Impact of endoscopic ultrasound-guided radiofrequency ablation in managing pancreatic malignancy

Pancreatic malignancy is still the most lethal gastrointestinal malignancy.It has a very poor prognosis with low survival rate.Surgery is still the main treatment option for pancreatic malignancy.Most patients already have locally advanced and even late stage disease due to non-specific abdominal symptoms.Even though some cases are still suitable for surgical treatment,due to its aggressiveness adjuvant chemotherapy is becoming the standard treatment for controlling the disease.Radiofrequency ablation(RFA)is a thermal therapy that has been used as one of the standard treatments for liver malignancy.It can also be performed intraoperatively.There are several reports on percutaneous RFA treatment for pancreatic malignancy using transabdominal ultrasound and guided by computed tomography scan.However,due to its anatomical location and the risk of high radiation exposure,these methods seem to be very limited.Endoscopic ultrasound(EUS)has been widely used for pancreatic abnormality evaluation due to its ability to detect more accurately,especially small pancreatic lesions,compared to other imaging modalities.By the EUS approach,it is easier to achieve good visualization of tumor ablation and necrosis as the echoendoscope position is closer to the tumor area.Based on studies and a recent meta-analysis,EUS-guided RFA is a promising treatment approach for most pancreatic malignancy cases,but most studies only collected data from a small sample size.Larger studies are needed before clinical recommendations can be made.

Record-Breaking Frequency of 44 GHz Based on the Higher Order Mode of Surface Acoustic Waves with LiNbO_(3)/SiO_(2)/SiC Heterostructures

Surface acoustic wave (SAW) technology has been extensively explored for wireless communication, sensors, microfluidics, photonics, and quantum information processing. However, due to fabrication issues, the frequencies of SAW devices are typically limited to within a few gigahertz, which severely restricts their applications in 5G communication, precision sensing, photonics, and quantum control. To solve this critical problem, we propose a hybrid strategy that integrates a nanomanufacturing process (i.e., nanolithography) with a LiNbO_(3)/SiO_(2)/SiC heterostructure and successfully achieve a record-breaking frequency of about 44 GHz for SAW devices, in addition to large electromechanical coupling coefficients of up to 15.7%. We perform a theoretical analysis and identify the guided higher order wave modes generated on these slow-on-fast SAW platforms. To demonstrate the superior sensing performance of the proposed ultra-high-frequency SAW platforms, we perform micro-mass sensing and obtain an extremely high sensitivity of approximately 33151.9 MHz·mm2·μg−1, which is about 1011 times higher than that of a conventional quartz crystal microbalance (QCM) and about 4000 times higher than that of a conventional SAW device with a frequency of 978 MHz.

High-frequency Ultrasound Evaluation of Effects of Early Treatment with Metoprolol on Myocardial Inflammatory Cytokine Expression in Rats with Acute Myocardial Infarction

This study evaluated the effects of early treatment with β-adrenergic blocker metoprolol on ventricular remodeling and function after acute myocardial infarction (AMI) by using high frequency ultrasound.The relationship between the efficacy and the expression level of cardiac myocardial inflammatory cytokine was examined in rats.The rat model of AMI was induced by ligating the left ante-rior descending artery.The surviving rats were randomly assigned to two experimental groups:MI control (MI) group and MI metoprolol (MI-B) group,with the rats undergoing sham operation serving as normal control (Sham).MI-B group was given metoprolol for 4 weeks (refer to the CCS-2 protocol) and the other two groups received equal volume of saline via intragastric (i.g.) administation.The ventricular remodeling and function were evaluated by high frequency ultrasound 4 weeks after the treatment.Then all rats were sacrificed for pathological examination and immunohistochemistrical detection of inflammatory cytokines,including IL-1β,IL-6,IL-10 and TNF-α.Compared with the MI group,the left ventricular end-systolic dimension,end-diastolic dimension,end-systolic volume and end-diastolic volume of the MI-B group were significantly decreased (P<0.01),while the left ventricular anterior wall end-diastolic thickness,ejection fraction and fractional shortening were obviously increased (P<0.01).The conspicuous improvement in the left ventricular morphology and function was coincident with the markedly reduced TNF-α and IL-1β expression and the increased IL-10 expression.We are led to conclude that early metoprolol treatment for AMI can regulate myocardial inflammatory cytokine expression to improve cardiac function and the underlying mechanism might be that it decreases the level of pro-inflammatory cytokines and increases the level of its anti-inflammatory counterparts in cardiac myocytes.Our study also showed that echocardiography is a useful technique for the structural and functional assessment of left ventricle after acute myocardial infarction.

