Association Between Heart Rate at Rest and Incident Atrial Fibrillation (from the Copenhagen Electrocardiographic Study)

DEFF Research Database (Denmark)

Skov, Morten W; Bachmann, Troels N; Rasmussen, Peter V.

2016-01-01

Heart rate (HR) at rest is a well-known marker of cardiovascular morbidity and mortality. Results on the association between HR and incident atrial fibrillation (AF) have, however, been conflicting. Using digital electrocardiograms from 281,451 primary care patients, we aimed to describe...

Real-time electrocardiogram transmission from Mount Everest during continued ascent.

Science.gov (United States)

Kao, Wei-Fong; Huang, Jyh-How; Kuo, Terry B J; Chang, Po-Lun; Chang, Wen-Chen; Chan, Kuo-Hung; Liu, Wen-Hsiung; Wang, Shih-Hao; Su, Tzu-Yao; Chiang, Hsiu-chen; Chen, Jin-Jong

2013-01-01

The feasibility of a real-time electrocardiogram (ECG) transmission via satellite phone from Mount Everest to determine a climber's suitability for continued ascent was examined. Four Taiwanese climbers were enrolled in the 2009 Mount Everest summit program. Physiological measurements were taken at base camp (5300 m), camp 2 (6400 m), camp 3 (7100 m), and camp 4 (7950 m) 1 hour after arrival and following a 10 minute rest period. A total of 3 out of 4 climbers were able to summit Mount Everest successfully. Overall, ECG and global positioning system (GPS) coordinates of climbers were transmitted in real-time via satellite phone successfully from base camp, camp 2, camp 3, and camp 4. At each camp, Resting Heart Rate (RHR) was transmitted and recorded: base camp (54-113 bpm), camp 2 (94-130 bpm), camp 3 (98-115 bpm), and camp 4 (93-111 bpm). Real-time ECG and GPS coordinate transmission via satellite phone is feasible for climbers on Mount Everest. Real-time RHR data can be used to evaluate a climber's physiological capacity to continue an ascent and to summit.

Analysis of electrocardiogram in chronic obstructive pulmonary disease patients.

Science.gov (United States)

Lazović, Biljana; Svenda, Mirjana Zlatković; Mazić, Sanja; Stajić, Zoran; Delić, Marina

2013-01-01

Chronic obstructive pulmonary disease is the fourth leading cause of mortality worldwide. It is defined as a persistent airflow limitation usually progressive and not fully reversible to treatment. The diagnosis of chronic obstructive pulmonary disease and severity of disease is confirmed by spirometry. Chronic obstructive pulmonary disease produces electrical changes in the heart which shows characteristic electrocardiogram pattern. The aim of this study was to observe and evaluate diagnostic values of electrocardiogram changes in chronic obstructive pulmonary disease patients with no other comorbidity. We analyzed 110 electrocardiogram findings in clinically stable chronic obstructive pulmonary disease patients and evaluated the forced expiratory volume in the first second, ratio of forces expiratory volume in the first second to the fixed vital capacity, chest radiographs and electrocardiogram changes such as p wave height, QRS axis and voltage, right bundle branch block, left bundle branch block, right ventricular hypertrophy, T wave inversion in leads V1-V3, S1S2S3 syndrome, transition zone in praecordial lead and QT interval. We found electrocardiogram changes in 64% patients, while 36% had normal electrocardiogram. The most frequent electrocardiogram changes observed were transition zone (76.36%) low QRS (50%) and p pulmonale (14.54%). Left axis deviation was observed in 27.27% patients. Diagnostic values of electrocardiogram in patients with chronic obstructive pulmonary disease suggest that chronic obstructive pulmonary disease patients should be screened electrocardiographically in addition to other clinical investigations.

MagnetoHemoDynamics in the aorta and electrocardiograms

International Nuclear Information System (INIS)

Martin, Vincent; Drochon, Agnès; Fokapu, Odette; Gerbeau, Jean-Frédéric

2012-01-01

This paper addresses a complex multi-physical phenomenon involving cardiac electrophysiology and hemodynamics. The purpose is to model and simulate a phenomenon that has been observed in magnetic resonance imaging machines: in the presence of a strong magnetic field, the T-wave of the electrocardiogram (ECG) gets bigger, which may perturb ECG-gated imaging. This is due to a magnetohydrodynamic (MHD) effect occurring in the aorta. We reproduce this experimental observation through computer simulations on a realistic anatomy, and with a three-compartment model: inductionless MHD equations in the aorta, bi-domain equations in the heart and electrical diffusion in the rest of the body. These compartments are strongly coupled and solved using finite elements. Several benchmark tests are proposed to assess the numerical solutions and the validity of some modeling assumptions. Then, ECGs are simulated for a wide range of magnetic field intensities (from 0 to 20 T). (paper)

Real-time electrocardiogram transmission from Mount Everest during continued ascent.

Directory of Open Access Journals (Sweden)

Wei-Fong Kao

Full Text Available The feasibility of a real-time electrocardiogram (ECG transmission via satellite phone from Mount Everest to determine a climber's suitability for continued ascent was examined. Four Taiwanese climbers were enrolled in the 2009 Mount Everest summit program. Physiological measurements were taken at base camp (5300 m, camp 2 (6400 m, camp 3 (7100 m, and camp 4 (7950 m 1 hour after arrival and following a 10 minute rest period. A total of 3 out of 4 climbers were able to summit Mount Everest successfully. Overall, ECG and global positioning system (GPS coordinates of climbers were transmitted in real-time via satellite phone successfully from base camp, camp 2, camp 3, and camp 4. At each camp, Resting Heart Rate (RHR was transmitted and recorded: base camp (54-113 bpm, camp 2 (94-130 bpm, camp 3 (98-115 bpm, and camp 4 (93-111 bpm. Real-time ECG and GPS coordinate transmission via satellite phone is feasible for climbers on Mount Everest. Real-time RHR data can be used to evaluate a climber's physiological capacity to continue an ascent and to summit.

RestKit for iOS standard guide

CERN Document Server

Kalapun, Taras

2013-01-01

A step-by-step, example-based guide to learning how you can link your apps and web services using RestKit.This book is for iOS developers of all levels who are interested in boosting their productivity by utilizing third party libraries and who have a willingness to learn how to build RESTful apps using the RestKit framework. A basic knowledge of Objective-C is required as well as a simple understanding of how to use CoreData.

Is Rest Really Rest? Resting State Functional Connectivity during Rest and Motor Task Paradigms.

Science.gov (United States)

Jurkiewicz, Michael T; Crawley, Adrian P; Mikulis, David J

2018-04-18

Numerous studies have identified the default mode network (DMN) within the brain of healthy individuals, which has been attributed to the ongoing mental activity of the brain during the wakeful resting-state. While engaged during specific resting-state fMRI paradigms, it remains unclear as to whether traditional block-design simple movement fMRI experiments significantly influence the default mode network or other areas. Using blood-oxygen level dependent (BOLD) fMRI we characterized the pattern of functional connectivity in healthy subjects during a resting-state paradigm and compared this to the same resting-state analysis performed on motor task data residual time courses after regressing out the task paradigm. Using seed-voxel analysis to define the DMN, the executive control network (ECN), and sensorimotor, auditory and visual networks, the resting-state analysis of the residual time courses demonstrated reduced functional connectivity in the motor network and reduced connectivity between the insula and the ECN compared to the standard resting-state datasets. Overall, performance of simple self-directed motor tasks does little to change the resting-state functional connectivity across the brain, especially in non-motor areas. This would suggest that previously acquired fMRI studies incorporating simple block-design motor tasks could be mined retrospectively for assessment of the resting-state connectivity.

Electrocardiogram Scanner-System Requirements

Science.gov (United States)

1973-03-01

An experimental and analytical study has been conducted to establish the feasibility for scanning and digitizing electrocardiogram records. The technical requirements and relative costs for two systems are discussed herein. One is designed to automat...

Electrocardiogram artifact caused by rigors mimicking narrow complex tachycardia: a case report.

Science.gov (United States)

Matthias, Anne Thushara; Indrakumar, Jegarajah

2014-02-04

The electrocardiogram (ECG) is useful in the diagnosis of cardiac and non-cardiac conditions. Rigors due to shivering can cause electrocardiogram artifacts mimicking various cardiac rhythm abnormalities. We describe an 80-year-old Sri Lankan man with an abnormal electrocardiogram mimicking narrow complex tachycardia during the immediate post-operative period. Electrocardiogram changes caused by muscle tremor during rigors could mimic a narrow complex tachycardia. Identification of muscle tremor as a cause of electrocardiogram artifact can avoid unnecessary pharmacological and non-pharmacological intervention to prevent arrhythmias.

Play the Electrocardiogram Game

Science.gov (United States)

... and Work Teachers' Questionnaire Electrocardiogram Play the ECG Game About the game ECG is used for diagnosing heart conditions by ... last will in Paris. Play the Blood Typing Game Try to save some patients and learn about ...

Evaluation of agreement between temporal series obtained from electrocardiogram and pulse wave.

Science.gov (United States)

Leikan, GM; Rossi, E.; Sanz, MCuadra; Delisle Rodríguez, D.; Mántaras, MC; Nicolet, J.; Zapata, D.; Lapyckyj, I.; Siri, L. Nicola; Perrone, MS

2016-04-01

Heart rate variability allows to study the cardiovascular autonomic nervous system modulation. Usually, this signal is obtained from the electrocardiogram (ECG). A simpler method for recording the pulse wave (PW) is by means of finger photoplethysmography (PPG), which also provides information about the duration of the cardiac cycle. In this study, the correlation and agreement between the time series of the intervals between heartbeats obtained from the ECG with those obtained from the PPG, were studied. Signals analyzed were obtained from young, healthy and resting subjects. For statistical analysis, the Pearson correlation coefficient and the Bland and Altman limits of agreement were used. Results show that the time series constructed from the PW would not replace the ones obtained from ECG.

Mathematical model with autoregressive process for electrocardiogram signals

Science.gov (United States)

Evaristo, Ronaldo M.; Batista, Antonio M.; Viana, Ricardo L.; Iarosz, Kelly C.; Szezech, José D., Jr.; Godoy, Moacir F. de

2018-04-01

The cardiovascular system is composed of the heart, blood and blood vessels. Regarding the heart, cardiac conditions are determined by the electrocardiogram, that is a noninvasive medical procedure. In this work, we propose autoregressive process in a mathematical model based on coupled differential equations in order to obtain the tachograms and the electrocardiogram signals of young adults with normal heartbeats. Our results are compared with experimental tachogram by means of Poincaré plot and dentrended fluctuation analysis. We verify that the results from the model with autoregressive process show good agreement with experimental measures from tachogram generated by electrical activity of the heartbeat. With the tachogram we build the electrocardiogram by means of coupled differential equations.

Resting Heart Rate Variability, Facets of Rumination and Trait Anxiety: Implications for the Perseverative Cognition Hypothesis

Directory of Open Access Journals (Sweden)

DeWayne P. Williams

2017-10-01

Full Text Available The perseverative cognition hypothesis (PCH posits that perseveration, defined as the repetitive or sustained activation of cognitive representations of a real or imagined stressor, is a primary mechanism linking psychological (or stress vulnerability with poor health and disease. Resting vagally mediated heart rate variability (vmHRV is an important indicator of self-regulatory abilities, stress vulnerability and overall health. Those with lower resting vmHRV are more vulnerable to stress, and thus more likely to engage in perseverative cognition and experience subsequent negative mental health outcomes such as anxiety. Recent research suggests that rumination—one of the core mechanisms underlying perseveration—is a construct containing (at least two maladaptive (depressive and brooding and one adaptive (reflective types of rumination. However, to date, research has not examined how the association between resting vmHRV may differ between these three facets of rumination, in addition to these facets’ mechanistic role in linking lower resting vmHRV with greater trait anxiety. The current cross-sectional study explores these relationships in a sample of 203 participants (112 females, 76 ethnic minorities, mean age = 19.43, standard deviation = 1.87. Resting vmHRV was assessed during a 5-min-resting period using an Electrocardiogram (ECG. Both trait rumination (including the three facets and anxiety were assessed via self-report scales. Significant negative associations were found between resting vmHRV and maladaptive, but not adaptive, forms of perseveration. Similarly, mediation analyses showed a significant indirect relationship between resting vmHRV and anxiety through maladaptive, but not adaptive, facets of rumination. Our findings support the PCH such that those with stress vulnerability, as indexed by lower resting vmHRV, are more likely to engage in maladaptive perseverative cognition and thus experience negative outcomes such as

Resting Heart Rate Variability, Facets of Rumination and Trait Anxiety: Implications for the Perseverative Cognition Hypothesis.

Science.gov (United States)

Williams, DeWayne P; Feeling, Nicole R; Hill, LaBarron K; Spangler, Derek P; Koenig, Julian; Thayer, Julian F

2017-01-01

The perseverative cognition hypothesis (PCH) posits that perseveration, defined as the repetitive or sustained activation of cognitive representations of a real or imagined stressor, is a primary mechanism linking psychological (or stress) vulnerability with poor health and disease. Resting vagally mediated heart rate variability (vmHRV) is an important indicator of self-regulatory abilities, stress vulnerability and overall health. Those with lower resting vmHRV are more vulnerable to stress, and thus more likely to engage in perseverative cognition and experience subsequent negative mental health outcomes such as anxiety. Recent research suggests that rumination-one of the core mechanisms underlying perseveration-is a construct containing (at least) two maladaptive (depressive and brooding) and one adaptive (reflective) types of rumination. However, to date, research has not examined how the association between resting vmHRV may differ between these three facets of rumination, in addition to these facets' mechanistic role in linking lower resting vmHRV with greater trait anxiety. The current cross-sectional study explores these relationships in a sample of 203 participants (112 females, 76 ethnic minorities, mean age = 19.43, standard deviation = 1.87). Resting vmHRV was assessed during a 5-min-resting period using an Electrocardiogram (ECG). Both trait rumination (including the three facets) and anxiety were assessed via self-report scales. Significant negative associations were found between resting vmHRV and maladaptive, but not adaptive, forms of perseveration. Similarly, mediation analyses showed a significant indirect relationship between resting vmHRV and anxiety through maladaptive, but not adaptive, facets of rumination. Our findings support the PCH such that those with stress vulnerability, as indexed by lower resting vmHRV, are more likely to engage in maladaptive perseverative cognition and thus experience negative outcomes such as anxiety. Our data

Resting and postexercise heart rate variability in professional handball players.

Science.gov (United States)

Kayacan, Yildirim; Yildiz, Sedat

2016-03-01

The aim of this study was to evaluate heart rate variability (HRV) in professional handball players during rest and following a 5 min mild jogging exercise. For that purpose, electrocardiogram (ECG) of male handball players (N.=12, mean age 25±3.95 years) and sedentary controls (N.=14, mean age 23.5±2.95 years) were recorded for 5 min at rest and just after 5 min of mild jogging. ECGs were recorded and following HRV parameters were calculated: time-domain variables such as heart rate (HR), average normal-to-normal RR intervals, standard deviation of normal-to-normal RR intervals, square root of the mean of the squares of differences between adjacent NN intervals, percentage of differences between adjacent NN intervals that are greater than 50 milliseconds (pNN50), and frequency-domain variables such as very low frequency, low (LF) and high frequency (HF) of the power and LF/HF ratio. Unpaired t-test was used to find out differences among groups while paired t-test was used for comparison of each group for pre- and postjogging HRV. Pearson correlations were carried out to find out the relationships between the parameters. Blood pressures were not different between handball players and sedentary controls but exercise increased systolic blood pressure (Phandball players (Phandball players (Phandball players in response to a mild, short-time (5 min) jogging exercise. However, in sedentary subjects, either the sympathetic regulation of the autonomous nervous system increased or vagal withdrawal occurred.

New micro waveforms firstly recorded on electrocardiogram in human.

Science.gov (United States)

Liu, Renguang; Chang, Qinghua; Chen, Juan

2015-10-01

In our study, not only the P-QRS-T waves but also the micro-wavelets before QRS complex (in P wave and PR segment) and after QRS complex (ST segment and upstroke of T wave) were first to be identified on surface electrocardiogram in human by the "new electrocardiogram" machine (model PHS-A10) according to conventional 12-lead electrocardiogram connection methods. By comparison to the conventional electrocardiogram in 100 cases of healthy individuals and several patients with arrhythmias, we have found that the wavelets before P wave theoretically reflected electrical activity of sinus node and the micro-wavelets before QRS complex may be related to atrioventricular conduction system (atrioventricular node, His bundle and bundle branch) potentials. Noninvasive atrioventricular node and His bundle potential tracing will contribute to differentiation of the origin of wide QRS and the location of the atrioventricular block. We also have found that the wavelets after QRS complex may be associated with phase 2 and 3 repolarization of ventricular action potential, which will further reveal ventricular repolarization changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantification of the first-order high-pass filter's influence on the automatic measurements of the electrocardiogram.

Science.gov (United States)

Isaksen, Jonas; Leber, Remo; Schmid, Ramun; Schmid, Hans-Jakob; Generali, Gianluca; Abächerli, Roger

2017-02-01

The first-order high-pass filter (AC coupling) has previously been shown to affect the ECG for higher cut-off frequencies. We seek to find a systematic deviation in computer measurements of the electrocardiogram when the AC coupling with a 0.05 Hz first-order high-pass filter is used. The standard 12-lead electrocardiogram from 1248 patients and the automated measurements of their DC and AC coupled version were used. We expect a large unipolar QRS-complex to produce a deviation in the opposite direction in the ST-segment. We found a strong correlation between the QRS integral and the offset throughout the ST-segment. The coefficient for J amplitude deviation was found to be -0.277 µV/(µV⋅s). Potential dangerous alterations to the diagnostically important ST-segment were found. Medical professionals and software developers for electrocardiogram interpretation programs should be aware of such high-pass filter effects since they could be misinterpreted as pathophysiology or some pathophysiology could be masked by these effects. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Electrocardiogram interpretation in general practice: relevance to prehospital thrombolysis.

Science.gov (United States)

McCrea, W A; Saltissi, S

1993-01-01

OBJECTIVE--To assess, in the context of their possible role in prehospital thrombolysis, the ability of general practitioners to recognise acute transmural myocardial ischaemia/infarction on an electrocardiogram. DESIGN--150 doctors (every fifth name) were selected from the alphabetical list of 750 on Merseyside general practitioner register and without prior warning were asked to interpret a series of six 12 lead electrocardiograms. Three of these showed acute transmural ischaemia/infarction, one was normal, and two showed non-acute abnormalities. Details of doctors' ages, postgraduate training, and clinical practice were sought. SETTING--General practitioners' surgeries and postgraduate centres within the Merseyside area. PARTICIPANTS--106 general practitioners (mean age 45 years) agreed to participate. MAIN OUTCOME MEASURE--Accuracy of general practitioners' interpretations of the six electrocardiograms. RESULTS--82% of general practitioners correctly recognised a normal electrocardiogram. Recognition of acute abnormalities was less reliable. Between 33% and 61% correctly identified acute transmural ischaemia/infarction depending on the specific trace presented. Accurate localisation of the site of the infarct was achieved only by between 8% and 30% of participants, while between 22% and 25% correctly interpreted non-acute abnormalities. Neither routine use of electrocardiography nor postgraduate hospital experience in general medicine was associated with significantly greater expertise. CONCLUSION--The current level of proficiency of a sample of general practitioners in the Merseyside area in recognising acute transmural ischaemia/infarction on an electrocardiogram suggests that refresher training is needed if general practitioners are to give prehospital thrombolysis. Images PMID:8398491

Electrocardiographic intricacies clarified by echocardiography--should the electrocardiogram be interpreted echocardiographically?

Science.gov (United States)

Ker, James

2012-07-12

During the past century the electrocardiogram (ECG) has established itself as an integral part of the cardiovascular examination. Since the first direct recordings of cardiac potentials by Waller in 1887, to the invention of the string galvanometer by Willem Einthoven in 1901, to use in the clinic by 1910, the electrocardiogram has become the most widely used clinical tool in the diagnosis of virtually every type of heart disease. Currently up to 20 million ECGs are performed annually in the United States alone. However, in this era of readily available echocardiography, an important caveat in the interpretation of the electrocardiogram has emerged: variants of intracardiac structures which might mimic disease on the ECG. In this perspective various structural variants of intracardiac structures, specifically variants of papillary muscles and subaortic muscular bands, will be shown, together with their associated electrocardiographic changes, mimicking disease. It is concluded that in this era of readily available echocardiography, the electrocardiogram should be interpreted echocardiographically in instances where intricate variations are seen on the surface electrocardiogram. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Value of exercise thallium-201 imaging in patients with diagnostic and nondiagnostic exercise electrocardiograms

International Nuclear Information System (INIS)

Iskandrian, A.S.; Segal, B.L.

1981-01-01

The role of exercise imaging with thallium-201 in the evaluation of patients suspected of having coronary artery disease was studied in 194 patients undergoing diagnostic coronary arteriography. Ninety-eight patients had 70 percent or more narrowing of one or more coronary vessels and 96 patients had either no or insignificant coronary artery disease. One hundren twenty-three of the 194 patients had conclusive treadmill exercise electrocardiograms (either positive or negative), and 71 had inconclusive exercise electrocardiograms. The specificity of exercise imaging (97 percent) was higher than that of exercise electrocardiograms (86 percent, p less than 0.02). The specificity of both tests combined was not significantly different from that of exercise electrocardiograms alone. The sensitivity (79 percent) and specificity (95 percent) of exercise imaging were not significantly different in patients with inconclusive exercise electrocardiograms when compared with those in patients whose exercise electrocardiograms were conclusive. These data indicate that exercise imaging is sensitive and specific in diagnosing coronary artery disease in the presence of diagnostic as well as nondiagnostic exercise electrocardiograms and that propranolol therapy does not affect the results

Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures

Science.gov (United States)

2014-11-01

Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures Allan Fong, MS1,3, Ranjeev...the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the...type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure waveforms. Several network

EMF-REST: Generation of RESTful APIs from Models

OpenAIRE

Hamza , Ed-Douibi; Cánovas Izquierdo , Javier Luis; Gómez , Abel; Tisi , Massimo; Cabot , Jordi

2016-01-01

In the last years, RESTful Web services have become more and more popular as a lightweight solution to connect remote systems in distributed and Cloud-based architectures. However, being an architectural style rather than a specification or standard, the proper design of RESTful Web services is not trivial since developers have to deal with a plethora of recommendations and best practices. Model-Driven Engineering (MDE) emphasizes the use of models and model transformations to raise the level...

ECG-ViEW II, a freely accessible electrocardiogram database

Science.gov (United States)

Park, Man Young; Lee, Sukhoon; Jeon, Min Seok; Yoon, Dukyong; Park, Rae Woong

2017-01-01

The Electrocardiogram Vigilance with Electronic data Warehouse II (ECG-ViEW II) is a large, single-center database comprising numeric parameter data of the surface electrocardiograms of all patients who underwent testing from 1 June 1994 to 31 July 2013. The electrocardiographic data include the test date, clinical department, RR interval, PR interval, QRS duration, QT interval, QTc interval, P axis, QRS axis, and T axis. These data are connected with patient age, sex, ethnicity, comorbidities, age-adjusted Charlson comorbidity index, prescribed drugs, and electrolyte levels. This longitudinal observational database contains 979,273 electrocardiograms from 461,178 patients over a 19-year study period. This database can provide an opportunity to study electrocardiographic changes caused by medications, disease, or other demographic variables. ECG-ViEW II is freely available at http://www.ecgview.org. PMID:28437484

Hypoglycemia-associated electroencephalogram and electrocardiogram changes appear simultaneously

DEFF Research Database (Denmark)

Larsen, Anine Poulsen; Højlund, Kurt; Poulsen, Mikael Kjær

2013-01-01

Tight glycemic control in type 1 diabetes mellitus (T1DM) may be accomplished only if severe hypoglycemia can be prevented. Biosensor alarms based on the body's reactions to hypoglycemia have been suggested. In the present study, we analyzed three lead electrocardiogram (ECG) and single-channel e......Tight glycemic control in type 1 diabetes mellitus (T1DM) may be accomplished only if severe hypoglycemia can be prevented. Biosensor alarms based on the body's reactions to hypoglycemia have been suggested. In the present study, we analyzed three lead electrocardiogram (ECG) and single...

Computer analysis of the exercise electrocardiogram and control of radionuclide ventriculography: an optimal statistical decision model for diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Hsia, P.W.E.

1987-01-01

A new automated technique for the diagnosis of coronary artery disease (CAD) by stress electrocardiography and radionuclide ventriculography (RNV) has been developed. The method employs digital signal processing of the electrocardiogram (ECG) for recognition of ischemic and arrhythmic events. On-line detection of abnormal beats is used for control image acquisition by the gamma camera resulting in improved image quality since only identical beats are included in the composite images of the cardiac cycle. A combined stress ECG analysis which measures ST changes indicative of ischemia, and radionuclide results, which reveal corresponding ejection fraction abnormalities yields greater sensitivity and specificity than either test alone. Digitized data from the electrocardiogram are analyzed in a beat-by-beat mode and a contextual diagnosis of underlying rhythm is given. Template generation, R wave detection, QRS window size, baseline correction, and continuous updating of heart rate are completely automated. A statistical model base on computerized ST segment measurements combined with radionuclide ventriculography data has been developed by using a logistic model with stepwise regression fitting. A previously acquired database of similar measurements was used for designing the model. The most significant parameters were found to be (1) ejection fraction of exercise RNV; (2) difference of ST level between exercise and resting test (stdif); and (3) ejection fraction difference between exercise and resting test. The new parameter stdif, not previously used in ECG interpretation, was found to be of great diagnostic significance

Changes in canine electrocardiogram values from three thermal floors in Cundinamarca, Colombia

Directory of Open Access Journals (Sweden)

Marta Elena Sánchez Klinge

2008-06-01

Full Text Available The electrocardiogram is a written register of electric changes that take place in the heart during a heart cycle. The voltage changes are the result of depolarization and repolarization of heart muscle fibers that produce electric changes able to reach body surface and that are detected by electrodes connected to a galvanometer called electrocardiograph. Heart problems are detected with the electrocardiogram, but it is necessary to know the normal values of canine electrocardiogram in a tropical country because values can change compared with normal values reported in other places. The purpose is to show variations of electrocardiogram values from clinically healthy canines from Bogotá D. C at 2600 mosl, Fusagasugá at 1700 mosl and Girardot at 326 mosl. Studied animals were separated in six groups depending on the altitude over sea level and the animal weight (less than 15 Kg and more than 15 Kg. The electrocardiograms were taken with a one channel portable electrocardiograph and derivations I, II, III, aVR, aVL, aVF, CV6LL, CV6LU, CV5RL and V10 were included. Significant differences of electrocardiogram values were observed in derivation II, in relation to the altitude over sea level and to the animals weight, which acquires importance when a diagnose of heart abnormalities is needed from animals located at different altitudes over sea levels.

The Influence of Age on Hemodynamic Parameters During Rest and Exercise in Healthy Individuals

DEFF Research Database (Denmark)

Wolsk, Emil; Bakkestrøm, Rine; Thomsen, Jacob H

2017-01-01

OBJECTIVES: The authors sought to obtain hemodynamic estimates across a wide age span and in both sexes for future reference and compare these estimates with current guideline diagnostic hemodynamic thresholds for abnormal filling pressure and pulmonary hypertension. BACKGROUND: At present....... METHODS: Sixty-two healthy participants, evenly distributed with respect to age (20 to 80 years) and sex (32 women/30 men), were prospectively enrolled in the study. Participants were all deemed healthy by medical history, echocardiography, exercise test, spirometry, blood tests, and electrocardiogram....... Participants had hemodynamic parameters measured using right heart catheterization during rest, passive leg raise, and incremental exercise. RESULTS: During rest, all hemodynamic parameters were similar between age groups, apart from blood pressure. During leg raise and incremental exercise...

Respiratory Information Extraction from Electrocardiogram Signals

KAUST Repository

Amin, Gamal El Din Fathy

2010-01-01

The Electrocardiogram (ECG) is a tool measuring the electrical activity of the heart, and it is extensively used for diagnosis and monitoring of heart diseases. The ECG signal reflects not only the heart activity but also many other physiological

Automated electrocardiogram interpretation programs versus cardiologists' triage decision making based on teletransmitted data in patients with suspected acute coronary syndrome

DEFF Research Database (Denmark)

Clark, Elaine N; Ripa, Maria Sejersten; Clemmensen, Peter

2010-01-01

The aims of this study were to assess the effectiveness of 2 automated electrocardiogram interpretation programs in patients with suspected acute coronary syndrome transported to hospital by ambulance in 1 rural region of Denmark with hospital discharge diagnosis used as the gold standard...

Gated single photon emission computer tomography for the detection of silent myocardial ischemia

International Nuclear Information System (INIS)

Pena Q, Yamile; Coca P, Marco Antonio; Batista C, Juan Felipe; Fernandez-Britto, Jose; Quesada P, Rodobaldo; Pena C; Andria

2009-01-01

Background: Asymptomatic patients with severe coronary atherosclerosis may have a normal resting electrocardiogram and stress test. Aim: To assess the yield of Gated Single Photon Emission Computer Tomography (SPECT) for the screening of silent myocardial ischemia in type 2 diabetic patients. Material and methods: Electrocardiogram, stress test and gated-SPECT were performed on 102 type 2 diabetic patients aged 60 ± 8 years without cardiovascular symptoms. All subjects were also subjected to a coronary angiography, whose results were used as gold standard. Results: Gated-SPECT showed myocardial ischemia on 26.5% of studied patients. The sensibility, specificity, accuracy, positive predictive value and negative predictive value were 92.3%, 96%, 95%, 88.8%, 97.3%, respectively. In four and six patients ischemia was detected on resting electrocardiogram and stress test, respectively. Eighty percent of patients with doubtful resting electrocardiogram results and 70% with a doubtful stress test had a silent myocardial ischemia detected by gated-SPECT. There was a good agreement between the results of gated-SPECT and coronary angiography (k =0.873). Conclusions: Gated-SPECT was an useful tool for the screening of silent myocardial ischemia

Electrocardiograms digitally processed for the investigation of new measures of cardiac diagnosis

International Nuclear Information System (INIS)

Gutierrez, Rafael M; Cerquera, Alexander

2003-01-01

The ECG F D 1 database that comprises electrocardiograms processed with digital filters is presented. The aim of this work is to build databases in order to perform high sensibility studies of new methods for electrocardiographic analysis based on statistical physics, actually on research. The changes in the original electrocardiograms generated by the digital filters used to build the ECG F D 1 database cannot be detected visually. The effect of these filters on the information, which escapes visual analysis, is actually object of study in order to develop its potential in the support of cardiac diagnosis using the electrocardiogram as the only source of information. The ECG F D 1 database may be very useful in the investigation directed to construct new diagnostic tools in cardiology, using simpler and less expensive electrocardiograms, obtained in more diverse conditions. the study of cardiac dynamics as a complex system starting from a source of information as simple as an electrocardiogram offers possibilities of creating new services that may improve the quality of human life and life expectancy at low costs and possibility of great coverage. One of the purposes of this publication is to draw the scientific community's attention to these investigative problems and its interdisciplinary applications

Personal Identification Based on Vectorcardiogram Derived from Limb Leads Electrocardiogram

Directory of Open Access Journals (Sweden)

Jongshill Lee

2012-01-01

Full Text Available We propose a new method for personal identification using the derived vectorcardiogram (dVCG, which is derived from the limb leads electrocardiogram (ECG. The dVCG was calculated from the standard limb leads ECG using the precalculated inverse transform matrix. Twenty-one features were extracted from the dVCG, and some or all of these 21 features were used in support vector machine (SVM learning and in tests. The classification accuracy was 99.53%, which is similar to the previous dVCG analysis using the standard 12-lead ECG. Our experimental results show that it is possible to identify a person by features extracted from a dVCG derived from limb leads only. Hence, only three electrodes have to be attached to the person to be identified, which can reduce the effort required to connect electrodes and calculate the dVCG.

Influence of mercury exposure on blood pressure, resting heart rate and heart rate variability in French Polynesians: a cross-sectional study

Directory of Open Access Journals (Sweden)

Valera Beatriz

2011-11-01

Full Text Available Abstract Background Populations which diet is rich in seafood are highly exposed to contaminants such as mercury, which could affect cardiovascular risk factors Objective To assess the associations between mercury and blood pressure (BP, resting heart rate (HR and HR variability (HRV among French Polynesians Methods Data were collected among 180 adults (≥ 18 years and 101 teenagers (12-17 years. HRV was measured using a two-hour ambulatory electrocardiogram (Holter and BP was measured using a standardized protocol. The association between mercury and HRV and BP parameters was studied using analysis of variance (ANOVA and analysis of covariance (ANCOVA Results Among teenagers, the high frequency (HF decreased between the 2nd and 3rd tertile (380 vs. 204 ms2, p = 0.03 and a similar pattern was observed for the square root of the mean squared differences of successive R-R intervals (rMSSD (43 vs. 30 ms, p = 0.005 after adjusting for confounders. In addition, the ratio low/high frequency (LF/HF increased between the 2nd and 3rd tertile (2.3 vs. 3.0, p = 0.04. Among adults, the standard deviation of R-R intervals (SDNN tended to decrease between the 1st and 2nd tertile (84 vs. 75 ms, p = 0.069 after adjusting for confounders. Furthermore, diastolic BP tended to increase between the 2nd and 3rd tertile (86 vs. 91 mm Hg, p = 0.09. No significant difference was observed in resting HR or pulse pressure (PP Conclusions Mercury was associated with decreased HRV among French Polynesian teenagers while no significant association was observed with resting HR, BP, or PP among teenagers or adults

The Electrocardiogram as an Example of Electrostatics

Science.gov (United States)

Hobbie, Russell K.

1973-01-01

Develops a simplified electrostatic model of the heart with conduction within the torso neglected to relate electrocardiogram patterns to the charge distribution within the myocardium. Suggests its application to explanation of Coulomb's law in general physics. (CC)

Nonlinear time series analysis of the human electrocardiogram

International Nuclear Information System (INIS)

Perc, Matjaz

2005-01-01

We analyse the human electrocardiogram with simple nonlinear time series analysis methods that are appropriate for graduate as well as undergraduate courses. In particular, attention is devoted to the notions of determinism and stationarity in physiological data. We emphasize that methods of nonlinear time series analysis can be successfully applied only if the studied data set originates from a deterministic stationary system. After positively establishing the presence of determinism and stationarity in the studied electrocardiogram, we calculate the maximal Lyapunov exponent, thus providing interesting insights into the dynamics of the human heart. Moreover, to facilitate interest and enable the integration of nonlinear time series analysis methods into the curriculum at an early stage of the educational process, we also provide user-friendly programs for each implemented method

Myocardial infarction false alarm: initial electrocardiogram and cardiac enzymes.

Science.gov (United States)

Gupta, Esha Das; Sakthiswary, Rajalingham

2014-05-01

The objectives of this study were to determine the incidence of a myocardial infarction "false alarm" and evaluate the efficacy of the initial electrocardiogram and cardiac enzymes in diagnosing myocardial infarction in Malaysia. We recruited patients who were admitted with suspected myocardial infarction from June to August 2008. The medical records of these patients were reviewed for the initial electrocardiogram, initial cardiac enzyme levels (creatinine kinase-MB and troponin T), and the final diagnosis upon discharge. The subjects were stratified into 2 groups: true myocardial infarction, and false alarm. 125 patients were enrolled in this study. Following admission and further evaluation, the diagnosis was revised from myocardial infarction to other medical conditions in 48 (38.4%) patients. The sensitivity and specificity of the initial ischemic electrocardiographic changes were 54.5% and 70.8%, respectively. Raised cardiac enzymes had a sensitivity of 44.3% and specificity of 95.8%. A significant proportion of patients in Malaysia are admitted with a false-alarm myocardial infarction. The efficacy of the electrocardiogram in diagnosing myocardial infarction in Malaysia was comparable to the findings of Western studies, but the cardiac enzymes had a much lower sensitivity.

ALTERATIONS IN ELECTROCARDIOGRAMS OF LABRADOR RETRIEVER DOGS DURING HANDLING WITH AND WITHOUT GLOVES

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Swagat Mohapatra

2016-12-01

Full Text Available Healthy male Labrador Retriever dogs (n=8 aged between one to three years constituted the study material. The study was carried out to peruse the alterations in electrocardiograms, when the attendant restrained the dogs with bare hands and when the dogs were restrained by the attendant wearing gloves. The mean amplitude of P wave was higher in dogs handled with gloves. Similarly, the amplitudes of QRS complex and T wave were higher in the electrocardiograms of dogs handled with insulated hands. Meanwhile, the duration of T wave and Q-T interval were higher in the electrocardiograms recorded without gloves in hands. However, no alterations were perceived with respect to the duration of P wave, duration of T wave, the P-R interval, R-R interval and the heart rate. Except for the amplitude of P wave, no other differences were statistically significant. The study reported the alterations in the electrocardiogram while handling the animals with bare hands.

Non-invasive electrocardiogram detection of in vivo zebrafish embryos using electric potential sensors

Science.gov (United States)

Rendon-Morales, E.; Prance, R. J.; Prance, H.; Aviles-Espinosa, R.

2015-11-01

In this letter, we report the continuous detection of the cardiac electrical activity in embryonic zebrafish using a non-invasive approach. We present a portable and cost-effective platform based on the electric potential sensing technology, to monitor in vivo electrocardiogram activity from the zebrafish heart. This proof of principle demonstration shows how electrocardiogram measurements from the embryonic zebrafish may become accessible by using electric field detection. We present preliminary results using the prototype, which enables the acquisition of electrophysiological signals from in vivo 3 and 5 days-post-fertilization zebrafish embryos. The recorded waveforms show electrocardiogram traces including detailed features such as QRS complex, P and T waves.

The Amsterdam Resting-State Questionnaire reveals multiple phenotypes of resting-state cognition

Science.gov (United States)

Diaz, B. Alexander; Van Der Sluis, Sophie; Moens, Sarah; Benjamins, Jeroen S.; Migliorati, Filippo; Stoffers, Diederick; Den Braber, Anouk; Poil, Simon-Shlomo; Hardstone, Richard; Van't Ent, Dennis; Boomsma, Dorret I.; De Geus, Eco; Mansvelder, Huibert D.; Van Someren, Eus J. W.; Linkenkaer-Hansen, Klaus

2013-01-01

Resting-state neuroimaging is a dominant paradigm for studying brain function in health and disease. It is attractive for clinical research because of its simplicity for patients, straightforward standardization, and sensitivity to brain disorders. Importantly, non-sensory experiences like mind wandering may arise from ongoing brain activity. However, little is known about the link between ongoing brain activity and cognition, as phenotypes of resting-state cognition—and tools to quantify them—have been lacking. To facilitate rapid and structured measurements of resting-state cognition we developed a 50-item self-report survey, the Amsterdam Resting-State Questionnaire (ARSQ). Based on ARSQ data from 813 participants assessed after 5 min eyes-closed rest in their home, we identified seven dimensions of resting-state cognition using factor analysis: Discontinuity of Mind, Theory of Mind, Self, Planning, Sleepiness, Comfort, and Somatic Awareness. Further, we showed that the structure of cognition was similar during resting-state fMRI and EEG, and that the test-retest correlations were remarkably high for all dimensions. To explore whether inter-individual variation of resting-state cognition is related to health status, we correlated ARSQ-derived factor scores with psychometric scales measuring depression, anxiety, and sleep quality. Mental health correlated positively with Comfort and negatively with Discontinuity of Mind. Finally, we show that sleepiness may partially explain a resting-state EEG profile previously associated with Alzheimer's disease. These findings indicate that the ARSQ readily provides information about cognitive phenotypes and that it is a promising tool for research on the neural correlates of resting-state cognition in health and disease. PMID:23964225

Comparative analyses of the effect of radiotherapy and chemotherapy or chemotherapy alone on patients' electrocardiogram

International Nuclear Information System (INIS)

Liang Li; Zhang Shulan; Zhang Zhaohui; Wang Junjie; Jia Tingzhen

2005-01-01

Objective: To investigate the change of breast cancer patients' electrocardiogram during combined radiotherapy and chemotherapy or chemotherapy alone for the sake of predicting the cardiotoxicity of combined radiotherapy and chemotherapy. Methods: From January, 1998 to June, 2004, 47 postoperative breast cancer patients were enrolled. Among them 29 patients received chemotherapy combined with radiotherapy (combinative group), and 18 patients received chemotherapy alone (non combinative group). The changes of electrocardiogram were observed and correlation factors were analyzed. Results: Abnormal electrocardiograms were noted in 11 (37.9%) and 2 patients (11.1%) of the combinative group and the non-combinative group respectively(z=-1.977, P=0.048). In the combinative group, heart events were significantly increased in patients above 60 years old (z=- 2.094 P=0.036). The changes of electrocardiogram were not significantly correlative with hypertension history, tumor site, dose of radiotherapy or chemotherapeutic drugs. But the incidence of abnormal electrocardiogram was higher in patients with a hypertension history than in those without it (54.5% vs 27.8%). Conclusion: The abnormalities of electrocardiogram were are more frequent in patients treated with both radiotherapy combined with chemotherapy. Our results suggest that breast cancer patients should be regularly reexamined with electrocardiography during therapy, especially whose age was those have a hypertension history and above 60 years old. (authors)

The electrocardiogram in traumatic right atrial rupture

NARCIS (Netherlands)

van Veldhuisen, DJ; van den Berg, MP

1999-01-01

We:report the case of a previously healthy 20-year-old man who had a traumatic rupture of the right atrium. On admission an electrocardiogram (ECG) was recorded which is highly remarkable and, retrospectively, suggestive for the diagnosis. The patient died soon after the EGG, and the diagnosis was

Electrocardiogram of Clinically Healthy Mithun (Bos frontalis): Variation among Strains

Science.gov (United States)

Sanyal, Sagar; Das, Pradip Kumar; Ghosh, Probal Ranjan; Das, Kinsuk; Vupru, Kezha V.; Rajkhowa, Chandan; Mondal, Mohan

2010-01-01

A study was conducted to establish the normal electrocardiogram in four different genetic strains of mithun (Bos frontalis). Electrocardiography, cardiac electrical axis, heart rate, rectal temperature and respiration rate were recorded in a total of 32 adult male mithun of four strains (n = 8 each). It was found that the respiration and heart rates were higher (P electrocardiogram of mithun revealed that the amplitude and duration of P wave, QRS complex and T wave were different among four different genetic strains of mithun and the electrical axis of QRS complex for Nagamese and Mizoram mithuns are dissimilar to bovine species. PMID:20886013

Mobile Messaging Services-Based Personal Electrocardiogram Monitoring System

Directory of Open Access Journals (Sweden)

Ashraf A. Tahat

2009-01-01

Full Text Available A mobile monitoring system utilizing Bluetooth and mobile messaging services (MMS/SMSs with low-cost hardware equipment is proposed. A proof of concept prototype has been developed and implemented to enable transmission of an Electrocardiogram (ECG signal and body temperature of a patient, which can be expanded to include other vital signs. Communication between a mobile smart-phone and the ECG and temperature acquisition apparatus is implemented using the popular personal area network standard specification Bluetooth. When utilizing MMS for transmission, the mobile phone plots the received ECG signal and displays the temperature using special application software running on the client mobile phone itself, where the plot can be captured and saved as an image before transmission. Alternatively, SMS can be selected as a transmission means, where in this scenario, dedicated application software is required at the receiving device. The experimental setup can be operated for monitoring from anywhere in the globe covered by a cellular network that offers data services.

Mobile messaging services-based personal electrocardiogram monitoring system.

