Este trabalho teve como objetivo avaliar o perfil eletrocardiográfico dos eqüinos praticantes de hipismo clássico em São Paulo e também se estes parâmetros sofrem influências em relação ao tipo de atividade física desempenhada pelo animal (provas de salto abaixo de 1,20 metros e provas acima de 1,20 metros), faixa etária e fatores sexuais. Foram utilizados 100 eqüinos de hipismo clássico, representados por 61 machos e 39 fêmeas, com idades entre 4 e 19 anos. A freqüência cardíaca variou de 18,50 batimentos por minuto (bpm) a 89,45bpm, com média de 40,2077±13,3321, o ritmo cardíaco mais freqüente foi o sinusal com 56%, seguido de taquicardia sinusal 23%, arritmia sinusal 20% e bradicardia sinusal com 1%. As alterações encontradas foram: marcapasso migratório 25%, bloqueio átrio-ventricular de 2°grau (BAV de 2°grau) 9%, BAV de 1°grau 7%, complexos ventriculares prematuros 2% e bloqueio sinoatrial/ \"sinus arrest\" e complexos atrial prematuro com 1%. O eixo elétrico no plano frontal em 87% dos casos esteve entre o e +90 graus. O score cardíaco médio foi de 94,9±16,1milisegundos e em relação à duração na derivação bipolar II, obteve-se onda P com 0,1100±0,0242 segundos, intervalo P-R com 0,3140±0,0744 seg., complexo QRS com 0,0908±0,0250 seg., intervalo QT com 0,4908±0,0536 seg. e onda T com 0,1130±0,0330 seg. Quanto à amplitude também na derivação bipolar II, obteve-se onda P única em 35% dos casos com média de 0,2671±0,0747 milivolts, onda P bifásica em 11% dos eqüinos com média de 0,3136±0,1098mV e onda P bífida em 54% dos animais, sendo esta dividida em porção 1 e 2 (P1 e P2), P1 teve média de 0,1352±0,0492mV e P2 teve média de 0,2259±0,0502mV. A onda R e a onda T estiveram presentes em 100% dos eqüinos obtendo média de 1,0220±0,5028mV e 0,4425±0,2042mV, respectivamente. Quanto à morfologia, considerando-se todas as derivações analisadas, encontraram-se 11 configurações distintas para a onda P e 5 configurações diferentes para o complexo QRS e para a onda T. Segundo as análises estatísticas, houve diferenças significativas na duração, amplitude e morfologia de algumas ondas, intervalos e complexos, em relação ao grupo de atividade física, sexo e idade. / This study aimed to evaluate the electrocardiographic profiles of horses practicing show jumping in São Paulo as well as whether these parameters are affected by kind of physical activity performed by the animal (competitions below 1.20m jumps or above 1.20m), the age level or gender. A hundred show jumping horses were used, being 61 males, and 39 females. Their ages ranged from 4 to 19 years. Heart rate ranged from 18.50 beats per minute (bpm) to 89.45bpm, with an average of 40.2077±13.3321, the most frequent rhythm was sinusal with 56%, followed by sinus tachycardia 23%, sinus arrhythmia 20% and sinus bradycardia 1%. The alterations found were: wandering pacemaker 25%, second-degree atrioventricular block (BAV 2°) 9%, first-degree BAV 7%, ventricular premature complexes 2% and sinoatrial block / sinus arrest as well as premature atrial complexes 1%. The electrical axis at the frontal plane in 87% of the cases was between 0 and +90°. The average cardiac score was 94.9±16.1 milliseconds. In relationship to the bipolar lead II, P wave with 0.1100±0.0242 seconds, P-R interval of 0.3140±0.0744 seconds, QRS complex of 0.0908±0.0250 seconds, QT interval of 0.4908±0.0536 seconds and T wave with 0.1130±0.0330 seconds were obtained. In the amplitude, also at the bipolar lead II a single-peaked P wave was obtained in 35% of the cases with an average of 0.2671±0.0747 millivoltz, biphasic P wave in 11% of horses with an average of 0.3136±0.1098 mV and bifid P wave in 54% of the animals, being the latter divided into portions 1 and 2 (P1 and P2). P1 got an average of 0.1352±0.0492mV and P2 got an average of 0.2259±0.0502 mV. R wave and T wave were present in 100% of the horses, getting an average of 1.0220±0.5028mV and 0.4425±0.2042mV respectively. In relationship to the morphology, considering all the analyzed leads, 11 different configurations for P wave, and 5 different configurations for T wave were observed. According to the statistical investigation, there were significant differences in duration, amplitude and morphology of some waves, intervals and complexes in relationship to the physical activity group, sex and age.