SIMULATION OF TEMPERATURE FIELD IN ULTRA-HIGH FREQUENCY INDUCTION HEATING AND VERIFICATION

An experimental and numerical study on the temperature field induced in the ultra-high frequency induction heating is carried out.With an aim of predicting the thermal history of the workpiece,the influence factors of temperature field,such as the induction frequency,the dimension of coil and the gap between coil and workpiece,are investigated considering temperature-dependent material properties by using FLUX 2Dsoftware.The temperature field characteristic in ultra-high induction heating is obtained and discussed.The numerical values are compared with the experimental results.A good agreement between them is observed with 7.9% errors.

A Static Bioimpedance and Dynamic Acoustic Myography Preliminary Assessment of Low Frequency Therapeutic Ultrasound Treatment of the Shoulder Muscle Trapezius: An Equine Study

Background: In horses, therapeutic ultrasound has been shown to be beneficial for suspensory ligament injuries, and more generally to stimulate tissue repair and reduce localized pain. However, it has yet to be examined in relation to soft tissue injuries sustained during competition or in connection with rider/saddle interactions. Aim: The aim of the present study was to examine the efficacy of topical low-frequency therapeutic ultrasound on the shoulder muscles of injured horses. Methods: Muscle mass and cellular health was assessed for M. trapezius using non-invasive multi-frequency bioimpedance, and dynamic improvements in M. trapezius and M. latissimus dorsi were examined using acoustic myography (AMG). A total of 8 injured horses (painful to palpation and atrophied) were treated using an EQ Pro Therapy unit, following a set protocol that comprised treatment every other day for 10 treatments. Pre-treatment values were then compared with post-treatment measurements (1 & 6 months later). Results: The mfBIA results for M. trapezius showed a significant improvement (P < 0.05) of EQ Pro Therapy treatment for the membrane capacitance (Mc) and phase angle (PA) parameters when comparing the Pre vs Post 1 and Post 1 vs Post 2 measurements. Similar improvements were seen for the AMG measurements for M. trapezius and M. latissimus dorsi where statistically significant improvements in the muscle efficiency (E-score) and temporal summation (T-score) as well as the spatial summation (S-score) and mean of the ST-scores were noted (P < 0.05 to P < 0.01). Conclusion: The present findings suggest that EQ Pro Therapy treatment is efficacious in terms of equine cases involving soft tissue shoulder muscle injuries (painful to palpation and atrophied). The main improvements noted were not only increased muscle mass and cellular health but also improved force production, better coordination, and lateral balance, which persisted for at least six months after treatment.

Clinical Value of Transperineal 3D Volume Ultrasound Combined with 2D High Frequency Ultrasound in Anal Fistula

Objective: To explore the clinical diagnostic value of transperineal volume ultrasound combined with two-dimensional high-frequency ultrasound for anal fistula. Methods: A total of 52 patients with anal fistula admitted to the Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine from December 2017 to July 2018 were selected. They were all undergoing transperineal 3D volume ultrasound combined with 2D high-frequency ultrasound examination, and the diagnosis results were analyzed. The results of ultrasonography and surgical pathology were compared. Results: Among 52 patients, 3D volume ultrasound combined with 2D high-frequency ultrasound were used to diagnose 32 cases of anal fistula intersphincteric type, 14 cases of transsphincter type, 5 cases of supra-sphincter type, and 1 case of extra-sphincter type. T supervisor classification accuracy rate is 90%. The detection rate of branch pipes was 92%, and the compliance rate of internal fistula was 95%. Two-dimensional high-frequency ultrasound was used to diagnose 34 cases of anal fistula intersphincteric type, 14 cases of transsphincter type, 4 cases of supra-sphincter type, and 0 cases of extra-sphincter type. The detection rate of branch canals was 42%, and the accuracy of type classification was 90%. The coincidence rate was 95%. There was a statistically significant difference in the detection rate of the anal fistula branch and the coincidence rate of the internal fistula between the two methods (both P Conclusion: 1) The overall coincidence rate of three-dimensional volumetric ultrasound combined with two-dimensional high-frequency ultrasound in the diagnosis of anal fistula is high;2) Three-dimensional volumetric ultrasound technology has great application prospects in infants and anal fistulas.