Science.gov (United States)

Tahat, Ashraf A

2009-01-01

A mobile monitoring system utilizing Bluetooth and mobile messaging services (MMS/SMSs) with low-cost hardware equipment is proposed. A proof of concept prototype has been developed and implemented to enable transmission of an Electrocardiogram (ECG) signal and body temperature of a patient, which can be expanded to include other vital signs. Communication between a mobile smart-phone and the ECG and temperature acquisition apparatus is implemented using the popular personal area network standard specification Bluetooth. When utilizing MMS for transmission, the mobile phone plots the received ECG signal and displays the temperature using special application software running on the client mobile phone itself, where the plot can be captured and saved as an image before transmission. Alternatively, SMS can be selected as a transmission means, where in this scenario, dedicated application software is required at the receiving device. The experimental setup can be operated for monitoring from anywhere in the globe covered by a cellular network that offers data services.

Restful API Architecture Based on Laravel Framework

Science.gov (United States)

Chen, Xianjun; Ji, Zhoupeng; Fan, Yu; Zhan, Yongsong

2017-10-01

Web service has been an industry standard tech for message communication and integration between heterogeneous systems. RESTFUL API has become mainstream web service development paradigm after SOAP, how to effectively construct RESTFUL API remains a research hotspots. This paper presents a development model of RESTFUL API construction based on PHP language and LARAVEL framework. The key technical problems that need to be solved during the construction of RESTFUL API are discussed, and implementation details based on LARAVEL are given.

The Amsterdam Resting-State Questionnaire reveals multiple phenotypes of resting-state cognition

Directory of Open Access Journals (Sweden)

B. Alexander eDiaz

2013-08-01

Full Text Available Resting-state neuroimaging is a dominant paradigm for studying brain function in health and disease. It is attractive for clinical research because of its simplicity for patients, straightforward standardization, and sensitivity to brain disorders. Importantly, non-sensory experiences like mind wandering may arise from ongoing brain activity. However, little is known about the link between ongoing brain activity and cognition, as phenotypes of resting-state cognition—and tools to quantify them—have been lacking. To facilitate rapid and structured measurements of resting-state cognition we developed a 50-item self-report survey, the Amsterdam Resting-State Questionnaire (ARSQ. Based on ARSQ data from 813 participants assessed after five minutes eyes-closed rest in their home, we identified seven dimensions of resting-state cognition using factor analysis: Discontinuity of Mind, Theory of Mind, Self, Planning, Sleepiness, Comfort, and Somatic Awareness. Further, we showed that the structure of cognition was similar during resting-state fMRI and EEG, and that the test-retest correlations were remarkably high for all dimensions. To explore whether inter-individual variation of resting-state cognition is related to health status, we correlated ARSQ-derived factor scores with psychometric scales measuring depression, anxiety, and sleep quality. Mental health correlated positively with Comfort and negatively with Discontinuity of Mind. Finally, we show that sleepiness may partially explain a resting-state EEG profile previously associated with Alzheimer’s disease. These findings indicate that the ARSQ readily provides information about cognitive phenotypes and that it is a promising tool for research on the neural correlates of resting-state cognition in health and disease.

Gender differences in the electrocardiogram screening of athletes

NARCIS (Netherlands)

Bessem, Bram; de Bruijn, Matthijs C.; Nieuwland, Wybe

Objectives: Gender-related differences are frequently used in medicine. Electrocardiograms are also subject to such differences. This study evaluated gender differences in ECG parameters of young athletes, discussing the possible implications of these differences for ECG criteria used in the

Assessment of the electrocardiogram in dogs with visceral leishmaniasis

Directory of Open Access Journals (Sweden)

Marlos G. Sousa

2013-05-01

Full Text Available As myocarditis and arrhythmias have been shown to occur in both human beings and dogs with leishmaniasis, electrocardiograms of 105 dogs serologically positive for this disease were assessed for rhythm disturbances and changes in ECG waves. A few expressive alterations were seen, including sinus arrest, right bundle branch block, and atrial premature beats in 14.3%, 4.8%, and 4.8% of the studied subjects, respectively. Also, the analysis of ECG waves showed changes suggestive of left atrium and ventricle enlargements, and myocardial hypoxia in some animals. Although cardiac compromise has been previously reported in dogs with leishmaniasis, only a small subset of dogs showed any alteration in the electrocardiogram, which cannot support the occurrence of myocarditis in this investigation.

Radiotelemetry recording of electroencephalogram in piglets during rest.

Science.gov (United States)

Saito, Toshiyuki; Watanabe, Yasuko; Nemoto, Tetsu; Kasuya, Etsuko; Sakumoto, Ryosuke

2005-04-13

A wireless recording system was developed to study the electroencephalogram (EEG) in unrestrained, male Landrace piglets. Under general anesthesia, ball-tipped silver/silver chloride electrodes for EEG recording were implanted onto the dura matter of the parietal and frontal cortex of the piglets. A pair of miniature preamplifiers and transmitters was then mounted on the surface of the skull. To examine whether other bioelectrical activities interfere with the EEG measurements, an electrocardiogram (ECG) or electromyogram (EMG) of the neck was simultaneously recorded with the EEG. Next, wire electrodes for recording movement of the eyelid were implanted with EEG electrodes, and EEG and eyelid movements were simultaneously measured. Power spectral analysis using a Fast Fourier Transformation (FFT) algorithm indicates that EEG was successfully recorded in unrestrained piglets, at rest, during the daytime in the absence of interference from ECG, EMG or eyelid movements. These data indicate the feasibility of using our radiotelemetry system for measurement of EEG under these conditions.

Pneumopyopericardium mimicking an inferior ST elevation myocardial infarction with regional electrocardiogram changes: a case report.

Science.gov (United States)

Ratnayake, Eranda Chamara; Premaratne, Sandamali; Lokunarangoda, Niroshan; Fernando, Sanduni; Fernando, Nilanthi; Ponnamperuma, Chandrike; Santharaj, W Samuel

2015-04-30

Pneumopyopericardium is a rare disease with poor prognosis. The usual presentation is with fever, shortness of breath and haemodynamic compromise. The Electrocardiogram changes associated with this disease entity would be similar to pericarditis such as concave shaped ST elevations in all leads with PR sagging. Pneumopyopericardium mimicking an acute ST Elevation Myocardial Infarction, with regional Electrocardiogram changes has hitherto not been described in world literature. We describe the case of a 48 year old native Sri Lankan man, presenting with chest pain and Electrocardiogram changes compatible with an Acute ST Elevation Myocardial Infarction, subsequently found to have Pneumopyopericardium secondary to an oesophageal tear. Retrospective history revealed repetitive vomiting due to heavy alcohol consumption, prior to presentation. It unfortunately led to a fatal outcome. Pneumopyopericardium may mimic an acute ST elevation myocardial infarction with associated regional Electrocardiogram changes. A high degree of suspicion should be maintained and an adequate history should always be obtained prior to any intervention in all ST Elevation Myocardial Infarction patients.

Framework for ReSTful Web Services in OSGi

Science.gov (United States)

Shams, Khawaja S.; Norris, Jeffrey S.; Powell, Mark W.; Crockett, Thomas M.; Mittman, David S.; Fox, Jason M.; Joswig, Joseph C.; Wallick, Michael N.; Torres, Recaredo J.; Rabe, Kenneth

2009-01-01

Ensemble ReST is a software system that eases the development, deployment, and maintenance of server-side application programs to perform functions that would otherwise be performed by client software. Ensemble ReST takes advantage of the proven disciplines of ReST (Representational State Transfer. ReST leverages the standardized HTTP protocol to enable developers to offer services to a diverse variety of clients: from shell scripts to sophisticated Java application suites

Assessment of left ventricular function by electrocardiogram-gated myocardial single photon emission computed tomography using quantitative gated single photon emission computed tomography software

International Nuclear Information System (INIS)

Morita, Koichi; Adachi, Itaru; Konno, Masanori

1999-01-01

Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT) can assess left ventricular (LV) perfusion and function easily using quantitative gated SPECT (QGS) software. ECG-gated SPECT was performed in 44 patients with coronary artery disease under post-stress and resting conditions to assess the values of LV functional parameters, by comparison to LV ejection fraction derived from gated blood pool scan and myocardial characteristics. A good correlation was obtained between ejection fraction using QGS and that using cardiac blood pool scan (r=0.812). Some patients with myocardial ischemia had lower ejection fraction under post-stress compared to resting conditions, indicating post-stress LV dysfunction. LV wall motion and wall thickening were significantly impaired in ischemic and infarcted myocardium, and the degree of abnormality in the infarcted areas was greater than in the ischemia area. LV functional parameters derived using QGS were useful to assess post-stress LV dysfunction and myocardial viability. In conclusion, ECG-gated myocardial SPECT permits simultaneous quantitative assessment of myocardial perfusion and function. (author)

Design and validation of a three-instrument toolkit for the assessment of competence in electrocardiogram rhythm recognition.

Science.gov (United States)

Hernández-Padilla, José M; Granero-Molina, José; Márquez-Hernández, Verónica V; Suthers, Fiona; López-Entrambasaguas, Olga M; Fernández-Sola, Cayetano

2017-06-01

Rapid and accurate interpretation of cardiac arrhythmias by nurses has been linked with safe practice and positive patient outcomes. Although training in electrocardiogram rhythm recognition is part of most undergraduate nursing programmes, research continues to suggest that nurses and nursing students lack competence in recognising cardiac rhythms. In order to promote patient safety, nursing educators must develop valid and reliable assessment tools that allow the rigorous assessment of this competence before nursing students are allowed to practise without supervision. The aim of this study was to develop and psychometrically evaluate a toolkit to holistically assess competence in electrocardiogram rhythm recognition. Following a convenience sampling technique, 293 nursing students from a nursing faculty in a Spanish university were recruited for the study. The following three instruments were developed and psychometrically tested: an electrocardiogram knowledge assessment tool (ECG-KAT), an electrocardiogram skills assessment tool (ECG-SAT) and an electrocardiogram self-efficacy assessment tool (ECG-SES). Reliability and validity (content, criterion and construct) of these tools were meticulously examined. A high Cronbach's alpha coefficient demonstrated the excellent reliability of the instruments (ECG-KAT=0.89; ECG-SAT=0.93; ECG-SES=0.98). An excellent context validity index (scales' average content validity index>0.94) and very good criterion validity were evidenced for all the tools. Regarding construct validity, principal component analysis revealed that all items comprising the instruments contributed to measure knowledge, skills or self-efficacy in electrocardiogram rhythm recognition. Moreover, known-groups analysis showed the tools' ability to detect expected differences in competence between groups with different training experiences. The three-instrument toolkit developed showed excellent psychometric properties for measuring competence in

Reconstruction of electrocardiogram using ionic current models for heart muscles.

Science.gov (United States)

Yamanaka, A; Okazaki, K; Urushibara, S; Kawato, M; Suzuki, R

1986-11-01

A digital computer model is presented for the simulation of the electrocardiogram during ventricular activation and repolarization (QRS-T waves). The part of the ventricular septum and the left ventricular free wall of the heart are represented by a two dimensional array of 730 homogeneous functional units. Ionic currents models are used to determine the spatial distribution of the electrical activities of these units at each instant of time during simulated cardiac cycle. In order to reconstruct the electrocardiogram, the model is expanded three-dimensionally with equipotential assumption along the third axis and then the surface potentials are calculated using solid angle method. Our digital computer model can be used to improve the understanding of the relationship between body surface potentials and intracellular electrical events.

[Parameters of cardiac muscle repolarization on the electrocardiogram when changing anatomical and electric position of the heart].

Science.gov (United States)

Chaĭkovskiĭ, I A; Baum, O V; Popov, L A; Voloshin, V I; Budnik, N N; Frolov, Iu A; Kovalenko, A S

2014-01-01

While discussing the diagnostic value of the single channel electrocardiogram a set of theoretical considerations emerges inevitably, one of the most important among them is the question about dependence of the electrocardiogram parameters from the direction of electrical axis of heart. In other words, changes in what of electrocardiogram parameters are in fact liable to reflect pathological processes in myocardium, and what ones are determined by extracardiac factors, primarily by anatomic characteristics of patients. It is arguable that while analyzing electrocardiogram it is necessary to orient to such physiologically based informative indexes as ST segment displacement. Also, symmetry of the T wave shape is an important parameter which is independent of patients anatomic features. The results obtained are of interest for theoretical and applied aspects of the biophysics of the cardiac electric field.

The Effect of Creative Tasks on Electrocardiogram: Using Linear and Nonlinear Features in Combination with Classification Approaches

Directory of Open Access Journals (Sweden)

Sahar Zakeri

2017-02-01

Full Text Available Objective: Interest in the subject of creativity and its impacts on human life is growing extensively. However, only a few surveys pay attention to the relation between creativity and physiological changes. This paper presents a novel approach to distinguish between creativity states from electrocardiogram signals. Nineteen linear and nonlinear features of the cardiac signal were extracted to detect creativity states. Method: ECG signals of 52 participants were recorded while doing three tasks of Torrance Tests of Creative Thinking (TTCT/ figural B. To remove artifacts, notch filter 50 Hz and Chebyshev II were applied. According to TTCT scores, participants were categorized into the high and low creativity groups: Participants with scores higher than 70 were assigned into the high creativity group and those with scores less than 30 were considered as low creativity group. Some linear and nonlinear features were extracted from the ECGs. Then, Support Vector Machine (SVM and Adaptive Neuro-Fuzzy Inference System (ANFIS were used to classify the groups.Results: Applying the Wilcoxon test, significant differences were observed between rest and each three tasks of creativity. However, better discrimination was performed between rest and the first task. In addition, there were no statistical differences between the second and third task of the test. The results indicated that the SVM effectively detects all the three tasks from the rest, particularly the task 1 and reached the maximum accuracy of 99.63% in the linear analysis. In addition, the high creative group was separated from the low creative group with the accuracy of 98.41%.Conclusion: the combination of SVM classifier with linear features can be useful to show the relation between creativity and physiological changes.

A Real-Time Intrauterine Catheter Technique for Fetal Electrocardiogram Monitoring

National Research Council Canada - National Science Library

Horner, S

2001-01-01

..., two sensors that include the invasive scalp electrode and intrauterine pressure catheter are used clink ally, Signal processing is required to obtain a FECG via the IC, Usually the maternal electrocardiogram (ECG...

Limited Relationship of Voltage Criteria for Electrocardiogram Left Ventricular Hypertrophy to Cardiovascular Mortality.

Science.gov (United States)

Ha, Le Dung; Elbadawi, Ayman; Froelicher, Victor F

2018-01-01

Numerous methods have been proposed for diagnosing left ventricular hypertrophy using the electrocardiogram. They have limited sensitivity for recognizing pathological hypertrophy, at least in part due to their inability to distinguish pathological from physiological hypertrophy. Our objective is to compare the major electrocardiogram-left ventricular hypertrophy criteria using cardiovascular mortality as a surrogate for pathological hypertrophy. This study was a retrospective analysis of 16,253 veterans electrocardiogram-left ventricular hypertrophy, and there were 744 cardiovascular deaths (annual cardiovascular mortality 0.25%). Receiver operating characteristic analysis demonstrated that the greatest area under the curve (AUC) for classification of cardiovascular death was obtained using the Romhilt-Estes score (0.63; 95% confidence interval, 0.61-0.65). Most of the voltage-only criteria had nondiagnostic area under the curves, with the Cornell being the best at 0.59 (95% confidence interval, 0.57-0.62). When the components of the Romhilt-Estes score were examined using step-wise Wald analysis, the voltage criteria dropped from the model. The Romhilt-Estes score ≥ 4, the Cornell, and the Peguero had the highest association with cardiovascular mortality (adjusted hazard ratios 2.2, 2.0, and 2.1, consecutively). None of the electrocardiogram leads with voltage criteria exhibited sufficient classification power for clinical use. Copyright © 2018 Elsevier Inc. All rights reserved.

Is 10-second electrocardiogram recording enough for accurately estimating heart rate in atrial fibrillation.

Science.gov (United States)

Shuai, Wei; Wang, Xi-Xing; Hong, Kui; Peng, Qiang; Li, Ju-Xiang; Li, Ping; Chen, Jing; Cheng, Xiao-Shu; Su, Hai

2016-07-15

At present, the estimation of rest heart rate (HR) in atrial fibrillation (AF) is obtained by apical auscultation for 1min or on the surface electrocardiogram (ECG) by multiplying the number of RR intervals on the 10second recording by six. But the reasonability of 10second ECG recording is controversial. ECG was continuously recorded at rest for 60s to calculate the real rest HR (HR60s). Meanwhile, the first 10s and 30s ECG recordings were used for calculating HR10s (sixfold) and HR30s (twofold). The differences of HR10s or HR30s with the HR60s were compared. The patients were divided into three sub-groups on the HR60s 100bpm. No significant difference among the mean HR10s, HR30s and HR60s was found. A positive correlation existed between HR10s and HR60s or HR30s and HR60s. Bland-Altman plot showed that the 95% reference limits were high as -11.0 to 16.0bpm for HR10s, but for HR30s these values were only -4.5 to 5.2bpm. Among the three subgroups with HR60s 100bpm, the 95% reference limits with HR60s were -8.9 to 10.6, -10.5 to 14.0 and -11.3 to 21.7bpm for HR10s, but these values were -3.9 to 4.3, -4.1 to 4.6 and -5.3 to 6.7bpm for HR30s. As 10s ECG recording could not provide clinically accepted estimation HR, ECG should be recorded at least for 30s in the patients with AF. It is better to record ECG for 60s when the HR is rapid. Copyright © 2016. Published by Elsevier Ireland Ltd.

Developing RESTful web services with Jersey 2.0

CERN Document Server

Gulabani, Sunil

2013-01-01

The book will follow a standard tutorial approach and will teach readers how to use the Jersey API for creating RESTful web services.This book is intended for Java EE developers who are building applications on the REST architecture. This is a quick, hands-on guide for learning JAX-RS 2.0. Developers should have some knowledge about RESTful web services but it's not essential to know JAX-RS 1.0.

Use of resting myocardial scintigraphy during chest pain to exclude diagnosis of acute myocardial infarction

International Nuclear Information System (INIS)

Barbirato, Gustavo Borges; Azevedo, Jader Cunha de; Felix, Renata Christian Martins; Correa, Patricia Lavatori; Volschan, Andre; Viegas, Monica; Pimenta, Lucia; Dohmann, Hans Fernando Rocha; Mesquita, Evandro Tinoco; Mesquita, Claudio Tinoco

2009-01-01

Background: Images of myocardial perfusion taken during an episode of chest pain have been used for patients in the emergency department. Objective: To evaluate the operating characteristics of 99m Tc-Tetrofosmin scintigraphy during an episode of chest pain to exclude the diagnosis of cute myocardial infarction. Methods: One hundred and eight patients admitted with chest pain, or up to four hours after the end of symptoms and non diagnostic electrocardiogram, underwent resting scintigraphy and measurement of troponin I concentrations. Patients with a history of myocardial infarction (MI) were not excluded (24 patients). Troponin I concentrations were determined at admission and 6 hours later. Nuclear physicians performed a blind analysis of the images, and myocardial infarction was confirmed whenever troponin I level increase was three times that of the control. Results: Resting perfusion image was abnormal in all 6 patients with MI. Only 1 patient had a normal image and increased troponin levels. Fifty-five patients had positive images without MI, and 46 patients had normal images and troponin levels. The prevalence of the disease was 6.5%. The sensitivity and specificity of the resting images during an episode of chest pain to diagnose MI was 85.7% and 45.5%, respectively. The negative predictive value was 97.7%. Conclusion: Patients undergoing chest pain protocol with SPECT showed an excellent negative predictive value to exclude diagnosis of myocardial infarction. These results suggest that resting perfusion image is an important tool at the chest pain unit. (author)

An Analysis Of QRS Interval Of The Electrocardiogram In ...

African Journals Online (AJOL)

Objectives: This cross-sectional study of the 12-lead electrocardiogram (ECG) was undertaken to establish the normal QRS interval of the adult Nigerian from Jos; to find significant correlation coefficients for QRS interval and the various anthropometric measurements and also to establish prediction equations for the QRS ...

Computerized electrocardiogram in agoutis (Dasyprocta prymnolopha Wagler, 1831 anesthetized with ketamine and midazolam

Directory of Open Access Journals (Sweden)

Anaemilia N. Diniz

Full Text Available ABSTRACT: An electrocardiogram is a test that assesses heart electrical activity and is applied more frequently in the veterinary care of wild animals. The present study aimed to define the electrocardiogram pattern of agoutis (Dasyprocta prymnolopha Wagler, 1831 anesthetized with ketamine and midazolam. Eighteen clinically healthy agoutis (D. prymnolopha were used from the Nucleus for Wild Animal Studies and Conservation (NEPAS of the Federal University of Piauí, Brazil. The animals were chemically restrained with 5% ketamine hydrochloride at a dose of 15mg/kg and midazolam at a dose of 1mg/kg by intramuscular injection. Electrocardiogram tests were carried out by a computerized method with the veterinary electrocardiogram [Acquisition Model for Computer (ECG - PC version Windows 95 Brazilian Electronic Technology (TEB consisting of an electronic circuit externally connected to a notebook computer with ECGPC-VET (TEB software installed on the hard disc. In analysing the EKG results, significant differences were observed for QRS complex duration, PR and QT intervals and for R wave millivoltage between the genders; but we observed a significant influence of weight despite the gender. In the present experiment, the anaesthetic protocol was shown to be well tolerated by the agoutis, and no arrhythmias occurred during the time the animals were monitored. The reference values obtained should be used to better understand the cardiac electrophysiology of the species and for its clinical and surgical management.

Evaluation of hemodynamic significance of coronary fistulae. Diagnostic integration between coronary angiography and stress/rest myocardial scintigraphy

International Nuclear Information System (INIS)

Rubini, G.; Sebastiani, M.

2000-01-01

It is here reported on the importance of the integration of data obtained from digital coronary angiography and stress/rest 99m Tc sestamibi myocardial perfusion single photon emission tomography in evaluationing the hemodynamic significance of coronary arteriovenous fistulae. Coronary fistulae were detected with coronary angiography in 9 patients. All patients underwent clinical examination, trans thoracic echocardiography, stress electrocardiogram and stress/rest 99m Tc sestamibi myocardial perfusion single photon emission tomography. Stress/rest 99m Tc sestamibi myocardial perfusion single photon tomography and stress electrocardiogram showed stress-induced myocardial ischemia in 2 patients. The first patient with familial predisposition and risk factors for ischemic heart disease presented a mesocardic heart murmur on clinical examination. At stress ECG (125 Watt, 153 b/m max frequency 93%, arterial pressure 230 mmHg, max frequency pressure product 35200) ischemic alterations were recorded at the first minute of the second stage of the Bruce protocol. Coronary angiography detected a circumflex artery fistula in the coronary sinus. Stress/rest 99m Tc sestamibi myocardial perfusion single photon emission tomography for the evaluation of stress/rest perfusion detected a reversible perfusion defect of the proximal portion of the posterolateral and lateral walls, thus confirming the hemodynamic importance of the flow through the fistula during stress cycloergometric testing. In the second patient familial predisposition to ischemic heart disease and previous inferior wall myocardial infarction and non-significant stress ECG, coronary angiography identified a seclusive stenosis of the right coronary artery and anomaly between the anterior interventricular artery and the left pulmonary artery. The presence of the contrast medium in the left pulmonary artery identified a flow from the left ventricle to the left pulmonary artery. Good angiographic results were obtained

Thallium-201 scintigraphy in diagnosis of coronary stenosis

International Nuclear Information System (INIS)

Corne, R.A.; Gotsman, M.S.; Weiss, A.; Enlander, D.; Samuels, L.D.; Salomon, J.A.; Warshaw, B.; Atlan, H.

1979-01-01

The sensitivity of rest and exercise thallium-201 scintigraphy for the detection of significant coronary artery disease and myocardial ischaemia was compared with rest and exercise electrocardiography in 46 patients with chest pain. Of 26 patients with greater that 70 per cent coronary stenosis, 16 had abnormal rest thallium-201 scintigrams and 13 had Q waves. Myocardial perfusion defects in the resting scintigram correlated very well with evidence of previous myocardial infarction (16 of 17 patients, 94%) significant Q waves were present in 13 of these 17 patients (76%). After exercise, abnormal thallium-201 scintigrams consistent with ischaemia were found in 21 patients (81%). Abnormal exercise electrocardiograms were present in 15 patients (58%). The combination of abnormal exercise thallium-201 scintigrams or exercise electrocardiograms (23/26, 88%) exceeded abnormal exercise electrocardiograms alone (15/26, 58%). The two procedures were thus complementary. Abnormal rest or exercise thallium-201 scintigrams were obtained in 25/26 patients (96%) compared with abnormal rest or exercise electrocardiograms in 21/26 patients (84%). Twenty patients with less than 50 per cent coronary stenosis had normal rest thallium-201 scintigrams and no Q waves. Two had abnormal exercise thallium-201 scintigrams and 7 had abnormal exercise electrocardiograms. Thus,exercise thallium scintigraphy has higher sensitivity than exercise electrocardiography in detecting exercise induced ischaemia and is more specific. Scintigraphy appears to have a higher sensitivity than electrocardiography in detecting coronary artery disease. (author)

Cardiorespiratory phase synchronization during normal rest and inward-attention meditation.

Science.gov (United States)

Wu, Shr-Da; Lo, Pei-Chen

2010-06-11

The cardiac and respiratory systems can be viewed as two self-sustained oscillators with various interactions between them. In this study, the cardiorespiratory phase synchronization (CRPS) quantified by synchrogram was investigated to explore the phase synchronization between these two systems. The synchrogram scheme was applied to electrocardiogram (ECG) and respiration signals. Particular focus was the distinct cardiac-respiratory regulation phenomena intervened by inward-attention meditation and normal relaxation. Four synchronization parameters were measured: frequency ratio, lasting length, number of epochs, and total length. The results showed that normal rest resulted in much weaker CRPS. Statistical analysis reveals that the number of synchronous epochs and the total synchronization length significantly increase (p=0.024 and 0.034 respectively) during meditation. Furthermore, a predominance of 4:1 and 5:1 rhythm-ratio synchronizations was observed during meditation. Consequently, this study concludes that CRPS can be enhanced during meditation, compared with normal relaxation, and reveals a predominance of specific frequency ratios. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Wavelet transform analysis of transient signals: the seismogram and the electrocardiogram

Energy Technology Data Exchange (ETDEWEB)

Anant, K.S.

1997-06-01

In this dissertation I quantitatively demonstrate how the wavelet transform can be an effective mathematical tool for the analysis of transient signals. The two key signal processing applications of the wavelet transform, namely feature identification and representation (i.e., compression), are shown by solving important problems involving the seismogram and the electrocardiogram. The seismic feature identification problem involved locating in time the P and S phase arrivals. Locating these arrivals accurately (particularly the S phase) has been a constant issue in seismic signal processing. In Chapter 3, I show that the wavelet transform can be used to locate both the P as well as the S phase using only information from single station three-component seismograms. This is accomplished by using the basis function (wave-let) of the wavelet transform as a matching filter and by processing information across scales of the wavelet domain decomposition. The `pick` time results are quite promising as compared to analyst picks. The representation application involved the compression of the electrocardiogram which is a recording of the electrical activity of the heart. Compression of the electrocardiogram is an important problem in biomedical signal processing due to transmission and storage limitations. In Chapter 4, I develop an electrocardiogram compression method that applies vector quantization to the wavelet transform coefficients. The best compression results were obtained by using orthogonal wavelets, due to their ability to represent a signal efficiently. Throughout this thesis the importance of choosing wavelets based on the problem at hand is stressed. In Chapter 5, I introduce a wavelet design method that uses linear prediction in order to design wavelets that are geared to the signal or feature being analyzed. The use of these designed wavelets in a test feature identification application led to positive results. The methods developed in this thesis; the

Noninvasive extraction of fetal electrocardiogram based on Support Vector Machine

Science.gov (United States)

Fu, Yumei; Xiang, Shihan; Chen, Tianyi; Zhou, Ping; Huang, Weiyan

2015-10-01

The fetal electrocardiogram (FECG) signal has important clinical value for diagnosing the fetal heart diseases and choosing suitable therapeutics schemes to doctors. So, the noninvasive extraction of FECG from electrocardiogram (ECG) signals becomes a hot research point. A new method, the Support Vector Machine (SVM) is utilized for the extraction of FECG with limited size of data. Firstly, the theory of the SVM and the principle of the extraction based on the SVM are studied. Secondly, the transformation of maternal electrocardiogram (MECG) component in abdominal composite signal is verified to be nonlinear and fitted with the SVM. Then, the SVM is trained, and the training results are compared with the real data to ensure the effect of the training. Meanwhile, the parameters of the SVM are optimized to achieve the best performance so that the learning machine can be utilized to fit the unknown samples. Finally, the FECG is extracted by removing the optimal estimation of MECG component from the abdominal composite signal. In order to evaluate the performance of FECG extraction based on the SVM, the Signal-to-Noise Ratio (SNR) and the visual test are used. The experimental results show that the FECG with good quality can be extracted, its SNR ratio is significantly increased as high as 9.2349 dB and the time cost is significantly decreased as short as 0.802 seconds. Compared with the traditional method, the noninvasive extraction method based on the SVM has a simple realization, the shorter treatment time and the better extraction quality under the same conditions.

The Ensembl REST API: Ensembl Data for Any Language.

Science.gov (United States)

Yates, Andrew; Beal, Kathryn; Keenan, Stephen; McLaren, William; Pignatelli, Miguel; Ritchie, Graham R S; Ruffier, Magali; Taylor, Kieron; Vullo, Alessandro; Flicek, Paul

2015-01-01

We present a Web service to access Ensembl data using Representational State Transfer (REST). The Ensembl REST server enables the easy retrieval of a wide range of Ensembl data by most programming languages, using standard formats such as JSON and FASTA while minimizing client work. We also introduce bindings to the popular Ensembl Variant Effect Predictor tool permitting large-scale programmatic variant analysis independent of any specific programming language. The Ensembl REST API can be accessed at http://rest.ensembl.org and source code is freely available under an Apache 2.0 license from http://github.com/Ensembl/ensembl-rest. © The Author 2014. Published by Oxford University Press.

Gender differences in the electrocardiogram screening of athletes.

Science.gov (United States)

Bessem, Bram B; de Bruijn, Matthijs M C; Nieuwland, Wybe W

2017-02-01

Gender-related differences are frequently used in medicine. Electrocardiograms are also subject to such differences. This study evaluated gender differences in ECG parameters of young athletes, discussing the possible implications of these differences for ECG criteria used in the cardiovascular screening of young athletes. Observational cross-sectional study. In 2013 and 2014 all the ECGs from the cardiovascular screenings performed at University Sports Medical Centre in Groningen of the student athletes who wanted to participate in a college sports program were collected. The ECG characteristics were scored using computer-based measurements and the Seattle ECG criteria. The study population included 1436 athletes, of which 72% were male. Male athletes were older (19.3 years vs. 18.6 years), participated in sports more frequently (4.0/week vs. 3.8/week) and spent more hours per week practising sports (6.4h/week vs. 5.8h/week) than female athletes. Male athletes had significantly higher PR intervals (149ms vs. 141ms), lead voltages and QRS duration (98ms vs. 88ms). Female athletes had significantly higher resting heart rates (69/min vs. 64/min) and QTc intervals (407ms vs. 400ms). Male athletes also had significantly higher amounts of sinus bradycardia (38.3% vs. 23.0%), incomplete RBBB (15.0% vs. 3.7%), early repolarisation (4.5% vs. 1.0%) and isolated QRS voltage criteria for LVH (26.3% vs. 4.6%). All P-values were ≤0.001. ECGs of young athletes demonstrate gender-related differences. These differences could be considered in their cardiovascular screening. For the Seattle ECG criteria we advise additional research into the clinical implications of using gender-based cut-off values for the QRS duration in the intraventricular conduction delay criterion. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The ability of an electrocardiogram to predict fatal and non-fatal cardiac events in asymptomatic middle-aged subjects.

Science.gov (United States)

Terho, Henri K; Tikkanen, Jani T; Kenttä, Tuomas V; Junttila, M Juhani; Aro, Aapo L; Anttonen, Olli; Kerola, Tuomas; Rissanen, Harri A; Knekt, Paul; Reunanen, Antti; Huikuri, Heikki V

2016-11-01

The long-term prognostic value of a standard 12-lead electrocardiogram (ECG) for predicting cardiac events in apparently healthy middle-aged subjects is not well defined. A total of 9511 middle-aged subjects (mean age 43 ± 8.2 years, 52% males) without a known cardiac disease and with a follow-up 40 years were included in the study. Fatal and non-fatal cardiac events were collected from the national registries. The predictive value of ECG was separately analyzed for 10 and 30 years. Major ECG abnormalities were classified according to the Minnesota code. Subjects with major ECG abnormalities (N = 1131) had an increased risk of cardiac death after 10-years (adjusted hazard ratio [HR] 1.7; 95% confidence interval [95% CI], 1.1-2.5, p = 0.009) and 30-years of follow-up (HR 1.3, 95% CI, 1.1-1.5, p electrocardiogram are shown to have prognostic significance for cardiac events in elderly subjects without known cardiac disease. Our results suggest that ECG abnormalities increase the risk of fatal cardiac events also in middle-aged healthy subjects.

Tripolar Laplacian electrocardiogram and moment of activation isochronal mapping.

Science.gov (United States)

Besio, W; Chen, T

2007-05-01

The electrocardiogram (ECG) provides useful global temporal assessment of the cardiac activity, but has limited spatial capabilities. The Laplacian electrocardiogram (LECG), an improvement over the ECG, provides high spatiotemporal distributed information about cardiac electrical activation. We designed and developed LECG tripolar concentric ring electrode active sensors based on the finite element algorithm 'nine-point method' (NPM). The active sensors were used in an array of 6 by 12 (72) locations to record bipolar and tripolar LECG from the body surface over the anterolateral chest. Compared to bipolar LECG, tripolar LECG showed significantly higher spatial selectivity which may be helpful in inferring information about cardiac activations detected on the body surface. In this study the moment of activation (MOA), an indicator of a depolarization wave passing below the active sensors, was used to surmise possible timing information of the cardiac electrical activation below the active sensors' recording sites. The MOA on the body surface was used to generate isochronal maps that may some day be used by clinicians in diagnosing arrhythmias and assessing the efficacy of therapies.

Bed rest versus early ambulation with standard anticoagulation in the management of deep vein thrombosis: a meta-analysis.

Directory of Open Access Journals (Sweden)

Zhenlei Liu

Full Text Available Bed rest has been considered as the cornerstone of management of deep vein thrombosis (DVT for a long time, though it is not evidence-base, and there is growing evidence favoring early ambulation.Electronic databases including Medline, PubMed, Cochrane Library and three Chinese databases were searched with key words of "deep vein thrombosis", "pulmonary embolism", "venous thrombosis", "bed rest", "immobilization", "mobilization" and "ambulation". We considered randomized controlled trials, prospective or retrospective cohort studies that compared the outcomes of acute DVT patients managed with early ambulation versus bed rest, in addition to standard anticoagulation. Meta-analysis pertaining to the incidence of new pulmonary embolism (PE, progression of DVT, and DVT related deaths were conducted, as well as the extent of remission of pain and edema.13 studies were included with a total of 3269 patients. Compared to bed rest, early ambulation was not associated with a higher incidence of new PE, progression of DVT, or DVT related deaths (RD -0.03, 95% CI -0.05∼ -0.02; Z = 1.24, p = 0.22; random effect model, Tau2 = 0.01. Moreover, if the patients suffered moderate or severe pain initially, early ambulation was related to a better outcome, with respect to remission of acute pain in the affected limb (SMD 0.42, 95%CI 0.09∼0.74; Z = 2.52, p = 0.01; random effect model, Tau2 = 0.04. Meta-analysis of alleviation of edema cannot elicit a solid conclusion because of significant heterogeneity among the few studies.Compared to bed rest, early ambulation of acute DVT patients with anticoagulation was not associated with a higher incidence of new PE, progression of DVT, and DVT related deaths. Furthermore, for the patients suffered moderate or severe pain initially, a better outcome can be seen in early ambulation group, regarding to the remission of acute pain in the affected limb.

Normal Limits of Electrocardiogram and Cut-Off Values for Left ...

African Journals Online (AJOL)

Gender difference exists in some cut-off values for LVH. This study defined the normal limits for electrocardiographic variables for young adult Nigerians. Racial factor should be taken into consideration in interpretation of ECG. Keywords: Normal limits, Electrocardiogram, Cut-off values, Left ventricular hypertrophy, Young ...

Gender Differences in Baroreflex Sensitivity after Bed Rest

Science.gov (United States)

Arzeno, Natalia M.; Stenger, M. B.; Ribeiro, L. C.; Lee, S. M.; Platts, S. H.

2009-01-01

Two potential contributing factors to post-spaceflight orthostatic intolerance are decreases in baroreflex sensitivity (BRS) and sympathetic nervous system response. The purpose of this study was to examine the shape of the BRS curve and sympathetic response to a wide range of blood pressures (BP) before and during 6 head-down bed rest (BR). METHODS: Normal volunteers were tested one day before BR (20M, 1 0F) and near BR days 30 (20M, 10F), 60 (16M, 8F), and 90 (1 0M, 5F). BP was pharmacologically manipulated by 10-min infusions of phenylephrine (PE) and sodium nitroprusside (SNP) at 3 increasing concentrations with a 20-min rest between PE and SNP. Electrocardiogram and continuous finger blood pressure were recorded. A blood sample was drawn at the end of each infusion to measure plasma norepinephrine levels. The spontaneous baroreflex slope (SBS), a measure of BRS, was calculated as the slope of a sequence of 3 or more beats in which the systolic BP (SBP) and following R-R interval (RR) both increased or decreased. The data included saturated responses at the upper but not the lower end of the BP range. Mean response curves were constructed using second-order mixed model analysis. Results are based on term significance in the models. RESULTS RR: RR was lower during BR than pre BR (pgenders were modeled by a linear response; compared to males, females had an attenuated (lower slope) RR response to changes in SBP (p=0.031). SBS: SBS vs SBP analysis showed a lower SBS during BR (pgender and BR. Not only do gender and BR baseline differences exist, but gender and BR also influence the slope and saturation of the BRS curves. Attenuated and saturating RR and SBS responses, as well as differences in baseline values, may contribute to the higher rates of orthostatic intolerance in women and after bed rest.

Sinabro: A Smartphone-Integrated Opportunistic Electrocardiogram Monitoring System

OpenAIRE

Sungjun Kwon; Dongseok Lee; Jeehoon Kim; Youngki Lee; Seungwoo Kang; Sangwon Seo; Kwangsuk Park

2016-01-01

In our preliminary study, we proposed a smartphone-integrated, unobtrusive electrocardiogram (ECG) monitoring system, Sinabro, which monitors a user?s ECG opportunistically during daily smartphone use without explicit user intervention. The proposed system also monitors ECG-derived features, such as heart rate (HR) and heart rate variability (HRV), to support the pervasive healthcare apps for smartphones based on the user?s high-level contexts, such as stress and affective state levels. In th...

Improving the Test-Retest Reliability of Resting State fMRI by Removing the Impact of Sleep.

Science.gov (United States)

Wang, Jiahui; Han, Junwei; Nguyen, Vinh T; Guo, Lei; Guo, Christine C

2017-01-01

Resting state functional magnetic resonance imaging (rs-fMRI) provides a powerful tool to examine large-scale neural networks in the human brain and their disturbances in neuropsychiatric disorders. Thanks to its low demand and high tolerance, resting state paradigms can be easily acquired from clinical population. However, due to the unconstrained nature, resting state paradigm is associated with excessive head movement and proneness to sleep. Consequently, the test-retest reliability of rs-fMRI measures is moderate at best, falling short of widespread use in the clinic. Here, we characterized the effect of sleep on the test-retest reliability of rs-fMRI. Using measures of heart rate variability (HRV) derived from simultaneous electrocardiogram (ECG) recording, we identified portions of fMRI data when subjects were more alert or sleepy, and examined their effects on the test-retest reliability of functional connectivity measures. When volumes of sleep were excluded, the reliability of rs-fMRI is significantly improved, and the improvement appears to be general across brain networks. The amount of improvement is robust with the removal of as much as 60% volumes of sleepiness. Therefore, test-retest reliability of rs-fMRI is affected by sleep and could be improved by excluding volumes of sleepiness as indexed by HRV. Our results suggest a novel and practical method to improve test-retest reliability of rs-fMRI measures.

The prevalence and relevance of the Brugada-type electrocardiogram in the Danish general population: data from the Copenhagen City Heart Study

DEFF Research Database (Denmark)

Pecini, Redi; Cedergreen, Pernille Kallerup; Theilade, Simone

2010-01-01

The prevalence of the Brugada-type electrocardiogram (ECG) in the Danish population is not known.......The prevalence of the Brugada-type electrocardiogram (ECG) in the Danish population is not known....

ASSESSMENT OF RELATION BETWEEN MICROALBUMINURIA AND ISCHEMIC ELECTROCARDIOGRAM IN IRANIAN GENERAL POPULATION

Directory of Open Access Journals (Sweden)

Alireza Khosravi

2010-12-01

Full Text Available Abstract    BACKGROUND: Enhancement of albumin exertion in urine increases the risk of renal and ischemic heart diseases (IHD. We assessed the association of urine albumin and sub-clinical IHD in a random sample of Iranian general population.    METHODS: The random sample in general population in Isfahan County was recruited to the cross-sectional study. From the all sample blood pressure and lipid profile were assessed and morning urine spot was measured for albumin and Creatinine. Microalbuminuria was defined either Albumin-Creatinine Ratio (ACR was 30-300mg. Also, the standard 12 lead electrocardiogram (ECG was carried out for all participants. The ECG pattern was divided to two categories; normal or ECG with ischemia. The logistic regression model was determined the odds of albuminuria for ischemic changes in ECG.    RESULTS: 999 subjects, age 35-70 years, participated to study. From all, 40.8% were male. Microalbuminuria was detected in 8% and sub-clinical ECG ischemic changes were found in 23.4%. The most frequent ischemic change was T wave inversion. The mean urine albumin levels in subjects with normal ECG was 9.6±14.6 mg/ml and in ischemic group was 8.5±12.2 mg/ml and they did not have statistically different. The odds ratios of neither Albumin-Creatinine ratio nor microalbuminuria were in significant range for risk to ischemic changes in ECG of apparently healthy participants. They was consecutively OR=0.9 (0.51-1.6, OR=0.99 (0.98-1.004.     CONCLUSION: Our finding didn’t declare any association between ACR and IHD. Because of showing this association in the other study; it needs more exploration regarding to association between microalbuminuria and cardiovascular diseases incidence.      Keywords: Ischemic heart diseases, electrocardiogram, Albumin-Creatinine Ratio, Urine Albumin

A new methodology to study customer electrocardiogram using RFM analysis and clustering

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Mohammad Reza Gholamian

2011-04-01

Full Text Available One of the primary issues on marketing planning is to know the customer's behavioral trends. A customer's purchasing interest may fluctuate for different reasons and it is important to find the declining or increasing trends whenever they happen. It is important to study these fluctuations to improve customer relationships. There are different methods to increase the customer's willingness such as planning good promotions, an increase on advertisement, etc. This paper proposes a new methodology to measure customer's behavioral trends called customer electrocardiogram. The proposed model of this paper uses K-means clustering method with RFM analysis to study customer's fluctuations over different time frames. We also apply the proposed electrocardiogram methodology for a real-world case study of food industry and the results are discussed in details.