No description available.

The present study was undertaken to determine if leads CM₅, CC₅, and V₅ are equally sensitive in detecting ST segment depression with exercise or hyperventilation in apparently normal males. Seven physically active men (29.4 + 2.9 yrs, 180.9 + 2.5 cm, 77.9 + 3.4 kg, x±SEM), free of risk factors for heart disease, were initially found to have J point (J₀) depression with mild exercise in lead V₅. Simultaneous ECG recordings from CM₅, CC₅ and V₅ during seated rest (REST), immediately post-moderate exercise (IPE), and after 30 s of hyperventilation (HVT). ECG signals were manually evaluated for ST segment depression at the J point and 60 ms and 80 ms past the J point (J₆₀, J₈₀). None of the three leads differed in their ability to detect ST segment changes. With exercise, J₀ was significantly (P<.05) reduced compared to REST; neither J₆₀ nor J₈₀ differed from REST. HVT reduced J₀ significantly but not J₆₀ or J₈₀ Exercise provoked greater reductions than HVT. These data suggest that, in apparently healthy adult males, these three ECG leads are equally able to detect J point changes with exercise and hyperventilation, but exercise results in a relatively greater downward ST segment shift than does hyperventilation. / Master of Science

An electrocardiogram analysis package is developed in this thesis. A parabolic smoothing with pre-set threshold for attenuating effects on high frequency components is applied. The GF and operational transforms are studied and examined for their constraints, applications and flexibility. These transforms are modified and adapted for recognition of QRS onset and offset in the Frank Orthogonal Lead System. An algorithm, based on a set of pre-set criteria and thresholds, is developed. Various clinical parameters, vectors and files for analysis. such as segment or wave intervals, magnitude, areas etc. are generated together with data two-dimensional and three-dimensional graphic In addition. a general purpose graphic package is supplied to create the vector displays for ECG analysis. The algorithm has been tested on three hundred cardiac cycles taken from ten patients with both normal and abnormal ECG characteristics. / Master of Science

O presente estudo procurou avaliar, prospectivamente, a segurança do sistema de tele-eletrocardiografia para a liberação de pacientes que se apresentem a postos de saúde com queixa de dor torácica. Avaliamos a incidência de infarto do miocárdio dessa população ao longo de seis meses. Como objetivo secundário, correlacionamos, retrospectivamente, a razão das probabilidades entre diferentes indicadores clínicos e eletrocardiográficos e a ocorrência do infarto do miocárdio. Entre junho e dezembro de 2006, 32444 pacientes foram atendidos em postos de saúde pública, carentes de cardiologistas e tiveram o seu tele-eletrocardiograma transmitido até uma central de telemedicina, através de linha telefônica fixa. Selecionaram-se 1535 pacientes atendidos devido a dor torácica, que tinham mais de 50 anos e apresentavam exame clínico, laboratorial (troponina I ou creatino fosfoquinase fração MB-CKMB) e tele-eletrocardiográfico normais além de consentirem em repetir o tele-eletrocardiograma após um e seis meses. Todos os pacientes foram seguidos durante seis meses. Não houve eventos durante o primeiro mês. No segundo mês houve 12(0,8%) infartos; no terceiro mês, 18(1,2%); no quarto mês, 38(2,4%) e no sexto, 18(1,2%). Ao longo dos seis meses houve 15(1%) óbitos, sendo 9(0,6%) de origem cardíaca; 9 (0,6%)acidentes vasculares encefálicos e 86(5,6%) infartos agudos do miocárdio. Entre as variáveis que se correlacionaram, independentemente, com