High Frequency Ultrasound Waves Research Articles

Rapid Estimation of Ethanol Concentration using Acousto‐Optic Diffraction

AbstractFast and accurate determination of ethanol concentration is important in alcohol industries for testing the purity and quality of their products. Here, we demonstrate a quick, robust, and accurate technique to estimate the concentration of ethanol in aqueous solutions. Our method utilizes the principle of diffraction of light in the presence of high frequency ultrasound waves that create diffraction grating in solution. A monochromatic light interacts with this acoustic grating and produces an intensity distribution pattern, which was used to determine the ethanol concentration. We measured ethanol concentrations in various alcoholic solutions and beverages at room temperature with very high accuracy down to 2 % over a concentration range of 30–100 %. The experimental results have been supported with analytical calculations and simulations. We believe that our method will benefit alcohol production industries and lead to the development of portable, inexpensive, and reliable ethanol concentration measurement devices.

High frequency ultrasound vibrational shear wave elastography for preclinical research

Preclinical evaluation of novel therapies using models of cancer is an important tool in cancer research, where imaging can provide non-invasive tools to characterise the internal structure and function of tumours. The short propagation paths when imaging tumours and organs in small animals allow the use of high frequencies for both ultrasound and shear waves, providing the opportunity for high-resolution shear wave elastography and hence its use for studying the heterogeneity of tissue elasticity, where heterogeneity may be a predictor of tissue response. Here we demonstrate vibrational shear wave elastography (VSWE) using a mechanical actuator to produce high frequency (up to 1000 Hz) shear waves in preclinical tumours, an alternative to the majority of preclinical ultrasound SWE studies where an acoustic radiation force impulse is required to create a relatively low-frequency broad-band shear-wave pulse. We implement VSWE with a high frequency (17.8 MHz) probe running a focused line-by-line ultrasound imaging sequence which as expected was found to offer improved detection of 1000 Hz shear waves over an ultrafast planar wave imaging sequence in a homogenous tissue-mimicking phantom. We test the VSWE in an ex vivo tumour xenograft, demonstrating the ability to detect shear waves up to 10 mm from the contactor position at 1000 Hz. By reducing the kernel size used for shear wave speed estimation to 1 mm we are able to produce shear wave speed images with spatial resolution of this order. Finally, we present VSWE data from xenograft tumours in vivo, demonstrating the feasibility of the technique in mice under isoflurane sedation. Mean shear wave speeds in the tumours are in good agreements with those reported by previous authors. Characterising the frequency dependence of shear wave speed demonstrates the potential to quantify the viscoelastic properties of tumours in vivo.

Use of High-Frequency Ultrasound Waves for Boiler Water Demineralization/Desalination Treatment

Isolated ultrasonic vibrations were used to treat feed water from a 20 bar steam-producing water tube boiler. Physical treatments such as ultrasounds and reverse osmosis (RO) are recommended as the most eco-friendly for this purpose. A novel bench-scale prototype delivering 6 L/h of treated water was designed and built. The ultrasonic atomization of raw water with 1.7 MHz piezoelectric transducers and subsequent humidification and dehumidification of drag airflow was the innovating sequence of operations used as a treatment technique. To ensure greater humidification capacity to the drag air, the energy available from the thermal inertia of the liquid column (raw water) in the prototype vaporization chamber was used to heat this air flow. After a single pass of raw water through the bench-scale prototype, a 98.0% reduction in conductivity and a 99.0% decrease in the content of total dissolved solids were obtained at a drag air temperature of 70 °C. Compared to RO, two of the main advantages of the proposed ultrasonic wave method are the elimination of the use of chemical agents in the pre-treatment phase and a significant reduction in maintenance costs by membrane replacement.

