shape by the recorded voltage at the receiver output and other various applications, including marine ecology, medical ultrasound studies, etc.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This article reports spatiotemporal deconvolution methods and simple empirical formulas to correct pressure and beamwidth measurements for spatial averaging across a hydrophone sensitive element. ...Readers who are uninterested in hydrophone theory may proceed directly to <xref ref-type="app" rid="app1">Appendix A for an easy method to estimate spatial-averaging correction factors. Hydrophones were modeled as angular spectrum filters. Simulations modeled nine circular transducers (1-10 MHz; F/1.4-F/3.2) driven at six power levels and measured with eight hydrophones (432 beam/hydrophone combinations). For example, the model predicts that if a 200-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> membrane hydrophone measures a moderately nonlinear 5-MHz beam from an F/1 transducer, spatial-averaging correction factors are 33% (peak compressional pressure or <inline-formula> <tex-math notation="LaTeX">{p}_{c} </tex-math></inline-formula>), 18% (peak rarefactional pressure or <inline-formula> <tex-math notation="LaTeX">{p}_{r} </tex-math></inline-formula>), and 18% (full width half maximum or FWHM). Theoretical and experimental estimates of spatial-averaging correction factors to were in good agreement (within 5%) for linear and moderately nonlinear signals. Criteria for maximum appropriate hydrophone sensitive element size as functions of experimental parameters were derived. Unlike the oft-cited International Electrotechnical Commission (IEC) criterion, the new criteria were derived for focusing rather than planar transducers and can accommodate nonlinear signals in addition to linear signals. Responsible reporting of hydrophone-based pressure and beamwidth measurements should always acknowledge spatial-averaging considerations.
•Air bubbles of 2.24 to 1.43 mm radii in a quiescent liquid are generated in laboratory.•A smoothed horizontal edge syringe tube and 97 degrees-rotated metallic sharp needles are the ...injectors.•Acoustical signals were recorded with a condenser microphone (PTFE-Electret) adapted as a hydrophone.•Physical-hydrodynamic events such as a beat phenomenon is observed as bubble shape changes.•Theoretical curve fits to bubble sound emissions is a promising tool to confirm the presence of beats.
Understanding the passive acoustic signals of gas bubbles has become increasingly imporant due to their growing relevance in ambient marine acoustics and medical areas, as well as the recent search for dark matter by Bubble Chamber Detectors. Here the acoustic signatures of 2.24, 1.83, 1.75, 1.66 and 1.43 mm radii bubbles are reported experimentaly. They were generated by two different air injectors in a quiescent liquid, a standard plastic syringe tube and 97 degrees-rotated metallic needles. The evolution of the sound pulse over time is presented alongside simultaneous images of the bubbles detaching from the injector and moving freely in the liquid. The beat-wave phenomenon is the standard interference pattern between two sounds of slightly different frequencies, generating a beat-period envelope of “rosary chain” form. In this study, beats are observed when the bubble exhibits changes in its shape through Cassini-oval, trapezoid, ‘guitar pick’, ellipsoid and oblate shapes, which is in agreement with earlier results on bubble fragmentation in a locally sheared flow. Finally, theoretical curve fits of freely-oscillating, lightly-damped bubble sound emissions confirm that the beats are due to changes in the bubble shapes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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