• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 26
  • 26
  • 8
  • 7
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A new approacch to the analysis of the third heart sound

Ewing, Gary John. January 1988 (has links) (PDF)
Errata sheet inserted. Bibliography: leaves 99-102.
2

A wavelet-based method for the classification of PCG signals

Daura, Ashiru Sani January 1998 (has links)
No description available.
3

Time-frequency and time-scale analysis of phonocardiograms with coronary artery disease before and after angioplasty / by Mohammad Ali Tinati.

Tinati, Mohammad Ali January 1998 (has links)
Bibliography: leaves 218-228. / xviii, 228 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the effects that coronary artery disease (CAD) has on heart sounds, by analyzing the heart sounds of patients with coronary artery disease before and after angioplasty operation. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1999?
4

Analysis of phonocardiographic signals using advanced signal processing techniques

Haghighi-Mood, Ali January 1996 (has links)
No description available.
5

Automatic detection and identification of cardiac sounds and murmurs

Baranek, Humberto Leon January 1987 (has links)
No description available.
6

Automatic detection and identification of cardiac sounds and murmurs

Baranek, Humberto Leon January 1987 (has links)
No description available.
7

Cardiac patterns during another infant's cry sound in neonates of depressed mothers

Unknown Date (has links)
Past research indicates there is a link between physiological responses and adaptive social responses to another individual's distress. Scholars have theorized that humans may be predisposed, both physiologically and behaviorally to responding to others, especially those who are in distress. Maternal depression has been associated with dysregulated emotional development and may possibly affect the physiological and behavioral responses of a neonate. The present research examined the relationship between neonates' physiological and behavioral responses to naturally generated (compared to artificial) stimuli of other neonates, as well as the role of maternal depression in the responses. Specifically, heart rate, heart period, and heart period variability were measured to assess the newborns' reaction to cries generated by both other newborns and digitally modulated sources. This study found that newborns of depressed mothers had higher heart period variability and showed less behavioral distress when hearing the cry of another infant. / by Joseph Cotler. / Thesis (M.A.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
8

Clinical application of acoustic cardiography.