maior chance de infarto agudo do miocárdio, encontrou-se a obesidade grau I [p=0,009 RC 4,5 IC 95%(1,5-13,8)], a dislipidemia [p< 0,0001 RC 3,4 IC 95%(2,0-5,8)], a baixa amplitude da onda T em V2 [p<0,001 RC 2,9 IC 95%(2,4-3,5)] e o sobrepeso [p=0,019 RC 2,6 IC 95%(1,2-5,7)]. Cada 0,5mm de redução na amplitude da onda T aumentou em quase três vezes a chance de ocorrência do infarto agudo do miocárdio durante seis meses. O tabagismo apresentou forte tendência [p=0,057 RC 1,7 IC 95%(1,0-2,8)] à regressão logística binária e foi significante após análise por árvore de decisão. Estes resultados permitiram as seguintes conclusões: o sistema de tele-eletrocardiografia oferece alta segurança ao estratificar o risco de pacientes com exame clínico, laboratorial e tele-eletrocardiográfico normais, queixando-se de dor torácica. Identificou-se, ao longo dos seis meses, a população de maior chance de apresentar o evento através de variáveis clínicas (obesidade, dislipidemia, tabagismo e sobrepeso) e tele-eletrocardiográficas (amplitude da onda T em V2), que determinaram, independentemente, a ocorrência de infarto agudo do miocárdio / The present study aimed at prospectively evaluating the reliability of teleeletrocardiography for the discharge of chest pain patients who present themselves at remote medical centers. The incidence of acute myocardial infarction among this population was evaluated during a period of six months. As a secondary objective, the correlation between different clinical and electrocardiographic features and the occurrence of myocardial infarction was retrospectively checked. Between June and December of 2006, 32.444 patients were treated in public medical centers which lacked the assistance of cardiologists. Those patients had their electrocardiogram transmitted to a telemedicine center over a fixed-wired telephone line. Among them 1535 patients who had been assisted due to chest pain were selected. Those patients were all older than 50 years and showed normal clinical and laboratorial (troponine I or creatine phosphokinase MB-CKMB fraction) exams, as well as normal tele-electrocardiograms. They also agreed to repeat the teleelectrocardiogram in a six-month period. All patients were followed up to the sixth-month. In the second month, there were 12 (0,8%) infarctions; in the third month there were 18 (1,2%) infarctions; in the fourth month there were 38 (2,4%) infarctions, and in the sixth month there were 18 (1,2%) infarctions. Over that six month period, there were 15 (1%) deaths, 9 (0,6%) of which were related to cardiac causes; 9 (0,6%) strokes, and 86 (5,6%) acute myocardial infarctions. Among the variables which independently correlated with greater risk of acute myocardial infarction, we found grade I obesity [p=0,009 RC 4,5 IC95%(1,5-13,8)]; dyslipidemia [p<0,0001 RC 3,4 IC 95%(2,0-5,8)]; low T-wave amplitude in V2 [p<0,001 RC 2,9 IC 95%(2,4-3,5)], and overweight [p=0,019 RC 2,6 IC 95%(1,2-5,7)]. Each 0,5mm reduction in the T-wave raised almost three times the chance for the occurrence of acute myocardial infarction in a sixmonth period. Smoking showed a strong tendency [p=0,057 RC 1,7 IC 95%(1,0-2,8)] to binary logistic regression and was significant after decision tree analysis. These results lead to the following conclusions: the teleelectrocardiographic system offers high level of safety and reliability due to its capacity to stratify chest pain patient risk. Over these six months the study identified the population who showed greater chances of presenting the event through clinical (obesity, dyslipidemia, smoking and overweight) and teleelectrocardiography (amplitude of T-wave in V2) variables, which independently, determined the occurrence of acute myocardial infarction