Automated electrocardiogram interpretation programs versus cardiologists' triage decision making based on teletransmitted data in patients with suspected acute coronary syndrome

DEFF Research Database (Denmark)

Clark, Elaine N; Ripa, Maria Sejersten; Clemmensen, Peter

2010-01-01

The aims of this study were to assess the effectiveness of 2 automated electrocardiogram interpretation programs in patients with suspected acute coronary syndrome transported to hospital by ambulance in 1 rural region of Denmark with hospital discharge diagnosis used as the gold standard...... infarction with respect to discharge diagnosis were 78%, 91%, and 81% for LIFEPAK 12 and 78%, 94%, and 87% for the Glasgow program. Corresponding data for attending cardiologists were 85%, 90%, and 81%. In conclusion, the Glasgow program had significantly higher specificity than the LIFEPAK 12 program (p = 0...

Computer Decision Support as a Source of Interpretation Error: The Case of Electrocardiograms

OpenAIRE

Tsai, Theodore L.; Fridsma, Douglas B.; Gatti, Guido

2003-01-01

Objective: The aim of this study was to determine the effect that the computer interpretation (CI) of electrocardiograms (EKGs) has on the accuracy of resident (noncardiologist) physicians reading EKGs.

Biometric identification with high frequency electrocardiogram: Unregistered user refusal method and performance evaluation.

Science.gov (United States)

Kyoso, Masaki

2015-08-01

As a new modality for biometric identification, electrocardiogram-based identification technique has been developed. We proposed a technique with high frequency component of electrocardiogram (HFECG) in QRS segment. In this report, an unregistered user refusal algorithm was combined with the artificial neural network based waveform classifier. The refusal function was realized by simple thresholding technique. HFECGs from twenty collaborators were used for supervised learning. Twenty HFECGs from the same collaborators were tested and false acceptance rate (FAR) and false rejection rate (FRR) were evaluated. Ten HFECGs from other collaborators were also tested to find unregistered user refusal performance. The results show that FAR and FRR in the registrants can be kept within 1%, however, unregistered user refusal performance was not acceptable under the same condition.

[Factors influencing electrocardiogram results in workers exposed to noise in steel-making and steel-rolling workshops of an iron and steel plant].

Science.gov (United States)

Li, Y H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Jiao, J

2016-02-20

To investigate the factors influencing the electrocardiogram results in the workers exposed to noise in steel-making and steel rolling workshops of an iron and steel plant. From September to December, 2013, cluster sampling was used to select 3 150 workers exposed to noise in the steel-making and steel-rolling workshops of an iron and steel plant, and a questionnaire survey and physical examinations were performed. The number of valid workers was 2 915, consisting of 1 606 workers in the steel-rolling workshop and 1 309 in the steel-making workshop. The electrocardiogram results of the workers in steel-making and steel-rolling workshops were analyzed. The overall abnormal rate of electrocardiogram was 26.35%, and the workers in the steel-making workshop had a significantly higher abnormal rate of electrocardiogram than those in the steel-rolling workshop(32.24% vs 21.54%, Pelectrocardiogram than female workers(27.59% vs 18.61%, Pelectrocardiogram than those who did not drink(28.17% vs 23.75%, Pelectrocardiogram than those who were not exposed to high temperature(29.43% vs 20.14%, Pelectrocardiogram in the workers with cumulative noise exposure levels of electrocardiogram results. High cumulative noise exposure, alcohol consumption, and high temperature may affect the abnormal rate of electrocardiogram in the workers exposed to noise in steel-making and steel-rolling workshops.

Diagnostic accuracy of pace spikes in the electrocardiogram to diagnose paced rhythm

DEFF Research Database (Denmark)

Andersson, Hedvig Bille; Hansen, Marco Bo; Thorsberger, Mads

2015-01-01

OBJECTIVE: To determine how often cardiac resynchronization therapy (CRT) pacing systems generate visible pace spikes in the electrocardiogram (ECG). METHODS: In 46 patients treated with CRT pacing systems, we recorded ECGs during intrinsic rhythm, atrial pacing and ventricular pacing. ECGs were...

Human Age Recognition by Electrocardiogram Signal Based on Artificial Neural Network

Science.gov (United States)

Dasgupta, Hirak

2016-12-01

The objective of this work is to make a neural network function approximation model to detect human age from the electrocardiogram (ECG) signal. The input vectors of the neural network are the Katz fractal dimension of the ECG signal, frequencies in the QRS complex, male or female (represented by numeric constant) and the average of successive R-R peak distance of a particular ECG signal. The QRS complex has been detected by short time Fourier transform algorithm. The successive R peak has been detected by, first cutting the signal into periods by auto-correlation method and then finding the absolute of the highest point in each period. The neural network used in this problem consists of two layers, with Sigmoid neuron in the input and linear neuron in the output layer. The result shows the mean of errors as -0.49, 1.03, 0.79 years and the standard deviation of errors as 1.81, 1.77, 2.70 years during training, cross validation and testing with unknown data sets, respectively.

Improving the Test-Retest Reliability of Resting State fMRI by Removing the Impact of Sleep

Directory of Open Access Journals (Sweden)

Jiahui Wang

2017-05-01

Full Text Available Resting state functional magnetic resonance imaging (rs-fMRI provides a powerful tool to examine large-scale neural networks in the human brain and their disturbances in neuropsychiatric disorders. Thanks to its low demand and high tolerance, resting state paradigms can be easily acquired from clinical population. However, due to the unconstrained nature, resting state paradigm is associated with excessive head movement and proneness to sleep. Consequently, the test-retest reliability of rs-fMRI measures is moderate at best, falling short of widespread use in the clinic. Here, we characterized the effect of sleep on the test-retest reliability of rs-fMRI. Using measures of heart rate variability (HRV derived from simultaneous electrocardiogram (ECG recording, we identified portions of fMRI data when subjects were more alert or sleepy, and examined their effects on the test-retest reliability of functional connectivity measures. When volumes of sleep were excluded, the reliability of rs-fMRI is significantly improved, and the improvement appears to be general across brain networks. The amount of improvement is robust with the removal of as much as 60% volumes of sleepiness. Therefore, test-retest reliability of rs-fMRI is affected by sleep and could be improved by excluding volumes of sleepiness as indexed by HRV. Our results suggest a novel and practical method to improve test-retest reliability of rs-fMRI measures.

Normal limits of the electrocardiogram derived from a large database of Brazilian primary care patients.

Science.gov (United States)

Palhares, Daniel M F; Marcolino, Milena S; Santos, Thales M M; da Silva, José L P; Gomes, Paulo R; Ribeiro, Leonardo B; Macfarlane, Peter W; Ribeiro, Antonio L P

2017-06-13

Knowledge of the normal limits of the electrocardiogram (ECG) is mandatory for establishing which patients have abnormal ECGs. No studies have assessed the reference standards for a Latin American population. Our aim was to establish the normal ranges of the ECG for pediatric and adult Brazilian primary care patients. This retrospective observational study assessed all the consecutive 12-lead digital electrocardiograms of primary care patients at least 1 year old in Minas Gerais state, Brazil, recorded between 2010 and 2015. ECGs were excluded if there were technical problems, selected abnormalities were present or patients with selected self-declared comorbidities or on drug therapy. Only the first ECG from patients with multiple ECGs was accepted. The University of Glasgow ECG analysis program was used to automatically interpret the ECGs. For each variable, the 1st, 2nd, 50th, 98th and 99th percentiles were determined and results were compared to selected studies. A total of 1,493,905 ECGs were recorded. 1,007,891 were excluded and 486.014 were analyzed. This large study provided normal values for heart rate, P, QRS and T frontal axis, P and QRS overall duration, PR and QT overall intervals and QTc corrected by Hodges, Bazett, Fridericia and Framingham formulae. Overall, the results were similar to those from other studies performed in different populations but there were differences in extreme ages and specific measurements. This study has provided reference values for Latinos of both sexes older than 1 year. Our results are comparable to studies performed in different populations.

Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study.

Science.gov (United States)

Kemp, Andrew H; López, Santiago Rodríguez; Passos, Valeria M A; Bittencourt, Marcio S; Dantas, Eduardo M; Mill, José G; Ribeiro, Antonio L P; Thayer, Julian F; Bensenor, Isabela M; Lotufo, Paulo A

2016-05-01

Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship. Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N=8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B). Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment. Copyright © 2016 Elsevier B.V. All rights reserved.

Value of electrocardiogram in predialytic chronic kidney disease patient without known coronary artery disease

Directory of Open Access Journals (Sweden)

Dutta PK, Das S

2014-11-01

Full Text Available Chronic Kidney disease (CKD is a pressing public health burden occurring in about 10% of the population. The majority of them die before reaching End Stage Renal Disease (ESRD due to cardiovascular disease (CVD. Hypertension (HTN and anaemia are two reversible factors for progression of CKD. Besides asymptomatic coronary artery disease, the electrolyte abnormalities such as hyperkalaemia and hypocalcaemia also subject these patients to sudden cardiac death. This study is aimed at to see the changes in electrocardiogram (ECG in hospitalized predialytic CKD patients due to these abnormalities. Methods: This is a 6 months cross-sectional study carried out at Chittagong Medical College Hospital in Chittagong, Bangladesh. 50 patients with stages 3, 4 and 5 CKD were recruited from the Nephrology and Medicine wards. Patients with prior history of coronary artery disease, cardiomyopathy, valvular heart disease and dialysis were excluded. All had their standard 12–lead electrocardiogram (ECG recorded and various findings were critically studied and interpreted independently by two consultant physicians including a cardiologist. Data analysis was done using SPSS version 19. Results: LVH (left ventricular hypertrophy (66%, LAE (left atrial enlargement (30% and unrecognized myocardial infarction (28% were very common ECG abnormalities in our predialytic CKD patients. HTN, anaemia, late presentation, and male gender appear to be associated with ECG abnormalities. Though 28 patients (56% were hyperkalaemic only 9 patients (38% of them had tall tented T wave in ECG. Conclusion: Detection of HTN and anaemia in male predialytic CKD patients will arouse suspicion which will help in early detection of cardiac outcome by ECG abnormality which will help in taking treatment strategy in resource limited country.

Factors associated with failure to identify the culprit artery by the electrocardiogram in inferior ST-elevation myocardial infarction

DEFF Research Database (Denmark)

Tahvanainen, Minna; Nikus, Kjell C; Holmvang, Lene

2011-01-01

Right and left circumflex coronary artery occlusions cause inferior myocardial infarction. To improve the targeting of diagnostic and therapeutic measures individually, factors interfering with identification of the culprit artery by the electrocardiogram (ECG) were explored.......Right and left circumflex coronary artery occlusions cause inferior myocardial infarction. To improve the targeting of diagnostic and therapeutic measures individually, factors interfering with identification of the culprit artery by the electrocardiogram (ECG) were explored....

An Unusual Case of Alternating Ventricular Morphology on the 12-Lead Electrocardiogram.

Science.gov (United States)

Sammon, Maura; Dawood, Alveena; Beaudoin, Scott; Harrigan, Richard A

2017-03-01

One of the principal tasks of an emergency physician is identifying potentially life-threatening conditions in the undifferentiated patient; cardiac dysrhythmia is an example of such a condition. A systematic approach to a patient with atypical dysrhythmia enables proper identification of such-life threatening conditions. We describe a 31-year-old man presenting to the emergency department with an undifferentiated dysrhythmia after naloxone reversal of an opiate overdose. A systematic approach to the electrocardiogram led to the rare diagnosis of Wolff-Parkinson-White (WPW) alternans. We review the differential diagnosis of this dysrhythmia and the initial evaluation of a patient with the WPW pattern present on their electrocardiogram. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be prepared to use a systematic approach to an undifferentiated dysrhythmia to identify potentially life-threatening conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

The asymptomatic teenager with an abnormal electrocardiogram.

Science.gov (United States)

Singh, Harinder R

2014-02-01

Use of medications for attention-deficit hyperkinetic disorder and preparticipation sports physical examination has led to an increase in number of electrocardiograms (ECG) performed during adolescence. Interpreting ECGs in children and young adults must take into account the evolutionary changes with age and the benign variants, which are usually not associated with heart disease. It is crucial for primary-care providers to recognize the changes on ECG associated with heart disease and risk of sudden death. In this article, the significance, sensitivity, specificity, and the diagnostic workup of these findings in the asymptomatic teenager are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

[Limits of cardiac functional adaptation in "top level" resistance athletes].

Science.gov (United States)

Carù, B; Righetti, G; Bossi, M; Gerosa, C; Gazzotti, G; Maranetto, D

2001-02-01

Sports activity, particularly when performed at high level, provokes cardiovascular adjustments depending on the type of sport and on the level of the load. We evaluated 15 athletes from the Italian national team during a non-agonistic period of cross country skiing, with non-invasive tests including exercise test, color Doppler echocardiography, Holter monitoring, physical examination and standard rest electrocardiogram. Physical examination, rest electrocardiogram, exercise testing and echocardiography were all within the range of the expected values for this type of subjects. Holter monitoring recorded during the periods of agonistic activity revealed significant hypokinetic arrhythmias such as severe bradycardia, pauses, I and II degree atrioventricular blocks, and complete atrioventricular block in 2 cases; these features were not observed on Holter monitoring recorded during the non-agonistic period. The perfect health status of subjects and their racing results may bring about physiological functional adjustments, but these observations suggest the need for a follow-up to evaluate possible pathologic outcomes.

Comparison of qtc duration on electrocardiogram between patients of liver cirrhosis and non cirrhotic controls

International Nuclear Information System (INIS)

Umair, M.; Nadeem, K.; Azam, M.N.; Mansoor, J.; Khan, H.

2012-01-01

Objective: To compare the QTc duration on electrocardiogram (ECG) of patients of cirrhosis (hep B and C origin) with non cirrhotic controls. Study Design: Case control study. Place and duration of study: The study was carried out at the Department of Medicine, Military Hospital, Rawalpindi, from 8th Feb 2009 to 8th Aug 2009. Material and Method: After meeting the exclusion and inclusion criteria, 80 cirrhotic patients were enrolled in group-I and equal number of non cirrhotic controls were enrolled in group-II. Three 12 lead ECG recording were taken for each patient, 5 minutes apart, and QTc value was calculated for each ECG and then mean of the three was used for the analysis. A QTc value more than 0.44 seconds was taken as prolonged. Results: The mean QTc interval on electrocardiogram in group-I i.e. cirrhotic was 0.4603 seconds (SD+-0.1312) and mean QTc interval on electrocardiogram in group-II i.e. noncirrhotic was 0.407 seconds (SD+-0.029). These findings were statistically significant (p value < 0.001). Conclusion: Cirrhotic patients have prolonged QTc interval as compared to noncirrhotic controls. (author)

Electrocardiogram application based on heart rate variability ontology and fuzzy markup language

NARCIS (Netherlands)

Wang, M.-H.; Lee, C.-S.; Acampora, G.; Loia, V.; Gacek, A.; Pedrycz, W.

2011-01-01

The electrocardiogram (ECG) signal is adopted extensively as a low-cost diagnostic procedure to provide information concerning the healthy status of the heart. Heart rate variability (HRV) is a physiological phenomenon where the time interval between heart beats varies. It is measured by the

Restful Implementation of Catalogue Service for Geospatial Data Provenance

Science.gov (United States)

Jiang, L. C.; Yue, P.; Lu, X. C.

2013-10-01

Provenance, also known as lineage, is important in understanding the derivation history of data products. Geospatial data provenance helps data consumers to evaluate the quality and reliability of geospatial data. In a service-oriented environment, where data are often consumed or produced by distributed services, provenance could be managed by following the same service-oriented paradigm. The Open Geospatial Consortium (OGC) Catalogue Service for the Web (CSW) is used for the registration and query of geospatial data provenance by extending ebXML Registry Information Model (ebRIM). Recent advance of the REpresentational State Transfer (REST) paradigm has shown great promise for the easy integration of distributed resources. RESTful Web Service aims to provide a standard way for Web clients to communicate with servers based on REST principles. The existing approach for provenance catalogue service could be improved by adopting the RESTful design. This paper presents the design and implementation of a catalogue service for geospatial data provenance following RESTful architecture style. A middleware named REST Converter is added on the top of the legacy catalogue service to support a RESTful style interface. The REST Converter is composed of a resource request dispatcher and six resource handlers. A prototype service is developed to demonstrate the applicability of the approach.

Comparison between exercise electrocardiogram and thallium 201 myocardial perfusion imaging during exercise, after dipyridamole and at rest, for the diagnosis of stable angina pectoris. 176 cases were studied with coronary angiography

International Nuclear Information System (INIS)

Machecourt, J.; Denis, B.; Comet, M.; Wolf, J.E.; Dimitriou, R.; Pellet, J.; Noel, P.M.

1981-01-01

The purpose of this study was to compare the diagnostic interest of the electrocardiogram stress test (EST) and the thallium myocardial imaging during exercise (TIE). For this, the cases of 176 patients with stable angina pectoris who underwent a coronary arteriogram were studied. These patients were divided into two groups: a first group of 113 patients without a previous history of myocardial infarction, nor a Q wave on their electrocardiogram and a second group of 63 patients with angina pectoris after a previous myocardial infarction. All patients underwent a combined EST and TIE. The sensitivity and the specificity of the EST and the TIE were studied, and the post-test risk after either a positive test or a negative test was calculated according to Bayes' theorem. In the first group 62 patients had a coronary stenosis and 51 had a normal arteriogram. The sensitivity of the TIE was higher than that of the EST: 80% versus 64%, p < 0.01. Even when the maximum effort was not reached during the EST, the TIE kept the same sensitivity. The diagnosis of angina pectoris cannot be absolutely established by the separate use of the TIE or the EST. However, their predictive value increases when both are correlated. Moreover, for female patients, the TIE is more specific than the EST because of the higher frequency of false positive or equivocal results of the EST in that population. (Auth.)

[Syncope: electrocardiogram and autonomic function tests].

Science.gov (United States)

Uribe, William; Baranchuk, Adrián; Botero, Federico

2016-12-23

Syncope represents one of the most frequent reasons for consultation in the emergency department. A proper identification will allow a precise etiologic approach and the optimization of delivery of health resources.
Once knowing the classification of syncope; it is the clinical interrogatory what enables to discriminate which of these patients present with a neurogenic mediated syncope or a cardiac mediated syncope. The use of diagnostic methods such as the tilt test, will clarify what type of neurally mediated syncope predominates in the patient.
The electrocardiogram is the cornerstone in the identification of those patients who had a true episode of self-limited or aborted sudden death as the first manifestation of their syncope, a fact which provides prognostic and therapeutic information that will impact the morbidity and mortality.

Assessment of left ventricular function using 201Tl electrocardiogram-gated myocardial single photon emission computed tomography

International Nuclear Information System (INIS)

Nishikubo, Naotsugu; Tamai, Hiroyuki

2013-01-01

Advances in computed tomography (CT) technology make it possible to obtain left ventricular wall motion using 3D reconstruction. In this study, we compared the images obtained from CT and 201 Tl electrocardiogram (ECG) gated single photon emission computed tomography (SPECT). In 20 patients with ischemic heart disease, we performed 201 Tl ECG gated SPECT (GE Healthcare Millennium VG) and ECG gated CT (Philips Medical Systems Brilliance iCT) to evaluate of left ventricular wall motion during the resting phase. In SPECT, left ventricular images were reconstructed using quantitative gated SPECT (QGS) software. In CT, the images were reconstructed using Virtual Place (AZE Software). The left ventricle was classified into five regions (anterior, lateral, inferior, septal, and apical). The amplitude of the wall motion was classified into five grades according to AHA classification. The values of the wall motion were separately checked by two radiographers. Assessment of left ventricular function myocardial wall movement using the three-dimensional movie display with ECG gated myocardial SPECT data was in agreement with the evaluation by cardiac CT inspection, and corresponded with wall motion in 88 of all 100 segments. SPECT analysis has the same quantity as that of obtained from CT for evaluation of left ventricular wall motion. (author)

Exercise thallium-201 scintigraphy in men with nondiagnostic exercise electrocardiograms. Prognostic implications

International Nuclear Information System (INIS)

Iskandrian, A.S.; Hakki, A.H.; Kane-Marsch, S.

1986-01-01

We studied the prognostic value of exercise thallium-201 imaging in 196 men with suspected or known coronary artery disease who had nondiagnostic exercise electrocardiograms. The perfusion images in each of three projections were divided into three segments; each segment was assessed for perfusion defects (fixed or reversible). There were 12 cardiac events at a mean follow-up of 15 months (range, one to 66 months). Of those, five patients died of cardiac causes and seven had nonfatal acute myocardial infarctions (MIs). Only the number of perfusion defects significantly predicted cardiac events; clinical presentation, history of MI, presence of Q-wave MI, exercise duration, and exercise heart rate and double product did not predict cardiac events or add to information provided by the number of defects. Furthermore, actuarial life-table analysis showed that patients with three or more perfusion defects had significantly worse prognoses than patients with fewer than three defects. Exercise thallium-201 imaging helps in risk stratification of men with nondiagnostic exercise electrocardiograms

Electrocardiogram of the Mixmaster universe

International Nuclear Information System (INIS)

Bini, Donato; Cherubini, Christian; Geralico, Andrea; Jantzen, Robert T

2009-01-01

The Mixmaster dynamics is revisited in a new light as revealing a series of transitions in the complex scale invariant scalar invariant of the Weyl curvature tensor best represented by the speciality index S, which gives a four-dimensional measure of the evolution of the spacetime independent of all the three-dimensional gauge-dependent variables except for the time used to parametrize it. Its graph versus time characterized by correlated isolated pulses in its real and imaginary parts corresponding to curvature wall collisions serves as a sort of electrocardiogram of the Mixmaster universe, with each such pulse pair arising from a single circuit or 'complex pulse' around the origin in the complex plane. These pulses in the speciality index and their limiting points on the real axis seem to invariantly characterize some of the so-called spike solutions in inhomogeneous cosmology and should play an important role as a gauge-invariant lens through which to view current investigations of inhomogeneous Mixmaster dynamics.

Towards Quasi-continuous Heart Rate Variability Estimation using a Patch Type Electrocardiogram Recorder

DEFF Research Database (Denmark)

Bodholt Saadi, Dorthe; Ahrens, Esben; Sørensen, Helge Bjarup Dissing

2015-01-01

electrocardiogram recorders facilitates new possibilities for long-term monitoring, real-time data analysis, and wireless transmission of clinically relevant parameters, e.g. short-term HRV measures. This information might in the future assist the healthcare professionals in timely notification of changes...

Cumulative dose of hydroxychloroquine is associated with a decrease of resting heart rate in patients with systemic lupus erythematosus: a pilot study.

Science.gov (United States)

Cairoli, E; Danese, N; Teliz, M; Bruzzone, M J; Ferreira, J; Rebella, M; Cayota, A

2015-10-01

The use of hydroxychloroquine (HCQ) in patients with systemic lupus erythematosus (SLE) offers a wide range of benefits. However, there are evidence in favour of cardiotoxicity, including heart conduction disturbances and congestive heart failure. To determine the effects of HCQ in the resting heart rate (RHR) of SLE patients. Included were patients with non active SLE, with a sedentary lifestyle and treated with HCQ. Excluded were patients on beta blocker treatment, trained patients, pacemaker's users and patients with clinical or analytical evidence of anemia, renal disease, obstructive pulmonary disease, obesity, uncontrolled thyroid disease, fever or current infection. Standard 12-lead electrocardiogram was performed in the resting condition (supine decubitus and orthostatic position). Comparison between groups was performed using Mann-Whitney U test. A multiple linear regression was performed. A p value 365 g). Non significant differences were found in age, sex, prednisone dose or SLEDAI. The mean RHR was 73 ± 6 beats/min in the low-HCQ and 65 ± 7 beats/min in the high-HCQ, with a significant decrease of 11% (p = 0.003). In multiple linear regressions, there were non significant association between the decrease of RHR and prednisone dose, age, SLEDAI or TSH, but there was significant association between RHR and CD-HCQ (p = 0.024) and RHR and time of exposure to HCQ (p = 0.029). CD-HCQ higher than 365 g was associated with a significant decrease (11%) in RHR in non-active SLE patients, although a larger prospective study is required to allow more definitive conclusions. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

WEB-SERVICE. RESTFUL ARCHITECTURE

Directory of Open Access Journals (Sweden)

M. Melnichuk

2018-04-01

Full Text Available Network technology for interaction between two applications via the HTTP protocol was considered in article.When client works with REST API - it means it works with "resources", and in SOAP work is performed with operations. To build REST web services, you must follow certain principles: explicit use of HTTP methods, access to resources by URI, stateless, HATEAOS, caching, transfer of objects in JSON or XML representation. But sometimes some principles are ignored to ensure a higher speed of work and to reduce development time.The pros and cons of using JSON and XML representations were considered, and it can be said that using the JSON format reduces the amount of data transfer, and with the use of XML, the readability of data increases.Also, two main ways of data transfer in REST web services were considered: converting the file to Base64 and transferring it as an object field or transferring the file using the usual HTTP multipart. The Base64 standard approach gives a higher speed for multiple files in a single request, because only one HTTP connection is created, but these files are stored in RAM during request processing, which increases chance of the application crashing.In the conclusion, the advantages of using web services and their wide use in other architectural approaches were considered, which increases the popularity of web services.

Wavelet-based unsupervised learning method for electrocardiogram suppression in surface electromyograms.

Science.gov (United States)

Niegowski, Maciej; Zivanovic, Miroslav

2016-03-01

We present a novel approach aimed at removing electrocardiogram (ECG) perturbation from single-channel surface electromyogram (EMG) recordings by means of unsupervised learning of wavelet-based intensity images. The general idea is to combine the suitability of certain wavelet decomposition bases which provide sparse electrocardiogram time-frequency representations, with the capacity of non-negative matrix factorization (NMF) for extracting patterns from images. In order to overcome convergence problems which often arise in NMF-related applications, we design a novel robust initialization strategy which ensures proper signal decomposition in a wide range of ECG contamination levels. Moreover, the method can be readily used because no a priori knowledge or parameter adjustment is needed. The proposed method was evaluated on real surface EMG signals against two state-of-the-art unsupervised learning algorithms and a singular spectrum analysis based method. The results, expressed in terms of high-to-low energy ratio, normalized median frequency, spectral power difference and normalized average rectified value, suggest that the proposed method enables better ECG-EMG separation quality than the reference methods. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Is there evidence for mandating electrocardiogram as part of the pre-participation examination?

Science.gov (United States)

Borjesson, Mats; Dellborg, Mikael

2011-01-01

The risk of sudden cardiac death may be increased up to 2.8 times in competitive athletes compared with nonathletes. The majority of sudden cardiac death cases are caused by an underlying abnormality that potentially may be identified on cardiovascular screening, depending on the specific abnormality and the content of the cardiovascular screening applied. Indeed, today, cardiac screening is universally recommended by the cardiac societies [European Society of Cardiology (ESC) and American Heart Association (AHA)] and required by the sporting bodies [Fédération Internationale de Football Association (FIFA) and Union of European Football Associations (UEFA)]. Pre-participation examination is by consensus understood to include personal history and physical examination; controversy exists regarding the usefulness and appropriateness of screening using resting 12-lead electrocardiogram (ECG), with an apparent transatlantic difference. The ESC recommends screening consisting of personal history, physical examination, and 12-lead resting ECG, whereas recommendations from the AHA includes only personal history and physical examination. There is firm scientific ground to state that the sensitivity of screening with ECG is vastly superior to, and the cost-effectiveness significantly better than, screening without ECG. Cardiac screening of elite athletes with personal history, physical examination, and ECG is cost-effective also in comparison with other well-accepted procedures of modern health care, such as dialysis and implantable cardiac defibrillators. Newly published recommendations for the interpretation of the ECG in athletes (ESC) and future studies on ECGs in athletes of different ethnicity, gender, and age may further increase the specificity of ECG in cardiac screening, refining the screening procedure and lowering the costs for additional follow-up testing. Cardiac screening without ECG is not cost-effective and may be only marginally better than no screening

The NASA Bed Rest Project

Science.gov (United States)

Rhodes, Bradley; Meck, Janice

2005-01-01

NASA s National Vision for Space Exploration includes human travel beyond low earth orbit and the ultimate safe return of the crews. Crucial to fulfilling the vision is the successful and timely development of countermeasures for the adverse physiological effects on human systems caused by long term exposure to the microgravity environment. Limited access to in-flight resources for the foreseeable future increases NASA s reliance on ground-based analogs to simulate these effects of microgravity. The primary analog for human based research will be head-down bed rest. By this approach NASA will be able to evaluate countermeasures in large sample sizes, perform preliminary evaluations of proposed in-flight protocols and assess the utility of individual or combined strategies before flight resources are requested. In response to this critical need, NASA has created the Bed Rest Project at the Johnson Space Center. The Project establishes the infrastructure and processes to provide a long term capability for standardized domestic bed rest studies and countermeasure development. The Bed Rest Project design takes a comprehensive, interdisciplinary, integrated approach that reduces the resource overhead of one investigator for one campaign. In addition to integrating studies operationally relevant for exploration, the Project addresses other new Vision objectives, namely: 1) interagency cooperation with the NIH allows for Clinical Research Center (CRC) facility sharing to the benefit of both agencies, 2) collaboration with our International Partners expands countermeasure development opportunities for foreign and domestic investigators as well as promotes consistency in approach and results, 3) to the greatest degree possible, the Project also advances research by clinicians and academia alike to encourage return to earth benefits. This paper will describe the Project s top level goals, organization and relationship to other Exploration Vision Projects, implementation

Resting state fMRI: A review on methods in resting state connectivity analysis and resting state networks.

Science.gov (United States)

Smitha, K A; Akhil Raja, K; Arun, K M; Rajesh, P G; Thomas, Bejoy; Kapilamoorthy, T R; Kesavadas, Chandrasekharan

2017-08-01

The inquisitiveness about what happens in the brain has been there since the beginning of humankind. Functional magnetic resonance imaging is a prominent tool which helps in the non-invasive examination, localisation as well as lateralisation of brain functions such as language, memory, etc. In recent years, there is an apparent shift in the focus of neuroscience research to studies dealing with a brain at 'resting state'. Here the spotlight is on the intrinsic activity within the brain, in the absence of any sensory or cognitive stimulus. The analyses of functional brain connectivity in the state of rest have revealed different resting state networks, which depict specific functions and varied spatial topology. However, different statistical methods have been introduced to study resting state functional magnetic resonance imaging connectivity, yet producing consistent results. In this article, we introduce the concept of resting state functional magnetic resonance imaging in detail, then discuss three most widely used methods for analysis, describe a few of the resting state networks featuring the brain regions, associated cognitive functions and clinical applications of resting state functional magnetic resonance imaging. This review aims to highlight the utility and importance of studying resting state functional magnetic resonance imaging connectivity, underlining its complementary nature to the task-based functional magnetic resonance imaging.

RESTful NET

CERN Document Server

Flanders, Jon

2008-01-01

RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

Resting 12-lead electrocardiogram reveals high-risk sources of cardioembolism in young adult ischemic stroke.

Science.gov (United States)

Pirinen, Jani; Putaala, Jukka; Aro, Aapo L; Surakka, Ida; Haapaniemi, Anita; Kaste, Markku; Haapaniemi, Elena; Tatlisumak, Turgut; Lehto, Mika

2015-11-01

The diagnostic work-up to reveal etiology in a young ischemic stroke (IS) patient includes evaluation for high-risk source of cardioembolism (HRCE), since this subtype associates with high early recurrence rate and mortality. We investigated the association of ECG findings with a final etiologic subgroup of HRCE in a cohort of young patients with first-ever IS. The Helsinki Young Stroke Registry includes IS patients aged 15 to 49 years admitted between 1994 and 2007. Blinded to other clinical data, we analyzed a 12-lead resting ECG obtained 1-14 days after the onset of stroke symptoms in 690 patients. We then compared the ECG findings between a final diagnosis of HRCE (n=78) and other/undetermined causes (n=612). We used multivariate logistic regression to study the association between ECG parameters and HRCE. Of our cohort (63% male), 35% showed ECG abnormality, the most common being T-wave inversion (16%), left ventricular hypertrophy (14%), prolonged P-wave (13%), and prolonged QTc (12%). 3% had atrial fibrillation (AF), and 4% P-terminal force (PTF). Of the continuous parameters, longer QRS-duration, QTc, and wider QRS-T-angle independently associated with HRCE. After AF, PTF had the strongest independent association with HRCE (odds ratio=44.32, 95% confidence interval=[10.51-186.83]), followed by a QRS-T angle >110° (8.29 [3.55-19.32]), T-wave inversion (5.06, 2.54-10.05), and prolonged QTc (3.02 [1.39-6.56]). Routine ECG provides useful information for directing the work-up of a young IS patient. In addition to AF, PTF in particular showed a strong association with etiology of HRCE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Value of admission electrocardiogram in predicting outcome of thrombolytic therapy in acute myocardial infarction

NARCIS (Netherlands)

F.W.H.M. Bär (Frits); C. de Zwaan (Chris); S.H. Braat (Simon); M.L. Simoons (Maarten); W.T. Hermens (Wim); A. van der Laarse (Arnoud); W.T. Wellens; M. Ramentol; F.W.A. Verheugt (Freek); F. Vermeer (Frank); X.H. Krauss

1987-01-01

textabstractTo determine the value of the admission 12-lead electrocardiogram to predict infarct size limitation by thrombolytic therapy, data were analyzed in 488 of 533 patients with acute myocardial infarction (AMI) from a randomized multicenter study. All patients had typical

Automatic Real-Time Embedded QRS Complex Detection for a Novel Patch-Type Electrocardiogram Recorder

DEFF Research Database (Denmark)

Saadi, Dorthe Bodholt; Tanev, George; Flintrup, Morten

2015-01-01

Cardiovascular diseases are projected to remain the single leading cause of death globally. Timely diagnosis and treatment of these diseases are crucial to prevent death and dangerous complications. One of the important tools in early diagnosis of arrhythmias is analysis of electrocardiograms (ECGs...

Automatic QRS complex detection algorithm designed for a novel wearable, wireless electrocardiogram recording device

DEFF Research Database (Denmark)

Saadi, Dorthe Bodholt; Egstrup, Kenneth; Branebjerg, Jens

2012-01-01

We have designed and optimized an automatic QRS complex detection algorithm for electrocardiogram (ECG) signals recorded with the DELTA ePatch platform. The algorithm is able to automatically switch between single-channel and multi-channel analysis mode. This preliminary study includes data from ...

Improvement of electrocardiogram by empirical wavelet transform

Science.gov (United States)

Chanchang, Vikanda; Kumchaiseemak, Nakorn; Sutthiopad, Malee; Luengviriya, Chaiya

2017-09-01

Electrocardiogram (ECG) is a crucial tool in the detection of cardiac arrhythmia. It is also often used in a routine physical exam, especially, for elderly people. This graphical representation of electrical activity of heart is obtained by a measurement of voltage at the skin; therefore, the signal is always contaminated by noise from various sources. For a proper interpretation, the quality of the ECG should be improved by a noise reduction. In this article, we present a study of a noise filtration in the ECG by using an empirical wavelet transform (EWT). Unlike the traditional wavelet method, EWT is adaptive since the frequency spectrum of the ECG is taken into account in the construction of the wavelet basis. We show that the signal-to-noise ratio increases after the noise filtration for different noise artefacts.

Chameleons: Electrocardiogram Imitators of ST-Segment Elevation Myocardial Infarction.

Science.gov (United States)

Nable, Jose V; Lawner, Benjamin J

2015-08-01

The imperative for timely reperfusion therapy for patients presenting with ST-segment elevation myocardial infarction (STEMI) underscores the need for clinicians to have an understanding of how to distinguish patterns of STEMI from its imitators. These imitating diagnoses may confound an evaluation, potentially delaying necessary therapy. Although numerous diagnoses may mimic STEMI, several morphologic clues may allow the physician to determine if the pattern is concerning for either STEMI or a mimicking diagnosis. Furthermore, obtaining a satisfactory history, comparing previous electrocardiograms, and assessing serial tests may provide valuable clues. Copyright © 2015 Elsevier Inc. All rights reserved.

Major depressive disorder with melancholia displays robust alterations in resting state heart rate and its variability: Implications for future morbidity and mortality

Directory of Open Access Journals (Sweden)

Andrew eKemp

2014-11-01

Full Text Available Background: Major depressive disorder (MDD is associated with increased heart rate and reductions in its variability (HRV – markers of future morbidity and mortality – yet prior studies have reported contradictory effects. We hypothesised that increases in heart rate and reductions in HRV would be more robust in melancholia relative to controls, than in patients with non-melancholia. Methods: A total of 72 patients with a primary diagnosis of MDD (age M: 36.26, SE: 1.34; 42 females and 94 controls (age M: 35.69, SE: 1.16; 52 females were included in this study. Heart rate and measures of its variability (HRV were calculated from two 2-minute electrocardiogram recordings during resting state. Propensity score matching controlled imbalance on potential confounds between patients with melancholia (n=40 and non-melancholia (n=32 including age, gender, disorder severity and comorbid anxiety disorders. Results: MDD patients with melancholia displayed significantly increased heart rate and lower resting-state HRV (including the square root of the mean squared differences between successive N–N intervals, the absolute power of high frequency and standard deviation of the Poincaré plot perpendicular to the line of identity measures of HRV relative to controls, findings associated with a moderate effect size (Cohens d’s = 0.56-0.58. Patients with melancholia also displayed an increased heart rate relative to those with non-melancholia (Cohen’s d = 0.20.Conclusion: MDD patients with melancholia – but not non-melancholia – display robust increases in heart rate and decreases in HRV. These findings may underpin a variety of behavioural impairments in patients with melancholia including somatic symptoms, cognitive impairment, reduced responsiveness to the environment, and over the longer-term, morbidity and mortality.

Holter-electrocardiogram-monitoring in patients with acute ischaemic stroke (Find-AFRANDOMISED): an open-label randomised controlled trial.

Science.gov (United States)

Wachter, Rolf; Gröschel, Klaus; Gelbrich, Götz; Hamann, Gerhard F; Kermer, Pawel; Liman, Jan; Seegers, Joachim; Wasser, Katrin; Schulte, Anna; Jürries, Falko; Messerschmid, Anna; Behnke, Nico; Gröschel, Sonja; Uphaus, Timo; Grings, Anne; Ibis, Tugba; Klimpe, Sven; Wagner-Heck, Michaela; Arnold, Magdalena; Protsenko, Evgeny; Heuschmann, Peter U; Conen, David; Weber-Krüger, Mark

2017-04-01

Atrial fibrillation is a major risk factor for recurrent ischaemic stroke, but often remains undiagnosed in patients who have had an acute ischaemic stroke. Enhanced and prolonged Holter-electrocardiogram-monitoring might increase detection of atrial fibrillation. We therefore investigated whether enhanced and prolonged rhythm monitoring was better for detection of atrial fibrillation than standard care procedures in patients with acute ischaemic stroke. Find-AF randomised is an open-label randomised study done at four centres in Germany. We recruited patients with acute ischaemic stroke (symptoms for 7 days or less) aged 60 years or older presenting with sinus rhythm and without history of atrial fibrillation. Patients were included irrespective of the suspected cause of stroke, unless they had a severe ipsilateral carotid or intracranial artery stenosis, which were the exclusion criteria. We used a computer-generated allocation sequence to randomly assign patients in a 1:1 ratio with permuted block sizes of 2, 4, 6, and 8, stratified by centre, to enhanced and prolonged monitoring (ie, 10-day Holter-electrocardiogram [ECG]-monitoring at baseline, and at 3 months and 6 months of follow-up) or standard care procedures (ie, at least 24 h of rhythm monitoring). Participants and study physicians were not masked to group assignment, but the expert committees that adjudicated endpoints were. The primary endpoint was the occurrence of atrial fibrillation or atrial flutter (30 sec or longer) within 6 months after randomisation and before stroke recurrence. Because Holter ECG is a widely used procedure and not known to harm patients, we chose not to assess safety in detail. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01855035. Between May 8, 2013, and Aug 31, 2014, we recruited 398 patients. 200 patients were randomly assigned to the enhanced and prolonged monitoring group and 198 to the standard care group. After 6

Scaling HEP to Web size with RESTful protocols: The frontier example

International Nuclear Information System (INIS)

Dykstra, Dave

2011-01-01

The World-Wide-Web has scaled to an enormous size. The largest single contributor to its scalability is the HTTP protocol, particularly when used in conformity to REST (REpresentational State Transfer) principles. High Energy Physics (HEP) computing also has to scale to an enormous size, so it makes sense to base much of it on RESTful protocols. Frontier, which reads databases with an HTTP-based RESTful protocol, has successfully scaled to deliver production detector conditions data from both the CMS and ATLAS LHC detectors to hundreds of thousands of computer cores worldwide. Frontier is also able to re-use a large amount of standard software that runs the Web: on the clients, caches, and servers. I discuss the specific ways in which HTTP and REST enable high scalability for Frontier. I also briefly discuss another protocol used in HEP computing that is HTTP-based and RESTful, and another protocol that could benefit from it. My goal is to encourage HEP protocol designers to consider HTTP and REST whenever the same information is needed in many places.

Common Atrium with Unusual Electrocardiogram in Ellis-van Creveld Syndrome: A Case Report

Directory of Open Access Journals (Sweden)

Amit Kumar

2015-01-01

This report describes a case of common atrium with unusual electrocardiographic findings in a patient with EVC syndrome. This 17-year-old male of Indian origin born of a consanguineous marriage had short stature, genu valgum, polydactyly, gingival hypertrophy, multiple frenula, common atrium, and right axis deviation of QRS with clockwise depolarization in electrocardiogram.

Effect of gender on computerized electrocardiogram measurements in college athletes.

Science.gov (United States)

Mandic, Sandra; Fonda, Holly; Dewey, Frederick; Le, Vy-van; Stein, Ricardo; Wheeler, Matt; Ashley, Euan A; Myers, Jonathan; Froelicher, Victor F

2010-06-01

Broad criteria for classifying an electrocardiogram (ECG) as abnormal and requiring additional testing prior to participating in competitive athletics have been recommended for the preparticipation examination (PPE) of athletes. Because these criteria have not considered gender differences, we examined the effect of gender on the computerized ECG measurements obtained on Stanford student athletes. Currently available computer programs require a basis for "normal" in athletes of both genders to provide reliable interpretation. During the 2007 PPE, computerized ECGs were recorded and analyzed on 658 athletes (54% male; mean age, 19 +/- 1 years) representing 22 sports. Electrocardiogram measurements included intervals and durations in all 12 leads to calculate 12-lead voltage sums, QRS amplitude and QRS area, spatial vector length (SVL), and the sum of the R wave in V5 and S wave in V2 (RSsum). By computer analysis, male athletes had significantly greater QRS duration, PR interval, Q-wave duration, J-point amplitude, and T-wave amplitude, and shorter QTc interval compared with female athletes (all P < 0.05). All ECG indicators of left ventricular electrical activity were significantly greater in males. Although gender was consistently associated with indices of atrial and ventricular electrical activity in multivariable analysis, ECG measurements correlated poorly with body dimensions. Significant gender differences exist in ECG measurements of college athletes that are not explained by differences in body size. Our tables of "normal" computerized gender-specific measurements can facilitate the development of automated ECG interpretation for screening young athletes.

Synergistic effect of polymorphisms of paraoxonase gene cluster and arsenic exposure on electrocardiogram abnormality

International Nuclear Information System (INIS)

Liao, Y.-T.; Li, W.-F.; Chen, C.-J.; Prineas, Ronald J.; Chen, Wei J.; Zhang Zhuming; Sun, C.-W.; Wang, S.-L.

