Acoustic Line Research Articles

Acoustic Shadowing to Facilitate Ultrasound Guided Arterial Cannulation: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Ultrasound-guided arterial catheterization is a frequently performed procedure. Additional techniques such as acoustic shadowing-assisted ultrasound may be useful in improving success rate. This systematic review aimed to assess the efficacy of acoustic shadowing assisted ultrasound for arterial catheterization. PubMed, Medline, EMBASE, Cochrane Library, EMCARE, and MedNar were searched in January 2024. Randomized controlled trials comparing the first attempt success rate of arterial catheterization using acoustic shadowing ultrasound vs unassisted ultrasound were included. Data were pooled for risk ratios (RRs) using the random-effects model. Subgroup analysis was conducted based on a single or double acoustic line. Sensitivity analysis was undertaken after excluding pediatric data. The certainty of evidence (COE) was assessed using the GRADE framework. Six randomized controlled trials (n = 777) were included. A meta-analysis found the first attempt success rate is significantly higher in the acoustic ultrasound group (n = 6, RR: 0.47, 95% CI: 0.34-0.66, p ≤ 0.00001). Hematoma formation was significantly less in the acoustic ultrasound group (n = 6, RR: 0.52, 95% CI: 0.34-0.80, p = 0.003). First attempt success was significantly higher in the single acoustic line ultrasound (USG) group compared to the unassisted ultrasound group (n = 3, RR: 0.41, 95% CI: 0.28-0.59, p ≤ 0.00001). Sensitivity analysis after excluding pediatric data was similar to the primary analysis (n = 5, RR: 0.50, 95% CI: 0.33-0.70, p ≤ 0.00001). Certainty of evidence was "Moderate" for the first attempt cannulation. Acoustic shadowing-assisted ultrasound improved first-attempt arterial catheterization success rate and was associated with reduced hematoma formation. Mishra L, Rath C, Wibrow B, Anstey M, Ho K. Acoustic Shadowing to Facilitate Ultrasound Guided Arterial Cannulation: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Indian J Crit Care Med 2024;28(7):677-685.

Advancements in wideband source localization with an acoustic vector sensor line array

A method is presented for localizing wideband acoustic sources using an array of acoustic vector sensors (AVS). The method focuses on leveraging the lack of correlation between acoustic pressure and particle velocity in the underwater environmental noise field. Coherent processing is introduced in the signal processing stage to suppress noise components in the observed data. By employing a focused transform that maps various frequency components of the wideband signal into the same signal subspace, an asymptotically unbiased Direction of Arrival (DOA) estimation is achieved using a multidimensional subspace method. A concise expression for the Cramér-Rao Bound (CRB) on the estimation errors is provided within the framework of the wideband multi-vector-sensor model. The performance of the proposed method for localizing sources is assessed through simulation and experimental data analysis. The research indicates that coherent processing effectively suppresses isotropic components in background noise, the proposed method achieves a lower estimation error, closer to the CRB, compared to the scalar array counterpart under identical signal-to-noise ratio (SNR) conditions.

A Dual-Mode Surface Acoustic Wave Delay Line for the Detection of Ice on 64°-Rotated Y-Cut Lithium Niobate.

Ice accumulation on infrastructure poses severe safety risks and economic losses, necessitating effective detection and monitoring solutions. This study introduces a novel approach employing surface acoustic wave (SAW) sensors, known for their small size, wireless operation, energy self-sufficiency, and retrofit capability. Utilizing a SAW dual-mode delay line device on a 64°-rotated Y-cut lithium niobate substrate, we demonstrate a solution for combined ice detection and temperature measurement. In addition to the shear-horizontal polarized leaky SAW, our findings reveal an electrically excitable Rayleigh-type wave in the X+90° direction on the same cut. Experimental results in a temperature chamber confirm capability for reliable differentiation between liquid water and ice loading and simultaneous temperature measurements. This research presents a promising advancement in addressing safety concerns and economic losses associated with ice accretion.

A mobile prototype-based localization approach using inertial navigation and acoustic tracking for underwater

During underwater operations, divers must determine their own trajectories using the Inertial Navigation System (INS) they carry to improve operational efficiency. However, the INS contains a sensor bias that is also incorporated into the quadratic integration process to obtain the displacement, resulting in trajectory drift of the divers during prolonged self-guidance. To overcome the above problem, other aids are needed to correct the accumulated error of the INS. The single-beacon Assisted Inertial Navigation (AIN) method can improve the flexibility of inertial error correction while simplifying the localization equipment, which is suitable for the INS cumulative error correction scenario of divers. However, most of the traditional single-beacon assisted correction methods do not consider the effect of acoustic line bending on hydroacoustic ranging, and at the same time, they do not consider the problem of singular or pathological coefficient matrices introduced by inertial navigation neighbor localization deviations. Based on the above two shortcomings, this paper uses the acoustic velocity profile for acoustic line tracking, combines the localization idea of Mobile Primitives (MP), and proposes an MP-based acoustic line tracking-Assisted Inertial Navigation Localization (AINL) method, which constructs a sliding time window (STW) by taking the historical positioning of divers as a virtual primitive, and combines the nonlinear optimization method for iterative optimization search as a means to improve the accuracy and stability of self-navigation of the divers.