by Hung King Fai Kevin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 82-85 (2nd gp.)). / Abstracts in English and Chinese. / ACKNOWLEDGEMENT --- p.ii / ABSTRACT --- p.iii / 摘要 --- p.v / TABLE OF CONTENTS --- p.vi / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- OBJECTIVES --- p.1 / Chapter 1.2 --- NEED FOR PATIENT-MONITORING SYSTEM --- p.1 / Chapter 1.2.1 --- Aging Population --- p.1 / Chapter 1.2.2 --- Increasing Population with Heart Diseases --- p.2 / Chapter 1.3 --- ECG BASICS --- p.3 / Chapter 1.4 --- EXISITING ECG-MONITORING TECHNOLOGIES --- p.4 / Chapter 1.5 --- CHALLENGES IN PATIENT-MONITORING --- p.5 / Chapter 1.6 --- DEVELOPMENT OF AN ECG-MONITORING SYSTEM --- p.6 / Chapter 1.6.1 --- Overall Structure --- p.6 / Chapter 1.6.2 --- Considerations --- p.7 / Chapter CHAPTER 2 --- EMI FILTERS IN ECG ACQUISITION CIRCUIT --- p.8 / Chapter 2.1 --- OVERVIEW OF NOISE SOURCES IN ECG ACQUISITION --- p.8 / Chapter 2.1.1 --- Other Biopotentials --- p.8 / Chapter 2.1.2 --- Motion Artifact --- p.8 / Chapter 2.1.3 --- Power-line Interference --- p.10 / Chapter 2.1.4 --- High-Frequency Electromagnetic Interference --- p.15 / Chapter 2.2 --- EMI FILTERS --- p.16 / Chapter 2.2.1 --- Introduction to EMI Filters --- p.16 / Chapter 2.2.2 --- Types of EMI Filter --- p.17 / Chapter 2.2.3 --- EMI Filters in ECG Monitoring --- p.21 / Chapter 2.3 --- MODELING OF INTERFERENCE IN ECG-MONITORING SYSTEM --- p.22 / Chapter 2.3.1 --- Model and Parameters --- p.22 / Chapter 2.3.2 --- Method --- p.24 / Chapter 2.3.2 --- Results --- p.27 / Chapter 2.3.3 --- Discussion --- p.30 / Chapter 2.4 --- BUILDING AN ECG ACQUISITION CIRCUIT WITH EMI FILTERS --- p.30 / Chapter 2.4.1 --- Purpose --- p.30 / Chapter 2.4.2 --- Experimental Setup and Method --- p.30 / Chapter 2.4.3 --- Results --- p.32 / Chapter 2.4.4 --- Discussion --- p.46 / Chapter CHAPTER 3 --- ADAPTIVE FILTER --- p.48 / Chapter 3.1 --- OBJECTIVE --- p.48 / Chapter 3.2 --- INTRODUCTION TO ADAPTIVE FILTER --- p.48 / Chapter 3.3 --- METHOD --- p.50 / Chapter 3.4 --- RESULTS --- p.52 / Chapter 3.5 --- DISCUSSION --- p.57 / Chapter CHAPTER 4 --- WAP-BASED TELEMEDICINE APPLICATIONS --- p.59 / Chapter 4.1 --- INTRODUCTION TO TELEMEDICINE --- p.59 / Chapter 4.2 --- INTRODUCTION TO WAP --- p.59 / Chapter 4.3 --- WAP APPLICATIONS --- p.60 / Chapter 4.4 --- SYSTEM IMPLEMENTATION --- p.63 / Chapter 4.4.1 --- Overall Structure --- p.63 / Chapter 4.4.2 --- Relational Database --- p.63 / Chapter 4.4.3 --- Program Flow --- p.64 / Chapter 4.4.4 --- ECG Browsing and Feature Extraction --- p.70 / Chapter 4.5 --- EMULATION --- p.72 / Chapter 4.6 --- EXPERIENCE WITH WAP PHONE --- p.74 / Chapter 4.7 --- DISCUSSION AND CONCLUSION --- p.75 / Chapter CHAPTER 5: --- CONCLUSION AND FUTURE WORK --- p.77 / Chapter 5.1 --- CONCLUSION --- p.77 / Chapter 5.2 --- FUTURE WORK --- p.77 / Chapter 5.3 --- MARKET ANALYSIS --- p.79 / BIBLIOGRAPHY --- p.80

O presente estudo procurou avaliar, prospectivamente, a segurança do sistema de tele-eletrocardiografia para a liberação de pacientes que se apresentem a postos de saúde com queixa de dor torácica. Avaliamos a incidência de infarto do miocárdio dessa população ao longo de seis meses. Como objetivo secundário, correlacionamos, retrospectivamente, a razão das probabilidades entre diferentes indicadores clínicos e eletrocardiográficos e a ocorrência do infarto do miocárdio. Entre junho e dezembro de 2006, 32444 pacientes foram atendidos em postos de saúde pública, carentes de cardiologistas e tiveram o seu tele-eletrocardiograma