2009-01-01

Arsenic has been linked to increased prevalence of cancer and cardiovascular disease (CVD), but the long-term impact of arsenic exposure remains unclear. Human paraoxonase (PON1) is a high-density lipoprotein-associated antioxidant enzyme which hydrolyzes oxidized lipids and is thought to be protective against atherosclerosis, but evidence remains limited to case-control studies. Only recently have genes encoding enzymes responsible for arsenic metabolism, such as AS3MT and GSTO, been cloned and characterized. This study was designed to evaluate the synergistic interaction of genetic factors and arsenic exposure on electrocardiogram abnormality. A total of 216 residents from three tap water implemented villages of previous arseniasis-hyperendemic regions in Taiwan were prospectively followed for an average of 8 years. For each resident, a 12-lead conventional electrocardiogram (ECG) was recorded and coded by Minnesota Code standard criteria. Eight functional polymorphisms of PON1, PON2, AS3MT, GSTO1, and GSTO2 were examined for genetic susceptibility to ECG abnormality. Among 42 incident cases with ECG deterioration identified among 121 baseline-normal subjects, arsenic exposure was significantly correlated with incidence of ECG abnormality. In addition, polymorphisms in two paraoxonase genes were also found associated with the incidence of ECG abnormality. A haplotype R-C-S constituted by polymorphisms of PON1 Q192R, -108C/T and PON2 C311S was linked to the increased risk. Subjects exposed to high levels of As (cumulative As exposure > 14.7 ppm-year or drinking artesian well water > 21 years) and carrying the R-C-S haplotype had significantly increased risks for ECG abnormality over those with only one risk factor. Results of this study showed a long-term arsenic effect on ECG abnormality and significant gene-gene and gene-environment interactions linked to the incidence of CVD. This finding might have important implications for a novel and potentially useful

201Tl myocard scintigraphy - a specialized non-invasive method in evaluating myocardial function

International Nuclear Information System (INIS)

Birke, S.; Deckart, H.; Mischke, W.; Schulz, J.; Koblitz, E.

1985-01-01

In 216 patients with ischemic heart disease (IHK) or with angina pectoris symptoms and suspected IHK the results of resting electrocardiograms were compared with those of 201 Tl scintigraphy under conditions of rest and exercise, resp. 201 Tl scintigraphy proved to be superior in sensitivity and specifity to the electrocardiograms of rest and under exercise as to the detection of coronary heart disease, the localization and assessment of the severity of coronary heart disease, and the evidence of load ischemia. Conclusions are drawn for a program of consecutive diagnostic steps in suspected IHK as well as for the evaluation of myocardial function in known IHK. (author)

77 FR 6127 - Submission of Extended Digital Electrocardiogram Waveform Data; Notice of Public Meeting

Science.gov (United States)

2012-02-07

...] Submission of Extended Digital Electrocardiogram Waveform Data; Notice of Public Meeting AGENCY: Food and... Drug Administration (FDA) is announcing a public meeting to consider changes in how digital... encouraged. There is no fee to attend the meeting, and attendees who do not wish to make an oral presentation...

Normal ranges for fetal electrocardiogram values for the healthy fetus of 18-24 weeks of gestation: a prospective cohort study.

Science.gov (United States)

Verdurmen, Kim M J; Lempersz, Carlijn; Vullings, Rik; Schroer, Christian; Delhaas, Tammo; van Laar, Judith O E H; Oei, S Guid

2016-08-17

The fetal anomaly ultrasound only detects 65 to 81 % of the patients with congenital heart disease, making it the most common structural fetal anomaly of which a significant part is missed during prenatal life. Therefore, we need a reliable non-invasive diagnostic method which improves the predictive value for congenital heart diseases early in pregnancy. Fetal electrocardiography could be this desired diagnostic method. There are multiple technical challenges to overcome in the conduction of the fetal electrocardiogram. In addition, interpretation is difficult due to the organisation of the fetal circulation in utero. We want to establish the normal ranges and values of the fetal electrocardiogram parameters in healthy fetuses of 18 to 24 weeks of gestation. Women with an uneventful singleton pregnancy between 18 and 24 weeks of gestation are asked to participate in this prospective cohort study. A certified and experienced sonographist performs the fetal anomaly scan. Subsequently, a fetal electrocardiogram recording is performed using dedicated signal processing methods. Measurements are performed at two institutes. We will include 300 participants to determine the normal values and 95 % confidence intervals of the fetal electrocardiogram parameters in a healthy fetus. We will evaluate the fetal heart rate, segment intervals, normalised amplitude and the fetal heart axis. Three months postpartum, we will evaluate if a newborn is healthy through a questionnaire. Fetal electrocardiography could be a promising tool in the screening program for congenital heart diseases. The electrocardiogram is a depiction of the intimate relationship between the cardiac nerve conduction pathways and the structural morphology of the fetal heart, and therefore particularly suitable for the detection of secondary effects due to a congenital heart disease (hypotrophy, hypertrophy and conduction interruption).

REST: a toolkit for resting-state functional magnetic resonance imaging data processing.

Directory of Open Access Journals (Sweden)

Xiao-Wei Song

Full Text Available Resting-state fMRI (RS-fMRI has been drawing more and more attention in recent years. However, a publicly available, systematically integrated and easy-to-use tool for RS-fMRI data processing is still lacking. We developed a toolkit for the analysis of RS-fMRI data, namely the RESting-state fMRI data analysis Toolkit (REST. REST was developed in MATLAB with graphical user interface (GUI. After data preprocessing with SPM or AFNI, a few analytic methods can be performed in REST, including functional connectivity analysis based on linear correlation, regional homogeneity, amplitude of low frequency fluctuation (ALFF, and fractional ALFF. A few additional functions were implemented in REST, including a DICOM sorter, linear trend removal, bandpass filtering, time course extraction, regression of covariates, image calculator, statistical analysis, and slice viewer (for result visualization, multiple comparison correction, etc.. REST is an open-source package and is freely available at http://www.restfmri.net.

Rejection of the maternal electrocardiogram in the electrohysterogram signal.

Science.gov (United States)

Leman, H; Marque, C

2000-08-01

The electrohysterogram (EHG) signal is mainly corrupted by the mother's electrocardiogram (ECG), which remains present despite analog filtering during acquisition. Wavelets are a powerful denoising tool and have already proved their efficiency on the EHG. In this paper, we propose a new method that employs the redundant wavelet packet transform. We first study wavelet packet coefficient histograms and propose an algorithm to automatically detect the histogram mode number. Using a new criterion, we compute a best basis adapted to the denoising. After EHG wavelet packet coefficient thresholding in the selected basis, the inverse transform is applied. The ECG seems to be very efficiently removed.

Availability of a baseline Electrocardiogram changes the application of the Sclarovsky-Birnbaum Myocardial Ischemia Grade

DEFF Research Database (Denmark)

Carlsen, Esben A; Bang, Lia E; Køber, Lars

2014-01-01

BACKGROUND AND AIMS: The electrocardiogram (ECG) based Sclarovsky-Birnbaum Ischemia Grade may be used to determine the prognosis of patients with ST-elevation myocardial infarction (STEMI). However, application of the method is based on assumption of the baseline QRS morphology. Thus, the aims...

REST based mobile applications

Science.gov (United States)

Rambow, Mark; Preuss, Thomas; Berdux, Jörg; Conrad, Marc

2008-02-01

Simplicity is the major advantage of REST based webservices. Whereas SOAP is widespread in complex, security sensitive business-to-business aplications, REST is widely used for mashups and end-user centric applicatons. In that context we give an overview of REST and compare it to SOAP. Furthermore we apply the GeoDrawing application as an example for REST based mobile applications and emphasize on pros and cons for the use of REST in mobile application scenarios.

[Research on electrocardiogram de-noising algorithm based on wavelet neural networks].

Science.gov (United States)

Wan, Xiangkui; Zhang, Jun

2010-12-01

In this paper, the ECG de-noising technology based on wavelet neural networks (WNN) is used to deal with the noises in Electrocardiogram (ECG) signal. The structure of WNN, which has the outstanding nonlinear mapping capability, is designed as a nonlinear filter used for ECG to cancel the baseline wander, electromyo-graphical interference and powerline interference. The network training algorithm and de-noising experiments results are presented, and some key points of the WNN filter using ECG de-noising are discussed.

Cost-effectiveness of cardiotocography plus ST analysis of the fetal electrocardiogram compared with cardiotocography only

NARCIS (Netherlands)

Vijgen, Sylvia M. C.; Westerhuis, Michelle E. M. H.; Opmeer, Brent C.; Visser, Gerard H. A.; Moons, Karl G. M.; Porath, Martina M.; Oei, Guid S.; van Geijn, Herman P.; Bolte, Antoinette C.; Willekes, Christine; Nijhuis, Jan G.; van Beek, Erik; Graziosi, Giuseppe C. M.; Schuitemaker, Nico W. E.; van Lith, Jan M. M.; van den Akker, Eline S. A.; Drogtrop, Addy P.; van Dessel, Hendrikus J. H. M.; Rijnders, Robbert J. P.; Oosterbaan, Herman P.; Mol, Ben Willem J.; Kwee, Anneke

2011-01-01

To assess the cost-effectiveness of addition of ST analysis of the fetal electrocardiogram (ECG; STAN) to cardiotocography (CTG) for fetal surveillance during labor compared with CTG only. Cost-effectiveness analysis based on a randomized clinical trial on ST analysis of the fetal ECG. Obstetric

Immediate rule-out of acute myocardial infarction using electrocardiogram and baseline high-sensitivity troponin I

DEFF Research Database (Denmark)

Neumann, Johannes Tobias; Sörensen, Nils Arne; Ojeda, Francisco

2017-01-01

AIMS: Serial measurements of high-sensitivity troponin are used to rule out acute myocardial infarction (AMI) with an assay specific cutoff at the 99th percentile. Here, we evaluated the performance of a single admission troponin with a lower cutoff combined with a low risk electrocardiogram (ECG...

64-slice spiral CT coronary angiography with prospective electrocardiogram-gating: an initial study

International Nuclear Information System (INIS)

Yuan Xuchun; Wang Xianzhu; Liao Wenling; Chen Qin; Deng Huiyi

2008-01-01

Objective: To evaluate the feasibility of prospective electrocardiogram (ECG)-gating computed tomography coronary angiography (CTCA). Methods: Sixty patients with suspected or known coronary artery disease underwent 64-slice CTCA using prospective ECG-gating. Multi-planar reconstruction ( MPR), curved-planar reconstruction (CPR), maximum intensity projection (MIP) and volume rendering (VR) were used to demonstrate the coronary arteries. The image quality and radiation dose was evaluated. Results: The mean effective radiation dose was (2.7±0.2) mSv. 93.3% (720/772) segments of all coronary arteries were of diagnostic image quality, 44.2% (341/772)was classified as excellent and 49.1% (379/772)was good. Non-diagnostic coronary segments were found in 6.7% (52/772) of all coronary arteries. There were 5(8.3%) cases with severe coronary stenosis(>75%) or occlusion, 17 (28.4%) cases with moderate stenosis (50%-75%), 18 (30.0%) cases with mild stenosis (<50% )or irregular lumen, 20(33.3%) cases with normal coronary, artery. Conclusion: With a low radiation dose, prospective electrocardiogram (ECG)-gated coronary 64-MSCT angiography has a good potential for the detection of coronary stenosis, especially for excluding coronary artery disease. (authors)

Prognostic value of predischarge 12 lead electrocardiogram after myocardial infarction compared with other routine clinical variables

NARCIS (Netherlands)

Fioretti, P.; Tijssen, J. G.; Azar, A. J.; Lazzeroni, E.; Brower, R. W.; ten Katen, H. J.; Lubsen, J.; Hugenholtz, P. G.

1987-01-01

The prognostic value of QRS score (Selvester), ST depression, ST elevation, extrasystoles, P terminal force in V1, and QTc derived from the predischarge 12 lead electrocardiogram was assessed after myocardial infarction in 474 patients without intraventricular conduction defects, ventricular

Resting-state EEG, impulsiveness, and personality in daily and nondaily smokers.

Science.gov (United States)

Rass, Olga; Ahn, Woo-Young; O'Donnell, Brian F

2016-01-01

Resting EEG is sensitive to transient, acute effects of nicotine administration and abstinence, but the chronic effects of smoking on EEG are poorly characterized. This study measures the resting EEG profile of chronic smokers in a non-deprived, non-peak state to test whether differences in smoking behavior and personality traits affect pharmaco-EEG response. Resting EEG, impulsiveness, and personality measures were collected from daily smokers (n=22), nondaily smokers (n=31), and non-smokers (n=30). Daily smokers had reduced resting delta and alpha EEG power and higher impulsiveness (Barratt Impulsiveness Scale) compared to nondaily smokers and non-smokers. Both daily and nondaily smokers discounted delayed rewards more steeply, reported lower conscientiousness (NEO-FFI), and reported greater disinhibition and experience seeking (Sensation Seeking Scale) than non-smokers. Nondaily smokers reported greater sensory hedonia than nonsmokers. Altered resting EEG power in daily smokers demonstrates differences in neural signaling that correlated with greater smoking behavior and dependence. Although nondaily smokers share some characteristics with daily smokers that may predict smoking initiation and maintenance, they differ on measures of impulsiveness and resting EEG power. Resting EEG in non-deprived chronic smokers provides a standard for comparison to peak and trough nicotine states and may serve as a biomarker for nicotine dependence, relapse risk, and recovery. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Resting-state EEG, Impulsiveness, and Personality in Daily and Nondaily Smokers†

Science.gov (United States)

Rass, Olga; Ahn, Woo-Young; O’Donnell, Brian F.

2015-01-01

Objectives Resting EEG is sensitive to transient, acute effects of nicotine administration and abstinence, but the chronic effects smoking on EEG are poorly characterized. This study measures the resting EEG profile of chronic smokers in a non-deprived, non-peak state to test whether differences in smoking behavior and personality traits affect pharmaco-EEG response. Methods Resting EEG, impulsiveness, and personality measures were collected from daily smokers (n=22), nondaily smokers (n=31), and non-smokers (n=30). Results Daily smokers had reduced resting delta and alpha EEG power and higher impulsiveness (Barratt Impulsiveness Scale) compared to nondaily smokers and non-smokers. Both daily and nondaily smokers discounted delayed rewards more steeply, reported lower conscientiousness (NEO-FFI) and reported greater disinhibition and experience seeking (Sensation Seeking Scale) than non-smokers. Nondaily smokers reported greater sensory hedonia than nonsmokers. Conclusions Altered resting EEG power in daily smokers demonstrates differences in neural signaling that correlated with greater smoking behavior and dependence. Although nondaily smokers share some characteristics with daily smokers that may predict smoking initiation and maintenance, they differ on measures of impulsiveness and resting EEG power. Significance Resting EEG in non-deprived chronic smokers provides a standard for comparison to peak and trough nicotine states and may serve as a biomarker for nicotine dependence, relapse risk, and recovery. PMID:26051750

Mechanism underlying the absence of ischemic changes on the exercise electrocardiogram in patients with abnormal exercise thallium-201 imaging and coronary artery disease

International Nuclear Information System (INIS)

Coplan, N.L.; Horowitz, S.F.; Hoffman, D.P.; Goldman, M.E.; Machac, J.

1985-01-01

Patients with coronary artery disease may have reversible abnormalities on a thallium myocardial perfusion study without simultaneous ischemic changes on the exercise electrocardiogram, but the mechanisms responsible for this disparity have not been fully elucidated. A group of 37 patients with angiographically demonstrated coronary artery disease and abnormal thallium perfusion imaging were divided into two groups on the basis of their exercise electrocardiographic ST segment response. Thirteen patients (Group A) had no significant electrocardiographic changes with exercise, while 24 patients (Group B) had ST changes consistent with ischemia during the test. There were no significant differences in clinical or angiographic characteristics between the two groups. Stress test results showed a similar mean duration of exercise in the two groups, but the patients in Group A achieved a significantly lower mean maximal heart rate and mean maximal double product. These results suggest that exercise thallium-electrocardiogram discordance is mediated by the level of myocardial workload achieved. An abnormal perfusion scan accompanying an exercise electrocardiogram which does not demonstrate any ischemic ST change may occur when there is sufficient increase in myocardial oxygen demand to result in differential augmentation of myocardial blood flow, but insufficient imbalance of supply and demand to result in signs of ischemia on the surface electrocardiogram

The normal electrocardiogram of four species of conscious raptors.

Science.gov (United States)

Talavera, J; Guzmán, M J; del Palacio, M J Fernández; Albert, A P; Bayón, A

2008-02-01

The aim of this study was to describe normal ECG patterns and values in four species of conscious raptors (Eurasian kestrel, Griffon vulture, Little owl, and Eurasian Eagle owl). Electrocardiograms were carried out in 75 conscious birds belonging to four species of raptors. Lead II waveforms were analysed to determine amplitudes and durations of waves and intervals. Morphologic patterns of P-QRS-T deflections were analysed in the six limb leads. Rhythm, heart rate, mean electrical axis, presence of Ta wave, ST slurring, and P-on-T phenomenon were also studied. The influence of species, body weight and heart rate in electrocardiographic variables were statistically analysed (P raptors that can be used to establish comparisons for clinical purposes.

Preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats.

Science.gov (United States)

Roy, Abhro Jyoti; Stanely Mainzen Prince, P

2013-10-01

The present study evaluated the preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats. Rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days and then injected with isoproterenol (100mg/kg body weight) on 8th and 9th day to induce myocardial infarction. Myocardial infarction induced by isoproterenol was indicated by increased level of cardiac sensitive marker and elevated ST-segments in the electrocardiogram. Also, the levels/concentrations of serum and heart cholesterol, triglycerides and free fatty acids were increased in myocardial infarcted rats. Isoproterenol also increased the levels of serum low density and very low density lipoprotein cholesterol and decreased the levels of high density lipoprotein cholesterol. It also enhanced the activity of liver 3-hydroxy-3 methyl glutaryl-Coenzyme-A reductase. p-Coumaric acid pretreatment revealed preventive effects on all the biochemical parameters and electrocardiogram studied in myocardial infarcted rats. The in vitro study confirmed the free radical scavenging property of p-coumaric acid. Thus, p-coumaric acid prevented cardiac hypertrophy and alterations in lipids, lipoproteins, and electrocardiogram, by virtue of its antihypertrophic, antilipidemic, and free radical scavenging effects in isoproterenol induced myocardial infarcted rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Bayesian-optimized spline representation of the electrocardiogram

International Nuclear Information System (INIS)

Guilak, F G; McNames, J

2013-01-01

We introduce an implementation of a novel spline framework for parametrically representing electrocardiogram (ECG) waveforms. This implementation enables a flexible means to study ECG structure in large databases. Our algorithm allows researchers to identify key points in the waveform and optimally locate them in long-term recordings with minimal manual effort, thereby permitting analysis of trends in the points themselves or in metrics derived from their locations. In the work described here we estimate the location of a number of commonly-used characteristic points of the ECG signal, defined as the onsets, peaks, and offsets of the P, QRS, T, and R′ waves. The algorithm applies Bayesian optimization to a linear spline representation of the ECG waveform. The location of the knots—which are the endpoints of the piecewise linear segments used in the spline representation of the signal—serve as the estimate of the waveform’s characteristic points. We obtained prior information of knot times, amplitudes, and curvature from a large manually-annotated training dataset and used the priors to optimize a Bayesian figure of merit based on estimated knot locations. In cases where morphologies vary or are subject to noise, the algorithm relies more heavily on the estimated priors for its estimate of knot locations. We compared optimized knot locations from our algorithm to two sets of manual annotations on a prospective test data set comprising 200 beats from 20 subjects not in the training set. Mean errors of characteristic point locations were less than four milliseconds, and standard deviations of errors compared favorably against reference values. This framework can easily be adapted to include additional points of interest in the ECG signal or for other biomedical detection problems on quasi-periodic signals. (paper)

Electrocardiogram signal quality measures for unsupervised telehealth environments

International Nuclear Information System (INIS)

Redmond, S J; Xie, Y; Chang, D; Lovell, N H; Basilakis, J

2012-01-01

The use of telehealth paradigms for the remote management of patients suffering from chronic conditions has become more commonplace with the advancement of Internet connectivity and enterprise software systems. To facilitate clinicians in managing large numbers of telehealth patients, and in digesting the vast array of data returned from the remote monitoring environment, decision support systems in various guises are often utilized. The success of decision support systems in interpreting patient conditions from physiological data is dependent largely on the quality of these recorded data. This paper outlines an algorithm to determine the quality of single-lead electrocardiogram (ECG) recordings obtained from telehealth patients. Three hundred short ECG recordings were manually annotated to identify movement artifact, QRS locations and signal quality (discrete quality levels) by a panel of three experts, who then reconciled the annotation as a group to resolve any discrepancies. After applying a published algorithm to remove gross movement artifact, the proposed method was then applied to estimate the remaining ECG signal quality, using a Parzen window supervised statistical classifier model. The three-class classifier model, using a number of time-domain features and evaluated using cross validation, gave an accuracy in classifying signal quality of 78.7% (κ = 0.67) when using fully automated preprocessing algorithms to remove gross motion artifact and detect QRS locations. This is a similar level of accuracy to the reported human inter-scorer agreement when generating the gold standard annotation (accuracy = 70–89.3%, κ = 0.54–0.84). These results indicate that the assessment of the quality of single-lead ECG recordings, acquired in unsupervised telehealth environments, is entirely feasible and may help to promote the acceptance and utility of future decision support systems for remotely managing chronic disease conditions. (paper)

Resting-state abnormalities in amnestic mild cognitive impairment: a meta-analysis.

Science.gov (United States)

Lau, W K W; Leung, M-K; Lee, T M C; Law, A C K

2016-04-26

Amnestic mild cognitive impairment (aMCI) is a prodromal stage of Alzheimer's disease (AD). As no effective drug can cure AD, early diagnosis and intervention for aMCI are urgently needed. The standard diagnostic procedure for aMCI primarily relies on subjective neuropsychological examinations that require the judgment of experienced clinicians. The development of other objective and reliable aMCI markers, such as neural markers, is therefore required. Previous neuroimaging findings revealed various abnormalities in resting-state activity in MCI patients, but the findings have been inconsistent. The current study provides an updated activation likelihood estimation meta-analysis of resting-state functional magnetic resonance imaging (fMRI) data on aMCI. The authors searched on the MEDLINE/PubMed databases for whole-brain resting-state fMRI studies on aMCI published until March 2015. We included 21 whole-brain resting-state fMRI studies that reported a total of 156 distinct foci. Significant regional resting-state differences were consistently found in aMCI patients relative to controls, including the posterior cingulate cortex, right angular gyrus, right parahippocampal gyrus, left fusiform gyrus, left supramarginal gyrus and bilateral middle temporal gyri. Our findings support that abnormalities in resting-state activities of these regions may serve as neuroimaging markers for aMCI.

Evaluation of an electrocardiogram on QR code.

Science.gov (United States)

Nakayama, Masaharu; Shimokawa, Hiroaki

2013-01-01

An electrocardiogram (ECG) is an indispensable tool to diagnose cardiac diseases, such as ischemic heart disease, myocarditis, arrhythmia, and cardiomyopathy. Since ECG patterns vary depend on patient status, it is also used to monitor patients during treatment and comparison with ECGs with previous results is important for accurate diagnosis. However, the comparison requires connection to ECG data server in a hospital and the availability of data connection among hospitals is limited. To improve the portability and availability of ECG data regardless of server connection, we here introduce conversion of ECG data into 2D barcodes as text data and decode of the QR code for drawing ECG with Google Chart API. Fourteen cardiologists and six general physicians evaluated the system using iPhone and iPad. Overall, they were satisfied with the system in usability and accuracy of decoded ECG compared to the original ECG. This new coding system may be useful in utilizing ECG data irrespective of server connections.

Inferior ST-Elevation Acute Myocardial Infarction or an Inferior-Lead Brugada-like Electrocardiogram Pattern Associated With the Use of Pregabalin and Quetiapine?

Science.gov (United States)

Brunetti, Natale D; Ieva, Riccardo; Correale, Michele; Cuculo, Andrea; Santoro, Francesco; Guaricci, Andrea I; De Gennaro, Luisa; Gaglione, Antonio; Di Biase, Matteo

2016-01-01

The Brugada electrocardiogram pattern is characterized by coved-type ST-elevation (>2 mm) in the right precordial leads. We report the case of a 62-year-old man, with bipolar disorder, admitted to the emergency department because of dyspnea and chest discomfort. The patient was on treatment with pregabalin and quetiapine. Unexpectedly, electrocardiogram at admission showed diffuse ST-elevation, more evident in inferior leads, where a Brugada-like pattern was present. The patient underwent coronary angiography with a diagnosis of suspected acute coronary syndrome. Coronary angiography, however, showed mild coronary artery disease not requiring coronary angioplasty. Echocardiography did not reveal left ventricular dysfunction or pericardial effusion. Troponin levels remained normal over serial controls. Eventually, chest radiography showed lung opacities and consolidation suggestive for pneumonia. To the best of our knowledge, this is one of the first cases showing a transient Brugada-like electrocardiogram pattern in inferior leads, probably amplified by the administration of pregabalin and quetiapine.

Resting states are resting traits--an FMRI study of sex differences and menstrual cycle effects in resting state cognitive control networks.

Science.gov (United States)

Hjelmervik, Helene; Hausmann, Markus; Osnes, Berge; Westerhausen, René; Specht, Karsten

2014-01-01

To what degree resting state fMRI is stable or susceptible to internal mind states of the individual is currently an issue of debate. To address this issue, the present study focuses on sex differences and investigates whether resting state fMRI is stable in men and women or changes within relative short-term periods (i.e., across the menstrual cycle). Due to the fact that we recently reported menstrual cycle effects on cognitive control based on data collected during the same sessions, the current study is particularly interested in fronto-parietal resting state networks. Resting state fMRI was measured in sixteen women during three different cycle phases (menstrual, follicular, and luteal). Fifteen men underwent three sessions in corresponding time intervals. We used independent component analysis to identify four fronto-parietal networks. The results showed sex differences in two of these networks with women exhibiting higher functional connectivity in general, including the prefrontal cortex. Menstrual cycle effects on resting states were non-existent. It is concluded that sex differences in resting state fMRI might reflect sexual dimorphisms in the brain rather than transitory activating effects of sex hormones on the functional connectivity in the resting brain.

Feasibility Study of a Lunar Analog Bed Rest Model

Science.gov (United States)

Cromwell, Ronita L.; Platts, Steven H.; Yarbough, Patrice; Buccello-Stout, Regina

2010-01-01

The purpose of this study was to determine the feasibility of using a 9.5deg head-up tilt bed rest model to simulate the effects of the 1/6 g load to the human body that exists on the lunar surface. The lunar analog bed rest model utilized a modified hospital bed. The modifications included mounting the mattress on a sled that rolled on bearings to provide freedom of movement. The weight of the sled was off-loaded using a counterweight system to insure that 1/6 body weight was applied along the long axis (z-axis) of the body. Force was verified through use of a force plate mounted at the foot of the bed. A seating assembly was added to the bed to permit periods of sitting. Subjects alternated between standing and sitting positions throughout the day. A total of 35% of the day was spent in the standing position and 65% was spent sitting. In an effort to achieve physiologic fluid shifts expected for a 1/6 G environment, subjects wore compression stockings and performed unloaded foot and ankle exercises. Eight subjects (3 females and 5 males) participated in this study. Subjects spent 13 days in the pre-bed rest phase, 6 days in bed rest and 3 days post bed rest. Subjects consumed a standardized diet throughout the study. To determine feasibility, measures of subject comfort, force and plasma volume were collected. Subject comfort was assessed using a Likert scale. Subjects were asked to assess level of comfort (0-100) for 11 body regions and provide an overall rating. Results indicated minimal to no discomfort as most subjects reported scores of zero. Force measures were performed for each standing position and were validated against subject s calculated 1/6 body weight (r(sup 2) = 0.993). The carbon monoxide rebreathing technique was used to assess plasma volume during pre-bed rest and on the last day of bed rest. Plasma volume results indicated a significant decrease (p = 0.001) from pre to post bed rest values. Subjects lost on average 8.3% (sd = 6.1%) during the

A wearable smartphone-based platform for real-time cardiovascular disease detection via electrocardiogram processing.

Science.gov (United States)

Oresko, Joseph J; Duschl, Heather; Cheng, Allen C

2010-05-01

Cardiovascular disease (CVD) is the single leading cause of global mortality and is projected to remain so. Cardiac arrhythmia is a very common type of CVD and may indicate an increased risk of stroke or sudden cardiac death. The ECG is the most widely adopted clinical tool to diagnose and assess the risk of arrhythmia. ECGs measure and display the electrical activity of the heart from the body surface. During patients' hospital visits, however, arrhythmias may not be detected on standard resting ECG machines, since the condition may not be present at that moment in time. While Holter-based portable monitoring solutions offer 24-48 h ECG recording, they lack the capability of providing any real-time feedback for the thousands of heart beats they record, which must be tediously analyzed offline. In this paper, we seek to unite the portability of Holter monitors and the real-time processing capability of state-of-the-art resting ECG machines to provide an assistive diagnosis solution using smartphones. Specifically, we developed two smartphone-based wearable CVD-detection platforms capable of performing real-time ECG acquisition and display, feature extraction, and beat classification. Furthermore, the same statistical summaries available on resting ECG machines are provided.

Electrocardiogram (ECG Signal Modeling and Noise Reduction Using Hopfield Neural Networks

Directory of Open Access Journals (Sweden)

F. Bagheri

2013-02-01

Full Text Available The Electrocardiogram (ECG signal is one of the diagnosing approaches to detect heart disease. In this study the Hopfield Neural Network (HNN is applied and proposed for ECG signal modeling and noise reduction. The Hopfield Neural Network (HNN is a recurrent neural network that stores the information in a dynamic stable pattern. This algorithm retrieves a pattern stored in memory in response to the presentation of an incomplete or noisy version of that pattern. Computer simulation results show that this method can successfully model the ECG signal and remove high-frequency noise.

Comparison of heart rate variability between resting state and external-cuff-inflation-and-deflation state: a pilot study.

Science.gov (United States)

Ji, Lizhen; Liu, Chengyu; Li, Peng; Wang, Xinpei; Yan, Chang; Liu, Changchun

2015-10-01

Heart rate variability (HRV) has been widely used in clinical research to provide an insight into the autonomic control of the cardiovascular system. Measurement of HRV is generally performed under a relaxed resting state. The effects of other conditions on HRV measurement, such as running, mountaineering, head-up tilt, etc, have also been investigated. This study aimed to explore whether an inflation-and-deflation process applied to a unilateral upper arm cuff would influence the HRV measurement. Fifty healthy young volunteers aged between 21 and 30 were enrolled in this study. Electrocardiogram (ECG) signals were recorded for each subject over a five minute resting state followed by a five minute external-cuff-inflation-and-deflation state (ECID state). A one minute gap was scheduled between the two measurements. Consecutive RR intervals in the ECG were extracted automatically to form the HRV data for each of the two states. Time domain (SDNN, RMSSD and PNN50), frequency domain (LFn, HFn and LF/HF) and nonlinear (VLI, VAI and SampEn) HRV indices were analyzed and compared between the two states. In addition, the effects of mean artery pressure (MAP) and heart rate (HR) on the aforementioned HRV indices were assessed for the two states, respectively, by Pearson correlation analysis. The results showed no significant difference in all aforementioned HRV indices between the resting and the ECID states (all p  >  0.05). The corresponding HRV indices had significant positive correlation (all p    0.05) for either state. Besides, none of the indices showed HR-related change (all p  >  0.05) for either state except the index of VLI in the resting state. To conclude, this pilot study suggested that the applied ECID process hardly influenced those commonly used HRV indices. It would thus be applicable to simultaneously measure both blood pressure and HRV indices in clinical practice.

Alternative REST Splicing Underappreciated

OpenAIRE

Chen, Guo-Lin; Miller, Gregory

2017-01-01

As a major orchestrator of the cellular epigenome, the repressor element-1 silencing transcription factor (REST) can either repress or activate thousands of genes depending on cellular context, suggesting a highly context-dependent REST function tuned by environmental cues. While REST shows cell-type non-selective active transcription, an N-terminal REST4 isoform caused by alternative splicing - inclusion of an extra exon (N3c) which introduces a pre-mature stop codon - has been implicated in...

The role of electrocardiogram in the diagnosis of dextrocardia with mirror image atrial arrangement and ventricular position in a young adult Nigerian in Ile-Ife: a case report.

Science.gov (United States)

Ogunlade, Oluwadare; Ayoka, Abiodun O; Akomolafe, Rufus O; Akinsomisoye, Olumide S; Irinoye, Adedayo I; Ajao, Adewale; Asafa, Muritala A

2015-09-28

Dextrocardia with situs inversus is a rare congenital disease. In patients with this condition, the heart is presented as a mirror image of itself with its apex pointing to the right. The pulmonary and abdominal anatomies are reversed. Dextrocardia with situs inversus occurs at birth but its diagnosis may be in adulthood. This case advances knowledge by graphically describing the unusual electrocardiographic features of dextrocardia in a young adult. We report a case of a 22-year-old Nigerian man of Yoruba ethnicity who presented himself for preadmission medical test. He had a standard 12-lead electrocardiogram which revealed uncommon features: inversion of P waves in leads I, aVL and aVR; dominantly negative QRS waves in leads I, V1 to V6; reverse R wave progression in chest leads; low voltage in V4 to V6; extreme QRS axis; flattened T waves in V4 to V6 and aVR; and inverted T waves in lead I and aVL. An electrocardiogram diagnosis of dextrocardia was made. The differential diagnosis considered was right ventricular hypertrophy. A cardiovascular examination showed pulse rate of 70 beats per minute, blood pressure of 119/62mmHg, visible cardiac impulse at right precordium, apex beat was located at his fifth right intercostal space mid-clavicular line. A chest X-ray (posterior anterior view) including upper abdomen showed dextrocardia; his aortic arch was located on the right. His stomach bubble was located below his right hemidiaphragm. His trachea was slightly deviated to the left. The findings in his lung fields were not remarkable. Abdominopelvic ultrasonography showed that right-sided intra-abdominal organs (liver, gallbladder) were located on the left while left-sided organs (stomach, spleen) were located on the right. His abdominal aorta was on the right while his inferior vena cava was located on the left. A diagnosis of dextrocardia with situs inversus was made ultrasonographically. A properly interpreted electrocardiogram was useful in suspecting the

Stress/Rest Tc-99m-MIBI SPECT in Comparison with Rest/Stress Rubidium - 82 PET

International Nuclear Information System (INIS)

Lee, D. S.; Kamg, K. W.; Lee, K. H.; Jeong, J. M.; Kwark, C. E.; Chung, J. K.; Lee, M.C.; Seo, J. D.; Koh, C. S.

1995-01-01

We compared stress/rest myocardial Tc-99m-MIBI tomographic image findings with rest/stress rubidium-82 tomographic images. In 23 patients with coronary artery disease (12 of them received bypass grafts before) and 6 normal subjects, rest rubidium PET study was performed, rubidium-82 and Tc-99m-MIBI were injected simultaneously to each patient after dipyridamole stress for rubidium PET and MIBI SPECT; and rest MIBI SPECT was performed 4 hours thereafter. We scored segmental decrease of rubidium, or MIBI uptakes into 5 grades for 29 segments from 3 short-axis, vertical and horizontal slices. Scores were summed for each major arterial territory. When more score than two grade-2's or one grade-3 was considered as the cue for significant stenosis for major arterial territories, 67% of 46 stenosed arteries were found with MIBI studies and 78% of them by rubidium studies. Fourteen among 28 grafted arterial territories of 12 post-CABG patients were found normal with both rubidium and MIBI. Segmental scores were concordant between rubidium and MIBI in 72% of 709-stress segments and in 80% of 825 rest segments. Stress rubidium segmental scores were less than stress MIBI scores in 9%, so were rest rubidium scores. Stress rubidium scores were more than stress MIBI scores in 20% of segments, and rest rubidium segmental scores were more than rest MIBI scores in 11%. Rank correlations (Spearman's rho's more than 0.7(stress) and 0.5(rest), slopes (MIBI/rubidium) around 0.7(stress) and 0.9(rest) suggested deeper and wider defects in stress with rubidium. Slope over 1 (MIBI/rubidium) with LAD segmental scores at rest and 7 territories which had much larger score with MIBI revealed exaggeration of rest defects with rest MIBI in same-day stress/rest study. Difference scores (stress-rest for each territory) suggesting ischemia were larger with rubidium (slope of MIBI/rubidium around 0.45). As has been implied by animal or separate-day- human studies, these segmental analyses with

A randomized control trial comparing use of a novel electrocardiogram simulator with traditional teaching in the acquisition of electrocardiogram interpretation skill.

Science.gov (United States)

Fent, Graham; Gosai, Jivendra; Purva, Makani

2016-01-01

Accurate interpretation of the electrocardiogram (ECG) remains an essential skill for medical students and junior doctors. While many techniques for teaching ECG interpretation are described, no single method has been shown to be superior. This randomized control trial is the first to investigate whether teaching ECG interpretation using a computer simulator program or traditional teaching leads to improved scores in a test of ECG interpretation among medical students and postgraduate doctors immediately after and 3months following teaching. Participants' opinions of the program were assessed using a questionnaire. There were no differences in ECG interpretation test scores immediately after or 3months after teaching in the lecture or simulator groups. At present therefore, there is insufficient evidence to suggest that ECG simulator programs are superior to traditional teaching. Copyright © 2016 Elsevier Inc. All rights reserved.

Investigating the Effects of the 0.05 Hz First-order High-pass Filter on the Electrocardiogram

DEFF Research Database (Denmark)

Isaksen, Jonas; Leber, Remo; Schmid, Ramun

2016-01-01

Background: A thorough review is needed for the first-order 0.05 Hz high-pass filter, which was introduced almost fifty years ago before modern techniques were available. We quantify the effectiveness of inverse filtering and assess the changes that the filter imposes on the electrocardiogram (ECG...

Prognostic value of myocardial perfusion SPECT versus exercise electrocardiography in patients with ST-segment depression on resting electrocardiography.

Science.gov (United States)

De Lorenzo, Andrea; Hachamovitch, Rory; Kang, Xingping; Gransar, Heidi; Sciammarella, Maria G; Hayes, Sean W; Friedman, John D; Cohen, Ishac; Germano, Guido; Berman, Daniel S

2005-01-01

The value of exercise-induced ST-segment depression for the prognostic evaluation of patients with 1 mm of ST depression or greater on the resting electrocardiogram is controversial. Patients who underwent exercise myocardial perfusion single photon emission computed tomography (MPS) and had resting ST depression of 1 mm or greater with a nondiagnostic exercise electrocardiographic response (n = 1122) were followed up for 3.4 +/- 2.3 years. Those with paced rhythm, pre-excitation, left bundle branch block, or myocardial revascularization within the first 60 days after MPS were excluded. Additional exercise-induced ST-segment depression was considered significant if > or = 2 mm MPS was scored semiquantitatively by use of a 20-segment model of the left ventricle; the percentage of myocardium involved with stress defects (% myo) was derived by normalizing to the maximal possible score of 80. Hard events were defined as nonfatal myocardial infarction or cardiac death. A Cox analysis was used to determine independent predictors of hard events among clinical, exercise, and nuclear variables. Hard event rates increased as a function of % myo for either patients with exercise-induced ST depression (1.4%/y for normal MPS vs 4.1%/y for % myo >10%, P 10%, P = .0001). Age, diabetes mellitus, shortness of breath as the presenting symptom, and % myo were independent predictors of hard events. Exercise-induced ST depression was predictive of hard events only when it was 3 mm or greater. The presence and extent of perfusion defects, reflected in the % myo, had incremental prognostic value over clinical variables and also over all degrees of exercise-induced ST depression. Although MPS effectively risk-stratifies patients with resting ST depression of 1 mm or greater, the prognostic value of exercise-induced ST depression is limited in these patients, with a small added risk when severe (> or = 3 mm).

Apical hypertrophy associated with rapid T wave inversion on the electrocardiogram.

Science.gov (United States)

Yamanari, H; Saito, D; Mikio, K; Nakamura, K; Nanba, T; Morita, H; Mizuo, K; Sato, T; Ohe, T

1995-01-01

A 53-year-old man who had no chest pain and no family history of heart disease demonstrated a rapid T wave change on an electrocardiogram, from a positive T wave to a giant negative T wave, within 1 year. Echocardiography showed no left ventricular hypertrophy before or after the T wave change. Cine-magnetic resonance imaging revealed focal apical hypertrophy after the appearance of the giant negative T wave. Although T wave inversions sometimes develop within a short period in patients with hypertrophic cardiomyopathy, they are rare in a patient without hypertension or chest pain.

Usefulness of the Electrocardiogram in Predicting Cardiovascular Mortality in Asymptomatic Adults With Aortic Stenosis (from the Simvastatin and Ezetimibe in Aortic Stenosis Study)

DEFF Research Database (Denmark)

Greve, Anders M; Dalsgaard, Morten; Bang, Casper N

2014-01-01

Hypertension and coronary heart disease are common in aortic stenosis (AS) and may impair prognosis for similar AS severity. Different changes in the electrocardiogram may be reflective of the separate impacts of AS, hypertension, and coronary heart disease, which could lead to enhanced risk...... stratification in AS. The aim of this study was therefore to examine if combining prognostically relevant electrocardiographic (ECG) findings improves prediction of cardiovascular mortality in asymptomatic AS. All patients with baseline electrocardiograms in the SEAS study were included. The primary end point...

Sinabro: A Smartphone-Integrated Opportunistic Electrocardiogram Monitoring System.

Science.gov (United States)

Kwon, Sungjun; Lee, Dongseok; Kim, Jeehoon; Lee, Youngki; Kang, Seungwoo; Seo, Sangwon; Park, Kwangsuk

2016-03-11

In our preliminary study, we proposed a smartphone-integrated, unobtrusive electrocardiogram (ECG) monitoring system, Sinabro, which monitors a user's ECG opportunistically during daily smartphone use without explicit user intervention. The proposed system also monitors ECG-derived features, such as heart rate (HR) and heart rate variability (HRV), to support the pervasive healthcare apps for smartphones based on the user's high-level contexts, such as stress and affective state levels. In this study, we have extended the Sinabro system by: (1) upgrading the sensor device; (2) improving the feature extraction process; and (3) evaluating extensions of the system. We evaluated these extensions with a good set of algorithm parameters that were suggested based on empirical analyses. The results showed that the system could capture ECG reliably and extract highly accurate ECG-derived features with a reasonable rate of data drop during the user's daily smartphone use.

Sinabro: A Smartphone-Integrated Opportunistic Electrocardiogram Monitoring System

Directory of Open Access Journals (Sweden)

Sungjun Kwon

2016-03-01

Full Text Available In our preliminary study, we proposed a smartphone-integrated, unobtrusive electrocardiogram (ECG monitoring system, Sinabro, which monitors a user’s ECG opportunistically during daily smartphone use without explicit user intervention. The proposed system also monitors ECG-derived features, such as heart rate (HR and heart rate variability (HRV, to support the pervasive healthcare apps for smartphones based on the user’s high-level contexts, such as stress and affective state levels. In this study, we have extended the Sinabro system by: (1 upgrading the sensor device; (2 improving the feature extraction process; and (3 evaluating extensions of the system. We evaluated these extensions with a good set of algorithm parameters that were suggested based on empirical analyses. The results showed that the system could capture ECG reliably and extract highly accurate ECG-derived features with a reasonable rate of data drop during the user’s daily smartphone use.

Changes in resting-state functionally connected parietofrontal networks after videogame practice.