Waveguide invariant navigation of an AUV with a towed line array

Passive acoustics navigation of an autonomous underwater vehicle (AUV) can reduce localization errors while being relatively low-cost. A promising approach for navigation in shallow water is to exploit the waveguide invariant, which makes it possible to estimate the range between an acoustic source with a known position and an acoustic receiver on the AUV. This range estimate can then be fused in a sequential Bayes framework to improve the navigation information of the AUV. While previously proposed methods consider a range-independent environment with a single acoustic source and a single receiver, we investigate a more realistic scenario with multiple sources in a potentially range-dependent environment. In particular, a shallow water environment with a constant slope and sound speed is considered. To resolve multiple sources, it is assumed that the AUV tows an acoustic line array. Simulated acoustic data provided by a normal mode program are used to study the feasibility of the AUV navigation in shallow water by exploiting the waveguide invariant in this setting.

Void-Engineered Metamaterial Delay Line with Built-In Impedance Matching for Ultrasonic Applications

Metamaterials exhibit unique ultrasonic properties that are not always achievable with traditional materials. However, the structures and geometries needed to achieve such properties are often complex and difficult to obtain using common fabrication techniques. In the present research work, we report a novel metamaterial acoustic delay line with built-in impedance matching that is fabricated using a common 3D printer. Delay lines are commonly used in ultrasonic inspection when signals need to be separated in time for improved sensitivity. However, if the impedance of the delay line is not perfectly matched with those of both the sensor and the target medium, a strong standing wave develops in the delay line, leading to a lower energy transmission. The presented metamaterial delay line was designed to match the acoustic impedance at both the sensor and target medium interfaces. This was achieved by introducing graded engineered voids with different densities at both ends of the delay line. The measured impedances of the designed metamaterial samples show a good match with the theoretical predictions. The experimental test results with concrete samples show that the acoustic energy transmission is increased by 120% and the standing wave in the delay line is reduced by over a factor of 2 compared to a commercial delay line.

Research on Multibeam Line Measurement Problem Based on Iterative Algorithms

With the continuous advancement of marine resource development, an efficient and reasonable multi beam acoustic survey line design scheme is crucial for accurate sea area measurement. Firstly, in order to make the model closer to the actual complex scene, a three-dimensional coverage model was derived that comprehensively considers the relative angle between the measurement line and the normal direction of the seabed terrain slope projected on the horizontal plane, referring to the three-dimensional sound beam propagation characteristics of multi beam sound waves. Then, based on the working principle and geometric relationship of multi beam recording, a formula for calculating the recording coverage width under multi-directional slope conditions considering measurement equipment parameters was derived, and an expression for the overlap rate of adjacent measurement lines was given. In addition, different measurement lines and slope normal direction angles . Finally, based on the actual sea area situation of the rectangular area within the specific given range, iteratively traverse and set different combinations of survey lines, calculate the total length of the combination and the corresponding coverage area, and calculate the coverage rate. Select the survey line combination with the shortest total length and the highest coverage rate as the optimal solution. This article focuses on the design of multi beam acoustic survey lines and establishes a universal mathematical model to achieve optimization solutions in different practical scenarios.

Impact of viscothermal loss on modulation instability and rogue waves in left-handed nonlinear diffractive acoustic transmission line metamaterials

In this study, the transmission line approach is used to describe the studied acoustic metamaterial model. Through Kirchoff’s pressure and volume-velocity laws and using multiple scales method, nonlinear coupled Schrödinger equations are obtained. Then, the amplitude disturbance method is applied to these equations to obtain and plot the modulational instability gain curves. Analytically, the impact of viscothermal loss on the modulational instability gain is studied. The similarity technique is used to derive integrable Manakov’s equations. First and second-order rational rogue wavelike solutions of coupled nonlinear Schrödinger are deduced. The results indicate that the modulational instability gain and Rogue wave intensities depend on the viscothermal parameter. This parameter can be considered in the design of nonlinear acoustic metamaterials to minimize the damage caused by the dynamics of freak waves.