transmitido até uma central de telemedicina, através de linha telefônica fixa. Selecionaram-se 1535 pacientes atendidos devido a dor torácica, que tinham mais de 50 anos e apresentavam exame clínico, laboratorial (troponina I ou creatino fosfoquinase fração MB-CKMB) e tele-eletrocardiográfico normais além de consentirem em repetir o tele-eletrocardiograma após um e seis meses. Todos os pacientes foram seguidos durante seis meses. Não houve eventos durante o primeiro mês. No segundo mês houve 12(0,8%) infartos; no terceiro mês, 18(1,2%); no quarto mês, 38(2,4%) e no sexto, 18(1,2%). Ao longo dos seis meses houve 15(1%) óbitos, sendo 9(0,6%) de origem cardíaca; 9 (0,6%)acidentes vasculares encefálicos e 86(5,6%) infartos agudos do miocárdio. Entre as variáveis que se correlacionaram, independentemente, com maior chance de infarto agudo do miocárdio, encontrou-se a obesidade grau I [p=0,009 RC 4,5 IC 95%(1,5-13,8)], a dislipidemia [p< 0,0001 RC 3,4 IC 95%(2,0-5,8)], a baixa amplitude da onda T em V2 [p<0,001 RC 2,9 IC 95%(2,4-3,5)] e o sobrepeso [p=0,019 RC 2,6 IC 95%(1,2-5,7)]. Cada 0,5mm de redução na amplitude da onda T aumentou em quase três vezes a chance de ocorrência do infarto agudo do miocárdio durante seis meses. O tabagismo apresentou forte tendência [p=0,057 RC 1,7 IC 95%(1,0-2,8)] à regressão logística binária e foi significante após análise por árvore de decisão. Estes resultados permitiram as seguintes conclusões: o sistema de tele-eletrocardiografia oferece alta segurança ao estratificar o risco de pacientes com exame clínico, laboratorial e tele-eletrocardiográfico normais, queixando-se de dor torácica. Identificou-se, ao longo dos seis meses, a população de maior chance de apresentar o evento através de variáveis clínicas (obesidade, dislipidemia, tabagismo e sobrepeso) e tele-eletrocardiográficas (amplitude da onda T em V2), que determinaram, independentemente, a ocorrência de infarto agudo do miocárdio / The present study aimed at prospectively evaluating the reliability of teleeletrocardiography for the discharge of chest pain patients who present themselves at remote medical centers. The incidence of acute myocardial infarction among this population was evaluated during a period of six months. As a secondary objective, the correlation between different clinical and electrocardiographic features and the occurrence of myocardial infarction was retrospectively checked. Between June and December of 2006, 32.444 patients were treated in public medical centers which lacked the assistance of cardiologists. Those patients had their electrocardiogram transmitted to a telemedicine center over a fixed-wired telephone line. Among them 1535 patients who had been assisted due to chest pain were selected. Those patients were all older than 50 years and showed normal clinical and laboratorial (troponine I or creatine phosphokinase MB-CKMB fraction) exams, as well as normal tele-electrocardiograms. They also agreed to repeat the teleelectrocardiogram in a six-month period. All patients were followed up to the sixth-month. In the second month, there were 12 (0,8%) infarctions; in the third month there were 18 (1,2%) infarctions; in the fourth month there were 38 (2,4%) infarctions, and in the sixth month there were 18 (1,2%) infarctions. Over that six month period, there were 15 (1%) deaths, 9 (0,6%) of which were related to cardiac causes; 9 (0,6%) strokes, and 86 (5,6%) acute myocardial infarctions. Among the variables which independently correlated with greater risk of acute myocardial infarction, we found grade I obesity [p=0,009 RC 4,5 IC95%(1,5-13,8)]; dyslipidemia [p<0,0001 RC 3,4 IC 95%(2,0-5,8)]; low