Application Value of High-Frequency Ultrasound and Contrast-Enhanced Ultrasound in Patients with Knee Osteoarthritis with Different TCM Syndromes

Objective: To explore the application value of high-frequency ultrasound and contrast-enhanced ultrasound in different syndrome types of knee osteoarthritis, and to provide more imaging evidence for clinical diagnosis and treatment. Method: Sixty patients with KOA were selected according to TCM classification, which were mainly divided into Qi stagnation and blood stasis type and cold-dampness blockage type. All knee joints were routinely examined by high frequency ultrasound, and those with synovial hyperplasia were examined by contrast-enhanced ultrasound. High frequency ultrasound is the examination of synovium, cartilage and collateral ligament of knee joint based on two-dimensional ultrasound. Contrast-enhanced ultrasound (CEUS) refers to the contrast examination of synovium in knee joint patients with synovial hyperplasia. Result: Among them, the suprapatellar sac effusion and synovial thickening of Qi stagnation and blood stasis type were more obvious than those of cold-dampness arthralgia type (P < 0.05), and the degree of wear of the intercondylar cartilage of cold-dampness arthralgia type was more obvious than that of Qi stagnation. The blood stasis type is heavier and the meniscus bulge is higher (P < 0.05). The radiography of synovial hyperplasia showed that the area under the curve of Qi stagnation and blood stasis type was higher than that of cold dampness arthralgia type (P < 0.05), and the peak time was significantly shorter than that of cold dampness arthralgia type. There was no statistical difference in effective peak gradient and onset time of type (P > 0.05). Conclusion: To a certain extent, the high-frequency ultrasound and contrast-enhanced ultrasound performance of knee osteoarthritis can be used as a dialectical reference for different TCM syndrome types.

Breast Lump Recognition Algorithms Based on Ultrasound Radio-Frequency Signals

A method for evaluating the benign and malignant breast tumors based on radio?frequency(RF)data was explored by extracting the characteristic parameters of breast ultrasound RF signals.The breast biopsy data were used as the reference data for judging the lump benign or malignant.The extracted ultrasound RF data were reconstructed and segmented by computer aided method to obtain the breast tumor region of interest(ROI)and its characteristic parameters(entropy and standard deviation).The characteristic parameters were statistically analyzed to evaluate the relationship between characteristic parameters and benign or malignant breast tumors.The results indicate the entropy and standard deviation of normal region is much higher than that of lump region,which shows that the standard deviation and entropy characteristic parameters of ultrasonic RF signals are meaningful in the diagnosis of breast tumors.The proposed method provides a new direction for computer?aided diagnosis of benign and malignant breast tumors.

Generation of Ultrasound Based on the Frequency Response Characteristics of the “Koss Pro Headphone” with R. David Case Sound Wave Files’—A Case Study

The research aim of this work is to analyse the characteristics of R. David Case Sound waves that are posited to have positive effects on people suffering from tinnitus. Moreover, the participants who listened to these sound wave files using specific headsets or headphones of the Koss models (ktx Pro, ksc-75) showed improved health condition such as alleviating tinnitus that they are suffering from. Therefore, these discoveries have encouraged R. David Case to pursue positively his journey into finding out what is special about those sounds when being listened specifically with Koss models. In this research, we focus mainly on the technical aspects of R. David Case sound signals which he has recorded. These specific sound waves were analysed using time domain, frequency domain as well as the effect of using the Koss Pro headphone frequency response characteristics applied to the sound. Results obtained from the analysis demonstrated that the generation of ultrasound can be the underlying reason for the treatment of the tinnitus.

High Frequency Ultrasound in Determining the Causes of Acute Shoulder Joint Pain

Shoulder ultrasonography is approved as the examination of choice for rotator cuff abnormality in many centers around the world since it is an inexpensive and safe tool for investigation of rotator cuff abnormalities. The goal of this study was to determine the ultrasound findings in patients with acute shoulder joint pain, and also to identify possible predictors of shoulder pain, as well as to compare the ultrasound diagnostic performance to that of MRI in such condition. A total of 65 (mean age 28 ± 1.2 years) consequential patients were recruited for a period of six months between July 2015 and June 2016 in this study. Collected data were confined on age, medical history, and clinical symptoms. Shoulder ultrasound was performed with a linear array transducer (10 - 15 MHz) connected to HI vision Avius ultrasound unit;Hitachi. MRI for the shoulder joint was performed in all cases to confirm the ultrasound results, using 1.5-T MRI system (Magnetom Espree);Siemens. Statistical analysis was completed using the standard Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 20 for windows. Ultrasound manages to determine the causes of acute shoulder joint pain in 98% of the patients. Fitted achievement values for shoulder ultrasound in the diagnosis the causes of shoulder joint pain were 100% sensitivity and a range of 96% to 100% of accuracy. Ultrasound presents a high sensitivity and accuracy in diagnosis a wide spectrum of shoulder joint lesions, with a diagnostic performance near to that of MRI.