A Voltage-Controlled Surface Acoustic Wave Oscillator Based on Lithium Niobate on Sapphire Low-Loss Acoustic Delay Line.

In this work, we investigate, for the first time, a low phase noise and wide tuning range voltage-controlled surface acoustic wave oscillator (VCSO) based on a lithium niobate on sapphire (LNOS) low-loss acoustic delay line (ADL). The thin-film LN/SiO2 bilayer acoustic waveguide, together with the single-phase unidirectional transducer (SPUDT) design, is key to attaining low insertion loss (IL) by enhancing energy confinement and directionality. Based on a high-performance ADL with an IL of only 5.2 dB, a fractional bandwidth (FBW) of 5.38%, and a group delay of 110 ns, the VCSO is implemented by commercially available circuit components using a series-resonant topology. The LNOS ADL oscillator operates at 888 MHz, showcasing a low phase noise of -94.1 dBc/Hz at 1-kHz offset and a root-mean-square (rms) jitter of only 30.26 fs (integrated from 12 kHz to 20 MHz) while only consuming 16 mA of supply current. Featuring a wide frequency tuning range of 6630 ppm, the proposed VCSO is a promising low-noise, low-power, and high-frequency timing device for emerging applications.Index Terms- Acoustic delay line (ADL), jitter, lithium niobate (LN), oscillator, phase noise, surface acoustic wave (SAW), thin film.skiptabldblfloatfix.

High-frequency measurement method of normal-incidence sound absorption coefficient with a square cross-section impedance tube using eight microphones

The authors have proposed a high-frequency measurement method of normal-incidence absorption coefficient with a circular cross-section impedance tube using eight microphones. This method enables measurement at frequencies about three times higher than the conventional two-microphone method. This study investigates the case of using an impedance tube with a square cross-section. Four microphones are placed at intersections of the (2, 2) acoustic mode nodal lines in one cross-section. When the signals of these microphones are summed, the effects of higher-order acoustic modes whose cut-on frequencies are lower than that of the (4, 0) acoustic mode are canceled. In this case, normal-incidence sound absorption coefficients can be measured at four times higher frequency than the conventional one. Numerical and experimental results are presented to demonstrate the validity and feasibility of the method.

Биосенсор на основе пленки Ленгмюра-Блоджетт с ферментом алкогольоксидазы

The work examined the sensor properties of a biofilm based on phospholipid molecules 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine with immobilized molecules of the enzyme alcohol oxidase to vapors of ethyl and isopropyl alcohols. The immobilization of alcohol oxidase enzyme molecules was carried out using a Langmuir monolayer process of phospholipid molecules. The sensor coating was obtained using the Langmuir-Schaeffer technology, in which the substrate is oriented parallel to the monolayer. The analysis of microimages of the film surface obtained by atomic force microscopy, allows to present of enzyme molecules in it was established. The study of the sensory properties of the formed coatings was carried out using acoustoelectronic technology. The presence of the enzyme in the sensor coating led to an increase in the amplitude and phase responses of the acoustic delay line when interacting with vapors of the detected substance. The maximum amplitude and phase responses were recorded when the film interacted with ethanol vapor and were 1.5 dB and 19°, respectively. The work showed that the formed sensor coating has selective sensitivity to ethanol vapor. This allows us to conclude that it is possible to use this sensor coating to create an acoustoelectronic ethanol biosensor. Increasing the sensitivity of such biosensors can be achieved by varying technological parameters such as the number of layers in the film, as well as the amount of immobilized enzyme in each layer.

Acousto-electric measurements at 2.5 GHz on graphene transferred onto YX128°-LiNbO3

Surface acoustic wave delay lines with an operational frequency of 2.5 GHz have been designed to measure the acousto-electric transport of carriers in graphene transferred onto YX128°-LiNbO3 piezoelectric substrate. The monolayer of graphene on LiNbO3 presented sheet resistance in the range of 733–1230 Ω/□ and ohmic contact resistance with gold of 1880 to 5200 Ωμm. The measurements with different interaction lengths on graphene bars have allowed the extraction of carrier absorption and mobility parameters from acousto-electric current. Graphene presented higher acousto-electronic interaction in the GHz range than previously reported values in the range of 100s MHz with carrier absorption losses of 109 m−1 and mobility for acoustically generated charges of 101 cm2V−1s−1.