T-wave amplitude in V2 [p<0,001 RC 2,9 IC 95%(2,4-3,5)], and overweight [p=0,019 RC 2,6 IC 95%(1,2-5,7)]. Each 0,5mm reduction in the T-wave raised almost three times the chance for the occurrence of acute myocardial infarction in a sixmonth period. Smoking showed a strong tendency [p=0,057 RC 1,7 IC 95%(1,0-2,8)] to binary logistic regression and was significant after decision tree analysis. These results lead to the following conclusions: the teleelectrocardiographic system offers high level of safety and reliability due to its capacity to stratify chest pain patient risk. Over these six months the study identified the population who showed greater chances of presenting the event through clinical (obesity, dyslipidemia, smoking and overweight) and teleelectrocardiography (amplitude of T-wave in V2) variables, which independently, determined the occurrence of acute myocardial infarction

Lu, Yan. / "October 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 65-68). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Electrocardiogram --- p.1 / Chapter 1.1.1 --- ECG Measurement --- p.2 / Chapter 1.1.2 --- Cardiac Conduction Pathway and ECG Morphology --- p.4 / Chapter 1.1.3 --- A Basic Clinical Approach to ECG Analysis --- p.6 / Chapter 1.2 --- Cardiovascular Disease --- p.7 / Chapter 1.3 --- Motivation --- p.9 / Chapter 1.4 --- Related Work --- p.10 / Chapter 1.5 --- Overview of Proposed Approach --- p.11 / Chapter 1.6 --- Thesis Outline --- p.13 / Chapter 2. --- ECG Signal Preprocessing --- p.14 / Chapter 2.1 --- ECG Model and Its Generalization --- p.14 / Chapter 2.1.1 --- ECG Dynamic Model --- p.14 / Chapter 2.1.2 --- Generalization of ECG Model --- p.15 / Chapter 2.2 --- Empirical Mode Decomposition --- p.17 / Chapter 2.3 --- Baseline Wander Removal --- p.20 / Chapter 2.3.1 --- Sources of Baseline Wander --- p.20 / Chapter 2.3.2 --- Baseline Wander Removal by EMD --- p.20 / Chapter 2.3.3 --- Experiments on Baseline Wander Removal --- p.21 / Chapter 2.4 --- ECG Denoising --- p.24 / Chapter 2.4.1 --- Introduction --- p.24 / Chapter 2.4.2 --- Instantaneous Frequency --- p.26 / Chapter 2.4.3 --- Problem of Direct ECG Denoising by EMD : --- p.28 / Chapter 2.4.4 --- Model-based Pre-filtering --- p.30 / Chapter 2.4.5 --- EMD Denoising Using Significance Test --- p.33 / Chapter 2.4.6 --- EMD Denoising using Instantaneous Frequency --- p.35 / Chapter 2.4.7 --- Experiments --- p.39 / Chapter 2.5 --- Chapter Summary --- p.44 / Chapter 3. --- ECG Classification --- p.45 / Chapter 3.1 --- Database --- p.45 / Chapter 3.2 --- Feature Extraction --- p.46 / Chapter 3.2.1 --- Feature Selection --- p.46 / Chapter 3.2.2 --- Feature Dimension Reduction by GDA --- p.48 / Chapter 3.3 --- Classification by Support Vector Machine --- p.50 / Chapter 3.4 --- Experiments --- p.53 / Chapter 3.4.1 --- Performance of Feature Reduction --- p.54 / Chapter 3.4.2 --- Performance of Classification --- p.57 / Chapter 3.4.3 --- Performance Comparison with Other Works --- p.60 / Chapter 3.5 --- Chapter Summary --- p.61 / Chapter 4. --- Conclusions --- p.63 / Reference --- p.65

Acousto-electric (AE) effect comes from an interaction between electrical current and acoustic pressure generated when acoustic waves travel through a conducting material. It currently has two main application areas, ultrasound current source density imaging (UCSDI) and AE hydrophone. UCSDI can detect the current direction by modulating the dipole field with ultrasound pulse, and it is now used to form 3D imaging of dipole changing in one period of treatment, such as arrhythmia in the heart and epilepsy in the brain. As ultrasound pulse passes