A FREQUENCY DOMAIN QUANTITATIVE MEASUREMENT METHOD FOR BLOOD FLOW VELOCITY WITH BIDIRECTIONAL DOPPLERULTRASOUND AVOIDING DOWN-BAND CHANNEL

The up-band signal of the second ultrasonic beam contained reversecomPOnent or blooll now. Using double ultrasonic beam,bidirectional Doppler ultrasound can avoid the use or two kinds or band filters and be simplified into a singlekind or band filter. In order to make the output more accurate,the inrluence of angle effect can be overcome by the table-out method and another special methodcalled cose recorrection.The experiment result is that when the deviation angle varies from-- 18' to +20' the relative error or output is less than 5%.

The High Frequency (HF) Ultrasound as a Useful Imaging Technique for the Efficacy Assessment of Different Anti-Cellulite Treatments

The purpose of the research was to evaluate the role of high frequency ultrasound in monitoring and efficacy assessment of anti-cellulite treatments. A group of 66 women used 3 different types of anti-cellulite treatments;additionally a placebo group (n = 18) was created. The μ-Scan ultrasound device with a 35 MHz mechanical probe was used for the examinations. The following parameters were subjected to the ultrasound evaluation: epidermis thickness, dermis thickness, dermis echogenicity, the length and area of subcutaneous tissue bands projecting into the dermis (dermis-hypodermis junction), as well as the presence/absence of edema within the dermis. As a result of anti-cellulite treatment, the length and area of dermis-hypodermis junction significantly decreased, and dermis echogenicity significantly increased. Ultrasound imaging made it possible to evaluate the efficacy of the applied treatments. The high frequency ultrasound is a useful imaging technique for the application in aesthetic dermatology and cosmetology.

Development of a High-frequency Ultrasound System for High-speed Image Scanning

High-frequency image technique has been widely applied in medical diagnosis recently. For high voltage protection, high speed stage and trigger control circuitry are difficult to implement a high-frequency ultrasound imaging system. In this study, we utilized a linear servo with high noise tolerance and a novel multi-depth expression method to overcome those issues in developed high-speed image system. B-mode image of the chicken phantom by 25 MHz transducer shows the resolution of lateral and axial resolutions are up to 123 μm and 59 μm respectively. In addition, the experiment demonstrates that the axial resolution and depth of field (DOF) can be improved by time gain compensation(TGC) and multi-depth method. The results indicate that the proposed system could achieve over 24 fps for 1 mm scan distance and 100 lines per frame. In the future, the developed system is potential for other clinical applications such as ophthalmology and dermatology.

A Flexible and High Speed Digital Scan Converter for High Frequency Ultrasound Imaging

This paper presents a flexible and high speed digital scan converter (DSC) with the ability to handle high frequency ultrasound imaging in real-time. The characteristics in imaging system such as focus length of transducer, the swing radius and sampling length etc. could be changed easily in compliance with the researcher's application based on this flexible digital scan converter. Linear interpolation is employed to achieve the coordinate transformations algorithm. Custom-built software is programmed to preliminarily handle the algorithm according to different ultrasound imaging applications. High performance FPGA will implement high speed interpolation calculation based on the preliminary data which are stored in the DDR2 SDRAM from the software. 64 bit 66 MHz PCI is employed to accomplish high speed data transmission. Experiment has shown that more than 500 frame rate could be achieved based on this high speed digital scan converter. The designed flexible and high speed digital scan converter could be used in current FPGA based high frequency ultrasound imaging system.

Dual Treatment Strategy by Venous Ulcers: Pilot Study to Dual-Frequency Ultrasound Application

We propose a new dual treatment strategy by venous ulcer, consisting in simultaneous modulation of matrix metalloproteinases (MMPs) and heat shock proteins (HSPs) in the wound. One treatment method which can efficiently modulate both these substances is based on the application of dual-frequency ultrasound (LDM). This strategy was checked in a pilot study on 10 patients with chronic venous ulcers and demonstrated excellent healing rate.

High frequency components in avian vocalizations

Ultrasonic communication in vertebrates is attracting increasing research interest.To determine if ultrasonic vocalization is common in birds,we recorded their vocalizations with ultrasound detectors in the Dongzhai National Nature Reserve of Henan Province,China.We found varying degrees of high frequency components in the vocalizations of 14 species and in several of these species,the frequency of harmonics was up to the range of ultrasound.We suggest that more studies are required to determine whether the high frequency components in avian vocalizations have functions and what these functions are.In addition,the ability of birds to hear sounds in the high frequency range also requires re-examination.