Improving the beamforming performance of a vector sensor line array with a coprime array configuration

Coprime arrays provide appealing performance in many scenarios. In this paper, we show the benefits of spatially undersampled acoustic vector hydrophone coprime line arrays over traditional uniform hydrophone line arrays for beamforming and direction-of-arrival (DOA) estimation. This paper presents the perceptiveness of the theoretical performance of an underwater vector sensor coprime line array (vCLA) in the physical array domain. Based on the Product and Min methods, an array extending approach for the vCLA has been proposed to reduce the area of grating lobes of beam output leading to unambiguous DOA estimates. To minimize the sidelobe and improve the left–right suppression ability of the array, we present a data-independent weighting design method based on sound pressure and vibration velocity joint processing (PVJP) and evaluate its performance in detail. The results suggest that the proposed method can improve the vCLA beam output directivity, enhance the spatial resolution, benefit the left–right ambiguity rejection capability, and productively mitigate the influence of side and grating lobes, thus promoting the DOA estimation accuracy.

Features of the Formation of Sensitive Films Based on Mycelium of Higher Fungi for Surface and Plate Acoustic Waves Gas Sensors.

A comparative analysis of the responses of two types of acoustic waves (surface SAW and plate APW) with close frequencies and the same type of waves (SAW) with different frequencies toward various liquid vapors (water, acetone, ethanol) was carried out in this paper. Two types of films based on mycelium of higher fungus Ganoderma lucidum (Curtis) P. Karst (G. lucidum) prepared by various methods were used as sensitive coatings. These films were based on G. lucidum mycelium ethanolic (48% v/v) homogenizate (MEGl) and extract (EGl). A film deposition procedure compatible with acoustic devices technology was developed. Various piezoelectric substrates (YX-LiNbO3, 128 YX-LiNbO3) were used for appropriate acoustic delay lines production. It was found that additional SAW and APW attenuation associated with the appearance of mycelium films on the surface of the acoustic waveguide is two times greater for MEGL than for EGL films in the frequency range of 20-80 MHz The changes in acoustic wave amplitude and phase due to vapor absorption were measured and compared with each other, taking into account the differences in geometry of the samples. It was found that the phase response of the SAW delay lines with EGL films is three times higher than one with the presence of MEGL films for water and ethanol vapors. The films used are demonstrated good reproducibility and long-term stability for at least 2 months. Based on the results obtained, it was concluded that MEGl film is not appropriate for use in high frequency SAW delay lines as a sensitive coating. However, both types of the films (MEGl and EGl) could be used as sensitive coatings for low frequency SAW and APW sensors based on corresponding delay lines. Additionally, it was found that the films used are not sensitive to acetone vapor. As a result of the work carried out, a technique for creating sensitive films based on the mycelium of higher fungi compatible with the planar technology of acoustoelectronic delay lines was developed. The possibility of using such films for the development of gas SAW and APW sensors was shown.

Gigahertz Acoustic Delay Lines in Lithium Niobate on Silicon Carbide With Propagation-Q of 11174

This work demonstrates gigahertz wideband acoustic delay lines (ADLs) with record-breaking propagation-Q using a thin-film X-cut lithium niobate on silicon carbide (LiNbO3-on-SiC) platform. Benefiting from the high bulk wave velocity and excellent mechanical <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{f}\times \text{Q}$ </tex-math></inline-formula> of SiC, the shear horizontal surface acoustic wave (SH-SAW) excited by unidirectional transducers propagates in the top-surface of LiNbO3-on-SiC with low acoustic loss. The zero power flow angle (PFA) of −3° to +Y axis is obtained through simulation analysis and experiment validation, which leads to acoustic wave transmission perpendicular to the electrodes. Oriented at zero PFA, the fabricated ADLs show scalable center frequencies from 1.19 GHz to 2.11 GHz, 3-dB fractional bandwidth ranging from 2.7% to 11.5%, and a record-high propagation-Q of 11174. The performance has shown the great potential of the LiNbO3-on-SiC acoustic platform for various signal processing applications.

Observation of a mesoscale warm eddy impacts acoustic propagation in the slope of the South China Sea

Acoustic rays are modified while propagating through oceanic eddies. However, due to the lack of field synchronous observation, the impact of mesoscale eddy on the acoustic propagation is less clarified. To address the issue, an eddy-acoustic synchronous observation (EASO) field experiment for a mesoscale warm eddy was carried out in the slope of the South China Sea (SCS) in October, 2021. During the field experiment, a total of 105 conductivity-temperature-depth (CTD) stations, as well as a zonal acoustic survey line through the center of the warm eddy, were obtained. The vertical structures of temperature and salinity indicate that the warm eddy is surface-intensified with temperature and salinity cores confined within depths from 70 m to 200 m and 10 m to 70 m, respectively. The acoustic observation shows two obvious convergency zones (CZs) at about 39 km and 92 km in the eastern half acoustic line, and one convergency zones (CZ) at about 25 km in the western half acoustic line. By comparing with the none eddy circumstance, the respective impacts of the topography and warm eddy are quantitatively analyzed with a ray-tracing model. The results indicate that the topography shortens the horizontal span of the CZ by 11.4 km, while the warm eddy lengthens it by 1.7 km. Additionally, the warm eddy shallows the depth and broadens the width of the CZ by 32 m and 1.4 km, respectively. The anisotropy of 3D sound fields jointly influenced by the warm eddy and the local topography show that the distance differences of the first CZs in different horizontal directions can be as long as 31 km.