Science.gov (United States)

Martínez, Kenia; Solana, Ana Beatriz; Burgaleta, Miguel; Hernández-Tamames, Juan Antonio; Alvarez-Linera, Juan; Román, Francisco J; Alfayate, Eva; Privado, Jesús; Escorial, Sergio; Quiroga, María A; Karama, Sherif; Bellec, Pierre; Colom, Roberto

2013-12-01

Neuroimaging studies provide evidence for organized intrinsic activity under task-free conditions. This activity serves functionally relevant brain systems supporting cognition. Here, we analyze changes in resting-state functional connectivity after videogame practice applying a test-retest design. Twenty young females were selected from a group of 100 participants tested on four standardized cognitive ability tests. The practice and control groups were carefully matched on their ability scores. The practice group played during two sessions per week across 4 weeks (16 h total) under strict supervision in the laboratory, showing systematic performance improvements in the game. A group independent component analysis (GICA) applying multisession temporal concatenation on test-retest resting-state fMRI, jointly with a dual-regression approach, was computed. Supporting the main hypothesis, the key finding reveals an increased correlated activity during rest in certain predefined resting state networks (albeit using uncorrected statistics) attributable to practice with the cognitively demanding tasks of the videogame. Observed changes were mainly concentrated on parietofrontal networks involved in heterogeneous cognitive functions. Copyright © 2012 Wiley Periodicals, Inc.

Atrial Fibrillation Predictors: Importance of the Electrocardiogram.

Science.gov (United States)

German, David M; Kabir, Muammar M; Dewland, Thomas A; Henrikson, Charles A; Tereshchenko, Larisa G

2016-01-01

Atrial fibrillation (AF) is the most common arrhythmia in adults and is associated with significant morbidity and mortality. Substantial interest has developed in the primary prevention of AF, and thus the identification of individuals at risk for developing AF. The electrocardiogram (ECG) provides a wealth of information, which is of value in predicting incident AF. The PR interval and P wave indices (including P wave duration, P wave terminal force, P wave axis, and other measures of P wave morphology) are discussed with regard to their ability to predict and characterize AF risk in the general population. The predictive value of the QT interval, ECG criteria for left ventricular hypertrophy, and findings of atrial and ventricular ectopy are also discussed. Efforts are underway to develop models that predict AF incidence in the general population; however, at present, little information from the ECG is included in these models. The ECG provides a great deal of information on AF risk and has the potential to contribute substantially to AF risk estimation, but more research is needed. © 2015 Wiley Periodicals, Inc.

Assessment of residual tissue viability by exercise testing in recent myocardial infarction: comparison of the electrocardiogram and myocardial perfusion scintigraphy.

Science.gov (United States)

Margonato, A; Ballarotto, C; Bonetti, F; Cappelletti, A; Sciammarella, M; Cianflone, D; Chierchia, S L

1992-04-01

The assessment of residual myocardial viability in infarcted areas is relevant for subsequent management and prognosis but requires expensive technology. To evaluate the possibility that simple, easily obtainable clinical markers may detect the presence of within-infarct viable tissue, the significance of exercise-induced ST elevation occurring in leads exploring the area of a recent Q wave myocardial infarction was assessed. Twenty-five patients with recent (less than 6 months) myocardial infarction were studied. All had angiographically documented coronary artery disease, diagnostic Q waves (n = 24) or negative T waves (n = 25) on the rest 12-lead electrocardiogram and exhibited during exercise greater than or equal to 1.5 mm ST segment elevation (n = 17) or isolated T wave pseudonormalization (n = 8) in the infarct-related leads. ST-T wave changes were reproduced in all patients during thallium-201 exercise myocardial scintigraphy. A fixed perfusion defect was observed in 24 of the 25 patients. A reversible defect was seen in 16 (94%) of 17 patients who exhibited transient ST elevation during exercise but in only 4 (50%) of the 8 patients who had only T wave pseudonormalization. In conclusion, in patients with recent myocardial infarction, analysis of simple ST segment variables obtained during exercise testing may allow a first-line discrimination of those who may potentially benefit from a revascularization procedure.

Metabolic, respiratory, and cardiological measurements during exercise and rest

Science.gov (United States)

1971-01-01

Low concentration effects of CO2 on metabolic respiration and circulation were measured during work and at rest. The relationship between heart rate and metabolic rate is examined, as well as calibration procedures, and rate measurement during submaximal and standard exercise tests. Alterations in acid base and electrolytes were found during exhaustive exercise, including changes in ECG and metabolic alkalosis effects.

Task vs. rest-different network configurations between the coactivation and the resting-state brain networks.

Science.gov (United States)

Di, Xin; Gohel, Suril; Kim, Eun H; Biswal, Bharat B

2013-01-01

There is a growing interest in studies of human brain networks using resting-state functional magnetic resonance imaging (fMRI). However, it is unclear whether and how brain networks measured during the resting-state exhibit comparable properties to brain networks during task performance. In the present study, we investigated meta-analytic coactivation patterns among brain regions based upon published neuroimaging studies, and compared the coactivation network configurations with those in the resting-state network. The strength of resting-state functional connectivity between two regions were strongly correlated with the coactivation strength. However, the coactivation network showed greater global efficiency, smaller mean clustering coefficient, and lower modularity compared with the resting-state network, which suggest a more efficient global information transmission and between system integrations during task performing. Hub shifts were also observed within the thalamus and the left inferior temporal cortex. The thalamus and the left inferior temporal cortex exhibited higher and lower degrees, respectively in the coactivation network compared with the resting-state network. These results shed light regarding the reconfiguration of the brain networks between task and resting-state conditions, and highlight the role of the thalamus in change of network configurations in task vs. rest.

Vectorcardiographic diagnostic & prognostic information derived from the 12-lead electrocardiogram: Historical review and clinical perspective.

Science.gov (United States)

Man, Sumche; Maan, Arie C; Schalij, Martin J; Swenne, Cees A

2015-01-01

In the course of time, electrocardiography has assumed several modalities with varying electrode numbers, electrode positions and lead systems. 12-lead electrocardiography and 3-lead vectorcardiography have become particularly popular. These modalities developed in parallel through the mid-twentieth century. In the same time interval, the physical concepts underlying electrocardiography were defined and worked out. In particular, the vector concept (heart vector, lead vector, volume conductor) appeared to be essential to understanding the manifestations of electrical heart activity, both in the 12-lead electrocardiogram (ECG) and in the 3-lead vectorcardiogram (VCG). Not universally appreciated in the clinic, the vectorcardiogram, and with it the vector concept, went out of use. A revival of vectorcardiography started in the 90's, when VCGs were mathematically synthesized from standard 12-lead ECGs. This facilitated combined electrocardiography and vectorcardiography without the need for a special recording system. This paper gives an overview of these historical developments, elaborates on the vector concept and seeks to define where VCG analysis/interpretation can add diagnostic/prognostic value to conventional 12-lead ECG analysis. Copyright © 2015 Elsevier Inc. All rights reserved.

Predicting new-onset of postoperative atrial fibrillation in patients undergoing cardiac surgery using semi-automatic reading of perioperative electrocardiograms

DEFF Research Database (Denmark)

Gu, Jiwei; Graff, Claus; Melgaard, Jacob

2015-01-01

P10 Predicting new-onset of postoperative atrial fibrillation in patients undergoingcardiac surgery using semi-automatic reading of perioperative electrocardiograms. Jiwei Gu, Claus Graff, Jacob Melgaard, Søren Lundbye-Christensen, Erik Berg Schmidt, Christian Torp-Pedersen, Kristinn Thorsteinsson......, Jan Jesper Andreasen. Aalborg, DenmarkBackground: Postoperative new onset atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery. The aim of this study was to evaluate if semi-automatic readings of perioperative electrocardiograms (ECGs) is of any value in predicting POAF after...... ECG monitoring. A semi-automatic machine capable of reading differentparameters of digitalized ECG’s was used to read both lead specific (P/QRS/T amplitudes/intervals) and global measurements (P-duration/QRS-duration/PR-interval/QT/Heart Rate/hypertrophy).Results: We divided the patients into two...

Development of electrocardiogram intervals during growth of FVB/N neonate mice

Science.gov (United States)

2010-01-01

Background Electrocardiography remains the best diagnostic tool and therapeutic biomarker for a spectrum of pediatric diseases involving cardiac or autonomic nervous system defects. As genetic links to these disorders are established and transgenic mouse models produced in efforts to understand and treat them, there is a surprising lack of information on electrocardiograms (ECGs) and ECG abnormalities in neonate mice. This is likely due to the trauma and anaesthesia required of many legacy approaches to ECG recording in mice, exacerbated by the fragility of many mutant neonates. Here, we use a non-invasive system to characterize development of the heart rate and electrocardiogram throughout the growth of conscious neonate FVB/N mice. Results We examine ECG waveforms as early as two days after birth. At this point males and females demonstrate comparable heart rates that are 50% lower than adult mice. Neonatal mice exhibit very low heart rate variability. Within 12 days of birth PR, QRS and QTc interval durations are near adult values while heart rate continues to increase until weaning. Upon weaning FVB/N females quickly develop slower heart rates than males, though PR intervals are comparable between sexes until a later age. This suggests separate developmental events may contribute to these gender differences in electrocardiography. Conclusions We provide insight with a new level of detail to the natural course of heart rate establishment in neonate mice. ECG can now be conveniently and repeatedly used in neonatal mice. This should serve to be of broad utility, facilitating further investigations into development of a diverse group of diseases and therapeutics in preclinical mouse studies. PMID:20735846

Potenciais tardios ao eletrocardiograma de alta resolução no domínio do tempo em portadores de insuficiência cardíaca de diferentes etiologias Time domain analysis of the signal averaged electrocardiogram to detect late potentials in heart failure patients with different etiologies

Directory of Open Access Journals (Sweden)

Ernani de Sousa Grell

2006-09-01

included 215 males (74.65% and 73 females (25.35% between the ages of 16 and 70 (mean 51.5, standard deviation 11.24. The heart failure etiologies were: hypertensive heart disease (78 patients, 27.1%; idiopathic dilated cardiomyopathy (73 patients, 25.4%; ischemic cardiomyopathy (65 patients, 22.6%; Chagas disease (42 patients, 14.6%; alcoholic cardiomyopathy (9 patients, 3.1%; peripartum cardiomyopathy (6 patients, 2.1%; valvular heart disease (2 patients, 4.2% and viral myocarditis (3 patients, 1.04%. The variables included the duration of the standard QRS complex, duration of the filtered QRS complex, duration of the signal below 40µV and the root mean square of the last 40ms which were analyzed in regard to age, gender, etiology and mortality as well as the findings of the 12-lead electrocardiogram at rest, echocardiogram and ambulatory electrocardiogram. The statistical analysis tests used were: the Fisher exact probability test, Student’s t-test, Mann Whitney test, variance analysis, Log-Hank and the Kaplan-Meyer method. RESULTS: Late potentials were diagnosed in 90 patients (31.3% and there was no association with the etiologies. The presence of this condition is associated with: a lower maximum oxygen uptake during the ergospirometry (p=0.001; sustained and non-sustained ventricular tachycardia during Holter monitoring (p=0.001, sudden death and mortality (p<0.05. Patients that did not present late potentials had a higher overlife rate. CONCLUSION: The presence of late potentials was not associated with the etiologies and proved to be an indication of a worse prognosis.

Using the 12-Lead Electrocardiogram in the Care of Athletic Patients.

Science.gov (United States)

Yeo, Tee Joo; Sharma, Sanjay

2016-11-01

This article summarizes the role of the 12-lead electrocardiogram (ECG) for the clinical care of athletes, with particular reference to the influence of age, gender, ethnicity, and type of sport on the appearance of the ECG, and its role in differentiating physiologic exercise-related changes from pathologic conditions implicated in sudden cardiac death (SCD). The article also explores the potential role of the ECG in detecting athletes at risk of SCD. In addition, the article reviews the evolution of ECG interpretation criteria and emphasizes the limitations of the ECG as well as the potential for future research. Copyright © 2016 Elsevier Inc. All rights reserved.

[Ischemic Changes in the Electrocardiogram and Circulatory Collapse Accompanied by Severe Anemia Owing to the Delay of Red Blood Cell Concentrate Transfusion in Two Patients with Intraoperative Massive Bleeding].

Science.gov (United States)

Horiuchi, Toshinori; Noguchi, Teruo; Kurita, Naoko; Yamaguchi, Ayako; Takeda, Masafumi; Sha, Keiichi; Nagahata, Toshihiro

2016-01-01

We present two patients developing intraoperative massive bleeding and showed ischemic changes in the electrocardiogram and circulatory collapse accompanied by severe anemia owing to the delay of red blood cell concentrate transfusion. One patient underwent hepatectomy and the other pancreaticoduodenectomy. Their lowest hemoglobin concentration was around 2 g x dl(-1), and they showed ischemic changes in the electrocardiogram and severe decreases in blood pressure. The former received compatible red blood cell concentrate and the latter received uncrossmatched same blood group red blood cell concentrate immediately, and their electrocardiogram and blood pressure quickly improved. To avoid life-threatening anemia, emergency red blood cell concentrate transfusion including compatible different blood group transfusion should be applied for intraoperative massive bleeding.

Classification of hydration status using electrocardiogram and machine learning

Science.gov (United States)

Kaveh, Anthony; Chung, Wayne

2013-10-01

The electrocardiogram (ECG) has been used extensively in clinical practice for decades to non-invasively characterize the health of heart tissue; however, these techniques are limited to time domain features. We propose a machine classification system using support vector machines (SVM) that uses temporal and spectral information to classify health state beyond cardiac arrhythmias. Our method uses single lead ECG to classify volume depletion (or dehydration) without the lengthy and costly blood analysis tests traditionally used for detecting dehydration status. Our method builds on established clinical ECG criteria for identifying electrolyte imbalances and lends to automated, computationally efficient implementation. The method was tested on the MIT-BIH PhysioNet database to validate this purely computational method for expedient disease-state classification. The results show high sensitivity, supporting use as a cost- and time-effective screening tool.

Proton spin structure in the rest frame

International Nuclear Information System (INIS)

Zavada, P.

1997-01-01

It is shown that the quark-parton model in the standard infinite momentum approach overestimates the proton spin structure function g 1 (x) in comparison with the approach taking consistently into account the internal motion of quarks described by a spherical phase space in the proton rest frame. Particularly, it is shown the first moment of the spin structure function in the latter approach, assuming only the valence quarks contribution to the proton spin, does not contradict the experimental data. copyright 1997 The American Physical Society

Robust suppression of nonstationary power-line interference in electrocardiogram signals

International Nuclear Information System (INIS)

Li, Guojun; Zeng, Xiaopin; Zhou, Yu; Liu, Guojin; Zhou, Xichuan; Zhou, Xiaona

2012-01-01

It is a challenge to suppress time-varying power-line interference (PLI) with various levels in electrocardiogram (ECG) signals. Most previous attempts of tracking and suppressing the nonstationary PLI signal are based on the least-squares (LS) algorithm. This makes these methods susceptible to QRS complex in suppressing a low-level PLI signal which is frequently coupled in battery-operated ECG equipment. To address the limitation of LS-based methods, this study presents a robust PLI suppression system based on a robust extension of the Kalman filter. In addition, we used an improved version of empirical mode decomposition to further attenuate the QRS complex. Experiments show that our system could effectively suppress the PLI while preserving meaningful ECG components at various interference levels. (paper)

The Electrocardiogram as an Electronic Filter and Why AC Circuits Are Important for Pre-Health Physics Students

Science.gov (United States)

Dunlap, Justin C.; Kutschera, Ellynne; Van Ness, Grace R.; Widenhorn, Ralf

2015-01-01

We present a general physics laboratory exercise that centres around the use of the electrocardiogram sensor as an application of circuits and electronic signal filtering. Although these topics are commonly taught in the general physics classroom, many students consider topics such as alternating current as unrelated to their future professions.…

Applicability of initial optimal maternal and fetal electrocardiogram combination vectors to subsequent recordings

International Nuclear Information System (INIS)

Yan Hua-Wen; Huang Xiao-Lin; Zhao Ying; Si Jun-Feng; Liu Hong-Xing; Liu Tie-Bing

2014-01-01

A series of experiments are conducted to confirm whether the vectors calculated for an early section of a continuous non-invasive fetal electrocardiogram (fECG) recording can be directly applied to subsequent sections in order to reduce the computation required for real-time monitoring. Our results suggest that it is generally feasible to apply the initial optimal maternal and fetal ECG combination vectors to extract the fECG and maternal ECG in subsequent recorded sections. (interdisciplinary physics and related areas of science and technology)

Programmatic access to logical models in the Cell Collective modeling environment via a REST API.

Science.gov (United States)

Kowal, Bryan M; Schreier, Travis R; Dauer, Joseph T; Helikar, Tomáš

2016-01-01

Cell Collective (www.cellcollective.org) is a web-based interactive environment for constructing, simulating and analyzing logical models of biological systems. Herein, we present a Web service to access models, annotations, and simulation data in the Cell Collective platform through the Representational State Transfer (REST) Application Programming Interface (API). The REST API provides a convenient method for obtaining Cell Collective data through almost any programming language. To ensure easy processing of the retrieved data, the request output from the API is available in a standard JSON format. The Cell Collective REST API is freely available at http://thecellcollective.org/tccapi. All public models in Cell Collective are available through the REST API. For users interested in creating and accessing their own models through the REST API first need to create an account in Cell Collective (http://thecellcollective.org). thelikar2@unl.edu. Technical user documentation: https://goo.gl/U52GWo. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Exercise electrocardiogram in middle-aged and older leisure time sportsmen: 100 exercise tests would be enough to identify one silent myocardial ischemia at risk for cardiac event.

Science.gov (United States)

Hupin, David; Edouard, Pascal; Oriol, Mathieu; Laukkanen, Jari; Abraham, Pierre; Doutreleau, Stéphane; Guy, Jean-Michel; Carré, François; Barthélémy, Jean-Claude; Roche, Frédéric; Chatard, Jean-Claude

2018-04-15

The importance of exercise electrocardiogram (ECG) has been controversial in the prevention of cardiac events among sportsmen. The aim of this study was to determine the frequency of silent myocardial ischemia (SMI) from an exercise ECG and its relationship with induced coronary angiographic assessment and potentially preventable cardiac events. This prospective cohort study included leisure time asymptomatic sportsmen over 35years old, referred from 2011 to 2014 in the Sports Medicine Unit of the University Hospital of Saint-Etienne. Of the cohort of 1500 sportsmen (1205 men; mean age 50.7±9.4years; physical activity level 32.8±26.8MET-h/week), 951 (63%) had at least one cardiovascular disease (CVD) risk factor. Family history, medical examination and standard resting 12-lead were collected. A total of 163 exercise ECGs (10.9%) were defined as positive, most of them due to SMI (n=129, 8.6%). SMI was an indication for coronary angiography in 23 cases, leading to 17 documented SMIs (1.1%), including 11 significant stenoses requiring revascularization. In multivariate logistic regression analysis, a high risk of CVD (OR=2.65 [CI 95%: 1.33-5.27], p=0.005) and an age >50years (OR=2.71 [CI 95%: 1.65-4.44], p<0.0001) were independently associated with confirmed SMI. The association of positive exercise ECG with significant coronary stenosis was stronger among sportsmen with CVD risk factors and older than 50years. Screening by exercise ECG can lower the risk of cardiac events in middle-aged and older sportsmen. One hundred tests would be enough to detect one silent myocardial ischemia at risk for cardiac event. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of the Surface Electrocardiogram to Define the Nature of Challenging Arrhythmias.

Science.gov (United States)

Singh, David K; Peter, C Thomas

2016-03-01

Despite unprecedented advances in technology, the electrocardiogram (ECG) remains essential to the practice of modern electrophysiology. Since its emergence at the turn of the nineteenth century, the form of the ECG has changed little. What has changed is our ability to understand the complex mechanisms that underlie various arrhythmias. In this article, the authors review several important principles of ECG interpretation by providing illustrative tracings. The authors also highlight several important concepts that be can used in ECG analysis. There are several fundamental principles that should be considered in ECG interpretation. Copyright © 2016 Elsevier Inc. All rights reserved.

Tremor frequency characteristics in Parkinson's disease under resting-state and stress-state conditions.

Science.gov (United States)

Lee, Hong Ji; Lee, Woong Woo; Kim, Sang Kyong; Park, Hyeyoung; Jeon, Hyo Seon; Kim, Han Byul; Jeon, Beom S; Park, Kwang Suk

2016-03-15

Tremor characteristics-amplitude and frequency components-are primary quantitative clinical factors for diagnosis and monitoring of tremors. Few studies have investigated how different patient's conditions affect tremor frequency characteristics in Parkinson's disease (PD). Here, we analyzed tremor characteristics under resting-state and stress-state conditions. Tremor was recorded using an accelerometer on the finger, under resting-state and stress-state (calculation task) conditions, during rest tremor and postural tremor. The changes of peak power, peak frequency, mean frequency, and distribution of power spectral density (PSD) of tremor were evaluated across conditions. Patients whose tremors were considered more than "mild" were selected, for both rest (n=67) and postural (n=25) tremor. Stress resulted in both greater peak powers and higher peak frequencies for rest tremor (pstate condition. The distributions of PSD of tremor were symmetrical, regardless of conditions. Tremor is more evident and typical tremor characteristics, namely a lower frequency as amplitude increases, are different in stressful condition. Patient's conditions directly affect neural oscillations related to tremor frequencies. Therefore, tremor characteristics in PD should be systematically standardized across patient's conditions such as attention and stress levels. Copyright © 2016. Published by Elsevier B.V.

The history, hotspots, and trends of electrocardiogram.

Science.gov (United States)

Yang, Xiang-Lin; Liu, Guo-Zhen; Tong, Yun-Hai; Yan, Hong; Xu, Zhi; Chen, Qi; Liu, Xiang; Zhang, Hong-Hao; Wang, Hong-Bo; Tan, Shao-Hua

2015-07-01

The electrocardiogram (ECG) has broad applications in clinical diagnosis and prognosis of cardiovascular disease. Many researchers have contributed to its progressive development. To commemorate those pioneers, and to better study and promote the use of ECG, we reviewed and present here a systematic introduction about the history, hotspots, and trends of ECG. In the historical part, information including the invention, improvement, and extensive applications of ECG, such as in long QT syndrome (LQTS), angina, and myocardial infarction (MI), are chronologically presented. New technologies and applications from the 1990s are also introduced. In the second part, we use the bibliometric analysis method to analyze the hotspots in the field of ECG-related research. By using total citations and year-specific total citations as our main criteria, four key hotspots in ECG-related research were identified from 11 articles, including atrial fibrillation, LQTS, angina and MI, and heart rate variability. Recent studies in those four areas are also reported. In the final part, we discuss the future trends concerning ECG-related research. The authors believe that improvement of the ECG instrumentation, big data mining for ECG, and the accuracy of diagnosis and application will be areas of continuous concern.

How restful is it with all that noise? Comparison of Interleaved silent steady state (ISSS) and conventional imaging in resting-state fMRI.

Science.gov (United States)

Andoh, J; Ferreira, M; Leppert, I R; Matsushita, R; Pike, B; Zatorre, R J

2017-02-15

Resting-state fMRI studies have become very important in cognitive neuroscience because they are able to identify BOLD fluctuations in brain circuits involved in motor, cognitive, or perceptual processes without the use of an explicit task. Such approaches have been fruitful when applied to various disordered populations, or to children or the elderly. However, insufficient attention has been paid to the consequences of the loud acoustic scanner noise associated with conventional fMRI acquisition, which could be an important confounding factor affecting auditory and/or cognitive networks in resting-state fMRI. Several approaches have been developed to mitigate the effects of acoustic noise on fMRI signals, including sparse sampling protocols and interleaved silent steady state (ISSS) acquisition methods, the latter being used only for task-based fMRI. Here, we developed an ISSS protocol for resting-state fMRI (rs-ISSS) consisting of rapid acquisition of a set of echo planar imaging volumes following each silent period, during which the steady state longitudinal magnetization was maintained with a train of relatively silent slice-selective excitation pulses. We evaluated the test-retest reliability of intensity and spatial extent of connectivity networks of fMRI BOLD signal across three different days for rs-ISSS and compared it with a standard resting-state fMRI (rs-STD). We also compared the strength and distribution of connectivity networks between rs-ISSS and rs-STD. We found that both rs-ISSS and rs-STD showed high reproducibility of fMRI signal across days. In addition, rs-ISSS showed a more robust pattern of functional connectivity within the somatosensory and motor networks, as well as an auditory network compared with rs-STD. An increased connectivity between the default mode network and the language network and with the anterior cingulate cortex (ACC) network was also found for rs-ISSS compared with rs-STD. Finally, region of interest analysis showed

An assessment of algorithms to estimate respiratory rate from the electrocardiogram and photoplethysmogram.

Science.gov (United States)

Charlton, Peter H; Bonnici, Timothy; Tarassenko, Lionel; Clifton, David A; Beale, Richard; Watkinson, Peter J

2016-04-01

Over 100 algorithms have been proposed to estimate respiratory rate (RR) from the electrocardiogram (ECG) and photoplethysmogram (PPG). As they have never been compared systematically it is unclear which algorithm performs the best. Our primary aim was to determine how closely algorithms agreed with a gold standard RR measure when operating under ideal conditions. Secondary aims were: (i) to compare algorithm performance with IP, the clinical standard for continuous respiratory rate measurement in spontaneously breathing patients; (ii) to compare algorithm performance when using ECG and PPG; and (iii) to provide a toolbox of algorithms and data to allow future researchers to conduct reproducible comparisons of algorithms. Algorithms were divided into three stages: extraction of respiratory signals, estimation of RR, and fusion of estimates. Several interchangeable techniques were implemented for each stage. Algorithms were assembled using all possible combinations of techniques, many of which were novel. After verification on simulated data, algorithms were tested on data from healthy participants. RRs derived from ECG, PPG and IP were compared to reference RRs obtained using a nasal-oral pressure sensor using the limits of agreement (LOA) technique. 314 algorithms were assessed. Of these, 270 could operate on either ECG or PPG, and 44 on only ECG. The best algorithm had 95% LOAs of  -4.7 to 4.7 bpm and a bias of 0.0 bpm when using the ECG, and  -5.1 to 7.2 bpm and 1.0 bpm when using PPG. IP had 95% LOAs of  -5.6 to 5.2 bpm and a bias of  -0.2 bpm. Four algorithms operating on ECG performed better than IP. All high-performing algorithms consisted of novel combinations of time domain RR estimation and modulation fusion techniques. Algorithms performed better when using ECG than PPG. The toolbox of algorithms and data used in this study are publicly available.

Expression of REST4 in human gliomas in vivo and influence of pioglitazone on REST in vitro

Energy Technology Data Exchange (ETDEWEB)

Ren, Huan [Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008 (China); Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078 (China); Gao, Zhangfeng [Department of Neurosurgery, Second Xiangya Hospital of Central South University, Changsha 410008 (China); Wu, Nayiyuan; Zeng, Liu; Tang, Xinyue; Chen, Xiaoping; Liu, Zhaoqian; Zhang, Wei; Wang, Liansheng [Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008 (China); Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078 (China); Li, Zhi, E-mail: lizhi489@163.com [Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008 (China); Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078 (China)

2015-08-07

The repressor element-1 (RE1) silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF) has an irreplaceable role during the differentiation of neurons. REST has multiple splice variants which link to various types of cancer. Previous work had highlighted the role of REST in glioma, where the expression of REST is enhanced. But whether alternative splicing of REST is expressed in glioma has not been described. Here, we show that a specific isoform REST4 is expressed in glioma specimens, and will influence the mRNA level of REST in vivo. Peroxisome proliferator-activated receptor-γ (PPARγ) agonists have a role of antineoplastic in various tumor cells, which including glioma cells. Moreover, study indicated that PPARγ agonist pioglitazone can promote alternative splicing of REST pre-mRNA. In this study, we selected pioglitazone as a tool drug to explore whether the role of pioglitazone in anti-glioma is mediated by regulating REST expression or promoting alternative splicing of REST in glioma cells. Results show that pioglitazone can inhibit proliferation and induce apoptosis of glioma cell in vitro, which may be mediated by down-regulating REST mRNA level but not by inducing alternative splicing of REST pre-mRNA. Our study firstly reports the expression of REST4 in glioma tissue samples. And we recommend that pioglitazone, which can reduce the expression level of REST, represents a promising drug for therapy of glioma. - Highlights: • A specific isoform REST4 is expressed in glioma specimens in vivo. • REST4 will influence the mRNA level of REST in vivo. • Pioglitazone can inhibit proliferation and induce apoptosis of glioma cells. • The role of pioglitazone in anti-glioma may be mediated by down-regulating REST.

Expression of REST4 in human gliomas in vivo and influence of pioglitazone on REST in vitro

International Nuclear Information System (INIS)

Ren, Huan; Gao, Zhangfeng; Wu, Nayiyuan; Zeng, Liu; Tang, Xinyue; Chen, Xiaoping; Liu, Zhaoqian; Zhang, Wei; Wang, Liansheng; Li, Zhi

2015-01-01

The repressor element-1 (RE1) silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF) has an irreplaceable role during the differentiation of neurons. REST has multiple splice variants which link to various types of cancer. Previous work had highlighted the role of REST in glioma, where the expression of REST is enhanced. But whether alternative splicing of REST is expressed in glioma has not been described. Here, we show that a specific isoform REST4 is expressed in glioma specimens, and will influence the mRNA level of REST in vivo. Peroxisome proliferator-activated receptor-γ (PPARγ) agonists have a role of antineoplastic in various tumor cells, which including glioma cells. Moreover, study indicated that PPARγ agonist pioglitazone can promote alternative splicing of REST pre-mRNA. In this study, we selected pioglitazone as a tool drug to explore whether the role of pioglitazone in anti-glioma is mediated by regulating REST expression or promoting alternative splicing of REST in glioma cells. Results show that pioglitazone can inhibit proliferation and induce apoptosis of glioma cell in vitro, which may be mediated by down-regulating REST mRNA level but not by inducing alternative splicing of REST pre-mRNA. Our study firstly reports the expression of REST4 in glioma tissue samples. And we recommend that pioglitazone, which can reduce the expression level of REST, represents a promising drug for therapy of glioma. - Highlights: • A specific isoform REST4 is expressed in glioma specimens in vivo. • REST4 will influence the mRNA level of REST in vivo. • Pioglitazone can inhibit proliferation and induce apoptosis of glioma cells. • The role of pioglitazone in anti-glioma may be mediated by down-regulating REST

EASIER ACCESS TO STANDARDS DOCUMENTATION

CERN Multimedia

2001-01-01

Many organizations issuing standards offer reduced prices for publications to their members. Paying a membership fee, even a site membership fee, can therefore be worthwhile - even if relatively few standards are needed. The Library is now exploring the possibility, in collaboration with the rest of the CERN community, of joining standards-issuing organizations. So why not share your costs with the rest of the organization wherever this can be done without violating copyright or access regulations? The Library now provides documentation and other member services from IPC, the Association Connecting Electronics Industries (http://www.ipc.org/html/fsabout.htm) at favourable prices for the entire CERN population. For more information, or if you are a member of any other organization which provides services which could be shared CERN-wide, please contact library.desk@cern.ch . We remind all users of international standards, that CERN has special agreements with ISO and IEC (see Bulletin 50/2000). You can order st...

DIRAC RESTful API

International Nuclear Information System (INIS)

Casajus Ramo, A; Graciani Diaz, R; Tsaregorodtsev, A

2012-01-01

The DIRAC framework for distributed computing has been designed as a flexible and modular solution that can be adapted to the requirements of any community. Users interact with DIRAC via command line, using the web portal or accessing resources via the DIRAC python API. The current DIRAC API requires users to use a python version valid for DIRAC. Some communities have developed their own software solutions for handling their specific workload, and would like to use DIRAC as their back-end to access distributed computing resources easily. Many of these solutions are not coded in python or depend on a specific python version. To solve this gap DIRAC provides a new language agnostic API that any software solution can use. This new API has been designed following the RESTful principles. Any language with libraries to issue standard HTTP queries may use it. GSI proxies can still be used to authenticate against the API services. However GSI proxies are not a widely adopted standard. The new DIRAC API also allows clients to use OAuth for delegating the user credentials to a third party solution. These delegated credentials allow the third party software to query to DIRAC on behalf of the users. This new API will further expand the possibilities communities have to integrate DIRAC into their distributed computing models.

Intrapartum electrocardiogram alteration in fetuses with congenital heart disease: a case-control study.

Science.gov (United States)

Gay, Estelle; Bornallet, Géraldine; Gaucherand, Pascal; Doret, Muriel

2015-11-01

To assess if the fetal electrocardiogram especially ST segment is modified by congenital heart diseases: modifications in frequencies of the different ST events and modifications in signal quality. A retrospective case-control study, comparing frequencies of the different ST events and the quality of the signal between fetuses with congenital heart diseases and fetuses without congenital heart disease. From 2000 to 2011, fifty-eight fetuses with congenital heart disease had their heart rate recording using a STAN device during labor. Control group was fetuses who were born just before a case and had a STAN as a second line for intrapartum surveillance. Cases and controls were matched on parity, gestational age at birth, presence of growth restriction and umbilical artery pH. Frequencies of the different ST event and quality of the signal were first analyzed for the global labor recording, and then separately for the first and the second phase of labor. No statistically significant difference in ST event frequencies between fetuses with congenital heart disease and the control group was found. Regarding the quality of the signal, 11.49% (±18.82) of recording time is a signal loss for fetus with congenital heart disease whereas only 5.18% (±10.67) for the control group (p=0.028). This is the first study investigating for intrapartum electrocardiogram modification in fetus with congenital heart disease. Congenital heart diseases do not modify frequencies of ST events. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Evaluation of proportional health impairment due to occupationally related myocardial infarction

International Nuclear Information System (INIS)

Szozda, R.; Schneiberg, P.

1995-01-01

The authors propose the principles how to calculate a proportional health impairment due to myocardial infarction. The proposals are based on own experience, literature and regulations. It is suggested that the following should be taken into account for the calculation purposes: case history, resting electrocardiogram, postexercise electrocardiogram, results of Holter's examination, chest X-ray including evaluation of the heart silhouette and UCG. (author). 8 refs, 3 tabs

Portable electrocardiogram device using Android smartphone.

Science.gov (United States)

Brucal, S G E; Clamor, G K D; Pasiliao, L A O; Soriano, J P F; Varilla, L P M

2016-08-01

Portable electrocardiogram (ECG) capturing device can be interfaced to a smart phone installed with an android-based application (app). This app processes and analyses the data sent by the device to provide an interpretation of the patient/user's heart current condition (e.g.: beats per minute, heart signal waveform, R-R interval). The ECG recorded by the app is stored in the smart phone's Secure Digital (SD) card and cloud storage which can be accessed remotely by a physician to aid in providing medical diagnosis. The project aims to help patients living at a far distance from hospitals and experience difficulty in consulting their physician for regular check-ups, and assist doctors in regularly monitoring their patient's heart condition. The hardware data acquisition device and software application were subjected to trials in a clinic with volunteer-patients to measure the ECG and heart rate, data saving speed on the SD card, success rate of the saved data and uploaded file. Different ECG tests using the project prototype were done for 12 patients/users and yielded a reading difference of 7.61% in an R-R interval reading and 5.35% in heart rate reading as compared with the cardiologist's conventional 12-electrode ECG machine. Using the developed ECG device, it took less than 5 seconds to save ECG reading using SD card and approximately 2 minutes to upload via cloud.

Respiratory Information Extraction from Electrocardiogram Signals

KAUST Repository

Amin, Gamal El Din Fathy

2010-12-01

The Electrocardiogram (ECG) is a tool measuring the electrical activity of the heart, and it is extensively used for diagnosis and monitoring of heart diseases. The ECG signal reflects not only the heart activity but also many other physiological processes. The respiratory activity is a prominent process that affects the ECG signal due to the close proximity of the heart and the lungs. In this thesis, several methods for the extraction of respiratory process information from the ECG signal are presented. These methods allow an estimation of the lung volume and the lung pressure from the ECG signal. The potential benefit of this is to eliminate the corresponding sensors used to measure the respiration activity. A reduction of the number of sensors connected to patients will increase patients’ comfort and reduce the costs associated with healthcare. As a further result, the efficiency of diagnosing respirational disorders will increase since the respiration activity can be monitored with a common, widely available method. The developed methods can also improve the detection of respirational disorders that occur while patients are sleeping. Such disorders are commonly diagnosed in sleeping laboratories where the patients are connected to a number of different sensors. Any reduction of these sensors will result in a more natural sleeping environment for the patients and hence a higher sensitivity of the diagnosis.

RESTful Web Services Cookbook

CERN Document Server

Allamaraju, Subbu

2010-01-01

While the REST design philosophy has captured the imagination of web and enterprise developers alike, using this approach to develop real web services is no picnic. This cookbook includes more than 100 recipes to help you take advantage of REST, HTTP, and the infrastructure of the Web. You'll learn ways to design RESTful web services for client and server applications that meet performance, scalability, reliability, and security goals, no matter what programming language and development framework you use. Each recipe includes one or two problem statements, with easy-to-follow, step-by-step i

A Review on the Nonlinear Dynamical System Analysis of Electrocardiogram Signal.

Science.gov (United States)

Nayak, Suraj K; Bit, Arindam; Dey, Anilesh; Mohapatra, Biswajit; Pal, Kunal

2018-01-01

Electrocardiogram (ECG) signal analysis has received special attention of the researchers in the recent past because of its ability to divulge crucial information about the electrophysiology of the heart and the autonomic nervous system activity in a noninvasive manner. Analysis of the ECG signals has been explored using both linear and nonlinear methods. However, the nonlinear methods of ECG signal analysis are gaining popularity because of their robustness in feature extraction and classification. The current study presents a review of the nonlinear signal analysis methods, namely, reconstructed phase space analysis, Lyapunov exponents, correlation dimension, detrended fluctuation analysis (DFA), recurrence plot, Poincaré plot, approximate entropy, and sample entropy along with their recent applications in the ECG signal analysis.

[Synchronous playing and acquiring of heart sounds and electrocardiogram based on labVIEW].

Science.gov (United States)

Dan, Chunmei; He, Wei; Zhou, Jing; Que, Xiaosheng

2008-12-01

In this paper is described a comprehensive system, which can acquire heart sounds and electrocardiogram (ECG) in parallel, synchronize the display; and play of heart sound and make auscultation and check phonocardiogram to tie in. The hardware system with C8051F340 as the core acquires the heart sound and ECG synchronously, and then sends them to indicators, respectively. Heart sounds are displayed and played simultaneously by controlling the moment of writing to indicator and sound output device. In clinical testing, heart sounds can be successfully located with ECG and real-time played.

Pit-a-Pat: A Smart Electrocardiogram System for Detecting Arrhythmia.

Science.gov (United States)

Park, Juyoung; Lee, Kuyeon; Kang, Kyungtae

2015-10-01

Electrocardiogram (ECG) telemonitoring is one of the most promising applications of medical telemetry. However, previous approaches to ECG telemonitoring have largely relied on public databases of ECG results. In this article we propose a smart ECG system called Pit-a-Pat, which extracts features from ECG signals and detects arrhythmia. It is designed to run on an Android™ (Google, Mountain View, CA) device, without requiring modifications to other software. We implemented the Pit-a-Pat system using a commercial ECG device, and the experimental results demonstrate the effectiveness and accuracy of Pit-a-Pat for monitoring the ECG signal and analyzing the cardiac activity of a mobile patient. The proposed system allows monitoring of cardiac activity with automatic analysis, thereby providing a convenient, inexpensive, and ubiquitous adjunct to personal healthcare.

Adaptive noise canceling of electrocardiogram artifacts in single channel electroencephalogram.

Science.gov (United States)

Cho, Sung Pil; Song, Mi Hye; Park, Young Cheol; Choi, Ho Seon; Lee, Kyoung Joung

2007-01-01

A new method for estimating and eliminating electrocardiogram (ECG) artifacts from single channel scalp electroencephalogram (EEG) is proposed. The proposed method consists of emphasis of QRS complex from EEG using least squares acceleration (LSA) filter, generation of synchronized pulse with R-peak and ECG artifacts estimation and elimination using adaptive filter. The performance of the proposed method was evaluated using simulated and real EEG recordings, we found that the ECG artifacts were successfully estimated and eliminated in comparison with the conventional multi-channel techniques, which are independent component analysis (ICA) and ensemble average (EA) method. From this we can conclude that the proposed method is useful for the detecting and eliminating the ECG artifacts from single channel EEG and simple to use for ambulatory/portable EEG monitoring system.

Comparison of stress-rest and rest-stress one day myocardial perfusion scintigraphies in detecting coronary artery diseases

International Nuclear Information System (INIS)

Bom, Hee Seung; Min, Jung Jun; Song, Ho Cheon; Kim, Ji Yeul

1997-01-01

It has been shown that both rest and stress myocardial perfusion imaging with technetium agents can be performed on the same day using two different doses injected within few hours. The purpose of this study was to compare the two protocols (stress-rest and rest-stress) in detecting coronary artery diseases. One hundred and sixty patients (101 males, 59 females, mean age 57±9 years) and 120 patients (79 males, 41 females, mean age 59±10 years) underwent stress-rest myocardial perfusion SPECT and rest-stress myocardial perfusion SPECT, respectively. All of them underwent both myocardial perfusion SPECT and coronary angiography within 1 month. A coronary stenosis was considered significant when it compromised the luminal diameter by ≥50%. The chi square test was used to compare differences in sensitivity, specificity and accuracy between the two groups. The overall sensitivity, specificity and accuracy of stress-rest protocol were 99%, 35% and 68%, respectively. Those of rest-stress protocol were 96%, 47% and 78%, respectively. There was no difference between the two protocols in identifying individual diseased coronary artery branches. Therefore, one day stress-rest and rest-stress myocardial SPECT using 99m Tc agents were comparable and were very sensitive tests in detecting coronary artery diseases

Clinical evaluation of automated processing of electrocardiograms by the Veterans Administration program (AVA 3.4).

Science.gov (United States)

Brohet, C R; Richman, H G

1979-06-01

Automated processing of electrocardiograms by the Veterans Administration program was evaluated for both agreement with physician interpretation and interpretative accuracy as assessed with nonelectrocardiographic criteria. One thousand unselected electrocardiograms were analyzed by two reviewer groups, one familiar and the other unfamiliar with the computer program. A significant number of measurement errors involving repolarization changes and left axis deviation occurred; however, interpretative disagreements related to statistical decision were largely language-related. Use of a printout with a more traditional format resulted in agreement with physician interpretation by both reviewer groups in more than 80 percent of cases. Overall sensitivity based on agreement with nonelectrocardiographic criteria was significantly greater with use of the computer program than with use of the conventional criteria utilized by the reviewers. This difference was particularly evident in the subgroup analysis of myocardial infarction and left ventricular hypertrophy. The degree of overdiagnosis of left ventricular hypertrophy and posteroinferior infarction was initially unacceptable, but this difficulty was corrected by adjustment of probabilities. Clinical acceptability of the Veterans Administration program appears to require greater physician education than that needed for other computer programs of electrocardiographic analysis; the flexibility of interpretation by statistical decision offers the potential for better diagnostic accuracy.

Inductive plethysmography potential as a surrogate for ventilatory measurements during rest and moderate physical exercise

Directory of Open Access Journals (Sweden)

Ramona Cabiddu

2016-01-01

Full Text Available Background: Portable respiratory inductive plethysmography (RIP systems have been validated for ventilatory assessment during resting conditions and during incremental treadmill exercise. However, in clinical settings and during field-based exercise, intensity is usually constant and submaximal. A demonstration of the ability of RIP to detect respiratory measurements accurately during constant intensity conditions would promote and validate the routine use of portable RIP devices as an alternative to ergospirometry (ES, the current gold standard technique for ventilatory measures. Objective: To investigate the agreement between respiratory variables recorded by a portable RIP device and by ES during rest and constant intensity exercise. Method: Tidal volume (VT, respiratory rate (RR and minute ventilation (VE were concurrently acquired by portable RIP and ES in seven healthy male volunteers during standing rest position and constant intensity treadmill exercise. Results: Significant agreement was found between RIP and ES acquisitions during the standing rest position and constant intensity treadmill exercise for RR and during the standing rest position for VE. Conclusion: Our results suggest that portable RIP devices might represent a suitable alternative to ES during rest and during constant submaximal exercise.

