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  • Open Access

    ARTICLE

    An Improved Lung Sound De-noising Method by Wavelet Packet Transform with Pso-Based Threshold Selection

    Qing-Hua Hea, Bin Yub, Xin Honga, Bo Lva, Tao Liub, Jian Ranb, Yu-Tian Bia

    Intelligent Automation & Soft Computing, Vol.24, No.2, pp. 223-230, 2018, DOI:10.1080/10798587.2016.1261957

    Abstract Lung abnormalities and respiratory diseases increase with the development of urban life. Lung sound analysis provides vital information of the present condition of the pulmonary. But lung sounds are easily interfered by noises in the transmission and record process, then it cannot be used for diagnosis of diseases. So the noised sound should be processed to reduce noises and to enhance the quality of signals received. On the basis of analyzing wavelet packet transform theory and the characteristics of traditional wavelet threshold de-noising method, we proposed a modified threshold selection method based on Particle Swarm Optimization (PSO) and support vector… More >

  • Open Access

    ARTICLE

    Ultrasound Speckle Reduction Based on Histogram Curve Matching and Region Growing

    Jinrong Hu1, Zhiqin Lei1, Xiaoying Li2, *, Yongqun He3, Jiliu Zhou1

    CMC-Computers, Materials & Continua, Vol.65, No.1, pp. 705-722, 2020, DOI:10.32604/cmc.2020.09878

    Abstract The quality of ultrasound scanning images is usually damaged by speckle noise. This paper proposes a method based on local statistics extracted from a histogram to reduce ultrasound speckle through a region growing algorithm. Unlike single statistical moment-based speckle reduction algorithms, this method adaptively smooths the speckle regions while preserving the margin and tissue structure to achieve high detectability. The criterion of a speckle region is defined by the similarity value obtained by matching the histogram of the current processing window and the reference window derived from the speckle region in advance. Then, according to the similarity value and tissue… More >

  • Open Access

    ARTICLE

    Cognitive dysfunction is associated with abnormal responses in cerebral blood flow in patients with single ventricular physiology: Novel insights from transcranial Doppler ultrasound

    Rachel Wong1, Mohammed Al‐Omary2, David Baker2, Neil Spratt1,2, Andrew Boyle1,2, Natasha Baker Cert1, Peter Howe1, Nicholas Collins2

    Congenital Heart Disease, Vol.14, No.4, pp. 638-644, 2019, DOI:10.1111/chd.12763

    Abstract Objectives: Improvements in the management of complex congenital heart disease, including those with single ventricle physiology, have resulted in increased survival. As this population ages, the recognition of cognitive impairment is increasingly im‐ portant. At present, little is known about the potential mechanisms of cognitive dys‐ function. In this cross‐sectional study, we aimed to characterize the nature of abnormalities in cerebral blood flow and the relationship to cognitive deficits in adults with single ventricular physiology.
    Patients: Ten adults with single ventricular physiology (age 18‐40 years) and 12 age‐ and gender‐matched controls underwent transcranial Doppler ultrasound and ac‐ companying cognitive assessment.
    More >

  • Open Access

    ARTICLE

    Systolic ejection click versus split first heart sound: Are our ears deceiving us?

    Natalie M. Hoeting1, Courtney E. McCracken1, Michael McConnell1,2, Denver Sallee1,2, Glen J. Iannucci1,2, Matthew E. Oster1,2

    Congenital Heart Disease, Vol.12, No.4, pp. 417-420, 2017, DOI:10.1111/chd.12460

    Abstract Objective: Bicuspid aortic valve (BAV) disease is associated with potential lifetime complications, but auscultation of a BAV click is commonly missed or mistaken for a benign split first heart sound. Our objective was to determine whether pediatric cardiologists could reliably distinguish between BAV clicks and benign split first heart sounds.
    Design: Quality evaluation project using de-identified recordings from an outpatient pediatric cardiology clinic.
    Outcome Measures: Twenty-one cardiologists listened to five de-identified recordings of pediatric heart sounds (three with BAV clicks, two with mitral components of benign split first heart sounds) and indicated whether they believed each recording was a BAV… More >

  • Open Access

    ARTICLE

    Sound Source Localization Based on SRP-PHAT Spatial Spectrum and Deep Neural Network

    Xiaoyan Zhao1, *, Shuwen Chen2, Lin Zhou3, Ying Chen3, 4

    CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 253-271, 2020, DOI:10.32604/cmc.2020.09848

    Abstract Microphone array-based sound source localization (SSL) is a challenging task in adverse acoustic scenarios. To address this, a novel SSL algorithm based on deep neural network (DNN) using steered response power-phase transform (SRP-PHAT) spatial spectrum as input feature is presented in this paper. Since the SRP-PHAT spatial power spectrum contains spatial location information, it is adopted as the input feature for sound source localization. DNN is exploited to extract the efficient location information from SRP-PHAT spatial power spectrum due to its advantage on extracting high-level features. SRP-PHAT at each steering position within a frame is arranged into a vector, which… More >