High-speed wide-field photoacoustic microscopy using a cylindrically focused transparent high-frequency ultrasound transducer

Combining focused optical excitation and high-frequency ultrasound detection, optical-resolution photoacoustic microscopy (OR-PAM) can provide micrometer-level spatial resolution with millimeter-level penetration depth and has been employed in a variety of biomedical applications. However, it remains a challenge for OR-PAM to achieve a high imaging speed and a large field of view at the same time. In this work, we report a new approach to implement high-speed wide-field OR-PAM, using a cylindrically-focused transparent ultrasound transducer (CFT-UT). The CFT-UT is made of transparent lithium niobate coated with indium-tin-oxide as electrodes. A transparent cylindrical lens is attached to the transducer surface to provide an acoustic focal line with a length of 9 mm. The excitation light can pass directly through the CFT-UT from the above and thus enables a reflection imaging mode. High-speed imaging is achieved by fast optical scanning of the focused excitation light along the CFT-UT focal line. With the confocal alignment of the optical excitation and acoustic detection, a relatively high detection sensitivity is maintained over the entire scanning range. The CFT-UT-based OR-PAM system has achieved a cross-sectional frame rate of 500 Hz over the scanning range of 9 mm. We have characterized the system’s performance on phantoms and demonstrated its application on small animal models in vivo. We expect the new CFT-UT-based OR-PAM will find matched biomedical applications that need high imaging speed over a large field of view.

Sperm whale acoustic abundance and dive behaviour in the western North Atlantic

Sperm whales are an ideal species to study using passive acoustic technology because they spend the majority of their time underwater and produce echolocation clicks almost continuously while foraging. Passive acoustic line transect data collected between June and August 2016 were used to estimate a depth-corrected acoustic abundance and study the dive behaviour of foraging sperm whales in the western North Atlantic Ocean. 2D localizations (n = 699) were truncated at a slant range of 6500 m and combined with the multipath arrivals of surface reflected echoes to calculate 3D localizations (n = 274). Distance sampling using depth-corrected perpendicular distances resulted in a 10.5% change in the acoustic abundance estimate (2199 whales, CV = 14.6%) compared to uncorrected slant ranges (1969 whales, CV = 14.1%), and a detection function that was a better fit for the data. Sperm whales exhibited multiple foraging strategies, with bottom phases occurring at depths of 400–800, 800–1200, or > 1200 m, accounting for an average 39.2, 49.5, or 44.9% of the total recorded dive time, respectively. These results suggest that estimating 3D localizations using acoustic line transect data improves acoustic abundance estimation and can be used to answer population level questions about foraging ecology.

Improvement of Surface Acoustic Wave Delay Lines Using c-Axis Tilted AlScN Thin Film

Improvement of Surface Acoustic Wave Delay Lines Using c-Axis Tilted AlScN Thin Film

Expansion of beam width in exposure and crystal structure beamline (BL09) of SAGA-LS and applications using expanded beams

In this study, for high-efficiency experiments of deep X-ray lithography, radiation mutation breeding, and X-ray topography, we expanded the beam width in the exposure and crystal structure beamline (BL09) using a synchrotron beam at the SAGA Light Source facility. BL09 was divided into a straight A-line for hard X-rays and a branch B-line for soft X-rays; however, we reconstructed the new BL09 as a single straight-line by unifying the A and B-lines. Vacuum components, such as a large beam shutter, large beryllium window, acoustic delay line, and monochromator chamber were newly located in the reconstructed BL09. A white (or monochromatic) beam can be switched by removing (or inserting) the monochromator into the beam path as needed. After the reconstruction, the widths of the white and monochromatic beams at the terminal of BL09 were expanded from 110 to 395 mm and from 70 to 128 mm, respectively. The expanded white beam has the width of the world-class in synchrotron radiation facilities. Furthermore, we demonstrated the effect of the expanded beams and improvement in the experimental efficiency through deep X-ray lithography, radiation mutation breeding, and X-ray topography. The use of expanded beams is also expected to lead to the fabrication of practicable fine-structures and provide a deeper understanding of defect structures.