Abstract 11701: Ultrasound Acceleration Does Not Provide Detectable Benefit During Catheter-Directed Thrombolysis for Massive or Submassive Pulmonary Embolism: A Meta-Analysis of the Available Evidence

Introduction: Compared with systemic thrombolysis, catheter-directed thrombolysis (CDT) for acute pulmonary embolism (PE) reduces the risk of mortality and major bleeding due to lower thrombolytic doses. The only FDA-approved device for CDT is a more expensive ultrasound-accelerated CDT (USAT) device, which uses high frequency ultrasound waves to disrupt the fibrin mesh of the thrombus. No trials comparing CDT vs USAT exist. We conducted a meta-analysis of all published studies that employed CDT and/or USAT for acute PE, stratified by PE severity. Hypothesis: Ultrasound acceleration will improve mortality, bleeding risk, and right heart strain in acute PE over standard CDT. Methods: We performed a retrospective non-time-limited literature search of PubMed for all studies of either catheter-directed thrombolysis technique. Outcome measures (30-day mortality, major bleeding, RV/LV ratio, pulmonary artery systolic pressure) were extracted. Meta-analyses were performed using RevMan Review Manager 5.3 (Cochrane Collaboration). Random Effects Model was used to calculate proportion, mean difference, and Chi-square with 95% confidence intervals. Results: Of 1260 patients in the 34 identified studies, 311 had massive PE, and 928 underwent USAT. There was no difference between CDT and USAT in 30-day mortality in massive PE (27% [7, 48] vs 30% [-2, 62], Chi2=0.02, p=0.90, I2=40%) or submassive PE (5% [-5, 15] vs 3% [0, 7], Chi2=0.16, p=0.69, I2=0%), in major bleeding in massive PE (21% [0, 43] vs 16% [2, 31], Chi2=0.15, p=0.70, I2=58%), in pulmonary artery systolic pressure in massive PE (md 25.73 [16.06, 35.40] vs 19.75 [5.38, 34.12], Chi2=0.46, p=0.50, I2=89%) or submassive PE (15.71 [10.31, 21.89] vs 15.62 [9.77, 21.47] Chi2=0.01, p=0.91, I2=85%). Conclusions: Both techniques are efficacious in improving mortality, bleeding, and right heart strain. However, few studies report outcomes for standard CDT, and between-study heterogeneity is high. Differences in 30-day mortality, major bleeding events, and markers of right heart strain were not detected between techniques in our met-analysis. Practitioners are left without evidence of benefit for ultrasound acceleration, pending the results of the ongoing randomized-controlled trial .

POSTERIOR SEGMENT PATHOLOGIES IN DENSE LENS CHANGES

INTRODUCTION : B scan makes use of high frequency ultrasound waves which are reected back and are converted to electric signals. The data which is not available from the clinical examination can be visualised by using the ultrasound B-scan. It is of immense visual prognostic value to modify the surgical plan in eyes who have hazy media. AIM : Evaluation of posterior segment using ultrasound B scan(US-B) in patients with dense lens changes Co relation of the type of dense lens changes with different posterior segment pathologies. METHODOLOGY : Study sample : 100 Study period : 1st July 2019 to 31st June 2020 Study duration :12 months Study area :All the patients presenting to Ophthalmology OPD at Meenakshi medical college and research institute , Kanchipuram ,Tamil Nadu. RESULTS : Majority of the B-scans turned out to be normal in dense lens changes. Posterior vitreous detachment, Asteroid hyalosis and Retinal detachment are the common abnormalities seen in the decreasing order of their occurrence.

Higher order modal dynamics of the flexural ultrasonic transducer

The flexural ultrasonic transducer (FUT) consists of a piezoelectric ceramic bonded to an edge-clamped elastic plate, for both generation and detection of ultrasound waves. It is typically employed for proximity measurement, such as in automotive parking systems, and for flow measurement in gases and liquids. Conventional industrial applications have generally incorporated FUTs with resonance frequencies up to around 50 kHz. However, there have been recent advances in the understanding of the FUT, both in terms of fabrication and operation, enabling the potential for measurement in a wider range of applications, including those of elevated pressure, temperature, and requiring multiple operating frequencies. Ultrasound measurement with FUTs at frequencies greater than 50 kHz is desirable in a range of applications, including gas and water metering in petrochemical plants, district heating, and power industries. The major restricting limitation of designing transducers to operate at these higher frequencies has been a relatively poor understanding of these transducers work, including optimisation of design and performance, and the few reports into how different modes of a FUT can be utilised for practical and reliable measurement. In this study, the higher order modal dynamics of the FUT are investigated through measurement of high frequency ultrasound waves in air, for different fundamental operating modes. A combination of experimental techniques is applied, comprising electrical impedance analysis and laser Doppler vibrometry. The experimental research is supported by analytical solutions to reveal complex higher order modal dynamics of the FUT. This investigation represents further development in widening the industrial application potential of the FUT.