Myocardial ischemia analysis based on electrocardiogram QRS complex

International Nuclear Information System (INIS)

Song, J.; Yan, H.; Xu, Z.; Yu, X.; Zhu, R.

2011-01-01

Full text: Electrocardiogram (ECG) is an economic, convenient, and non-invasive detecting tool in myocardial ischemia (MI), and its clinical appearance is mainly exhibited by the changes in ST-T complex. Recently, QRS complex characters were proposed to analyze MI by more and more researchers. In this paper, various QRS complex characters were extracted in ECG signals, and their relationship was analyzed systematically. As a result, these characters were divided into two groups, and there existed good relationship among them for each group, while the poor relationship between the groups. Then these QRS complex characters were applied for statistical analysis on MI, and five characters had significant differences after ECG recording verification, which were: QRS upward and downward slopes, transient heart rate, angle R and angle Q. On the other hand, these QRS complex characters were analyzed in frequency domain. Experimental results showed that the frequency features of RR interval series (Heart Rate Variability, HRV), and QRS barycenter sequence had signjficant differences between MI states and normal states. Moreover, QRS barycenter sequence performed better. (author)

Comparison of Ocular Outcomes in Two 14-Day Bed Rest Studies

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Cromwell, R. L.; Zanello, S. B.; Yarbough, P. O.; Taibbi, G.; Vizzeri, G.

2011-01-01

Reports of astronauts visual changes raised concern about ocular health during long-duration spaceflight. Some of these findings included hyperopic shifts, choroidal folds, optic disc edema, retinal nerve fiber layer (RNFL) thickening, and cotton wool spots. While the etiology remains unknown, hypotheses speculate that hypertension in the brain caused by cephalad fluid shifts during spaceflight is a possible mechanism for these ocular changes. Head-down tilt (HDT) bed rest is a spaceflight analog that induces cephalad fluid shifts. In addition, previous studies of the HDT position demonstrated body fluid shifts associated with changes in intraocular pressure (IOP). For these reasons, vision monitoring of HDT bed rest subjects was implemented for NASA bed rest studies. Subjects selected for these studies were healthy adults (14 males and 5 females). Average age was 37.5 plus or minus 9.1 years, weight was 77.4 plus or minus 11.3 Kg, and height was 173.4 plus or minus 7.2 14 cm. Controlled conditions followed for all NASA bed rest studies were implemented. These conditions included factors such as eating a standardized diet, maintaining a strict sleep wake cycle, and remaining in bed for 24 hours each day. In one study, subjects maintained a horizontal (0 degree) position while in bed and were exercised six days per week with an integrated resistance and aerobic training (iRAT) program. In the other study, subjects were placed at 6 degrees HDT while in bed and did not engage in exercise. All subjects underwent pre- and post bed rest vision testing. While the battery of vision tests for each study was not identical, measures common to both studies will be presented. These measures included IOP and measures that provided an indication of optic disc swelling as derived from optical coherence tomography (OCT) testing: average retinal nerve fiber layer (RNFL) thickness (millimeters), disc area (square millimeters), rim area (square millimters), and average cup to disc (C

Measurement and monitoring of electrocardiogram belt tension in premature infants for assessment of respiratory function

OpenAIRE

Hegyi Thomas; Hiatt Mark; Ciaccio Edward J; Drzewiecki Gary M

2007-01-01

Abstract Background Monitoring of the electrocardiogram (ECG) in premature infants with conventional adhesive-backed electrodes can harm their sensitive skin. Use of an electrode belt prevents skin irritation, but the effect of belt pressure on respiratory function is unknown. A strain gauge sensor is described which measures applied belt tension. Method The device frame was comprised of an aluminum housing and slide to minimize the device weight. Velcro tabs connected housing and slide to op...

The Effect Of Resting Time To Work Productivity On Surya Hutani Jaya Company

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Purbawati

2015-08-01

Full Text Available Purbawati Rachmat M Ruslim Y B.D.A.S.Simarangkir. 2016. The Effect of resting time to work produktivity to the activity of Seedling Eucalyptus Pellitawith mini cutting.Productivity is the ratio between the output and the input. Rated productivity indicates how effectively the production process has been empowered to increase the output and how efficiently are also sources of input has been successfully saved. Many factors can affect productivity example is the resting time factor. In this study which examined is how the influence of rest periods of the Productivity and how much the standard output produced by the female labor force.Research conducted on women workers who are working at the cutting shoots cutting house.Nurseries with mini cutting process is done by cutting the of the leaves on each leaf so that the remaining 2 to 3 pairs of strands shoots that have undergone a process of cutting in its leaves called ready plant bud shoot. Ready plant bud is the output of this research while the input is the time used to do the cutting. This study aims to determine the influence of rest periods of the productivity of female workers and to determine the standard output produced by the female labor force. Data processing method used is the partial productivity measurement methods and measurement methods of working time. The results stated that the amount of labor productivity of women without giving time off is 0.0911 shoots second -1 whereas labor productivity by granting time off for 5 minutes every hour C1 by granting a 10 minute break every two hours C2 by granting time off for 30 minutes per one working day C3 by granting time off for 60 minutes per one working day C4 and the provision of rest periods combined mixed which is 5 minutes every hour and 60 minutes per one working day C5 respectively is 00908 shoots second -1 0.0761 shoots second-1 0.0972 shoots second-1 0.0857 shoots second-1 and 0.0860 shoots second -1. The calculation output

Use of Electrocardiogram as Part of the Preparticipation Examination.

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Chain, Kelly; Gregory, Andrew

2016-01-01

A sudden cardiac event or death in a young athlete is a traumatic and memorable event. These tragic events have long-lasting and widespread influences that not only affect the person's immediate family, but also have profound effects on the team, school, and entire community. Over the past several decades there has been a significant research effort in the area of sudden cardiac death (SCD) in athletes in hopes of decreasing preventable deaths. One area of research and discussion that has emerged is the use of electrocardiograms (EKGs) in preparticipation screening examinations as a tool to help identify athletes at risk for SCD. The use of an EKG in addition to a detailed history and physical examination is a controversial and frequently debated topic. To help sort through some of the controversy, this article discusses some of the pros and cons of incorporating the EKG as a screening modality in the preparticipation evaluation for clearance to participate in sports. Copyright 2016, SLACK Incorporated.

Teaching the interpretation of electrocardiograms: which method is best?

Science.gov (United States)

Fent, Graham; Gosai, Jivendra; Purva, Makani

2015-01-01

Electrocardiogram (ECG) interpretation is poorly performed at undergraduate and post-graduate level. Incorrect ECG interpretation can lead to serious clinical error. Despite the incorporation of computerized ECG interpretation software into modern ECG machines, the sensitivity and specificity of current technology remain poor, emphasizing the on-going need for doctors to perform ECG interpretation accurately. This is the first review in this important area and aims to critically evaluate the current literature in relation to the optimal format and method of teaching ECG interpretation at undergraduate and postgraduate level. No single method or format of teaching is most effective in delivering ECG interpretation skills; however, self-directed learning appears to be associated with poorer interpretation competence. Summative in preference to formative assessment is associated with improved interpretation competence. Web-based learning offers a promising modern approach to learning ECG interpretation, though caution must be exercised in accessing user-uploaded content to supplement learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Utility of electrocardiogram in the assessment and monitoring of pulmonary hypertension (idiopathic or secondary to pulmonary developmental abnormalities) in patients≤18 years of age.

Science.gov (United States)

Lau, Kelvin C; Frank, David B; Hanna, Brian D; Patel, Akash R

2014-07-15

Electrocardiograms have utility in disease stratification and monitoring in adult pulmonary arterial hypertension (PAH). We examined the electrocardiographic findings that are common in pediatric PAH and assessed for correlation with disease severity and progression. We retrospectively identified patients aged≤18 years followed at a single institution from January 2001 to June 2012 with catheterization-confirmed diagnosis of idiopathic PAH and PAH secondary to pulmonary developmental abnormalities. Patients with an electrocardiography performed within 60 days of catheterization were included. Primary and secondary outcomes are the prevalence of abnormal electrocardiographic findings at the time of catheterization and the association between electrocardiographic and hemodynamic findings and electrocardiographic changes with disease progression on follow-up catheterization, respectively. Of the 100 electrocardiography-catheterization pairs derived from the 46 patients identified, 93% had an electrocardiographic abnormality: 78% had right ventricular hypertrophy (RVH) and 52% had right axis deviation (RAD) for age. In patients with idiopathic PAH, the presence of RVH and RAD correlated with pulmonary vascular resistance and transpulmonary gradient. RAD and RVH on baseline electrocardiogram was associated with an increased risk of disease progression on subsequent catheterization (odds ratio 11.0, 95% confidence interval 1.3 to 96.2, p=0.03) after adjusting for PAH subgroup. The sensitivity, specificity, and positive and negative predictive values of RAD and RVH on baseline electrocardiogram for disease progression were 92%, 48%, 33%, and 95%, respectively. In conclusion, electrocardiographic abnormalities are common in pediatric PAH. RAD and RVH on electrocardiogram were associated with worse hemodynamics, whereas their absence is suggestive of a lack of disease progression. Copyright © 2014 Elsevier Inc. All rights reserved.

AgNOR Count in Resting Cells (Resting NOR Is a New Prognostic Marker in Invasive Bladder Tumor

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Mitsuro Tomobe

2001-01-01

Full Text Available Purpose: We have previously demonstrated that the AgNOR count in proliferating cells is a predictor of tumor recurrence in superficial bladder tumor (J. Urol. 162 (1999, 63–68. In the present study, we evaluate the type of AgNOR associated with cell cycles as a prognostic factor in invasive bladder tumor using a double staining technique employing both AgNOR and MIB-1 labelling. Materials and methods: Forty-four paraffin sections of invasive bladder tumors were stained simultaneously with AgNOR and MIB-1. The number of AgNORs in proliferating (MIB-1 positive or resting (MIB-1 negative cells were counted from a total of 100 nuclei. Correlations between MIB-1 associated AgNOR count and clinicopathological parameters were statistically analyzed. Results: The AgNOR count in proliferating cells (proliferating NOR was significantly higher than that in resting cells (resting NOR (p < 0.01. The resting NOR in tumors with distant metastases was significantly higher than that in tumors without metastases (p < 0.05. Patients with a low resting NOR tumor had a better prognosis than those with a high resting NOR tumor, whereas the proliferating NOR was not associated with survival. Survival analysis revealed that the resting NOR was the most powerful prognostic marker in patients with invasive bladder tumor (p < 0.05. Conclusions: Resting NOR had a predictive value in the prognosis of patients with invasive bladder tumor. Keywords: Transitional cell carcinoma, invasive, resting cell, AgNORs, MIB-1

A Review on the Nonlinear Dynamical System Analysis of Electrocardiogram Signal

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Mohapatra, Biswajit

2018-01-01

Electrocardiogram (ECG) signal analysis has received special attention of the researchers in the recent past because of its ability to divulge crucial information about the electrophysiology of the heart and the autonomic nervous system activity in a noninvasive manner. Analysis of the ECG signals has been explored using both linear and nonlinear methods. However, the nonlinear methods of ECG signal analysis are gaining popularity because of their robustness in feature extraction and classification. The current study presents a review of the nonlinear signal analysis methods, namely, reconstructed phase space analysis, Lyapunov exponents, correlation dimension, detrended fluctuation analysis (DFA), recurrence plot, Poincaré plot, approximate entropy, and sample entropy along with their recent applications in the ECG signal analysis. PMID:29854361

Retrospective study of pre-anesthetic electrocardiogram examination of 700 dogs conducted at the Veterinary Hospital of UFMG (2013-2014

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Ana Flávia Machado Botelho

2016-02-01

Full Text Available Abstract: Pre-operative electrocardiograms performed in 700 dogs were analyzed in order to establish correlation between sex, age, indication for surgery, body condition score, breed and weight. Initially a clinical questionnaire was filled out from each owner, including age, breed, sex, weight, clinical history and surgical indication. Dogs above 6 years of age or those showing any kind of cardiac auscultation disturbances were referred to electrocardiogram (ECG evaluation. All ECG were performed and analyzed by the same veterinary specialist. Abnormalities at ECG were founnd in 364 of 700 (52% evaluated dogs, and the most frequent variation was sinus arrhythmia, observed in 293 dogs (25.4%. No significant correlation was found between the electrocardiographic alterations with weight, sex and age of the animals. Therefore ECG should be conducted routinely regardless of age, sex, breed or surgical indication, highlighting its value for determining a safe anesthetic protocol that promotes minimal cardiopulmonary depression and allows rapid post-surgical recovery.

Electrocardiogram pattern of some exotic breeds of trained dogs: A variation study

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Joydip Mukherjee

2015-11-01

Full Text Available Aim: The present study has been conducted to evaluate the variation in electrocardiogram (ECG parameters among different trained breeds of dogs (viz. Labrador, German Shepherd, and Golden Retriever used for security reasons. Materials and Methods: The ECG was recorded by single channel ECG at a paper speed of 25 mm/s and calibration of 10 mm=1 mV. The recordings were taken from all the standard bipolar limb leads (Lead-I, II, and III and unipolar augmented limb leads (Lead-aVR, aVL, and aVF. Results: Heart rate was found to be highest in Labrador and lowest in German Shepherd. P-wave duration was maximum in Golden Retriever breed and lowest in Labrador. Maximum amplitude of P-wave was found in Labrador followed by German Shepherd and Golden Retriever. There was significantly (p<0.05 higher values of PR interval in German Shepherd compared to other breeds. The variation in QRS duration, ST segment duration, T-wave duration, and T-wave amplitude was found to be non-significant among breeds. Inverted T-waves were most common in Golden Retriever and German Shepherd, whereas positive T-waves were found in Labrador. There was significant (p<0.05 variation in mean electrical axis of QRS complex among different breeds and it ranges from +60° to +80°. Conclusion: The present study provides the reference values for different ECG parameters to monitor the cardiac health status among Labrador, German Shepherd, and Golden Retriever breeds.

Intelligent classification of electrocardiogram (ECG) signal using extended Kalman Filter (EKF) based neuro fuzzy system.

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Meau, Yeong Pong; Ibrahim, Fatimah; Narainasamy, Selvanathan A L; Omar, Razali

2006-05-01

This study presents the development of a hybrid system consisting of an ensemble of Extended Kalman Filter (EKF) based Multi Layer Perceptron Network (MLPN) and a one-pass learning Fuzzy Inference System using Look-up Table Scheme for the recognition of electrocardiogram (ECG) signals. This system can distinguish various types of abnormal ECG signals such as Ventricular Premature Cycle (VPC), T wave inversion (TINV), ST segment depression (STDP), and Supraventricular Tachycardia (SVT) from normal sinus rhythm (NSR) ECG signal.

A Correction Formula for the ST Segment Measurements for the AC-coupled Electrocardiograms

DEFF Research Database (Denmark)

Schmid, Ramun; Isaksen, Jonas; Leber, Remo

2017-01-01

Goal: The ST segment of an electrocardiogram (ECG) is very important for the correct diagnosis of an acute myocardial infarction. Most clinical ECGs are recorded using an AC-coupled ECG amplifier. It is well known, that first-order high-pass filters used for the AC coupling can affect the ST...... segment of an ECG. This effect is stronger the higher the filter's cut-off frequency is and the larger the QRS integral is. We present a formula that estimates these changes in the ST segment and therefore allows for correcting ST measurements that are based on an AC-coupled ECG. Methods: The presented...

Normalizing Electrocardiograms of Both Healthy Persons and Cardiovascular Disease Patients for Biometric Authentication

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Zhao, Miaomiao; Li, Fan; Wang, Guoqing; Zhou, Fengfeng

2013-01-01

Although electrocardiogram (ECG) fluctuates over time and physical activity, some of its intrinsic measurements serve well as biometric features. Considering its constant availability and difficulty in being faked, the ECG signal is becoming a promising factor for biometric authentication. The majority of the currently available algorithms only work well on healthy participants. A novel normalization and interpolation algorithm is proposed to convert an ECG signal into multiple template cycles, which are comparable between any two ECGs, no matter the sampling rates or health status. The overall accuracies reach 100% and 90.11% for healthy participants and cardiovascular disease (CVD) patients, respectively. PMID:23977063

Sleep and alertness during alternating monophasic and polyphasic rest-activity cycles.

Science.gov (United States)

Porcú, S; Casagrande, M; Ferrara, M; Bellatreccia, A

1998-07-01

People involved in shift work often have to face altered patterns of sleep and wakefulness. This is particularly true for schedules involving night shifts and/or fragmentation of duty periods throughout the 24-hr day. In such conditions, it can be difficult to obtain satisfactory periods of sleep, and sleepiness on duty is a frequent and dangerous occurrence. The aim of this study was to evaluate sleep and wakefulness periods of subjects whose work schedule was characterized by an alternation of 2 hours of activity and 4 hours of rest (sleep allowed), repeated 4 times throughout the 24-hr day. This schedule was alternated with 24 hours off duty. Nine healthy male volunteers were monitored by means of ambulatory polysomnography while attending their 24-hr rest-activity schedule. Sleep periods were visually scored according to standard criteria. Wake periods were visually scored using both 30 s and 5 s epochs in order to reveal episodes of drowsiness and/or microsleep. Results showed that total sleep time was substantially reduced as compared to the usual 7-8 hour monophasic nocturnal sleep. Subjects did not sleep during the first rest period (11.00-15.00). Time in sleep linearly increased in the course of the 3 remaining rest periods. Normal sleep stage distribution was substantially spared only in the last rest period (3.00-7.00 a.m.). With regard to duty periods, only a few microsleeps were detected and their number did not significantly vary across the four 2-hr activity periods. In conclusion, this rest-activity schedule, despite the considerable sleep reduction, allowed maintaining good levels of vigilance as shown by the virtual absence of EEG microsleeps. Whether future research will prove that this regimen does not cause an impairment of performance, it should be a suitable strategy for the management of continuous operations.

The Effects of Long Duration Bed Rest on Functional Mobility and Balance: Relationship to Resting State Motor Cortex Connectivity

Science.gov (United States)

Erdeniz, B.; Koppelmans, V.; Bloomberg, J. J.; Kofman, I. S.; DeDios, Y. E.; Riascos-Castaneda, R. F.; Wood, S. J.; Mulavara, A. P.; Seidler, R. D.

2014-01-01

NASA offers researchers from a variety of backgrounds the opportunity to study bed rest as an experimental analog for space flight. Extended exposure to a head-down tilt position during long duration bed rest can resemble many of the effects of a low-gravity environment such as reduced sensory inputs, body unloading and increased cephalic fluid distribution. The aim of our study is to a) identify changes in brain function that occur with prolonged bed rest and characterize their recovery time course; b) assess whether and how these changes impact behavioral and neurocognitive performance. Thus far, we completed data collection from six participants that include task based and resting state fMRI. The data have been acquired through the bed rest facility located at the University of Texas Medical Branch (Galveston, TX). Subjects remained in bed with their heads tilted down 6 degrees below their feet for 70 consecutive days. Behavioral measures and neuroimaging assessments were obtained at seven time points: a) 7 and 12 days before bed rest; b) 7, 30, and 65 days during bed rest; and c) 7 and 12 days after bed rest. Functional connectivity magnetic resonance imaging (FcMRI) analysis was performed to assess the connectivity of motor cortex in and out of bed rest. We found a decrease in motor cortex connectivity with vestibular cortex and the cerebellum from pre bed rest to in bed rest. We also used a battery of behavioral measures including the functional mobility test and computerized dynamic posturography collected before and after bed rest. We will report the preliminary results of analyses relating brain and behavior changes. Furthermore, we will also report the preliminary results of a spatial working memory task and vestibular stimulation during in and out of bed rest.

Recognizing mild cognitive impairment based on network connectivity analysis of resting EEG with zero reference

International Nuclear Information System (INIS)

Xu, Peng; Xiong, Xiu Chun; Tian, Yin; Zhang, Rui; Li, Pei Yang; Yao, De Zhong; Xue, Qing; Wang, Yu Ping; Peng, Yueheng

2014-01-01

The diagnosis of mild cognitive impairment (MCI) is very helpful for early therapeutic interventions of Alzheimer's disease (AD). MCI has been proven to be correlated with disorders in multiple brain areas. In this paper, we used information from resting brain networks at different EEG frequency bands to reliably recognize MCI. Because EEG network analysis is influenced by the reference that is used, we also evaluate the effect of the reference choices on the resting scalp EEG network-based MCI differentiation. The conducted study reveals two aspects: (1) the network-based MCI differentiation is superior to the previously reported classification that uses coherence in the EEG; and (2) the used EEG reference influences the differentiation performance, and the zero approximation technique (reference electrode standardization technique, REST) can construct a more accurate scalp EEG network, which results in a higher differentiation accuracy for MCI. This study indicates that the resting scalp EEG-based network analysis could be valuable for MCI recognition in the future. (paper)

Long-term prognostic performance of low-dose coronary computed tomography angiography with prospective electrocardiogram triggering

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Clerc, Olivier F.; Kaufmann, Basil P.; Possner, Mathias; Liga, Riccardo; Vontobel, Jan; Mikulicic, Fran; Graeni, Christoph; Benz, Dominik C.; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Gaemperli, Oliver; Kaufmann, Philipp A.; Buechel, Ronny R. [University Hospital Zurich, Cardiac Imaging, Department of Nuclear Medicine, Zurich (Switzerland)

2017-11-15

To assess long-term prognosis after low-dose 64-slice coronary computed tomography angiography (CCTA) using prospective electrocardiogram-triggering. We included 434 consecutive patients with suspected or known coronary artery disease referred for low-dose CCTA. Patients were classified as normal, with non-obstructive or obstructive lesions, or previously revascularized. Coronary artery calcium score (CACS) was assessed in 223 patients. Follow-up was obtained regarding major adverse cardiac events (MACE): cardiac death, myocardial infarction and elective revascularization. We performed Kaplan-Meier analysis and Cox regressions. Mean effective radiation dose was 1.7 ± 0.6 mSv. At baseline, 38% of patients had normal arteries, 21% non-obstructive lesions, 32% obstructive stenosis and 8% were revascularized. Twenty-nine patients (7%) were lost to follow-up. After a median follow-up of 6.1 ± 0.6 years, MACE occurred in 0% of patients with normal arteries, 6% with non-obstructive lesions, 30% with obstructive stenosis and 39% of those revascularized. MACE occurrence increased with increasing CACS (P < 0.001), but 4% of patients with CACS = 0 experienced MACE. Multivariate Cox regression identified obstructive stenosis, lesion burden in CCTA and CACS as independent MACE predictors (P ≤ 0.001). Low-dose CCTA with prospective electrocardiogram-triggering has an excellent long-term prognostic performance with a warranty period >6 years for patients with normal coronary arteries. (orig.)

Long-term prognostic performance of low-dose coronary computed tomography angiography with prospective electrocardiogram triggering

International Nuclear Information System (INIS)

Clerc, Olivier F.; Kaufmann, Basil P.; Possner, Mathias; Liga, Riccardo; Vontobel, Jan; Mikulicic, Fran; Graeni, Christoph; Benz, Dominik C.; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Gaemperli, Oliver; Kaufmann, Philipp A.; Buechel, Ronny R.

2017-01-01

To assess long-term prognosis after low-dose 64-slice coronary computed tomography angiography (CCTA) using prospective electrocardiogram-triggering. We included 434 consecutive patients with suspected or known coronary artery disease referred for low-dose CCTA. Patients were classified as normal, with non-obstructive or obstructive lesions, or previously revascularized. Coronary artery calcium score (CACS) was assessed in 223 patients. Follow-up was obtained regarding major adverse cardiac events (MACE): cardiac death, myocardial infarction and elective revascularization. We performed Kaplan-Meier analysis and Cox regressions. Mean effective radiation dose was 1.7 ± 0.6 mSv. At baseline, 38% of patients had normal arteries, 21% non-obstructive lesions, 32% obstructive stenosis and 8% were revascularized. Twenty-nine patients (7%) were lost to follow-up. After a median follow-up of 6.1 ± 0.6 years, MACE occurred in 0% of patients with normal arteries, 6% with non-obstructive lesions, 30% with obstructive stenosis and 39% of those revascularized. MACE occurrence increased with increasing CACS (P < 0.001), but 4% of patients with CACS = 0 experienced MACE. Multivariate Cox regression identified obstructive stenosis, lesion burden in CCTA and CACS as independent MACE predictors (P ≤ 0.001). Low-dose CCTA with prospective electrocardiogram-triggering has an excellent long-term prognostic performance with a warranty period >6 years for patients with normal coronary arteries. (orig.)

United in prevention-electrocardiographic screening for chronic obstructive pulmonary disease.

Science.gov (United States)

Lazovic, Biljana; Mazic, Sanja; Stajic, Zoran; Djelic, Marina; Zlatkovic-Svenda, Mirjana; Putnikovic, Biljana

2013-01-01

NONE DECLARED. P-wave abnormalities on the resting electrocardiogram have been associated with cardiovascular or pulmonary disease. So far, "Gothic" P wave and verticalization of the frontal plane axis is related to lung disease, particularly obstructive lung disease. We tested if inverted P wave in AVl as a lone criteria of P wave axis >70° could be screening tool for emphysema. 1095 routine electrocardiograms (ECGs) were reviewed which yielded 478 (82,1%) ECGs with vertical P-axis in sinus rhythm. Charts were reviewed for the diagnosis of COPD and emphysema based on medical history and pulmonary function tests. Electrocardiogram is very effective screening tool not only in cardiovascular field but in chronic obstructive pulmonary disease. The verticality of the P axis is usually immediately apparent, making electrocardiogram rapid screening test for emphysema.

Intrinsic Resting-State Functional Connectivity in the Human Spinal Cord at 3.0 T.

Science.gov (United States)

San Emeterio Nateras, Oscar; Yu, Fang; Muir, Eric R; Bazan, Carlos; Franklin, Crystal G; Li, Wei; Li, Jinqi; Lancaster, Jack L; Duong, Timothy Q

2016-04-01

To apply resting-state functional magnetic resonance (MR) imaging to map functional connectivity of the human spinal cord. Studies were performed in nine self-declared healthy volunteers with informed consent and institutional review board approval. Resting-state functional MR imaging was performed to map functional connectivity of the human cervical spinal cord from C1 to C4 at 1 × 1 × 3-mm resolution with a 3.0-T clinical MR imaging unit. Independent component analysis (ICA) was performed to derive resting-state functional MR imaging z-score maps rendered on two-dimensional and three-dimensional images. Seed-based analysis was performed for cross validation with ICA networks by using Pearson correlation. Reproducibility analysis of resting-state functional MR imaging maps from four repeated trials in a single participant yielded a mean z score of 6 ± 1 (P 3, P 3.0-T clinical MR imaging unit and standard MR imaging protocols and hardware reveals prominent functional connectivity patterns within the spinal cord gray matter, consistent with known functional and anatomic layouts of the spinal cord.

Design of portable electrocardiogram device using DSO138

Science.gov (United States)

Abuzairi, Tomy; Matondang, Josef Stevanus; Purnamaningsih, Retno Wigajatri; Basari, Ratnasari, Anita

2018-02-01

Cardiovascular disease has been one of the leading causes of sudden cardiac deaths in many countries, covering Indonesia. Electrocardiogram (ECG) is a medical test to detect cardiac abnormalities by measuring the electrical activity generated by the heart, as the heart contracts. By using ECG, we can observe anomaly at the time of heart abnormalities. In this paper, design of portable ECG device is presented. The portable ECG device was designed to easily use in the village clinic or houses, due to the small size device and other benefits. The device was designed by using four units: (1) ECG electrode; (2) ECG analog front-end; (3) DSO138; and (4) battery. To create a simple electrode system in the portable ECG, 1-lead ECG with two electrodes were applied. The analog front-end circuitry consists of three integrated circuits, an instrumentation amplifier AD820AN, a low noise operational amplifier OPA134, and a low offset operational amplifier TL082. Digital ECG data were transformed to graphical data on DSO138. The results show that the portable ECG is successfully read the signal from 1-lead ECG system.

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection.

Science.gov (United States)

Son, Junggab; Park, Juyoung; Oh, Heekuck; Bhuiyan, Md Zakirul Alam; Hur, Junbeom; Kang, Kyungtae

2017-06-12

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan-Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities.

Clinical physiology of bed rest

Science.gov (United States)

Greenleaf, John E.

1993-01-01

Maintenance of optimal health in humans requires the proper balance between exercise, rest, and sleep as well as time in the upright position. About one-third of a lifetime is spent sleeping; and it is no coincidence that sleeping is performed in the horizontal position, the position in which gravitational influence on the body is minimal. Although enforced bed rest is necessary for the treatment of some ailments, in some cases it has probably been used unwisely. In addition to the lower hydrostatic pressure with the normally dependent regions of the cardiovascular system, body fuid compartments during bed rest in the horizontal body position, and virtual elimination of compression on the long bones of the skeletal system during bed rest (hypogravia), there is often reduction in energy metabolism due to the relative confinement (hypodynamia) and alteration of ambulatory circadian variations in metabolism, body temperature, and many hormonal systems. If patients are also moved to unfamiliar surroundings, they probably experience some feelings of anxiety and some sociopsychological problems. Adaptive physiological responses during bed rest are normal for that environment. They are attempts by the body to reduce unnecessary energy expenditure, to optimize its function, and to enhance its survival potential. Many of the deconditioning responses begin within the first day or two of bed rest; these early responses have prompted physicians to insist upon early resumption of the upright posture and ambulation of bedridden patients.

Clustering of resting state networks.

Directory of Open Access Journals (Sweden)

Megan H Lee

Full Text Available The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm.The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization.The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

Pro REST API development with nodejs

CERN Document Server

Doglio, Fernando

2015-01-01

Pro REST API Development with Node.js is your guide to managing and understanding the full capabilities of successful REST development. API design is a hot topic in the programming world, but not many resources exist for developers to really understand how you can leverage the advantages. This book will provide a brief background on REST and the tools it provides (well known and not so well known). Understand how there is more to REST than just JSON and URLs. You will then cover and compare the maintained modules currently available in the npm community, including Express, Restify, Vatican,

Resting state EEG correlates of memory consolidation.

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Brokaw, Kate; Tishler, Ward; Manceor, Stephanie; Hamilton, Kelly; Gaulden, Andrew; Parr, Elaine; Wamsley, Erin J

2016-04-01

Numerous studies demonstrate that post-training sleep benefits human memory. At the same time, emerging data suggest that other resting states may similarly facilitate consolidation. In order to identify the conditions under which non-sleep resting states benefit memory, we conducted an EEG (electroencephalographic) study of verbal memory retention across 15min of eyes-closed rest. Participants (n=26) listened to a short story and then either rested with their eyes closed, or else completed a distractor task for 15min. A delayed recall test was administered immediately following the rest period. We found, first, that quiet rest enhanced memory for the short story. Improved memory was associated with a particular EEG signature of increased slow oscillatory activity (rest can facilitate memory, and that this may occur via an active process of consolidation supported by slow oscillatory EEG activity and characterized by decreased attention to the external environment. Slow oscillatory EEG rhythms are proposed to facilitate memory consolidation during sleep by promoting hippocampal-cortical communication. Our findings suggest that EEG slow oscillations could play a significant role in memory consolidation during other resting states as well. Copyright © 2016 Elsevier Inc. All rights reserved.

Clinical and Financial Impact of Ordering an Echocardiogram in Children with Left Axis Deviation on Their Electrocardiogram.

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Ravi, Prasad; Ashwath, Ravi; Strainic, James; Li, Hong; Steinberg, Jon; Snyder, Christopher

2016-01-01

Left axis deviation (LAD) on the electrocardiogram (ECG) is associated with congenital heart disease (CHD), prompting the clinician to order further testing when evaluating a patient with this finding. The purpose is to (1) compare the physical examination (PE) by a pediatric cardiologist to echocardiogram (ECHO) findings in patients with LAD on resting ECG and (2) assess cost of performing ECHO on all patients with LAD on ECG. An IRB approved, retrospective cohort study was performed on patients with LAD (QRS axis ≥0° to -90°) on ECG between 01/02 and 12/12. age >0.25 and <18 years, non-postoperative, and PE and ECHO by pediatric cardiologist. A decision tree model analyzed cost of ECHO in patients with LAD and normal/abnormal PE. Cost of complete ECHO ($239.00) was obtained from 2014 Medicare reimbursement rates. A total of 146 patients met inclusion criteria with 46.5% (68) having normal PE and ECHO, 1.4% (2) having normal PE and abnormal ECHO, 47.3% (69) having abnormal PE and ECHO, and 4.8% (7) having an abnormal PE and normal ECHO. Sensitivity and specificity of PE for detecting abnormalities in this population was 97% and 90%. Positive and negative predictive value of PE was 91% and 97.5%. In patients with normal PE, the cost to identify an ECHO abnormality was $8365, and $263 for those with abnormal PE. In presence of LAD on ECG, the sensitivity, specificity, and positive and negative predictive values of PE by a pediatric cardiologist are excellent at identifying CHD. Performing an ECHO on patients with LAD on ECG is only cost effective in the presence of an abnormal PE. In the presence of normal PE, there is a possibility of missing incidental structural cardiac disease in approximately 2% if an ECHO is not performed. © 2015 Wiley Periodicals, Inc.

Electrocardiogram interpretation skills among ambulance nurses.

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Werner, Kristoffer; Kander, Kristofer; Axelsson, Christer

2016-06-01

To describe ambulance nurses' practical electrocardiogram (ECG) interpretation skills and to measure the correlation between these skills and factors that may impact on the level of knowledge. This study was conducted using a prospective quantitative survey with questionnaires and a knowledge test. A convenience sample collection was conducted among ambulance nurses in three different districts in western Sweden. The knowledge test consisted of nine different ECGs. The score of the ECG test were correlated against the questions in the questionnaire regarding both general ECG interpretation skill and ability to identify acute myocardial infarction using Mann-Whitney U test, Kruskal-Wallis test and Spearman's rank correlation. On average, the respondents had 54% correct answers on the test and identified 46% of the ECGs indicating acute myocardial infarction. The median total score was 9 of 16 (interquartile range 7-11) and 1 of 3 (IQR 1-2) in infarction points. No correlation between ECG interpretation skill and factors such as education and professional experience was found, except that coronary care unit experience was associated with better results on the ECG test. Ambulance nurses have deficiencies in their ECG interpretation skills. This also applies to conditions where the ambulance crew has great potential to improve the outcome of the patient's health, such as myocardial infarction and cardiac arrest. Neither education, extensive experience in ambulance service nor in nursing contributed to an improved result. The only factor of importance for higher ECG interpretation knowledge was prior experience of working in a coronary care unit. © The European Society of Cardiology 2014.

Electrocardiogram voltage discordance: Interpretation of low QRS voltage only in the precordial leads.

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Kim, Diana H; Verdino, Ralph J

To define clinical correlates of low voltage isolated to precordial leads on the surface electrocardiogram (ECG). Low voltage (V) on the ECG is defined as QRS Vvoltage isolated to the precordial leads with normal limb lead voltages is unclear. Twelve-lead ECGs with QRS V>5mm in one or more limb leads and voltage was found in 256 of 150,000 ECGs (~0.2%). 50.4% of patients had discordant ECGs that correlated with classic etiologies, with a higher incidence of LV dilation in those with classic etiologies than those without. Low precordial voltage is associated with classic etiologies and LV dilation. Copyright © 2017 Elsevier Inc. All rights reserved.

Rapid dual-injection single-scan 13N-ammonia PET for quantification of rest and stress myocardial blood flows

International Nuclear Information System (INIS)

Rust, T C; DiBella, E V R; McGann, C J; Christian, P E; Hoffman, J M; Kadrmas, D J

2006-01-01

Quantification of myocardial blood flows at rest and stress using 13 N-ammonia PET is an established method; however, current techniques require a waiting period of about 1 h between scans. The objective of this study was to test a rapid dual-injection single-scan approach, where 13 N-ammonia injections are administered 10 min apart during rest and adenosine stress. Dynamic PET data were acquired in six human subjects using imaging protocols that provided separate single-injection scans as gold standards. Rest and stress data were combined to emulate rapid dual-injection data so that the underlying activity from each injection was known exactly. Regional blood flow estimates were computed from the dual-injection data using two methods: background subtraction and combined modelling. The rapid dual-injection approach provided blood flow estimates very similar to the conventional single-injection standards. Rest blood flow estimates were affected very little by the dual-injection approach, and stress estimates correlated strongly with separate single-injection values (r = 0.998, mean absolute difference = 0.06 ml min -1 g -1 ). An actual rapid dual-injection scan was successfully acquired in one subject and further demonstrates feasibility of the method. This study with a limited dataset demonstrates that blood flow quantification can be obtained in only 20 min by the rapid dual-injection approach with accuracy similar to that of conventional separate rest and stress scans. The rapid dual-injection approach merits further development and additional evaluation for potential clinical use

Observational and Genetic Associations of Resting Heart Rate With Aortic Valve Calcium.

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Whelton, Seamus P; Mauer, Andreas C; Pencina, Karol M; Massaro, Joseph M; D'Agostino, Ralph B; Fox, Caroline S; Hoffmann, Udo; Michos, Erin D; Peloso, Gina M; Dufresne, Line; Engert, James C; Kathiresan, Sekar; Budoff, Matthew; Post, Wendy S; Thanassoulis, George; O'Donnell, Christopher J

2018-05-15

It is unknown if lifelong exposure to increased hemodynamic stress from an elevated resting heart rate (HR) may contribute to aortic valve calcium (AVC). We performed multivariate regression analyses using data from 1,266 Framingham Heart Study (FHS) Offspring cohort participants and 6,764 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We constructed a genetic risk score (GRS) for HR using summary-level data in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) AVC Consortium to investigate if there was evidence in favor of a causal relation. AVC was present in 39% of FHS Offspring cohort participants and in 13% of MESA cohort participants. In multivariate adjusted models, participants in the highest resting HR quartiles had significantly greater prevalence of AVC, with a prevalence ratio of 1.19 (95% confidence interval [CI] 0.99 to 1.44) for the FHS Offspring cohort and 1.32 (95% CI 1.12 to 1.63) for the MESA cohort, compared with those in the lowest quartile. There was a similar increase in the prevalence of AVC per standard deviation increase in resting HR in both FHS Offspring (prevalence ratio 1.08, 95% CI 1.01 to 1.15) and MESA (1.10, 95% CI 1.03 to 1.17). In contrast with these observational findings, a HR associated GRS was not significantly associated with AVC. Although our observational analysis indicates that a higher resting HR is associated with AVC, our genetic results do not support a causal relation. Unmeasured environmental and/or lifestyle factors associated with both increased resting HR and AVC that are not fully explained by covariates in our observational models may account for the association between resting HR and AVC. Copyright © 2018. Published by Elsevier Inc.

Resting electrocardiogram and stress myocardial perfusion imaging in the determination of left ventricular systolic function: an assessment enhancing the performance of gated SPET.

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Moralidis, Efstratios; Spyridonidis, Tryfon; Arsos, Georgios; Skeberis, Vassilios; Anagnostopoulos, Constantinos; Gavrielidis, Stavros

2010-01-01

This study aimed to determine systolic dysfunction and estimate resting left ventricular ejection fraction (LVEF) from information collected during routine evaluation of patients with suspected or known coronary heart disease. This approach was then compared to gated single photon emission tomography (SPET). Patients having undergone stress (201)Tl myocardial perfusion imaging followed by equilibrium radionuclide angiography (ERNA) were separated into derivation (n=954) and validation (n=309) groups. Logistic regression analysis was used to develop scoring systems, containing clinical, electrocardiographic (ECG) and scintigraphic data, for the discrimination of an ERNA-LVEFstatistic (mean+/-2SD) provided values of 0.001+/-0.176, 0.071+/-0.196 and 0.040+/-0.152, respectively. The average LVEF was a better discriminator of systolic dysfunction than gated SPET-LVEF in receiver operating characteristic (ROC) analysis and identified more patients (89%) with a stress myocardial perfusion imaging variables. This model provides reliable LVEF estimations, comparable to those from (201)Tl gated SPET, and can enhance the clinical performance of the latter.

Influence of ROI selection on Resting Functional Connectivity: An Individualized Approach for Resting fMRI Analysis

Directory of Open Access Journals (Sweden)

William Seunghyun Sohn

2015-08-01

Full Text Available The differences in how our brain is connected are often thought to reflect the differences in our individual personalities and cognitive abilities. Individual differences in brain connectivity has long been recognized in the neuroscience community however it has yet to manifest itself in the methodology of resting state analysis. This is evident as previous studies use the same region of interest (ROIs for all subjects. In this paper we demonstrate that the use of ROIs which are standardized across individuals leads to inaccurate calculations of functional connectivity. We also show that this problem can be addressed by taking an individualized approach by using subject-specific ROIs. Finally we show that ROI selection can affect the way we interpret our data by showing different changes in functional connectivity with ageing.

Assessing the mean strength and variations of the time-to-time fluctuations of resting-state brain activity.

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Li, Zhengjun; Zang, Yu-Feng; Ding, Jianping; Wang, Ze

2017-04-01

The time-to-time fluctuations (TTFs) of resting-state brain activity as captured by resting-state fMRI (rsfMRI) have been repeatedly shown to be informative of functional brain structures and disease-related alterations. TTFs can be characterized by the mean and the range of successive difference. The former can be measured with the mean squared successive difference (MSSD), which is mathematically similar to standard deviation; the latter can be calculated by the variability of the successive difference (VSD). The purpose of this study was to evaluate both the resting state-MSSD and VSD of rsfMRI regarding their test-retest stability, sensitivity to brain state change, as well as their biological meanings. We hypothesized that MSSD and VSD are reliable in resting brain; both measures are sensitive to brain state changes such as eyes-open compared to eyes-closed condition; both are predictive of age. These hypotheses were tested with three rsfMRI datasets and proven true, suggesting both MSSD and VSD as reliable and useful tools for resting-state studies.

Combined electrocardiogram and photoplethysmogram measurements as an indicator of objective sleepiness

International Nuclear Information System (INIS)

Chua, Chern-Pin; McDarby, Gary; Heneghan, Conor

2008-01-01

There is considerable interest in unobtrusive and portable methods of monitoring sleepiness outside the laboratory setting. This study evaluates the usefulness of combined electrocardiogram (ECG) and photoplethysmogram (PPG) measurements for estimating psychomotor vigilance. The psychomotor vigilance test (PVT) was performed at various points over the course of a day, and one channel each of ECG and PPG was recorded simultaneously. Features derived from ECG and PPG were entered into multiple linear regression models to estimate PVT values. A double-loop, subject-independent validation scheme was used to develop and validate the models. We show that features obtained from the RR interval were reasonably useful for estimating absolute PVT levels, but were somewhat inadequate for estimating within-subject PVT changes. Combined ECG and PPG measurements appear to be useful for predicting PVT values, and deserve further investigation for portable sleepiness monitoring

A random walk description of individual animal movement accounting for periods of rest

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Tilles, Paulo F. C.; Petrovskii, Sergei V.; Natti, Paulo L.