through electrical field, it convolutes or correlates with the inner product of the electric fields formed by the dipole and detector. The polarity of UCSDI is not determined by Doppler effect that exists in pulse echo (PE) signal, but the gradient of lead field potentials created by dipole and recording electrode, making the base-banded AE voltage positive at the anode and negative at cathode. As convolution shifts spectrum lower, the base band frequency for polarity is different from the center frequency of AE signal. The simulation uses the principles of UCSDI, and helps to understand the phenomena in the experiment. 3-D Fast Fourier Transform accelerates the computing velocity to resolve the correlation in the simulation of AE signal. Most single element hydrophones depend on a piezoelectric material that converts pressure changes to electricity. These devices, however, can be expensive, susceptible to damage at high pressure, and/or have limited bandwidth and sensitivity. An AE hydrophone requires only a conductive material and can be constructed out of common laboratory supplies to generate images of an ultrasound beam pattern consistent with more expensive hydrophones. Its sensitivity is controlled by the injected bias current, hydrophone shape, thickness and width of sensitivity zone. The design of this device needs to be the tradeoff of these parameters. Simulations were made to optimize the design with experimental validation using specifically fabricated devices composed of a resistive element of indium tin oxide (ITO).

Familial amyloidosis with polyneuropathy (FAP) is a neuropathic form of heredofamilial systemic amyloidosis. Clusters of patients have been reported predominantly from Portugal, Japan and Sweden. The present study examines the involvement of the heart in individuals with the Swedish variety of FAP. During long-term ECG recording in 16 patients, a high frequency of disturbances of sinus node function and atrioventricular conduction were observed. Long-term ECG may help considerably in the evaluation of symptoms attributable to disturbances of heart rhythm in FAP. A retrospective survey of 20 patients with FAP treated with a pacemaker showed that the indication for pacing was advanced atrioventricular block (12 cases), dysfunction of the sinus node (5 cases), and atrial fibrillation with a slow ventricular response (3 cases). All patients experienced the effective relief of symptoms attributable to a slow ventricular rate. The long-term prognosis, however, seemed unaffected by this treatment. Histopathological examination of the sinoatrial (9 cases) and atrioventricular (6 cases) parts of the conduction system showed marked amyloid infiltration in all cases, which may explain the high occurrence of disturbances of cardiac rhythm and conduction. Twelve patients were examined by two-dimensional echocardiography and changes of varying degrees, such as highly refractile myocardial echoes (12 cases) and thickened ventricular walls (8 cases) and valves (7 cases), could be observed. Technetium-99m-pyrophosphate scintigraphy of the same patients revealed abnormal myocardial uptake of the isotope only in four. Echocardiography thus seems to be superior to scintigraphy for non-invasive detection of cardiac involvement in FAP. Myocardial samples from regions producing highly refractile myocardial echoes were obtained at in vitro échocardiographie examination of hearts from FAP autopsy cases. Histological examination showed that the highly refractile echoes corresponded to more or less sharply delineated nodules, containing amyloid and collagen in various amounts. / digitalisering@umu