Acoustic Waves in Axonal Membrane and Caveolins are the New Targets for Pain Treatment with High Frequency Ultrasound.

Reciprocal interaction between electrical and mechanical waves observed in axonal membrane during its excitation leads to a paradigm shift in pain research making the uncoupling of electro-mechanical signals an interesting target in pain treatment. This uncoupling can be realized either through direct disturbance of the mechanical surface waves in axonal membrane or through shifting of the thermodynamic state of this membrane far from its phase transition point. Both effects can be effectively realized through application of the very high frequency ultrasound waves. Additional target for application of ultrasound in pain treatment is the caveolin-1, which is abundantly present in Schwann cells as well as in the non-axonal tissues. Both targets demonstrate frequency-dependent reactions, thus making a very high frequency ultrasound a promising treatment modality in pain treatment.

2Pb5-8 Preliminary Study of Skin Microvasculature Visualization by High Frequency Ultrasound Plane Wave Imaging

2Pb5-8 Preliminary Study of Skin Microvasculature Visualization by High Frequency Ultrasound Plane Wave Imaging

A High Sensitivity 20-MHz Endoscopic Transducer With Integrated Miniature Amplifier

Endoscopic transducer with small size and high frequency has been widely studied and applied in medical ultrasound imaging. However, attenuation affects high frequency ultrasound waves to a greater degree than lower frequency waves, which results in limited endoscopic ultrasound detection depth and poor signal-to-noise ratio in the image. High sensitivity transducer is an effective way to improve this problem. In this paper, a high sensitivity endoscopic ultrasound transducer (HSEUST) with an integrated miniature amplifier was proposed, where the amplifier can effectively enhance the received ultrasound signal and reduce the impact of noise. According to the tests and experimental results, this sensor is about 4 times more in sensitive, 20% more in resolution than conventional endoscopic transducer. With high sensitivity, this transducer holds the potential for visualization of deeper tissue in the body with high resolution, which will greatly expand the application capabilities and fields of endoscope ultrasound imaging.

Adaptation of a Mice Doppler Echocardiography Platform to Measure Cardiac Flow Velocities for Embryonic Chicken and Adult Zebrafish.

Ultrasonography is the most widely used imaging technique in cardiovascular medicine. In this technique, a piezoelectric crystal produces, sends, and receives high frequency ultrasound waves to the body to create an image of internal organs. It enables practical real time visualization in a non-invasive manner, making the modality especially useful to image dynamic cardiac structures. In the last few decades, echocardiography has been applied to in vivo cardiac disease models, mainly to rodents. While clinical echocardiography platforms can be used for relatively large animals such as pigs and rats, specialized systems are needed for smaller species. Theoretically, as the size of the imaged sample decreases, the frequency of the ultrasound transducer needed to image the sample increases. There are multiple modes of echocardiography imaging. In Doppler mode, erythrocytes blood flow velocities are measured from the frequency shift of the sent ultrasound waves compared to received echoes. Recorded data are then used to calculate cardiac function parameters such as cardiac output, as well as the hemodynamic shear stress levels in the heart and blood vessels. The multi-mode (i.e., b-mode, m-mode, Pulsed Doppler, Tissue Doppler, etc.) small animal ultrasound systems in the market can be used for most in vivo cardiac disease models including mice, embryonic chick and zebrafish. These systems are also associated with significant costs. Alternatively, there are more economical single-mode echocardiography platforms. However, these are originally built for mice studies and they need to be tested and evaluated for smaller experimental models. We recently adapted a mice Doppler echocardiography system to measure cardiac flow velocities for adult zebrafish and embryonic chicken. We successfully assessed cardiac function and hemodynamic shear stress for normal as well as for diseased embryonic chicken and zebrafish. In this paper, we will present our detailed protocols for Doppler flow measurements and further cardiac function analysis on these models using the setup. The protocols will involve detailed steps for animal stabilization, probe orientation for specific measurements, data acquisition, and data analysis. We believe this information will help cardiac researchers to establish similar echocardiography platforms in their labs in a practical and economical manner.