2016-11-01

Animals do not move all the time but alternate the period of actual movement (foraging) with periods of rest (e.g. eating or sleeping). Although the existence of rest times is widely acknowledged in the literature and has even become a focus of increased attention recently, the theoretical approaches to describe animal movement by calculating the dispersal kernel and/or the mean squared displacement (MSD) rarely take rests into account. In this study, we aim to bridge this gap. We consider a composite stochastic process where the periods of active dispersal or `bouts' (described by a certain baseline probability density function (pdf) of animal dispersal) alternate with periods of immobility. For this process, we derive a general equation that determines the pdf of this composite movement. The equation is analysed in detail in two special but important cases such as the standard Brownian motion described by a Gaussian kernel and the Levy flight described by a Cauchy distribution. For the Brownian motion, we show that in the large-time asymptotics the effect of rests results in a rescaling of the diffusion coefficient. The movement occurs as a subdiffusive transition between the two diffusive asymptotics. Interestingly, the Levy flight case shows similar properties, which indicates a certain universality of our findings.

The Use of RESTful Web Services in Medical Informatics and Clinical Research and Its Implementation in Europe.

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Aerts, Jozef

2017-01-01

RESTful web services nowadays are state-of-the-art in business transactions over the internet. They are however not very much used in medical informatics and in clinical research, especially not in Europe. To make an inventory of RESTful web services that can be used in medical informatics and clinical research, including those that can help in patient empowerment in the DACH region and in Europe, and to develop some new RESTful web services for use in clinical research and regulatory review. A literature search on available RESTful web services has been performed and new RESTful web services have been developed on an application server using the Java language. Most of the web services found originate from institutes and organizations in the USA, whereas no similar web services could be found that are made available by European organizations. New RESTful web services have been developed for LOINC codes lookup, for UCUM conversions and for use with CDISC Standards. A comparison is made between "top down" and "bottom up" web services, the latter meant to answer concrete questions immediately. The lack of RESTful web services made available by European organizations in healthcare and medical informatics is striking. RESTful web services may in short future play a major role in medical informatics, and when localized for the German language and other European languages, can help to considerably facilitate patient empowerment. This however requires an EU equivalent of the US National Library of Medicine.

Resting heart rate associates with one-year risk of major adverse cardiovascular events in patients with acute coronary syndrome after percutaneous coronary intervention.

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Wang, Shao-Li; Wang, Cheng-Long; Wang, Pei-Li; Xu, Hao; Du, Jian-Peng; Zhang, Da-Wu; Gao, Zhu-Ye; Zhang, Lei; Fu, Chang-Geng; Chen, Ke-Ji; Shi, Da-Zhuo

2016-03-01

The study was to access the association between resting heart rate (RHR) and one-year risk of major adverse cardiovascular events (MACE) in acute coronary syndrome (ACS) patients after percutaneous coronary intervention (PCI). Patients with ACS after PCI (n = 808) were prospectively followed-up for MACE. RHR was obtained from electrocardiogram. MACE was defined as a composite of cardiac death, nonfatal recurrent myocardial infarction, ischemic-driven revascularization, and ischemic stroke. The association between RHR and one-year risk of MACE was assessed using Cox proportional hazards regression model. Compared with patients with RHR >76 bpm, the adjusted hazard ratio (AHR) was 0.51 (95% confidence intervals [CI]: 0.23-1.14; P = 0.100) for patients with RHR 76 bpm were at higher risk of MACE during one-year follow-up compared with patients with RHR 61-76 bpm. An elevated RHR ≥ 61 bpm was associated with increased risk of one-year MACE in ACS patients. © 2015 by the Society for Experimental Biology and Medicine.

Exercise electrocardiogram testing in two brothers with different outcome – a case study exercise testing in master cyclists

Directory of Open Access Journals (Sweden)

Rüst CA

2013-06-01

Full Text Available Christoph Alexander Rüst,1 Beat Knechtle,1,2 Thomas Rosemann11Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, SwitzerlandAbstract: The cases of two brothers training and competing as master cyclists and both preparing for a cycling tour are presented. The older brother aged 66 years went first to the primary care physician and presented with an asymptomatic depression in the exercise stress test of the ST segment in V5 and V6 during recovery after complete exhaustion. Coronary angiography revealed a multi vessel coronary artery disease and he underwent bypass surgery. One year later, he successfully completed his planned cycling tour of ~600 km in seven stages and covering ~12,000 m of total ascent. The younger brother aged 59 years went a few months later to the primary care physician and also performed asymptomatic exercise stress testing without changes in the ST segments. Unfortunately, 2 months later he suffered a cardiac arrest during his cycling tour and survived following immediate successful cardiopulmonary resuscitation on the road by his cycling colleagues. Immediate invasive coronary arteriography showed a complete stenosis of the trunk of arteria coronaria sinistra (left coronary artery, a 40%–50% stenosis of ramus circumflexus, and a 20% stenosis of arteria coronaria dextra (right coronary artery. The left coronary artery was dilated and he continued cycling 2 months later. In both brothers, familial hypercholesterolemia was the main cardiovascular risk factor for the multi vessel coronary artery disease. A negative exercise electrocardiogram in siblings with an increased risk for coronary artery disease seemed not to exclude an advanced multi vessel coronary artery disease. In master athletes with asymptomatic exercise electrocardiogram but a positive family history, further examinations should be performed in order to detect

Accuracy of electrocardiogram reading by family practice residents.

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Sur, D K; Kaye, L; Mikus, M; Goad, J; Morena, A

2000-05-01

This study evaluated the electrocardiogram (EKG) reading skills of family practice residents. A multicenter study was carried out to evaluate the accuracy of EKG reading in the family practice setting. Based on the frequency and potential for clinical significance, we chose 18 common findings on 10 EKGs for evaluation. The EKGs were then distributed to residents at six family practice residencies. Residents were given one point for the identification of each correct EKG finding and scored based on the number correct over a total of 18. Sixty-one residents (20 first year, 23 second year, and 18 third year) completed readings for 10 EKGs and were evaluated for their ability to identify 18 EKG findings. The median score out of 18 possible points for all first-, second-, and third-year residents was 12, 12, and 11.5, respectively. Twenty-one percent of residents did not correctly identify a tracing of an acute myocardial infarction. Data analysis showed no statistically significant difference among the three groups of residents. We evaluated the accuracy of EKG reading skills of family practice residents at each year of training. This study suggests that EKG reading skills do not improve during residency, and further study of curricular change to improve these skills should be considered.

What goes on in the resting-state? A qualitative glimpse into resting-state experience in the scanner

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Hurlburt, Russell T.; Alderson-Day, Ben; Fernyhough, Charles; Kühn, Simone

2015-01-01

The brain’s resting-state has attracted considerable interest in recent years, but currently little is known either about typical experience during the resting-state or about whether there are inter-individual differences in resting-state phenomenology. We used descriptive experience sampling (DES) in an attempt to apprehend high fidelity glimpses of the inner experience of five participants in an extended fMRI study. Results showed that the inner experiences and the neural activation patterns (as quantified by amplitude of low frequency fluctuations analysis) of the five participants were largely consistent across time, suggesting that our extended-duration scanner sessions were broadly similar to typical resting-state sessions. However, there were very large individual differences in inner phenomena, suggesting that the resting-state itself may differ substantially from one participant to the next. We describe these individual differences in experiential characteristics and display some typical moments of resting-state experience. We also show that retrospective characterizations of phenomena can often be very different from moment-by-moment reports. We discuss implications for the assessment of inner experience in neuroimaging studies more generally, concluding that it may be possible to use fMRI to investigate neural correlates of phenomena apprehended in high fidelity. PMID:26500590

Rest tremor in idiopathic adult-onset dystonia.

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Gigante, A F; Berardelli, A; Defazio, G

2016-05-01

Tremor in dystonia has been described as a postural or kinetic abnormality. In recent series, however, patients with idiopathic adult-onset dystonia also displayed rest tremor. The frequency and distribution of rest tremor were studied in a cohort of 173 consecutive Italian patients affected by various forms of idiopathic adult-onset dystonia attending our movement disorder clinic over 8 months. Examination revealed tremor in 59/173 patients (34%): 12 patients had head tremor, 34 patients had arm tremor, whilst 13 patients presented tremor in both sites. Head tremor was postural in all patients, whereas arm tremor was postural/kinetic in 28 patients, only at rest in one and both postural/kinetic and at rest in 18 patients. Patients with tremor were more likely to have segmental/multifocal dystonia. Patients who had rest tremor (either alone or associated with action tremor) had a higher age at dystonia onset and a greater frequency of dystonic arm involvement than patients with action tremor alone or without tremor. Both action and rest tremor are part of the tremor spectrum of adult-onset dystonia and are more frequently encountered in segmental/multifocal dystonia. The higher age at dystonia onset and the greater frequency of arm dystonia in patients with rest tremor may have pathophysiological implications and may account, at least in part, for the previous lack of identification of rest tremor as one possible type of tremor present in dystonia. © 2016 EAN.

Actigraphy-Derived Daily Rest-Activity Patterns and Body Mass Index in Community-Dwelling Adults.

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Cespedes Feliciano, Elizabeth M; Quante, Mirja; Weng, Jia; Mitchell, Jonathan A; James, Peter; Marinac, Catherine R; Mariani, Sara; Redline, Susan; Kerr, Jacqueline; Godbole, Suneeta; Manteiga, Alicia; Wang, Daniel; Hipp, J Aaron

2017-12-01

To examine associations between 24-hour rest-activity patterns and body mass index (BMI) among community-dwelling US adults. Rest-activity patterns provide a field method to study exposures related to circadian rhythms. Adults (N = 578) wore an actigraph on their nondominant wrist for 7 days. Intradaily variability and interdaily stability (IS), M10 (most active 10-hours), L5 (least active 5-hours), and relative amplitude (RA) were derived using nonparametric rhythm analysis. Mesor, acrophase, and amplitude were calculated from log-transformed count data using the parametric cosinor approach. Participants were 80% female and mean (standard deviation) age was 52 (15) years. Participants with higher BMI had lower values for magnitude, RA, IS, total sleep time (TST), and sleep efficiency. In multivariable analyses, less robust 24-hour rest-activity patterns as represented by lower RA were consistently associated with higher BMI: comparing the bottom quintile (least robust) to the top quintile (most robust 24-hour rest-activity pattern) of RA, BMI was 3-kg/m2 higher (p = .02). Associations were similar in magnitude to an hour less of TST (1-kg/m2 higher BMI) or a 10% decrease in sleep efficiency (2-kg/m2 higher BMI), and independent of age, sex, race, education, and the duration of rest and/or activity. Lower RA, reflecting both higher night activity and lower daytime activity, was associated with higher BMI. Independent of the duration of rest or activity during the day or night, 24-hour rest, and activity patterns from actigraphy provide aggregated measures of activity that associate with BMI in community-dwelling adults. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Effect of a real-time tele-transmission system of 12-lead electrocardiogram on the first-aid for athletes with ST-elevation myocardial infarction.

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Zhang, Huan; Song, Donghan; An, Lina

2016-05-01

To study the effect of a real-time tele-transmission system of 12-lead electrocardiogram on door-to-balloon time in athletes with ST-elevation myocardial infarction. A total of 60 athletes with chest pain diagnosed as ST-elevation myocardial infarction (STEMI) from our hospital were randomly divided into group A (n=35) and group B (n=25), the patients in group A transmitted the real-time tele-transmission system of 12-lead electrocardiogram to the chest pain center before arriving in hospital, however, the patients in group B not. The median door-to-balloon time was significant shorter in-group A than group B (38min vs 94 min, p0.05). The median length of stay was significant reduced in-group A (5 days vs 7 days, pelectrocardiogram is beneficial to the pre-hospital diagnosis of STEMI.

Physiology Of Prolonged Bed Rest

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Greenleaf, John E.

1991-01-01

Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

High-resolution MRI for the quantitative evaluation of subendocardial and subepicardial perfusion under pharmalogical stress and at rest

International Nuclear Information System (INIS)

Ritter, C.O.; Savio, K. del; Brackertz, A.; Beer, M.; Hahn, D.; Koestler, H.

2007-01-01

Purpose: MR stress perfusion imaging of the heart allows the quantification of myocardial perfusion and the evaluation of myocardial perfusion reserve (MPR) and the ratio of subendocardial to subepicardial perfusion at rest and under adenosine stress. The aim of this study was to evaluate a high-resolution GRAPPA sequence for quantitative MR first pass perfusion imaging in healthy volunteers. Materials and Methods: First pass stress and rest perfusion studies were performed on 10 healthy volunteers using a 1.5 T MR scanner with a multislice SR-TrueFISP first pass perfusion sequence with a GRAPPA algorithm (acceleration factor 3) in prebolus technique and an image resolution of 1.8 x 1.8 mm. For the comparison group, we examined 12 different healthy volunteers with a standard first pass perfusion SR-TrueFISP sequence using a resolution of 2.7 x 3.3 mm. Myocardial contours were manually delineated followed by an automatic division of the myocardium into two rings with an equal thickness for the subendo- and subepicardial layer. Eight sectors per slice were evaluated using contamination and baseline correction. Results: Using the GRAPPA sequence, the ratio of subendo- to subepimyocardial perfusion was 1.18 ± 0.32 for the examination at rest. Under pharmacologically induced stress, the ratio was 1.08 ± 0.27. For the standard sequence the ratio was 1.15 ± 0.28 at rest and 1.11 ± 0.33 under stress. For the high resolution sequence higher mean values for the subendo- to subepimyocardial ratio were obtained with comparable standard deviations. The difference between the sequences was not significant. Conclusion: The evaluation of subendomyocardial and subepimyocardial perfusion is feasible with a high-resolution first pass perfusion sequence. The use of a higher resolution to avoid systematic error leads to increased image noise. However, no relevant reduction in the quantitative perfusion values under stress and at rest was able to be depicted. (orig.)

Dose and effect of inhaled ozone in resting versus exercising human subjects: comparison with resting rats

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Dose and effect of inhaled ozone in resting versus exercising human subjects: comparison with resting rats Authors: Gary E. Hatch, John McKee, James Brown, Bill McDonnell, Elston Seal, Joleen Soukup, Ralph Slade, Kay Crissman and Robert Devlin, National Health and Environmental...

Clinical applications of resting state functional connectivity

Directory of Open Access Journals (Sweden)

Michael D Fox

2010-06-01

Full Text Available During resting conditions the brain remains functionally and metabolically active. One manifestation of this activity that has become an important research tool is spontaneous fluctuations in the blood oxygen level dependent (BOLD signal of fMRI. The identification of correlation patterns in these spontaneous fluctuations has been termed resting state functional connectivity (fcMRI and has the potential to greatly increase the translation of fMRI into clinical care. In this article we review the advantages of the resting state signal for clinical applications including detailed discussion of signal to noise considerations. We include guidelines for performing resting state research on clinical populations, outline the different areas for clinical application, and identify important barriers to be addressed to facilitate the translation of resting state fcMRI into the clinical realm.

Sustainable Rest Area Design and Operations

Science.gov (United States)

2017-10-01

One way in which State Departments of Transportation (DOTs) can modernize their rest areas while reducing operations and maintenance costs is by incorporating sustainable practices into rest area design and operations. Sustainability practices that D...

The Physiology of Bed Rest. Chapter 39

Science.gov (United States)

Fortney, Suzanne M.; Schneider, Victor S.; Greenleaf, John E.

1996-01-01

Prolonged rest in bed has been utilized by physicians and other health-care workers to immobilize and confine patients for rehabilitation and restoration of health since time immemorial. The sitting or horizontal position is sought by the body to relieve the strain of the upright or vertical postures, for example during syncopal situations, bone fractures, muscle injuries, fatigue, and probably also to reduce energy expenditure. Most health-care personnel are aware that adaptive responses occurring during bed rest proceed concomitantly with the healing process; signs and symptoms associated with the former should be differentiated from those of the latter. Not all illnesses and infirmities benefit from prolonged bed rest. Considerations in prescribing bed rest for patients-including duration, body position, mode and duration of exercise, light-dark cycles, temperature, and humidity-have not been investigated adequately. More recently, adaptive physiological responses have been measured in normal, healthy subjects in the horizontal or slightly head-down postures during prolonged bed rest as analogs for the adaptive responses of astronauts exposed to the microgravity environment of outer and bed-rest research.

Referral of patients with ST-segment elevation acute myocardial infarction directly to the catheterization suite based on prehospital teletransmission of 12-lead electrocardiogram

DEFF Research Database (Denmark)

Sillesen, Martin; Sejersten, Maria; Strange, Søren

2008-01-01

BACKGROUND: Time from symptom onset to reperfusion is essential in patients with ST-segment elevation acute myocardial infarction. Prior studies have indicated that prehospital 12-lead electrocardiogram (ECG) transmission can reduce time to reperfusion. PURPOSE: Determine 12-lead ECG transmission...

The Effects of Long Duration Bed Rest as a Spaceflight Analogue on Resting State Sensorimotor Network Functional Connectivity and Neurocognitive Performance

Science.gov (United States)

Cassady, K.; Koppelmans, V.; Yuan, P.; Cooke, K.; De Dios, Y.; Stepanyan, V.; Szecsy, D.; Gadd, N.; Wood, S.; Reuter-Lorenz, P.;

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection †

Science.gov (United States)

Son, Junggab; Park, Juyoung; Oh, Heekuck; Bhuiyan, Md Zakirul Alam; Hur, Junbeom; Kang, Kyungtae

2017-01-01

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan–Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities. PMID:28604628

Correlation of resting ECG, stress ECG and thallium scan in the evaluation of coronary artery disease

International Nuclear Information System (INIS)

Khan, A.; Amin, W.; Khan, M.Z.A.; Ahmed, A.; Kiani, M.R.

1987-01-01

This study includes 70 cases who underwent myocardial perfusion studies with thallium 201 during the year 1984-85. They were studied clinically, had their resting ECGs, stress ECGs and coronary angiograms. Majority of these patients were males, their ages ranged between 34-70 years. The patients population included with typical/atypical chest pain, some with resting ECG abnormalities, after coronary angiography and a few after coronary artery bypass graft surgery. The result of all the modalities were compared with the conventional gold standard for ischaemic heart disease, i.e. coronary angiogram. It is concluded that the sensitivity of resting ECG in the diagnosis of ischaemic heart disease is very low. The exercise test alone was found conclusive in about 74% of patients while sensitivity of thallium scan was 66% in this particular group of patients. (author)

An obstructive sleep apnea detection approach using kernel density classification based on single-lead electrocardiogram.

Science.gov (United States)

Chen, Lili; Zhang, Xi; Wang, Hui

2015-05-01

Obstructive sleep apnea (OSA) is a common sleep disorder that often remains undiagnosed, leading to an increased risk of developing cardiovascular diseases. Polysomnogram (PSG) is currently used as a golden standard for screening OSA. However, because it is time consuming, expensive and causes discomfort, alternative techniques based on a reduced set of physiological signals are proposed to solve this problem. This study proposes a convenient non-parametric kernel density-based approach for detection of OSA using single-lead electrocardiogram (ECG) recordings. Selected physiologically interpretable features are extracted from segmented RR intervals, which are obtained from ECG signals. These features are fed into the kernel density classifier to detect apnea event and bandwidths for density of each class (normal or apnea) are automatically chosen through an iterative bandwidth selection algorithm. To validate the proposed approach, RR intervals are extracted from ECG signals of 35 subjects obtained from a sleep apnea database ( http://physionet.org/cgi-bin/atm/ATM ). The results indicate that the kernel density classifier, with two features for apnea event detection, achieves a mean accuracy of 82.07 %, with mean sensitivity of 83.23 % and mean specificity of 80.24 %. Compared with other existing methods, the proposed kernel density approach achieves a comparably good performance but by using fewer features without significantly losing discriminant power, which indicates that it could be widely used for home-based screening or diagnosis of OSA.

United in Prevention–Electrocardiographic Screening for Chronic Obstructive Pulmonary Disease

Science.gov (United States)

Mazic, Sanja; Stajic, Zoran; Djelic, Marina; Zlatkovic-Svenda, Mirjana; Putnikovic, Biljana

2013-01-01

CONFLICT OF INTEREST: NONE DECLARED Introduction P-wave abnormalities on the resting electrocardiogram have been associated with cardiovascular or pulmonary disease. So far, “Gothic” P wave and verticalization of the frontal plane axis is related to lung disease, particularly obstructive lung disease. Aim We tested if inverted P wave in AVl as a lone criteria of P wave axis >70° could be screening tool for emphysema. Material and method 1095 routine electrocardiograms (ECGs) were reviewed which yielded 478 (82,1%) ECGs with vertical P-axis in sinus rhythm. Charts were reviewed for the diagnosis of COPD and emphysema based on medical history and pulmonary function tests. Conclusion Electrocardiogram is very effective screening tool not only in cardiovascular field but in chronic obstructive pulmonary disease. The verticality of the P axis is usually immediately apparent, making electrocardiogram rapid screening test for emphysema. PMID:24058253

Incidence of major vascular events after cardiac surgery: impact of preoperative monitoring with troponin and electrocardiogram

International Nuclear Information System (INIS)

Sandra M Quiroga; Juan C Villar; Luz X, Martinez

2009-01-01

Recent demographic changes have led to an increased risk of major vascular events among patients undergoing non-cardiac surgery. Troponin and electrocardiogram monitoring would further identify these major vascular events. Methods: we prospectively collected data on eligible patients (non-selected individuals aged 45 or older undergoing non-cardiac surgery under general or regional anesthesia in two hospitals in Bucaramanga, with expected length of stay longer than 24 hours) during a time-interrupted series,before and after postoperative diagnostic monitoring (blinded assessment of troponin T and electrocardiograms ignoring clinical data). For the period before the intervention (usual clinical care),two independent reviewers extracted clinical information from clinical histories (of all eligible patients from 3 randomly-selected months of 2005). For the period after diagnostic monitoring, we followed 100 consecutive eligible patients. Primary outcome was a composite of major vascular events within hospital, including myocardial infarction (defined as any troponin elevation associated with electrocardiographic changes suggesting ischemia, regardless of symptoms). Results: we included 534 clinical charts and 100 prospective surgical patients (mean age 62.2, SD 12.9 years; 56% women). The more frequent surgical procedures were orthopedics (26.8%) followed by abdominal (20.2%).The incidence of major vascular events recorded in clinical charts was 2.8%, compared with 7% among monitored patients (p=0,071). All four myocardial infarctions identified among the later group were silent. Conclusion: postoperative monitoring with troponin and electrocardiography identified a higher proportion of major vascular events, mainly silent myocardial infarctions.

P-wave characteristics on routine preoperative electrocardiogram improve prediction of new-onset postoperative atrial fibrillation in cardiac surgery.

Science.gov (United States)

Wong, Jim K; Lobato, Robert L; Pinesett, Andre; Maxwell, Bryan G; Mora-Mangano, Christina T; Perez, Marco V

2014-12-01

To test the hypothesis that including preoperative electrocardiogram (ECG) characteristics with clinical variables significantly improves the new-onset postoperative atrial fibrillation prediction model. Retrospective analysis. Single-center university hospital. Five hundred twenty-six patients, ≥ 18 years of age, who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement/repair, or a combination of valve surgery and coronary artery bypass grafting requiring cardiopulmonary bypass. Retrospective review of medical records. Baseline characteristics and cardiopulmonary bypass times were collected. Digitally-measured timing and voltages from preoperative electrocardiograms were extracted. Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Two hundred eight (39.5%) patients developed postoperative atrial fibrillation. Clinical predictors were age, ejection fractionelectrocardiogram variables to the prediction model with only clinical predictors significantly improved the area under the receiver operating characteristic curve, from 0.71 to 0.78 (p<0.01). Overall net reclassification improvement was 0.059 (p = 0.09). Among those who developed postoperative atrial fibrillation, the net reclassification improvement was 0.063 (p = 0.03). Several p-wave characteristics are independently associated with postoperative atrial fibrillation. Addition of these parameters improves the postoperative atrial fibrillation prediction model. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Teaching crucial skills: An electrocardiogram teaching module for medical students.

Science.gov (United States)

Chudgar, Saumil M; Engle, Deborah L; Grochowski, Colleen O'Connor; Gagliardi, Jane P

2016-01-01

Medical student performance in electrocardiogram (ECG) interpretation at our institution could be improved. Varied resources exist to teach students this essential skill. We created an ECG teaching module (ECGTM) of 75 cases representing 15 diagnoses to improve medical students' performance and confidence in ECG interpretation. Students underwent pre- and post-clerkship testing to assess ECG interpretation skills and confidence and also end-of-clinical-year testing in ECG and laboratory interpretation. Performance was compared for the years before and during ECGTM availability. Eighty-four percent of students (total n=101) reported using the ECGTM; 98% of those who used it reported it was useful. Students' performance and confidence were higher on the post-test. Students with access to the ECGTM (n=101) performed significantly better than students from the previous year (n=90) on the end-of-year ECG test. The continuous availability of an ECGTM was associated with improved confidence and ability in ECG interpretation. The ECGTM may be another available tool to help students as they learn to read ECGs. Copyright © 2016 Elsevier Inc. All rights reserved.

Noninvasive recording of electrocardiogram in conscious rat: A new device.

Science.gov (United States)

Kumar, Pradeep; Srivastava, Pooja; Gupta, Ankit; Bajpai, Manish

2017-01-01

Electrocardiogram (ECG) is an important tool for the study of cardiac electrophysiology both in human beings and experimental animals. Existing methods of ECG recording in small animals like rat have several limitations and ECG recordings of the anesthetized rat lack validity for heart rate (HR) variability analysis. The aim of the present study was to validate the ECG data from new device with ECG of anesthetized rat. The ECG was recorded on student's physiograph (BioDevice, Ambala) and suitable coupler and electrodes in six animals first by the newly developed device in conscious state and second in anesthetized state (stabilized technique). The data obtained were analyzed using unpaired t -test showed no significant difference ( P < 0.05) in QTc, QRS, and HR recorded by new device and established device in rats. No previous study describes a similar ECG recording in conscious state of rats. Thus, the present method may be a most physiological and inexpensive alternative to other methods. In this study, the animals were not restrained; they were just secured and represent a potential strength of the study.

The electrocardiogram signal of Seba's short-tailed bat, Carollia perspicillata.

Science.gov (United States)

Mihova, Diana; Hechavarría, Julio C

2016-07-01

A number of studies have successfully used electrocardiogram (ECG) signals to characterize complex physiological phenomena such as associative learning in bats. However, at present, no thorough characterization of the structure of ECG signals is available for these animals. The aim of the present study was to quantitatively characterize features of the ECG signals in the bat species Carollia perspicillata, a species that is commonly used in neuroethology studies. Our results show that the ECG signals of C. perspicillata follow the typical mammalian pattern, in that they are composed by a P wave, QRS complex and a T wave. Peak-to-peak amplitudes in the bats' ECG signals were larger in measuring configurations in which one of the electrodes was attached to the right thumb. In addition, large differences in the instantaneous heart rate (HR) distributions were observed between ketamine/xylazine anesthetized and awake bats. Ketamine/xylazine might target the neural circuits that control HR, therefore, instantaneous HR measurements should only be used as physiological marker in awake animals.

Coronary spasm: 201Tl scintiscanning following pharmacological provocation

International Nuclear Information System (INIS)

Montz, R.; Mathey, D.; Bleifeld, W.; Hamburg Univ.

1981-01-01

According to the authors' experience so far, 201 Tl myocardial scintiscanning is a sufficiently sensitive non-invasive method for detection of coronary vasospasm provoked by ergotamine administration. Mild incomplete and asymptotic forms of coronary vasospasm were detected by scintiscanning. Indications for myocardial scintiscanning of ergotamine-provoked vasospasm are: Cases of angina pectoris at rest in which electrocardiograms during spasm are not available; elleviated symptoms after nitroglycerine administration; exercise electrocardiograms without any sign of ischaemia; negative results of exercise 201 Tl myocardial scintiscanning. (orig.) [de

Exercise countermeasures for bed-rest deconditioning

Science.gov (United States)

Greenleaf, John (Editor)

1993-01-01

The purpose for this 30-day bed rest study was to investigate the effects of short-term, high intensity isotonic and isokinetic exercise training on maintenance of working capacity (peak oxygen uptake), muscular strength and endurance, and on orthostatic tolerance, posture and gait. Other data were collected on muscle atrophy, bone mineralization and density, endocrine analyses concerning vasoactivity and fluid-electrolyte balance, muscle intermediary metabolism, and on performance and mood of the subjects. It was concluded that: The subjects maintained a relatively stable mood, high morale, and high esprit de corps throughout the study. Performance improved in nearly all tests in almost all the subjects. Isotonic training, as opposed to isokinetic exercise training, was associated more with decreasing levels of psychological tension, concentration, and motivation; and improvement in the quality of sleep. Working capacity (peak oxygen uptake) was maintained during bed rest with isotonic exercise training; it was not maintained with isokinetic or no exercise training. In general, there was no significant decrease in strength or endurance of arm or leg muscles during bed rest, in spite of some reduction in muscle size (atrophy) of some leg muscles. There was no effect of isotonic exercise training on orthostasis, since tilt-table tolerance was reduced similarly in all three groups following bed rest. Bed rest resulted in significant decreases of postural stability and self-selected step length, stride length, and walking velocity, which were not influenced by either exercise training regimen. Most pre-bed rest responses were restored by the fourth day of recovery.

[The primary research and development of software oversampling mapping system for electrocardiogram].

Science.gov (United States)

Zhou, Yu; Ren, Jie

2011-04-01

We put forward a new concept of software oversampling mapping system for electrocardiogram (ECG) to assist the research of the ECG inverse problem to improve the generality of mapping system and the quality of mapping signals. We then developed a conceptual system based on the traditional ECG detecting circuit, Labview and DAQ card produced by National Instruments, and at the same time combined the newly-developed oversampling method into the system. The results indicated that the system could map ECG signals accurately and the quality of the signals was good. The improvement of hardware and enhancement of software made the system suitable for mapping in different situations. So the primary development of the software for oversampling mapping system was successful and further research and development can make the system a powerful tool for researching ECG inverse problem.

Resting-state FMRI confounds and cleanup

Science.gov (United States)

Murphy, Kevin; Birn, Rasmus M.; Bandettini, Peter A.

2013-01-01

The goal of resting-state functional magnetic resonance imaging (FMRI) is to investigate the brain’s functional connections by using the temporal similarity between blood oxygenation level dependent (BOLD) signals in different regions of the brain “at rest” as an indicator of synchronous neural activity. Since this measure relies on the temporal correlation of FMRI signal changes between different parts of the brain, any non-neural activity-related process that affects the signals will influence the measure of functional connectivity, yielding spurious results. To understand the sources of these resting-state FMRI confounds, this article describes the origins of the BOLD signal in terms of MR physics and cerebral physiology. Potential confounds arising from motion, cardiac and respiratory cycles, arterial CO2 concentration, blood pressure/cerebral autoregulation, and vasomotion are discussed. Two classes of techniques to remove confounds from resting-state BOLD time series are reviewed: 1) those utilising external recordings of physiology and 2) data-based cleanup methods that only use the resting-state FMRI data itself. Further methods that remove noise from functional connectivity measures at a group level are also discussed. For successful interpretation of resting-state FMRI comparisons and results, noise cleanup is an often over-looked but essential step in the analysis pipeline. PMID:23571418

Novel modeling of task versus rest brain state predictability using a dynamic time warping spectrum: comparisons and contrasts with other standard measures of brain dynamics

Directory of Open Access Journals (Sweden)

Martin eDinov

2016-05-01

Full Text Available Dynamic time warping, or DTW, is a powerful and domain-general sequence alignment method for computing a similarity measure. Such dynamic programming-based techniques like DTW are now the backbone and driver of most bioinformatics methods and discoveries. In neuroscience it has had far less use, though this has begun to change. We wanted to explore new ways of applying DTW, not simply as a measure with which to cluster or compare similarity between features but in a conceptually different way. We have used DTW to provide a more interpretable spectral description of the data, compared to standard approaches such as the Fourier and related transforms. The DTW approach and standard discrete Fourier transform (DFT are assessed against benchmark measures of neural dynamics. These include EEG microstates, EEG avalanches and the sum squared error (SSE from a multilayer perceptron (MLP prediction of the EEG timeseries, and simultaneously acquired FMRI BOLD signal. We explored the relationships between these variables of interest in an EEG-FMRI dataset acquired during a standard cognitive task, which allowed us to explore how DTW differentially performs in different task settings. We found that despite strong correlations between DTW and DFT-spectra, DTW was a better predictor for almost every measure of brain dynamics. Using these DTW measures, we show that predictability is almost always higher in task than in rest states, which is consistent to other theoretical and empirical findings, providing additional evidence for the utility of the DTW approach.

Noninvasive detection of regional myocardial ischemia using rubidium-81 and scintillation camera. Comparison with stress electrocardiography in patients with arteriographically documented coronary stenosis

International Nuclear Information System (INIS)

Berman, D.S.; Salel, A.F.; DeNardo, G.L.; Mason, D.T.

1975-01-01

The sensitivity of rest and stress myocardial perfusion studies using scintillation camera imaging of intravenously administered rubidium-81 ( 81 Rb) in the detection of myocardial ischemia was compared to that of stress electrocardiography by relating results in 40 patients to the degree of stenosis delineated by coronary arteriography. Of 33 patients with greater than 75 percent stenosis of at least one of the three major coronary vessels (significant stenosis), rest and stress 81 Rb imaging detected ventricular ischemia in 29 (88 percent), whereas simultaneous stress electrocardiography was positive (1 mm or greater horizontal ST-segment depression) in only 19 (58 percent) of the same patients. Five of the 29 patients who developed stress-induced scintigraphic evidence of ischemia did not develop angina or a positive electrocardiogram with stress. In 31 of the 33 patients with significant coronary stenosis, either the stress scintigram or the stress electrocardiogram was positive. In seven patients with less than 50 percent narrowing of a major coronary vessel on coronary arteriography, the stress scintigrams were negative, whereas the stress electrocardiograms were positive in the two of these patients with the syndrome of angina with normal coronary arteriograms. It is concluded that high resolution images of the myocardium can be obtained with 81 Rb using the scintillation camera with special shielding, and that rest and stress 81 Rb scintigraphy appears to provide greater sensitivity and specificity when compared to stress electrocardiography in the noninvasive identification of significant coronary stenosis

Same day injections of Tc-99m methoxy isobutyl isonitrile (hexamibi) for myocardial tomographic imaging: Comparison between rest-stress and stress-rest injection sequences

International Nuclear Information System (INIS)

Taillefer, R.; Gagnon, A.; Laflamme, L.; Leveille, J.; Phaneuf, D.C.

1989-01-01

It has been shown that both rest and stress 99m Tc-hexamibi myocardial perfusion imaging can be performed on the same day using two different doses injected within few h (the first one at rest followed by a second at stress). In order to evaluate and compare 2 sequences (rest-stress and stress-rest) of 99m Tc-hexamibi injections performed the same day, 18 patients with either abnormal 201 Tl myocardial scan or abnormal coronary angiography were studied with 2 99m Tc-hexamibi injections protocols. The rest-stress study was performed as follows: 7 mCi 99m Tc-hexamibi was injected at rest. Single photon emission computed tomography (SPECT) was performed 60 min later. Immediately after the rest study, patients were injected at peak stress with 25 mCi 99m Tc-hexamibi. Tomographic imaging was repeated 1 h later. Patients were submitted to the stress-rest protocol within 3 days. Tomographic imaging was done 1 h after a 7 mCi injection at stress. This study was followed by an injection of 25 mCi 99m Tc-hexamibi at rest, a tomographic study was performed 60 min later. Myocardial sections were reconstructed in horizontal long, vertical long, and short axes. Data analysis also included polar map representation. A total of 324 segments were interpreted blind by 3 observers, there was an agreement in 283/324 (87.3%) segments between the 2 protocols. However, 24 segments (7.4%) judged ischemic on rest-stress were called scars on stress-rest. In three patients, myocardial segments were judged normal on the rest image of the rest-stress protocol while they were found abnormal (false positive images) on the stress-rest sequence. Stress images from both protocols were judged similar in 17 patients. In conclusion, when using a short time interval (less than 2 h) between two 99m Tc-hexamibi injections, it is preferable to do a rest-stress sequence since the rest image performed initially represents a true rest study, which is not necessarily the case with the stress-rest sequence

Resting technetium-99m methoxyisobutylisonitrile cardiac imaging in chronic coronary artery disease: comparison with rest-redistribution thallium-201 scintigraphy

International Nuclear Information System (INIS)

Cuocolo, A.; Maurea, S.; Pace, L.; Nicolai, E.; Nappi, A.; Imbriaco, M.; Trimarco, B.; Salvatore, M.

1993-01-01

We studied 19 patients with angiographically proven coronary artery disease and left ventricular dysfunction (ejection fraction 33%±8%) by resting technetium-99m methoxyisobutylisonitrile ( 99m Tc-MIBI) and rest-redistribution thallium-201 cardiac imaging. Thallium and 99m Tc-MIBI studies were visually analysed. Of 285 segments, 203 (71%) had normal thallium uptake, 48 (17%) showed reversible thallium defects and 34 (12%) showed irreversible thallium defects. Of these 34 irreversible thallium defects, 19 (56%) were moderate and 15 (44%) were severe. Of the corresponding 285 segments, 200 (70%) had normal 99m Tc-MIBI uptake, while 37 (13%) showed moderate and 48 (17%) showed severe reduction of MIBI uptake. Myocardial segmental agreement for regional uptake score between initial thallium and resting 99m Tc-MIBI images was 90% (κ=0.78). Segmental agreement between delayed thallium and resting 99m Tc-MIBI images was 77% (κ=0.44). In particular, in 26 (9%) segments 99m Tc-MIBI uptake was severely reduced while delayed thallium uptake was normal or only moderately reduced. These data suggest that although rest-redistribution thallium and resting 99m Tc-MIBI cardiac imaging provide concordant results in the majority of myocardial segments, some segments with severely reduced resting 99m Tc-MIBI uptake may contain viable but hypoperfused myocardium. Thus, conclusions on myocardial viability based on 99m Tc-MIBI uptake should be made with caution in chronic coronary artery disease. (orig.)

Resting state glutamate predicts elevated pre-stimulus alpha during self-relatedness: A combined EEG-MRS study on "rest-self overlap".

Science.gov (United States)

Bai, Yu; Nakao, Takashi; Xu, Jiameng; Qin, Pengmin; Chaves, Pedro; Heinzel, Alexander; Duncan, Niall; Lane, Timothy; Yen, Nai-Shing; Tsai, Shang-Yueh; Northoff, Georg

2016-01-01

Recent studies have demonstrated neural overlap between resting state activity and self-referential processing. This "rest-self" overlap occurs especially in anterior cortical midline structures like the perigenual anterior cingulate cortex (PACC). However, the exact neurotemporal and biochemical mechanisms remain to be identified. Therefore, we conducted a combined electroencephalography (EEG)-magnetic resonance spectroscopy (MRS) study. EEG focused on pre-stimulus (e.g., prior to stimulus presentation or perception) power changes to assess the degree to which those changes can predict subjects' perception (and judgment) of subsequent stimuli as high or low self-related. MRS measured resting state concentration of glutamate, focusing on PACC. High pre-stimulus (e.g., prior to stimulus presentation or perception) alpha power significantly correlated with both perception of stimuli judged to be highly self-related and with resting state glutamate concentrations in the PACC. In sum, our results show (i) pre-stimulus (e.g., prior to stimulus presentation or perception) alpha power and resting state glutamate concentration to mediate rest-self overlap that (ii) dispose or incline subjects to assign high degrees of self-relatedness to perceptual stimuli.

Resting States Are Resting Traits – An fMRI Study of Sex Differences and Menstrual Cycle Effects in Resting State Cognitive Control Networks

OpenAIRE

Hjelmervik, Helene; Hausmann, Markus; Osnes, Berge; Westerhausen, René; Specht, Karsten

2014-01-01

To what degree resting state fMRI is stable or susceptible to internal mind states of the individual is currently an issue of debate. To address this issue, the present study focuses on sex differences and investigates whether resting state fMRI is stable in men and women or changes within relative short-term periods (i.e., across the menstrual cycle). Due to the fact that we recently reported menstrual cycle effects on cognitive control based on data collected during the same sessions, the c...

Heart rate variability reveals that a decrease in parasympathetic ('rest-and-digest') activity dominates autonomic stress responses in a free-living seabird.

Science.gov (United States)

Müller, Martina S; Vyssotski, Alexei L; Yamamoto, Maki; Yoda, Ken

2017-10-01

The autonomic stress response, often referred to as the 'fight-or-flight' response, is a highly conserved physiological reaction to stress in vertebrates that occurs via a decrease in parasympathetic (PNS) activity, which promotes self-maintenance 'rest and digest' processes, and an increase in sympathetic (SNS) activity, which prepares an animal for danger ('fight-or-flight'). Though the PNS and SNS both innervate most organs, they often control different tissues and functions within those organs (though the pacemaker of the heart is controlled by both). Moreover the PNS and SNS are regulated independently. Yet until now, most studies of autonomic stress responses in non-model species focused only on the SNS response. We used external electrocardiogram loggers to measure heart rate and heart rate variability indexes that reflect PNS and SNS activity in a seabird, the Streaked Shearwater (Calonectris leucomelas), during the stress of handling, and during recovery in the nest burrow or during restraint in a cloth bag. We show for the first time in a free-living animal that the autonomic stress response is mediated primarily by a rapid decrease in PNS activity: handling stress induced a large and long-lasting depression of PNS 'rest-and-digest' activity that required two hours to recover. We also found evidence for a substantially smaller and shorter-lasting SNS 'fight-or-flight' response. Confinement in a cloth bag was less stressful for birds than handling, but more stressful than recovering in nest burrows. We show that quantifying autonomic activity from heart rate variability is effective for non-invasively studying stress physiology in free-living animals. Copyright © 2017 Elsevier Inc. All rights reserved.

Measurement and monitoring of electrocardiogram belt tension in premature infants for assessment of respiratory function

Directory of Open Access Journals (Sweden)

Hegyi Thomas

2007-04-01

Full Text Available Abstract Background Monitoring of the electrocardiogram (ECG in premature infants with conventional adhesive-backed electrodes can harm their sensitive skin. Use of an electrode belt prevents skin irritation, but the effect of belt pressure on respiratory function is unknown. A strain gauge sensor is described which measures applied belt tension. Method The device frame was comprised of an aluminum housing and slide to minimize the device weight. Velcro tabs connected housing and slide to opposite tabs located at the electrode belt ends. The slide was connected to a leaf spring, to which were bonded two piezoresistive transducers in a half-bridge circuit configuration. The device was tested for linearity and calibrated. The effect on infant respiratory function of constant belt tension in the normal range (30 g–90 g was determined. Results The mechanical response to a step input was second order (fn = 401 Hz, ζ = 0.08. The relationship between applied tension and output voltage was linear in the range 25–225 gm of applied tension (r2 = 0.99. Measured device sensitivity was 2.18 mV/gm tension using a 5 V bridge excitation voltage. When belt tension was increased in the normal range from 30 gm to 90 gm, there was no significant change in heart rate and most respiratory functions during monitoring. At an intermediate level of tension of 50 gm, pulmonary resistance and work of breathing significantly decreased. Conclusion The mechanical and electrical design of a device for monitoring electrocardiogram electrode belt tension is described. Within the typical range of application tension, cardiovascular and respiratory function are not substantially negatively affected by electrode belt force.

Measurement and monitoring of electrocardiogram belt tension in premature infants for assessment of respiratory function.