January 2012 (has links)
儘管心力衰竭的診斷和治療已取得了長足進步,但是心力衰竭依然是目前主要的致殘和致死病因。而且,隨著人口的老齡化,心力衰竭的發病率不斷上升。然而心力衰竭的快速診斷、心功能評價以及患者的危險分層依然面臨眾多挑戰。Acoustic cardiography 是一項經濟簡單的新技術。憑藉獨有的雙功能感測器,這項技術可以同時評估收縮間期(systolic time intervals)以及舒張期心音(diastolic heart sounds)。這項技術提供的主要參數包括:第三心音分數(S3 score;第三心音存在的可能性),電機械時間(EMAT, electromechanical activation time;從心電圖Q 波到心音圖第一心音的時間)及電機械時間比例(%EMAT;電機械時間占整個心動週期的比例),收縮障礙指數(SDI, systolic dysfunctionindex)。本論文主要涵蓋Acoustic cardiography 在心力衰竭患者中如下三個方面 的應用: / 一、心力衰竭的診斷和不同亞型的識別 / 本研究入組了 94 名高血壓但無心力衰竭患者、109 名射血分數正常的心力衰竭患者以及89 名射血分數減低的心力衰竭患者,我們發現%EMAT 可以鑒別射血分數正常的心力衰竭和高血壓患者。另一方面,SDI 是鑒別分射血分數正常和射血分數減低患者的最好指標。 / 二、心力衰竭患者心功能障礙嚴重程度評估 / 此研究共招募 94 名高血壓患者和127 名射血分數減低的心力衰竭患者。結果顯示:SDI 可以鑒別射血分數減低的心力衰竭和高血壓患者。亞組分析顯示:SDI 可以區分射血分數嚴重減低和中度減低的心力衰竭患者;S3 score 可以識別伴舒張功能嚴重障礙的心力衰竭患者。 / 三、心力衰竭患者的危險分層 / 共計 474 名心力衰竭患者被納入此研究,平均隨訪時間484±316 天,169名患者死亡,其中125 名死於心臟病。SDI 和S3 score 都是全因死亡率的獨立預測因數;Kaplan Meier 分析顯示:SDI ≥ 5 或S3 score ≥ 4.12 的心力衰竭患者的生存率顯著降低。 / 通過以上三個方面的研究,我們發現這項新技術有助於(1)心力衰竭的診斷和不同亞型的識別;(2)評估心力衰竭患者的心功能障礙嚴重程度,進而發現其中的高危人群;(3)心力衰竭患者的危險分層。因此,這項新技術有望在心力衰竭患者的管理中扮演早期診斷、評估以及危險分層的重要角色。 / Despite recent advances in its management, heart failure remains a major cause of disability and death and its prevalence is still increasing as the population ages. However, rapid and accurate bedside diagnosis, evaluation as well as risk stratification of heart failure still remain challenging. / Acoustic cardiography (AUDICOR, Inovise Medical, Inc., Portland, OR, USA) is a novel and user friendly equipment which can be used in a wide variety of clinical conditions. With proprietary dual-functional sensors, this technology permits simultaneous acquisition of detailed information regarding systolic time intervals and diastolic heart sounds and provides a computerized interpretation of the findings. Major acoustic cardiographic parameters include S3 score (probability that the third heart sound exists), electromechanical activation time (EMAT, interval from Q wave to the first heart sound; %EMAT is the proportion of cardiac cycle that EMAT occupies), and systolic dysfunction index (SDI= exp [S3 score/10] x QRS interval x QR interval x %EMAT).This thesis will cover 3 aspects of clinical application of acoustic cardiography in heart failure patients. / I. Identification of heart failure and its phenotypes / We performed one study involving 94 patients with hypertension without heart failure, 109 patients with heart failure with normal ejection fraction (HFNEF, EF > 50%) and 89 patients with heart failure and reduced ejection fraction (HFREF, EF < 50%). We found that %EMAT significantly differentiated HFNEF from hypertension. Whereas SDI out-performed the other acoustic cardiographic parameters in differentiating HFREF from HFNEF. / II. Assessment of HFREF patients at high risk by evaluating the severity of left ventricular (LV) systolic and diastolic dysfunction / Ninety-four hypertensive patients without heart failure and 127 HFREF patients (EF < 50%) were consecutively recruited for the study. SDI significantly differentiated HFREF from hypertension. In subgroup analysis, SDI discriminated HFREF patients with severely impaired EF (EF ≤ 35%) from those with moderately impaired EF (35% < EF <50%). S3 score > 4.67 identified HFREF patients with restrictive LV filling pattern. / III. Risk stratification in patients with heart failure / A total of 474 patients hospitalized for heart failure were enrolled into our study. During a mean follow-up time of 484±316 days, 169 (35.7%) patients died and 125 (26.4%) of them died of cardiac causes. After controlling for other potential confounders, we found that S3 score ≥ 4.12, and SDI ≥ 5 were both independent predictors for all-cause mortality. Kaplan-Meier analysis showed that heart failure patients with SDI ≥ 5 or S3 score ≥ 4.12 had a significantly lower survival rate than those with lower SDI or S3 score. / In summary, this bedside technology offers a wide variety of clinical applications in (1) identification of heart failure and its phenotypes; (2) assessmet of HFREF patients at high risk by evaluating the severity of LV systolic and diastolic dysfunction; (3) risk stratification in patients with heart failure. Thus, acoustic cardiography is likely to be helpful in the management of heart failure patients, acting as an early detection, evaluation and risk-stratification tool. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Shang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 123-135). / Abstract also in Chinese. / DECLARATION OF ORIGINALITY --- p.i / ACKNOWLEDGEMENTS --- p.ii / PUBLICATIONS RELATED TO THIS THESIS --- p.iv / Full publications --- p.iv / Conference presentations --- p.v / TABLE OF CONTENTS --- p.vi / LIST OF TABLES --- p.xi / LIST OF FIGURES --- p.xiii / LIST OF ABBREVIATIONS --- p.xv / ABSTRACT --- p.xviii / 論文摘要 --- p.xx / Chapter PART I --- LITERATURE REVIEW --- p.1 / Chapter Chapter 1 --- Introduction to Acoustic Cardiography --- p.2 / Chapter 1.1 --- History of auscultation, phonocardiography --- p.2 / Chapter 1.2 --- STIs --- p.3 / Chapter 1.2.1 --- Conventional STIs --- p.3 / Chapter 1.1.2 --- Echocardiographic STI --- p.5 / Chapter 1.3 --- Acoustic cardiography --- p.7 / Chapter 1.3.1 --- ECG parameters of acoustic cardiography --- p.11 / Chapter 1.3.2 --- Systolic parameters of acoustic cardiography --- p.12 / Chapter 1.3.3 --- Diastolic Parameters of acoustic cardiography --- p.13 / Chapter 1.4 --- Comparison between acoustic cardiography and traditional phonocardiography --- p.19 / Chapter Chapter 2 --- Clinical Application of Acoustic Cardiography --- p.27 / Chapter 2.1 --- Mechanism of generation of S3 and S4 --- p.27 / Chapter 2.2 --- Prevalence of S3 and S4 --- p.28 / Chapter 2.3 --- Clinical auscultation of S3 and S4 problems --- p.29 / Chapter 2.4 --- Rapid identification of heart failure or LV dysfunction --- p.32 / Chapter 2.4.1 --- S3 and S4 --- p.32 / Chapter 2.4.2 --- EMAT --- p.33 / Chapter 2.4.3 --- SDI --- p.34 / Chapter 2.4.5 --- Other derived acoustic cardiographic parameters --- p.34 / Chapter 2.5 --- Predicting elevated LV filling pressure --- p.35 / Chapter 2.6 --- Improving diagnostic utility of BNP in detection of heart failure or LV dysfunction --- p.36 / Chapter 2.7 --- Hemodynamic correlations of acoustic cardiographic parameters --- p.37 / Chapter 2.8 --- Prognostic value of acoustic cardiography --- p.38 / Chapter 2.9 --- Cardiac resynchronization therapy --- p.39 / Chapter 2.10 --- Detection of ischemia --- p.40 / Conclusions --- p.42 / Chapter PART II --- STUDIES ON APPLICATION OF ACOUSTIC CARDIOGRAPHY --- p.48 / Chapter Chapter 3 --- Acoustic Cardiography Helps to Identify Heart Failure and Its Phenotypes --- p.49 / Introduction --- p.49 / Methods --- p.50 / Participants and study design --- p.50 / Echocardiography --- p.51 / Acoustic cardiography --- p.52 / Assessment of reproducibility --- p.55 / Statistical analysis --- p.55 / Results --- p.56 / Characteristics of study subjects --- p.56 / Acoustic cardiographic and echocardiographic characteristics --- p.59 / Diagnostic characteristics of acoustic cardiography --- p.64 / Analysis of covariance results --- p.68 / Inter-operator reproducibility --- p.68 / Discussion --- p.68 / Chapter Chapter 4 --- Rapid Bedside Identification of High-Risk Population in Heart Failure with Reduced Ejection Fraction by Acoustic Cardiography --- p.72 / Introduction --- p.72 / Methods --- p.73 / Study population --- p.73 / Echocardiography --- p.73 / Acoustic cardiography --- p.74 / Assessment of reproducibility --- p.74 / Statistical analysis --- p.74 / Results --- p.75 / Baseline characteristics of study subjects --- p.75 / Acoustic cardiographic and echocardiographic characteristics --- p.78 / Diagnostic test characteristics of acoustic cardiography --- p.84 / Analysis of covariance results --- p.89 / Inter-operator reproducibility --- p.89 / Discussion --- p.89 / Chapter Chapter 5 --- Prognostic value of Acoustic Cardiography in Risk Stratification of Patients With Heart Failure --- p.93 / Introduction --- p.93 / Methods --- p.94 / Study population --- p.94 / Acoustic cardiography --- p.94 / Echocardiography --- p.94 / Endpoint --- p.95 / Assessment of reproducibility --- p.95 / Statistical analysis --- p.95 / Results --- p.96 / Study population --- p.96 / All-cause mortality --- p.100 / Cardiac death --- p.100 / Subgroup analysis in 232 patients undergoing echocardiography --- p.107 / Inter-operator reproducibility --- p.107 / Discussion --- p.114 / Strengths and potential limitations --- p.115 / Chapter PART III --- CONCLUSIONS --- p.117 / Chapter Chapter 6 --- Summary of the Present Studies --- p.118 / Chapter I. --- Identification of heart failure and its phenotypes --- p.118 / Chapter II. --- Assessment of HFREF patients at high risk by evaluating the severity of LV systolic and diastolic dysfunction --- p.119 / Chapter III. --- Risk stratification in patients with heart failure --- p.119 / Chapter Chapter 7 --- Future Research Directions --- p.121 / References --- p.123
9