Reference values of carotid intima-media thickness and arterial stiffness in Chinese adults based on ultrasound radio frequency signal:A nationwide,multicenter study

Background:Carotid intima-media thickness(IMT)and diameter,stiffness,and wave reflections,are independent and important clinical biomarkers and risk predictors for cardiovascular diseases.The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods:A total of 3053 healthy Han Chinese adults(1922 women)aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022.The real-time tracking of common carotid artery walls was achieved by the radio frequency(RF)ultrasound system.The IMT,diameter,compliance coefficient,βstiffness,local pulse wave velocity(PWV),local systolic blood pressure,augmented pressure(AP),and augmentation index(AIx)were then automatically measured and reported.Data were stratified by age groups and sex.The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions.The major clinical determinants of carotid properties were identified by Pearson’s correlation,multiple linear regression,and analyses of covariance.Results:All the parameters of carotid properties demonstrated significantly age-related trajectories.Women showed thinner IMT,smaller carotid diameter,larger AP,and AIx than men.Theβstiffness and PWV were significantly higher in men than women before forties,but the differences reversed after that.The increase rate of carotid IMT(5.5µm/year in women and 5.8µm/year in men)and diameter(0.03 mm/year in both men and women)were similar between men and women.For the stiffness and wave reflections,women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes(all P for age by sex interaction<0.05).The blood pressures,body mass index(BMI),and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex.Conclusions:The age-and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established.The blood pressures,BMI,and triglyceride levels should be considered for clinical application of corresponding reference values.

Structure optimization of connection frames based on frequency sensitivity in macro-micro motion platforms

High-performance connection frames are of great significance for ultra-high acceleration and ultra-precision positioning in macro-micro motion platforms. This paper first takes the connection frame as a research object,builds a finite element model(FEM) of the natural frequency of the frame, and then verifies the correctness of this model. The frequency sensitivity method is then used to perturb the structural parameters of the FEM of the connection frame, and the sensitivities of the first-order natural frequency and mass of the corresponding structural parameters are obtained by calculation and analysis. The design variables are also determined. The natural frequency is used as the optimization objective, and the design parameters and mass of the connection frame are constrained. The structural parameters of the connecting frame are obtained through optimization, and the model is built and verified by experiments. The results show that the first-order natural frequency of the connecting frame is effectively improved by the frequency sensitivity method, avoids resonance between the connecting frame and the voice coil motor, and realizes the lightweight design of the connection frame. This research provides a reliable basis for the stable operation and ultra-precision positioning of ultra-high acceleration macro-motion platforms.

Influence enhancement effect of bi-frequency ultrasonic irradiation by TA fluorescence method

Based on a previous research of cavitation effect under bi-frequency ultrasound irradiation, this paper studies bi-frequency irradiations with similar experimental settings. The additional irradiation sources with frequencies of 1.04MHz, 0.8MHz and 1.7MHz are individually combined with the main ultrasonic irradiation source with frequency of 28kHz to form bi-frequency ultrasonic irradiation. The intensity of 28kHz irradiation was fixed at 12.5W/cm^2, while the intensity of the ultrasound at the other three frequencies is varied from1 W/cm^2 to 18 W/cm^2. It turns out that under the influence of the bi-frequency irradiation, the fluorescence intensity is obviously greater than the sum of those at individual frequencies. So the frequency of the additional sonication strikingly influences the fluorescence enhancement effect. For example, the fluorescence enhancement effect of 1.04MHz is stronger than that of 1.7MHz, and the enhancement effect of 0.8MHz is further stronger than that of 1.04MHz. Under the sonic intensity of (7.9)W/cm^2, the fluorescence intensity of 1.04MHz is approximately twice that of 1.7MHz while the fluorescence intensity of 0.8MHz is approximately 1.5 times that of 1.04MHz.

The effect of frequency and sample shape on fatigue behaviors of DZ125 superalloy

The effect of frequency and sample shape on fatigue behaviors of DZ125 superalloy are systematically studied.The results show that fatigue fracture still occurs above the cycle of 10~8 for tests carried out at the frequency of f=20 kHz and stress ratio R =-1,so the traditional fatigue limit at cycle of 10~7 is not appropriate for fatigue design.Fatigue fracture surfaces are perpendicular to stress axis for cylindrical and plate specimens,and the fatigue cracks originate from the extra surface of the specimens.Fatigue crack is apt to propagate from cutting direction to forward direction,which occurs mainly in the second propagation stage at higher stress amplitude. There is an obvious frequency effect for DZ125 superalloy.The higher the test frequency is,the more serious the effect of frequency on fatigue behaviors of the alloy.After the frequency correction,the ultra-high cycle fatigue S-N curve well coincide with the traditional fatigue S-N curve.