  • Open Access

    ARTICLE

    Clinical yield of fetal echocardiography for suboptimal cardiac visualization on obstetric ultrasound

    Rick D. Vavolizza1,2, Pe’er Dar3,4, Barrie Suskin3,4, Robert M. Moore4,5, Kenan W.D. Stern1,4

    Congenital Heart Disease, Vol.13, No.3, pp. 407-412, 2018, DOI:10.1111/chd.12584

    Abstract Objective: Suboptimal cardiac imaging on obstetric ultrasound is a frequent referral indication for fetal echocardiography, even in the absence of typical risk factors for fetal cardiac disease. The clinical profile of patients and findings of examinations performed for such an indication are not well defined. Given the increased cost, time and resource utilization of fetal echocardiography, we sought to determine the clinical findings of such referrals.
    Study Design: We performed a single-center review of such referrals from January 2010 to June 2016. Patients with commonly accepted indications for fetal echocardiography were excluded. Demographic variables and echocardiogram findings were collected. Findings… More >

  • Open Access

    ARTICLE

    Analytical Study on the Rate of Sound Transmission Loss in Single Row Honeycomb Sandwich Panel Using a Numerical Method

    Rohollah Fallah Madvari1, Mohammad Reza Monazzam2, Mohsen Niknam Sharak3, Mohsen Mosa Farkhani4,*

    Sound & Vibration, Vol.54, No.2, pp. 127-137, 2020, DOI:10.32604/sv.2020.08158

    Abstract Honeycomb structures have recently, replaced with conventional homogeneous materials. Given the fact that sandwich panels containing a honeycomb core are able to adjust geometric parameters, including internal angles, they are suitable for acoustic control applications. The main objective of this study was to obtain a transmission loss curve in a specific honeycomb frequency range along with same overall dimensions and weight. In this study, a finite element model (FEM) in ABAQUS software was used to simulate honeycomb panels, evaluate resonant frequencies, and for acoustic analysis. This model was used to obtain acoustic pressure and then to calculate the sound transmission… More >

  • Open Access

    ARTICLE

    Effect of Input Waveform to Vibration Speaker on Sound Quality of Electric Artificial Voice

    T. Asakura*, K. Shindo

    Sound & Vibration, Vol.54, No.2, pp. 85-98, 2020, DOI:10.32604/sv.2020.08119

    Abstract A number of studies have been conducted on the improvement of the sound quality of electrical artificial laryngeal speech, the speech produced has been difficult to hear compared to a natural voice. For this reason, it is necessary to effectively improve the frequency characteristics of the input signal. In the present study, to improve the sound quality of vocalization using an electrical artifi- cial larynx, first, a comparison of the frequency characteristics between the real and artificial voices was conducted, and three filters that can make the frequency characteristics of the artificial voice closer to those of a real voice… More >

  • Open Access

    ARTICLE

    Hand‐held echocardiography in children with hypoplastic left heart syndrome

    Alan F. Riley1, Elena C. Ocampo1, Joseph Hagan2, M. Regina Lantin‐Hermoso1

    Congenital Heart Disease, Vol.14, No.5, pp. 706-712, 2019, DOI:10.1111/chd.12774

    Abstract Background: When performed by cardiologists, hand‐held echocardiography (HHE) can assess ventricular systolic function and valve disease in adults, but its accuracy and utility in congenital heart disease is unknown. In hypoplastic left heart syndrome (HLHS), the echocardiographic detection of depressed right ventricular (RV) systolic function and higher grade tricuspid regurgitation (TR) can identify patients who are at increased risk of morbidity and mortality and who may benefit from additional imaging or medical therapies.
    Methods: Children with HLHS after Stage I or II surgical palliation (Norwood or Glenn procedures) were prospectively enrolled. Subjects underwent HHE by a pediatric cardiologist on the… More >

  • Open Access

    ARTICLE

    A Joint Delay-and-Sum and Fourier Beamforming Method for High Frame Rate Ultrasound Imaging

    Wei Zhao1, 2, Shuai Feng1, Yadan Wang1, Yuanguo Wang1, Zhihui Han1, Hu Peng1, *

    CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 427-440, 2020, DOI:10.32604/cmes.2020.09387

    Abstract Frame rate is an important metric for ultrasound imaging systems, and high frame rates (HFR) benefit moving-target imaging. One common way to obtain HFR imaging is to transmit a plane wave. Delay-and-sum (DAS) beamformer is a conventional beamforming algorithm, which is simple and has been widely implemented in clinical application. Fourier beamforming is an alternative method for HFR imaging and has high levels of imaging efficiency, imaging speed, and good temporal dynamic characteristics. Nevertheless, the resolution and contrast performance of HFR imaging based on DAS or Fourier beamforming are insufficient due to the single plane wave transmission. To address this… More >

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