Low noise heart sound acquisition in wearable system for individual-centered CVD diagnosis

Tan, Zhen, January 2017 (has links)
University of Macau / Faculty of Science and Technology / Department of Electrical and Computer Engineering
10

A comparison of an acoustic stethoscope and an amplified stethoscope in white noise and cafeteria noise during cardiac auscultation

Gigstad, Lynda Lynell 01 January 1990 (has links)
A basic relationship between stethoscopic auscultation and background noise interference was reviewed and examined in this study. The principle experimental design of the study questioned whether hospital background noise levels are capable of masking the threshold of detection for auscultated heart sounds. Several cited studies monitoring background noise levels in various hospital locations have reported averages exceeding the U.S. Environmental Protection Agency (EPA) (1974) and World Health Organization (WHO) (1980) recommendations of "quiet", namely 35 to 40 dBA (Falk & Woods, 1973; Hilton, 1985, 1987; Shapiro & Berland, 1972; Turner, et al., 1975; Woods & Falk, 1974) by as much as 46 to 51 dB, i.e., up to 86 dBA (Shapiro & Berland 1972). In addition to the previous query, a review of the literature reflected a lack of implementatory standards regarding the acoustic stethoscopic output and the masking effects of noise during the auscultation process. Specifically, this study ascertained the effective masking level (EML) intensities of two noise environments, white noise and cafeteria noise, for cardiac auscultation through an acoustic stethoscope and an amplified stethoscope. Two principle measurements were employed in the experimental protocol: an objective measurement employing a method of adjustment detection identification task of the EML, and subjective responses solicited by a forced-choice questionnaire. Sixteen normal hearing listener's were selected to participate in the experiment. Objective measures were analyzed using a MANOVA and a Pearson Product Moment Coefficient of correlation. The subjective questionnaire data were analyzed with a two-tailed T-test. All analyses were based on a .05 level of confidence.

Page generated in 0.073 seconds