CFD Modeling of Mixing Enhancement in a Pitted Micromixer by High Frequency Ultrasound Waves

CFD Modeling of Mixing Enhancement in a Pitted Micromixer by High Frequency Ultrasound Waves

High-intensity focused ultrasound in the treatment of breast fibroadenomata (HIFU-F trial)

Background: High-intensity focussed ultrasound (HIFU) is a non-invasive ablative technique utilising the application of high frequency ultrasound (US) pressure waves to cause tissue necrosis. This emerging technology is currently limited by prolonged treatment times. The aim of the HIFU-F trial was to perform circumferential HIFU treatment as a means of shortening treatment times.Methods: A prospective trial was set up to treat 50 consecutive patients ≥18 years of age. Eligible patients possessed symptomatic fibroadenomata, visible on US. Patients ≥25 years of age required histological confirmation of the diagnosis. Primary outcome measures were reduction in treatment time, reduction in volume on US after 12 months and complication rates.Results: HIFU treatment was performed in 51 patients (53 treatments) with a mean age of 29.8 years (SD 7.2 years) and a diameter of 2.6 cm (SD 1.4 cm). Circumferential ablation reduced treatment times by an estimated 19.9 min (SD 25.1 min), which is a 29.4% (SD 15.2%) reduction compared with whole lesion ablation. Volume reduction of 43.2% (SD 35.4%; p < 0.005, paired t-test) was observed on US at 12 months post-treatment. Local complications completely resolved at 1 month apart from skin hyper-pigmentation, which persisted in nine cases at three months, six cases at 6 months and six at 12 months.Conclusion: Circumferential HIFU treatment for breast fibroadenomata is feasible to reduce both lesion size and treatment time. HIFU is a non-invasive alternative technique for the treatment of breast fibroadenomata.ISRCTN registration: 76622747

A Novel Laser Ultrasound Transducer Using Candle Soot Carbon Nanoparticles

As a novel composite material for laser ultrasound transducer, candle soot nanoparticles polydimethylsiloxane (CSPs-PDMS) has been demonstrated to generate high frequency, broadband, and high-amplitude ultrasound waves. In this study, we investigated the mechanism of the high-optoacoustic conversion efficiency exhibited by the composite. A thermal-acoustic coupling model was proposed for analyzing the performance of the composite. The theoretical result matches well with the experimental observation. The acoustic beam profile was compared with Field II simulation results. The 4.41 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> energy conversion coefficient and 21 MHz--6 dB frequency bandwidth of the composite suggest that CSPs-PDMS composites is promising for a broad range of ultrasound therapy and non-destructive testing applications.

Removal of High Concentration of Methyl tert-Butyl ether in Synthetic Wastewater by Employing High Frequency Ultrasound Waves

Removal of High Concentration of Methyl tert-Butyl ether in Synthetic Wastewater by Employing High Frequency Ultrasound Waves

Process modeling and optimization of Rhodamine B dye ozonation in a novel microreactor equipped with high frequency ultrasound wave

This paper reports the effect of 1.7 MHz ultrasound wave on decolorization efficiency of Rhodamine B (RB) solution by ozone in a T-type microreactor. Response surface methodology using central composite design (CCD) was used for analysis and optimization of the reaction conditions. The effective parameters such as solution pH, dye initial concentration, liquid volumetric flow rate, ozone dosage and the length of microreactor on decolorization process were investigated. Rhodamine B removal from solution was determined in presence of and without sonication. The results indicate that for both modes, the decolorization efficiency of RB increased with increase of the ozone dosage as well as the length of employed microreactor. However, with increase of RB initial concentration and liquid flow rate, the decolorization efficiency was decreased. The comparison between the reactors with and without sonication shows that the application of ultrasound wave is effective more than 15% on removal efficiency of RB at various conditions. At optimum conditions, the experimental RB removal yield of 97. 3% and 95. 8 was obtained for with and without irradiation layouts, respectively. The statistical analyses and the agreement of the experimental results with model predictions showed the reliability of the regression model.

High frequency ultrasound waves for degradation of amoxicillin in the presence of hydrogen peroxides for industrial pharmaceutical wastewater treatment

&lt;div&gt;&#x0D; &lt;p&gt;Amoxicillin degradation with and without high frequency ultrasound waves of 2.4 MHz has been investigated. The concentration of amoxicillin was selected to be similar to that of outlet wastewater effluent concentration in pharmaceutical industry namely 50 and 100 ppm. The application of ultrasound waves together with the addition of hydrogen peroxide H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; increased the rate of degradation of antibiotic amoxicillin. The doses of H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2 &lt;/sub&gt;used were 5, 2, 1, and 0.1 ml in a solution of 50 ml of amoxicillin. The study showed that ultrasound waves and H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2 &lt;/sub&gt;had improved amoxicillin degradation. The ultrasound has improved the degradation rate more than two times in comparison to amoxicillin solution without ultrasound waves. This degradation rate has been achieved within 90 minutes.&amp;nbsp;&lt;/p&gt;&#x0D; &lt;/div&gt;&#x0D; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&#x0D;

High frequency ultrasound penetration through concentric tubes: illustrating cooling effects and cavitation intensity

Effective cooling of water by using high frequency ultrasound waves in two concentric straight tubes was investigated. The outer tube was equipped with eight 1.7 MHz ultrasound transducers. The cavitation intensity in both tubes was examined by employing the Weissler reaction. The experimental results showed that employing the 1.7 MHz ultrasound waves caused high temperature drop in the internal tube while no significant thermal effects occurred in the outer tube.

High frequency ultrasound-induced sequence batch reactor as a practical solution for high rate wastewater treatment

In practice, operation of conventional treatment systems with high biomass concentration is limited due to difficulty in the sludge sedimentation in clarifiers. In this study, high frequency ultrasound wave (1.7MHz) was applied to enhance the sludge settling at high biomass concentration. Hence, performance of two sequence batch reactors (SBR) (with and without ultrasound) treating a synthetic dairy wastewater were compared. Experiments were conducted based on a central composite face-centered design and analyzed using response surface methodology. Aeration time (2–24h), mixed liquor volatile suspended solids (2000–6000mg/l), and CODin (500–1500mg/l) were selected as the operating variables to analyze, optimize and model the process. The results showed that high frequency ultrasound led to considerable increase in sludge settling velocity at high MLSS. COD removal and final turbidity were almost similar in the both systems, indicating that the ultrasound applied has not had any adverse effect on the microbial activity.

Effect of high frequency ultrasound on micromixing efficiency in microchannels

In the present work, an investigation on the effect of high frequency ultrasound wave on micromixing in the studied microchannels was carried out. Three types of microchannels with different shapes are examined. A 1.7MHz piezoelectric transducer (PZT) was employed to induce the vibration in these microchannels through an indirect contact. A method based on the Villermaux–Dushman reaction was employed to study the micromixing in these microchannels. The segregation intensity was determined for layouts with and in the absence of ultrasound irradiation. Further, the effect of ultrasound waves, in various flow rates and initial concentrations of acid, on the segregation index (XS) and micromixing time (tm) was investigated. The experimental results showed that the ultrasound waves have a significant influence on product distribution and segregation index at various flow rate ratios. The data obtained in all cases showed that the segregation index was reduced when the flow rate ratios were increased. Also the results demonstrate that in spite of a low energy consumption of PZT, the relative segregation index improved up to 18–36% at various flow rate ratios.

Curso de ecografía abdominal. Introducción a la técnica ecográfica. Principios físicos. Lenguaje ecográfico

Ultrasound is a non-invasive, accessible, and versatile diagnostic technique that uses high frequency ultrasound waves to define outline the organs of the human body, with no ionising radiation, in real time and with the capacity to visual several planes.The high diagnostic yield of the technique, together with its ease of uses plus the previously mentioned characteristics, has currently made it a routine method in daily medical practice. It is for this reason that the multidisciplinary character of this technique is being strengthened every day.To be able to perform the technique correctly requires knowledge of the physical basis of ultrasound, the method and the equipment, as well as of the human anatomy, in order to have the maximum information possible to avoid diagnostic errors due to poor interpretation or lack of information.