Science.gov (United States)

Ciaccio, Edward J; Hiatt, Mark; Hegyi, Thomas; Drzewiecki, Gary M

2007-04-19

Monitoring of the electrocardiogram (ECG) in premature infants with conventional adhesive-backed electrodes can harm their sensitive skin. Use of an electrode belt prevents skin irritation, but the effect of belt pressure on respiratory function is unknown. A strain gauge sensor is described which measures applied belt tension. The device frame was comprised of an aluminum housing and slide to minimize the device weight. Velcro tabs connected housing and slide to opposite tabs located at the electrode belt ends. The slide was connected to a leaf spring, to which were bonded two piezoresistive transducers in a half-bridge circuit configuration. The device was tested for linearity and calibrated. The effect on infant respiratory function of constant belt tension in the normal range (30 g-90 g) was determined. The mechanical response to a step input was second order (fn = 401 Hz, zeta = 0.08). The relationship between applied tension and output voltage was linear in the range 25-225 gm of applied tension (r2 = 0.99). Measured device sensitivity was 2.18 mV/gm tension using a 5 V bridge excitation voltage. When belt tension was increased in the normal range from 30 gm to 90 gm, there was no significant change in heart rate and most respiratory functions during monitoring. At an intermediate level of tension of 50 gm, pulmonary resistance and work of breathing significantly decreased. The mechanical and electrical design of a device for monitoring electrocardiogram electrode belt tension is described. Within the typical range of application tension, cardiovascular and respiratory function are not substantially negatively affected by electrode belt force.

The electrocardiogram as an electronic filter and why ac circuits are important for pre-health physics students

Science.gov (United States)

Dunlap, Justin C.; Kutschera, Ellynne; Van Ness, Grace R.; Widenhorn, Ralf

2015-01-01

We present a general physics laboratory exercise that centres around the use of the electrocardiogram sensor as an application of circuits and electronic signal filtering. Although these topics are commonly taught in the general physics classroom, many students consider topics such as alternating current as unrelated to their future professions. This exercise provides the motivation for life science and pre-health majors to learn concepts such as voltage, resistance, alternating and direct current, RLC circuits, as well as signal and noise, in an introductory undergraduate physics lab.

Efficiency at rest: magnetoencephalographic resting-state connectivity and individual differences in verbal working memory.

Science.gov (United States)

del Río, David; Cuesta, Pablo; Bajo, Ricardo; García-Pacios, Javier; López-Higes, Ramón; del-Pozo, Francisco; Maestú, Fernando

2012-11-01

Inter-individual differences in cognitive performance are based on an efficient use of task-related brain resources. However, little is known yet on how these differences might be reflected on resting-state brain networks. Here we used Magnetoencephalography resting-state recordings to assess the relationship between a behavioral measurement of verbal working memory and functional connectivity as measured through Mutual Information. We studied theta (4-8 Hz), low alpha (8-10 Hz), high alpha (10-13 Hz), low beta (13-18 Hz) and high beta (18-30 Hz) frequency bands. A higher verbal working memory capacity was associated with a lower mutual information in the low alpha band, prominently among right-anterior and left-lateral sensors. The results suggest that an efficient brain organization in the domain of verbal working memory might be related to a lower resting-state functional connectivity across large-scale brain networks possibly involving right prefrontal and left perisylvian areas. Copyright © 2012 Elsevier B.V. All rights reserved.

Optimization of work and rest hours for navigation officers on the ship

Directory of Open Access Journals (Sweden)

Simkuva H.

2016-01-01

Full Text Available The topic of the research as a whole is dedicated to studies of the work load of navigation officers and, consequently, is related to the current international research on the quality of working life. Issues of seafarers' working time are very topical because in recent years the load of navigation officers has significantly increased, either due to increase in shipping intensity, or in the context of the new international maritime law, for example, compliance with the requirements of the ISM CODE (International Management safety Code, THE ISPS (The International Ship and Port Facility Security Code. Irregularities are observed in practice of the seafarers' working hours and rest hours, and even the mismatch, as presented in the port of inspection materials. This article is intended to assess the 2nd and 3rd Officer's load compliance with the regulatory enactments for the work and rest regime to develop proposals to load optimization. Load analysis of Navigation officers is based on international maritime regulations that determine the work and rest regime on ships STCW (The International Convention on Standards of Training, Certification and Watchkeeping for Seafarers, MLC (Maritime Labour Convention. In the article, concrete data is used from the research, which was conducted 18 months on the Handy type of tanker from July, 2012 till December, 2013 in the real time mode. In the article is also concrete data used from 340 survey respondents, which reflects the views of the navigation officers on violations of the work and rest regime on the ship and the fatigue issue.

Resting site use of giant pandas in Wanglang Nature Reserve.

Science.gov (United States)

Kang, Dongwei; Wang, Xiaorong; Li, Junqing

2017-10-23

Little is known about the resting sites used by the giant panda (Ailuropoda melanoleuca), which restricts our understanding of their resting habits and limits conservation efforts. To enhance our understanding of resting site requirements and factors affecting the resting time of giant pandas, we investigated the characteristics of resting sites in the Wanglang Nature Reserve, Sichuan Province, China. The results indicated that the resting sites of giant pandas were characterised by a mean slope of 21°, mean nearest tree size of 53.75 cm, mean nearest shrub size of 2.82 cm, and mean nearest bamboo number of 56. We found that the resting sites were closer to bamboo than to trees and shrubs, suggesting that the resting site use of giant pandas is closely related to the presence of bamboo. Considering that giant pandas typically rest near a large-sized tree, protection of large trees in the forests is of considerable importance for the conservation of this species. Furthermore, slope was found to be an important factor affecting the resting time of giant pandas, as they tended to rest for a relatively longer time in sites with a smaller degree of slope.

Robust electrocardiogram (ECG) beat classification using discrete wavelet transform

International Nuclear Information System (INIS)

Minhas, Fayyaz-ul-Amir Afsar; Arif, Muhammad

2008-01-01

This paper presents a robust technique for the classification of six types of heartbeats through an electrocardiogram (ECG). Features extracted from the QRS complex of the ECG using a wavelet transform along with the instantaneous RR-interval are used for beat classification. The wavelet transform utilized for feature extraction in this paper can also be employed for QRS delineation, leading to reduction in overall system complexity as no separate feature extraction stage would be required in the practical implementation of the system. Only 11 features are used for beat classification with the classification accuracy of ∼99.5% through a KNN classifier. Another main advantage of this method is its robustness to noise, which is illustrated in this paper through experimental results. Furthermore, principal component analysis (PCA) has been used for feature reduction, which reduces the number of features from 11 to 6 while retaining the high beat classification accuracy. Due to reduction in computational complexity (using six features, the time required is ∼4 ms per beat), a simple classifier and noise robustness (at 10 dB signal-to-noise ratio, accuracy is 95%), this method offers substantial advantages over previous techniques for implementation in a practical ECG analyzer

Measurement of ECG abnormalities and cardiovascular risk classification: a cohort study of primary care patients in the Netherlands

NARCIS (Netherlands)

de Groot, A.; Bots, M.L.; Rutten, F.H.; den Ruijter, H.M.; Numans, M.E.; Vaartjes, I.

2015-01-01

Background: GPs need accurate tools for cardiovascular (CV) risk assessment. Abnormalities in resting electrocardiograms (ECGs) relate to increased CV risk. Aim: To determine whether measurement of ECG abnormalities on top of established risk estimation (SCORE) improves CV risk classification in a

I think therefore I am: Rest-related prefrontal cortex neural activity is involved in generating the sense of self.

Science.gov (United States)

Gruberger, M; Levkovitz, Y; Hendler, T; Harel, E V; Harari, H; Ben Simon, E; Sharon, H; Zangen, A

2015-05-01

The sense of self has always been a major focus in the psychophysical debate. It has been argued that this complex ongoing internal sense cannot be explained by any physical measure and therefore substantiates a mind-body differentiation. Recently, however, neuro-imaging studies have associated self-referential spontaneous thought, a core-element of the ongoing sense of self, with synchronous neural activations during rest in the medial prefrontal cortex (PFC), as well as the medial and lateral parietal cortices. By applying deep transcranial magnetic stimulation (TMS) over human PFC before rest, we disrupted activity in this neural circuitry thereby inducing reports of lowered self-awareness and strong feelings of dissociation. This effect was not found with standard or sham TMS, or when stimulation was followed by a task instead of rest. These findings demonstrate for the first time a critical, causal role of intact rest-related PFC activity patterns in enabling integrated, enduring, self-referential mental processing. Copyright © 2015 Elsevier Inc. All rights reserved.

Cognitive Rest: An Integrated Literature Review

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Schneider, Kathleen H.

2016-01-01

Cognitive rest has been suggested as a treatment for school athletes who have sustained a concussion, but the concept has rarely been defined. The purpose of this article is to provide a comprehensive definition of cognitive rest, based on an integrative literature review. The method of synthesis was guided by Avant and Walker's concept analysis…

Identification of Resting State Networks Involved in Executive Function.

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Connolly, Joanna; McNulty, Jonathan P; Boran, Lorraine; Roche, Richard A P; Delany, David; Bokde, Arun L W

2016-06-01

The structural networks in the human brain are consistent across subjects, and this is reflected also in that functional networks across subjects are relatively consistent. These findings are not only present during performance of a goal oriented task but there are also consistent functional networks during resting state. It suggests that goal oriented activation patterns may be a function of component networks identified using resting state. The current study examines the relationship between resting state networks measured and patterns of neural activation elicited during a Stroop task. The association between the Stroop-activated networks and the resting state networks was quantified using spatial linear regression. In addition, we investigated if the degree of spatial association of resting state networks with the Stroop task may predict performance on the Stroop task. The results of this investigation demonstrated that the Stroop activated network can be decomposed into a number of resting state networks, which were primarily associated with attention, executive function, visual perception, and the default mode network. The close spatial correspondence between the functional organization of the resting brain and task-evoked patterns supports the relevance of resting state networks in cognitive function.

RESTful Java web services security

CERN Document Server

Enríquez, René

2014-01-01

A sequential and easy-to-follow guide which allows you to understand the concepts related to securing web apps/services quickly and efficiently, since each topic is explained and described with the help of an example and in a step-by-step manner, helping you to easily implement the examples in your own projects. This book is intended for web application developers who use RESTful web services to power their websites. Prior knowledge of RESTful is not mandatory, but would be advisable.

Spatiotemporal psychopathology I: No rest for the brain's resting state activity in depression? Spatiotemporal psychopathology of depressive symptoms.

Science.gov (United States)

Northoff, Georg

2016-01-15

Despite intense neurobiological investigation in psychiatric disorders like major depressive disorder (MDD), the basic disturbance that underlies the psychopathological symptoms of MDD remains, nevertheless, unclear. Neuroimaging has focused mainly on the brain's extrinsic activity, specifically task-evoked or stimulus-induced activity, as related to the various sensorimotor, affective, cognitive, and social functions. Recently, the focus has shifted to the brain's intrinsic activity, otherwise known as its resting state activity. While various abnormalities have been observed during this activity, their meaning and significance for depression, along with its various psychopathological symptoms, are yet to be defined. Based on findings in healthy brain resting state activity and its particular spatial and temporal structure - defined in a functional and physiological sense rather than anatomical and structural - I claim that the various depressive symptoms are spatiotemporal disturbances of the resting state activity and its spatiotemporal structure. This is supported by recent findings that link ruminations and increased self-focus in depression to abnormal spatial organization of resting state activity. Analogously, affective and cognitive symptoms like anhedonia, suicidal ideation, and thought disorder can be traced to an increased focus on the past, increased past-focus as basic temporal disturbance o the resting state. Based on these findings, I conclude that the various depressive symptoms must be conceived as spatiotemporal disturbances of the brain's resting state's activity and its spatiotemporal structure. Importantly, this entails a new form of psychopathology, "Spatiotemporal Psychopathology" that directly links the brain and psyche, therefore having major diagnostic and therapeutic implications for clinical practice. Copyright © 2015 Elsevier B.V. All rights reserved.

Resting eggs in free living marine and estuarine copepods

DEFF Research Database (Denmark)

Holm, Mark Wejlemann; Kiørboe, Thomas; Brun, Philipp Georg

2018-01-01

Marine free living copepods can survive harsh periods and cope with seasonal fluctuations in environmental conditions using resting eggs (embryonic dormancy). Laboratory experiments show that temperature is the common driver for resting egg production. Hence, we hypothesize (i) that seasonal...... temperature variation, rather than variation in food abundance is the main driver for the occurrence of the resting eggs strategy in marine and estuarine copepod species; and (ii) that the thermal boundaries of the distribution determine where resting eggs are produced and whether they are produced to cope...... with warm or cold periods. We compile literature information on the occurrence of resting egg production and relate this to spatio-temporal patterns in sea surface temperature and chlorophyll a concentration obtained from satellite observations. We find that the production of resting eggs has been reported...

Cerebral Blood Flow during Rest Associates with General Intelligence and Creativity

Science.gov (United States)

Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Nagase, Tomomi; Nouchi, Rui; Kawashima, Ryuta

2011-01-01

Recently, much scientific attention has been focused on resting brain activity and its investigation through such methods as the analysis of functional connectivity during rest (the temporal correlation of brain activities in different regions). However, investigation of the magnitude of brain activity during rest has focused on the relative decrease of brain activity during a task, rather than on the absolute resting brain activity. It is thus necessary to investigate the association between cognitive factors and measures of absolute resting brain activity, such as cerebral blood flow (CBF), during rest (rest-CBF). In this study, we examined this association using multiple regression analyses. Rest-CBF was the dependent variable and the independent variables included two essential components of cognitive functions, psychometric general intelligence and creativity. CBF was measured using arterial spin labeling and there were three analyses for rest-CBF; namely mean gray matter rest-CBF, mean white matter rest-CBF, and regional rest-CBF. The results showed that mean gray and white matter rest-CBF were significantly and positively correlated with individual psychometric intelligence. Furthermore, mean white matter rest-CBF was significantly and positively correlated with creativity. After correcting the effect of mean gray matter rest-CBF the significant and positive correlation between regional rest-CBF in the perisylvian anatomical cluster that includes the left superior temporal gyrus and insula and individual psychometric intelligence was found. Also, regional rest-CBF in the precuneus was significantly and negatively correlated with individual creativity. Significance of these results of regional rest-CBF did not change when the effect of regional gray matter density was corrected. The findings showed mean and regional rest-CBF in healthy young subjects to be correlated with cognitive functions. The findings also suggest that, even in young cognitively intact

The Diagnostic Agreement of Original and Faxed Copies of Electrocardiograms

Directory of Open Access Journals (Sweden)

Sadrihe Hajesmaeel-Gohari

2013-02-01

Full Text Available Background: General practitioners working in remote and rural areas sometimes need consultation with cardiologists. One practical and cost-effective way is transmission of patients’ electrocardiographic images via ordinary fax machine to the cardiologists, but there is an important question that how much agreement exists between the diagnoses made by reading an original electrocardiogram and its copy transmitted via fax.Materials and Methods: In this cross-sectional study, 60 original electrocardiographic images were given to cardiologists for diagnosis. In the next step those electrocardiographic images were faxed to the hospital through a simple cheap fax machine, one month later the same cardiologist was asked to put his diagnosis on the copied versions of electrocardiographs, and the results were compared. Results: In 59 studied cases, the two method of diagnoses were exactly the same and only in one case the diagnoses were different. Therefore, Kappa agreement coefficient was calculated as 96%.Conclusion: According to the results of this study, general practitioners working in deprived areas can be certainly recommended to send patients’ electrocardiographic images to the cardiologists via fax in the case of needing consultation.

Evaluation of hemodynamic significance of coronary fistulae. Diagnostic integration between coronary angiography and stress/rest myocardial scintigraphy; Valutazione del significato emodinamico di fistole coronariche artero-venose. Integrazione diagnostica tra angiografia coronarica e scintigrafia miocardica a riposo e sotto sforzo

Energy Technology Data Exchange (ETDEWEB)

Rubini, G.; Sebastiani, M. [Bari Univ., Bari (Italy). Cattedra di Medicina Nucleare; Ettorre, G. C. [Foggia Univ., Foggia (Italy). Cattedra di Radiologia; Bovenzi, F. [Ospedale Policlinico, Unita' Operativa di Cardiologia, Bari (Italy)

2000-12-01

It is here reported on the importance of the integration of data obtained from digital coronary angiography and stress/rest {sup 99m}Tc sestamibi myocardial perfusion single photon emission tomography in evaluationing the hemodynamic significance of coronary arteriovenous fistulae. Coronary fistulae were detected with coronary angiography in 9 patients. All patients underwent clinical examination, trans thoracic echocardiography, stress electrocardiogram and stress/rest {sup 99m}Tc sestamibi myocardial perfusion single photon emission tomography. Stress/rest {sup 99m}Tc sestamibi myocardial perfusion single photon tomography and stress electrocardiogram showed stress-induced myocardial ischemia in 2 patients. The first patient with familial predisposition and risk factors for ischemic heart disease presented a mesocardic heart murmur on clinical examination. At stress ECG (125 Watt, 153 b/m max frequency 93%, arterial pressure 230 mmHg, max frequency pressure product 35200) ischemic alterations were recorded at the first minute of the second stage of the Bruce protocol. Coronary angiography detected a circumflex artery fistula in the coronary sinus. Stress/rest {sup 99m}Tc sestamibi myocardial perfusion single photon emission tomography for the evaluation of stress/rest perfusion detected a reversible perfusion defect of the proximal portion of the posterolateral and lateral walls, thus confirming the hemodynamic importance of the flow through the fistula during stress cycloergometric testing. In the second patient familial predisposition to ischemic heart disease and previous inferior wall myocardial infarction and non-significant stress ECG, coronary angiography identified a suocclusive stenosis of the right coronary artery and anomaly between the anterior interventricular artery and the left pulmonary artery. The presence of the contrast medium in the left pulmonary artery identified a flow from the left ventricle to the left pulmonary artery. Good angiographic

Resting metabolic rate and postprandial thermogenesis in polycystic ovarian syndrome.

Science.gov (United States)

Segal, K R; Dunaif, A

1990-07-01

To determine whether the high frequency of obesity in women with polycystic ovary syndrome (PCO) is related to a defect in energy expenditure, resting metabolic rate (RMR) and the thermic response to a standard meal were compared in 10 obese PCO women, nine obese but otherwise normal women, and 11 lean women. All groups were matched with respect to age and fat-free mass and the two obese groups were matched for degree of obesity. RMR was measured by indirect calorimetry for 3 h on two days: (1) in the postabsorptive state; and (2) after a 720 kcal (3014 kJ) liquid mixed meal. The thermic effect of food, calculated as 3 h postprandial minus fasting RMR, was significantly greater for the lean [52.9 +/- 5.5 kcal/3 h (221 +/- 23 kJ/3 h)] than the obese [17.2 +/- 5.1 kcal/3 h (72 +/- 21 kJ/3 h)] and the PCO women [22.8 +/- 5.2 kcal/3 h (95 +/- 22 kJ/3)], P less than 0.001). The thermic effect of food was negatively related to percent body fat (r = -0.694, P less than 0.001). Resting metabolic rate did not differ significantly among the three groups, and was strongly related to fat-free mass (r = 0.687, P less than 0.001). These results confirm previous reports of blunted thermogenesis in obese individuals, but provide no evidence of altered resting metabolic rate or postprandial thermogenesis in women with PCO compared with normal women of similar degree of obesity.

Quantifying agreement between anatomical and functional interhemispheric correspondences in the resting brain.

Directory of Open Access Journals (Sweden)

Hang Joon Jo

Full Text Available The human brain is composed of two broadly symmetric cerebral hemispheres, with an abundance of reciprocal anatomical connections between homotopic locations. However, to date, studies of hemispheric symmetries have not identified correspondency precisely due to variable cortical folding patterns. Here we present a method to establish accurate correspondency using position on the unfolded cortical surface relative to gyral and sulcal landmarks. The landmark method is shown to outperform the method of reversing standard volume coordinates, and it is used to quantify the functional symmetry in resting fMRI data throughout the cortex. Resting brain activity was found to be maximally correlated with locations less than 1 cm away on the cortical surface from the corresponding anatomical location in nearly half of the cortex. While select locations exhibited asymmetric patterns, precise symmetric relationships were found to be the norm, with fine-grained symmetric functional maps demonstrated in motor, occipital, and inferior frontal cortex.

Brief wakeful resting can eliminate directed forgetting.

Science.gov (United States)

Schlichting, Andreas; Bäuml, Karl-Heinz T

2017-02-01

When cued to intentionally forget previously encoded memories, participants typically show reduced recall of the memories on a later recall test. We examined how such directed forgetting is affected by a brief period of wakeful resting between encoding and test. Encoding was followed by a "passive" wakeful resting period in which subjects heard emotionally neutral music or perceived neutral pictures, or it was followed by an "active" distraction period in which subjects were engaged in counting or calculation tasks. Whereas typical directed forgetting was present after active distraction, the forgetting was absent after wakeful resting. The findings indicate that the degree to which people can intentionally forget memories is influenced by the cognitive activity that people engage in shortly after learning takes place. The results provide first evidence on the interplay between wakeful resting and intentional forgetting.

Low-dose dobutamine stress gated SPET for identification of viable myocardium: comparison with stress-rest perfusion SPET and PET

International Nuclear Information System (INIS)

Yoshinaga, Keiichiro; Tamaki, Nagara; Katoh, Chietsugu; Kuge, Yuji; Noriyasu, Kazuyuki; Yamada, Satoshi; Ito, Yoshinori; Kohya, Tetsuro; Kitabatake, Akira; Kawai, Yuko

2002-01-01

The detection of viable myocardium is important for the prediction of functional recovery after revascularisation. However, a fixed perfusion defect often includes viable myocardium, and perfusion imaging then underestimates myocardial viability. We previously reported that low-dose dobutamine stress gated single-photon emission tomography (SPET) provides similar findings to dobutamine stress echocardiography in the assessment of myocardial viability. The present study investigated whether low-dose dobutamine stress gated SPET is of additional value as compared with stress-rest technetium-99m tetrofosmin SPET for the detection of myocardial viability. Standard stress-rest perfusion SPET, low-dose dobutamine stress gated SPET and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) were studied in 23 patients (mean age 67±7.6 years) with previous myocardial infarction. Twenty-one of them were successfully studied with each technique. FDG PET viability (FDG uptake ≥50%) was employed as the gold standard. One-day stress-rest 99m Tc-tetrofosmin myocardial SPET was performed. After the resting study, gated SPET was acquired following infusion of 7.5 μg kg -1 min -1 of dobutamine. Left ventricular wall motion in 16 segments was assessed by cine mode display using a four-point scale. Myocardial viability was considered present when there was improvement by one point. Of a total of 336 segments analysed, 53 had persistent defects on stress-rest perfusion SPET. FDG viability was seen in 16 of 17 dobutamine-responsive segments, but in only 11 of 36 dobutamine non-responsive segments (P<0.01). Thus, in the segments with persistent defects, viability findings on low-dose dobutamine stress gated SPET were concordant with those on FDG PET in 77% of segments (kappa value =0.55). For the detection of FDG-viable myocardium, the combination of stress-rest perfusion SPET and low-dose dobutamine stress gated SPET achieved a better sensitivity than stress-rest

Effects of Bed Rest on Conduction Velocity of the Triceps Surae Stretch Reflex and Postural Control

Science.gov (United States)

Reschke, M. F.; Wood, S. J.; Cerisano, J. M.; Kofman, I. S.; Fisher, E. A.; Esteves, J. T.; Taylor, L. C.; DeDios, Y. E.; Harm, D. L.

2011-01-01

Despite rigorous exercise and nutritional management during space missions, astronauts returning from microgravity exhibit neuromuscular deficits and a significant loss in muscle mass in the postural muscles of the lower leg. Similar changes in the postural muscles occur in subjects participating in long-duration bed rest studies. These adaptive muscle changes manifest as a reduction in reflex conduction velocity during head-down bed rest. Because the stretch reflex encompasses both the peripheral (muscle spindle and nerve axon) and central (spinal synapse) components involved in adaptation to calf muscle unloading, it may be used to provide feedback on the general condition of neuromuscular function, and might be used to evaluate the effectiveness of countermeasures aimed at preserving muscle mass and function during periods of unloading. Stretch reflexes were measured on 18 control subjects who spent 60 to 90 days in continuous 6 deg head-down bed rest. Using a motorized system capable of rotating the foot around the ankle joint (dorsiflexion) through an angle of 10 degrees at a peak velocity of about 250 deg/sec, a stretch reflex was recorded from the subject's left triceps surae muscle group. Using surface electromyography, about 300 reflex responses were obtained and ensemble-averaged on 3 separate days before bed rest, 3 to 4 times in bed, and 3 times after bed rest. The averaged responses for each test day were examined for reflex latency and conduction velocity (CV) across gender. Computerized posturography was also conducted on these same subjects before and after bed rest as part of the standard measures. Peak-to-peak sway was measured during Sensory Organization Tests (SOTs) to evaluate changes in the ability to effectively use or suppress visual, vestibular, and proprioceptive information for postural control. Although no gender differences were found, a significant increase in reflex latency and a significant decrease in CV were observed during the bed

Comparison of infarct size changes with delayed contrast-enhanced magnetic resonance imaging and electrocardiogram QRS scoring during the 6 months after acutely reperfused myocardial infarction

DEFF Research Database (Denmark)

Bang, L.E.; Ripa, R.S.; Grande, P.

2008-01-01

INTRODUCTION: Magnetic resonance imaging using the delayed contrast-enhanced (DE-MRI) method can be used for characterizing and quantifying myocardial infarction (MI). Electrocardiogram (ECG) score after the acute phase of MI can be used to estimate the portion of left ventricular myocardium...

Microalbuminuria modifies the mortality risk associated with electrocardiographic ST-T segment changes

NARCIS (Netherlands)

Diercks, GFH; Hillege, HL; van Boven, AJ; Kors, JA; Crijns, HJGM; Grobbee, DE; de Jong, PE; van Gilst, WH

2002-01-01

OBJECTIVES We sought to investigate whether microalbuminuria, a proposed marker of generalized vascular damage, enhances the prognostic value of ST-T segment changes for all-cause and cardiovascular mortality in the general population. BACKGROUND ST-T segment changes on the rest electrocardiogram

Volunteer Work, Religious Commitment, and Resting Pulse Rates.

Science.gov (United States)

Krause, Neal; Ironson, Gail; Hill, Peter C

2017-04-01

Research indicates that greater involvement in volunteer activities is associated with better health. We aim to contribute to this literature in two ways. First, rather than rely on self-reports of health, measured resting pulse rates serve as the dependent variable. Second, an effort is made to see if religious commitment moderates the relationship between volunteering and resting pulse rates. Data that come from a recent nationwide survey (N = 2265) suggest that volunteer work is associated with lower resting pulse rates. The results also reveal that the relationship between engaging in volunteer work and resting pulse rates improves among study participants who are more deeply committed to religion.

REST-mediated recruitment of polycomb repressor complexes in mammalian cells

DEFF Research Database (Denmark)

Dietrich, Nikolaj; Lerdrup, Mads; Landt, Eskild

2012-01-01

Polycomb Repressive Complex (PRC) 1 and PRC2 regulate genes involved in differentiation and development. However, the mechanism for how PRC1 and PRC2 are recruited to genes in mammalian cells is unclear. Here we present evidence for an interaction between the transcription factor REST, PRC1......, and increased gene expression. Genome-wide analysis of Polycomb binding in Rest¿/¿ and Eed¿/¿ mouse embryonic stem (mES) cells showed that Rest was required for PRC1 recruitment to a subset of Polycomb regulated neuronal genes. Furthermore, we found that PRC1 can be recruited to Rest binding sites independently...... of CpG islands and the H3K27Me3 mark. Surprisingly, PRC2 was frequently increased around Rest binding sites located in CpG-rich regions in the Rest¿/¿ mES cells, indicating a more complex interplay where Rest also can limit PRC2 recruitment. Therefore, we propose that Rest has context...

Electrocardiogram signal denoising based on empirical mode decomposition technique: an overview

International Nuclear Information System (INIS)

Han, G.; Lin, B.; Xu, Z.

2017-01-01

Electrocardiogram (ECG) signal is nonlinear and non-stationary weak signal which reflects whether the heart is functioning normally or abnormally. ECG signal is susceptible to various kinds of noises such as high/low frequency noises, powerline interference and baseline wander. Hence, the removal of noises from ECG signal becomes a vital link in the ECG signal processing and plays a significant role in the detection and diagnosis of heart diseases. The review will describe the recent developments of ECG signal denoising based on Empirical Mode Decomposition (EMD) technique including high frequency noise removal, powerline interference separation, baseline wander correction, the combining of EMD and Other Methods, EEMD technique. EMD technique is a quite potential and prospective but not perfect method in the application of processing nonlinear and non-stationary signal like ECG signal. The EMD combined with other algorithms is a good solution to improve the performance of noise cancellation. The pros and cons of EMD technique in ECG signal denoising are discussed in detail. Finally, the future work and challenges in ECG signal denoising based on EMD technique are clarified.

Electrocardiogram signal denoising based on empirical mode decomposition technique: an overview

Science.gov (United States)

Han, G.; Lin, B.; Xu, Z.

2017-03-01

Electrocardiogram (ECG) signal is nonlinear and non-stationary weak signal which reflects whether the heart is functioning normally or abnormally. ECG signal is susceptible to various kinds of noises such as high/low frequency noises, powerline interference and baseline wander. Hence, the removal of noises from ECG signal becomes a vital link in the ECG signal processing and plays a significant role in the detection and diagnosis of heart diseases. The review will describe the recent developments of ECG signal denoising based on Empirical Mode Decomposition (EMD) technique including high frequency noise removal, powerline interference separation, baseline wander correction, the combining of EMD and Other Methods, EEMD technique. EMD technique is a quite potential and prospective but not perfect method in the application of processing nonlinear and non-stationary signal like ECG signal. The EMD combined with other algorithms is a good solution to improve the performance of noise cancellation. The pros and cons of EMD technique in ECG signal denoising are discussed in detail. Finally, the future work and challenges in ECG signal denoising based on EMD technique are clarified.

Electrocardiogram interpretation and arrhythmia management: a primary and secondary care survey.

Science.gov (United States)

Begg, Gordon; Willan, Kathryn; Tyndall, Keith; Pepper, Chris; Tayebjee, Muzahir

2016-05-01

There is increasing desire among service commissioners to treat arrhythmia in primary care. Accurate interpretation of the electrocardiogram (ECG) is fundamental to this. ECG interpretation has previously been shown to vary widely but there is little recent data. To examine the interpretation of ECGs in primary and secondary care. A cross-sectional survey of participants' interpretation of six ECGs and hypothetical management of patients based on those ECGs, at primary care educational events, and a cardiology department in Leeds. A total of 262 primary care clinicians and 20 cardiology clinicians were surveyed via questionnaire. Answers were compared with expert electrophysiologist opinion. In primary care, abnormal ECGs were interpreted as normal by 23% of responders. ST elevation and prolonged QT were incorrectly interpreted as normal by 1% and 22%, respectively. In cardiology, abnormal ECGs were interpreted as normal by 3%. ECG provision and interpretation remains inconsistent in both primary and secondary care. Primary care practitioners are less experienced and less confident with ECG interpretation than cardiologists, and require support in this area. © British Journal of General Practice 2016.

Algorithm for the classification of multi-modulating signals on the electrocardiogram.

Science.gov (United States)

Mita, Mitsuo

2007-03-01

This article discusses the algorithm to measure electrocardiogram (ECG) and respiration simultaneously and to have the diagnostic potentiality for sleep apnoea from ECG recordings. The algorithm is composed by the combination with the three particular scale transform of a(j)(t), u(j)(t), o(j)(a(j)) and the statistical Fourier transform (SFT). Time and magnitude scale transforms of a(j)(t), u(j)(t) change the source into the periodic signal and tau(j) = o(j)(a(j)) confines its harmonics into a few instantaneous components at tau(j) being a common instant on two scales between t and tau(j). As a result, the multi-modulating source is decomposed by the SFT and is reconstructed into ECG, respiration and the other signals by inverse transform. The algorithm is expected to get the partial ventilation and the heart rate variability from scale transforms among a(j)(t), a(j+1)(t) and u(j+1)(t) joining with each modulation. The algorithm has a high potentiality of the clinical checkup for the diagnosis of sleep apnoea from ECG recordings.

Do resting brain dynamics predict oddball evoked-potential?

Directory of Open Access Journals (Sweden)

Lee Tien-Wen

2011-11-01

Full Text Available Abstract Background The oddball paradigm is widely applied to the investigation of cognitive function in neuroscience and in neuropsychiatry. Whether cortical oscillation in the resting state can predict the elicited oddball event-related potential (ERP is still not clear. This study explored the relationship between resting electroencephalography (EEG and oddball ERPs. The regional powers of 18 electrodes across delta, theta, alpha and beta frequencies were correlated with the amplitude and latency of N1, P2, N2 and P3 components of oddball ERPs. A multivariate analysis based on partial least squares (PLS was applied to further examine the spatial pattern revealed by multiple correlations. Results Higher synchronization in the resting state, especially at the alpha spectrum, is associated with higher neural responsiveness and faster neural propagation, as indicated by the higher amplitude change of N1/N2 and shorter latency of P2. None of the resting quantitative EEG indices predict P3 latency and amplitude. The PLS analysis confirms that the resting cortical dynamics which explains N1/N2 amplitude and P2 latency does not show regional specificity, indicating a global property of the brain. Conclusions This study differs from previous approaches by relating dynamics in the resting state to neural responsiveness in the activation state. Our analyses suggest that the neural characteristics carried by resting brain dynamics modulate the earlier/automatic stage of target detection.

Utility of the exercise electrocardiogram testing in sudden cardiac death risk stratification.

Science.gov (United States)

Refaat, Marwan M; Hotait, Mostafa; Tseng, Zian H

2014-07-01

Sudden cardiac death (SCD) remains a major public health problem. Current established criteria identifying those at risk of sudden arrhythmic death, and likely to benefit from implantable cardioverter defibrillators (ICDs), are neither sensitive nor specific. Exercise electrocardiogram (ECG) testing was traditionally used for information concerning patients' symptoms, exercise capacity, cardiovascular function, myocardial ischemia detection, and hemodynamic responses during activity in patients with hypertrophic cardiomyopathy. We conducted a systematic review of MEDLINE on the utility of exercise ECG testing in SCD risk stratification. Exercise testing can unmask suspected primary electrical diseases in certain patients (catecholaminergic polymorphic ventricular tachycardia or concealed long QT syndrome) and can be effectively utilized to risk stratify patients at an increased (such as early repolarization syndrome and Brugada syndrome) or decreased risk of SCD, such as the loss of preexcitation on exercise testing in asymptomatic Wolff-Parkinson-White syndrome. Exercise ECG testing helps in SCD risk stratification in patients with and without arrhythmogenic hereditary syndromes. © 2014 Wiley Periodicals, Inc.

Resting heart rate variability is associated with ex-Gaussian metrics of intra-individual reaction time variability.

Science.gov (United States)

Spangler, Derek P; Williams, DeWayne P; Speller, Lassiter F; Brooks, Justin R; Thayer, Julian F

2018-03-01

The relationships between vagally mediated heart rate variability (vmHRV) and the cognitive mechanisms underlying performance can be elucidated with ex-Gaussian modeling-an approach that quantifies two different forms of intra-individual variability (IIV) in reaction time (RT). To this end, the current study examined relations of resting vmHRV to whole-distribution and ex-Gaussian IIV. Subjects (N = 83) completed a 5-minute baseline while vmHRV (root mean square of successive differences; RMSSD) was measured. Ex-Gaussian (sigma, tau) and whole-distribution (standard deviation) estimates of IIV were derived from reaction times on a Stroop task. Resting vmHRV was found to be inversely related to tau (exponential IIV) but not to sigma (Gaussian IIV) or the whole-distribution standard deviation of RTs. Findings suggest that individuals with high vmHRV can better prevent attentional lapses but not difficulties with motor control. These findings inform the differential relationships of cardiac vagal control to the cognitive processes underlying human performance. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

The spectral diversity of resting-state fluctuations in the human brain.

Directory of Open Access Journals (Sweden)

Klaudius Kalcher

Full Text Available In order to assess whole-brain resting-state fluctuations at a wide range of frequencies, resting-state fMRI data of 20 healthy subjects were acquired using a multiband EPI sequence with a low TR (354 ms and compared to 20 resting-state datasets from standard, high-TR (1800 ms EPI scans. The spatial distribution of fluctuations in various frequency ranges are analyzed along with the spectra of the time-series in voxels from different regions of interest. Functional connectivity specific to different frequency ranges (<0.1 Hz; 0.1-0.25 Hz; 0.25-0.75 Hz; 0.75-1.4 Hz was computed for both the low-TR and (for the two lower-frequency ranges the high-TR datasets using bandpass filters. In the low-TR data, cortical regions exhibited highest contribution of low-frequency fluctuations and the most marked low-frequency peak in the spectrum, while the time courses in subcortical grey matter regions as well as the insula were strongly contaminated by high-frequency signals. White matter and CSF regions had highest contribution of high-frequency fluctuations and a mostly flat power spectrum. In the high-TR data, the basic patterns of the low-TR data can be recognized, but the high-frequency proportions of the signal fluctuations are folded into the low frequency range, thus obfuscating the low-frequency dynamics. Regions with higher proportion of high-frequency oscillations in the low-TR data showed flatter power spectra in the high-TR data due to aliasing of the high-frequency signal components, leading to loss of specificity in the signal from these regions in high-TR data. Functional connectivity analyses showed that there are correlations between resting-state signal fluctuations of distant brain regions even at high frequencies, which can be measured using low-TR fMRI. On the other hand, in the high-TR data, loss of specificity of measured fluctuations leads to lower sensitivity in detecting functional connectivity. This underlines the advantages of low

Technical standards in the law of technical safety

International Nuclear Information System (INIS)

Marburger, P.

1985-01-01

Technical standards are of great importance for the closer definition of inexact terms of law, for instance ''generally accepted technical rules'', ''state of the art'', ''state of science and technology'' or similar normative terms, in the law of technical safety. The paper discusses with whom the authority for regulating this sector of law rests, deals with the different ways of how technical standards are used by the law (''anticipated expert opinion'', reference to such standards in law and administration) and points out demands on the procedure of standardization. (orig.) [de

[Incidence of long (short) PR interval in electrocardiogram among healthy people in Changsha and its clinical significance].

Science.gov (United States)

Liu, Liping; Lin, Ping; Xu, Yi; Wu, Lijia; Zou, Runmei; Xie, Zhenwu; Wang, Cheng

2016-04-01

To analyze the incidence of long (short) PR interval in electrocardiogram among healthy people in Changsha and the clinical significance.
 Twelve-lead body surface electrocardiogram was taken to measure the heart rates and PR intervals from 4 025 healthy individuals (age range from 6 min after birth to 83 years old) who performed physical examination from Jan, 1993 to Dec, 2012 in the Second Xiangya Hospital, Central South University. Statistics were analyzed by SPSS 16.0.
 The total incidence of short PR interval was 19.65% (791/4 025). The age group from birth to 13 years old had a higher incidence than the other age groups (χ2=432, PPR intervals was 3.58% (144/4 025). The 1 year-old group had the highest incidence (6.74%), which decreased with the increase of age. The lowest incidence of long PR intervals occurred in the age group from 14-17 years old, which gradually increased after 50 years old. There were no significant differences in long (short) PR intervals between the gender (P>0.05).
 The incidence of long (short) PR intervals varies in different age groups of healthy people. The incidences of long (short) PR intervals in children before 10 years old are higher than those in adults, especially the short PR intervals, as a result of the heart rate affected by childhood autonomic nervous function and the change in atrial volume with age. Adults have long (short) PR interval should be regularly followed-up to prevent cardiovascular events.

Biomarkers of Dose and Effect of inhaled ozone in resting versus exercising human subjects: comparison with resting rats

Science.gov (United States)

Background: Human controlled exposure studies have generally focused on subjects exposed to ozone (O3) while exercising while exposures in rats have been done at rest. We exposed resting subjects to labeled O3 (18O3, 0.4 ppm, for 2 hr) and compared O3 dose and effects with our...

Diagnostic advantages of the association of electrocardiograms and thallium 201 exercise scintigraphy in detecting coronary disease

International Nuclear Information System (INIS)

Tubau, J.F.; Chaitman, B.R.; Dupras, G.; Waters, D.D.; Bourassa, M.G.

1979-01-01

Thallium 201 exercise scintigraphy combined with 14-lead exercise electrocardiography detects coronary artery disease in 95-96 percent of the patients, whether men or women. When both tests were positive, 93 percent of the men and 100 percent of the women had coronary artery disease. In women, thallium 201 seems to do better than 14-lead exercise electrocardiogram, detecting the presence of coronary artery disease in 72 percent and its absence in 83 percent of the cases. In approximately 50 percent of the cases, the results of thallium 201 and multiple-lead exercise testing were discordant; in these cases, an accurate clinical history is helpful. (author) [fr

Individual identification via electrocardiogram analysis.

Science.gov (United States)

Fratini, Antonio; Sansone, Mario; Bifulco, Paolo; Cesarelli, Mario

2015-08-14

During last decade the use of ECG recordings in biometric recognition studies has increased. ECG characteristics made it suitable for subject identification: it is unique, present in all living individuals, and hard to forge. However, in spite of the great number of approaches found in literature, no agreement exists on the most appropriate methodology. This study aimed at providing a survey of the techniques used so far in ECG-based human identification. Specifically, a pattern recognition perspective is here proposed providing a unifying framework to appreciate previous studies and, hopefully, guide future research. We searched for papers on the subject from the earliest available date using relevant electronic databases (Medline, IEEEXplore, Scopus, and Web of Knowledge). The following terms were used in different combinations: electrocardiogram, ECG, human identification, biometric, authentication and individual variability. The electronic sources were last searched on 1st March 2015. In our selection we included published research on peer-reviewed journals, books chapters and conferences proceedings. The search was performed for English language documents. 100 pertinent papers were found. Number of subjects involved in the journal studies ranges from 10 to 502, age from 16 to 86, male and female subjects are generally present. Number of analysed leads varies as well as the recording conditions. Identification performance differs widely as well as verification rate. Many studies refer to publicly available databases (Physionet ECG databases repository) while others rely on proprietary recordings making difficult them to compare. As a measure of overall accuracy we computed a weighted average of the identification rate and equal error rate in authentication scenarios. Identification rate resulted equal to 94.95 % while the equal error rate equal to 0.92 %. Biometric recognition is a mature field of research. Nevertheless, the use of physiological signals

Rest but busy: Aberrant resting-state functional connectivity of triple network model in insomnia.

Science.gov (United States)

Dong, Xiaojuan; Qin, Haixia; Wu, Taoyu; Hu, Hua; Liao, Keren; Cheng, Fei; Gao, Dong; Lei, Xu

2018-02-01

One classical hypothesis among many models to explain the etiology and maintenance of insomnia disorder (ID) is hyperarousal. Aberrant functional connectivity among resting-state large-scale brain networks may be the underlying neurological mechanisms of this hypothesis. The aim of current study was to investigate the functional network connectivity (FNC) among large-scale brain networks in patients with insomnia disorder (ID) during resting state. In the present study, the resting-state fMRI was used to evaluate whether patients with ID showed aberrant FNC among dorsal attention network (DAN), frontoparietal control network (FPC), anterior default mode network (aDMN), and posterior default mode network (pDMN) compared with healthy good sleepers (HGSs). The Pearson's correlation analysis was employed to explore whether the abnormal FNC observed in patients with ID was associated with sleep parameters, cognitive and emotional scores, and behavioral performance assessed by questionnaires and tasks. Patients with ID had worse subjective thought control ability measured by Thought Control Ability Questionnaire (TCAQ) and more negative affect than HGSs. Intriguingly, relative to HGSs, patients with ID showed a significant increase in FNC between DAN and FPC, but a significant decrease in FNC between aDMN and pDMN. Exploratory analysis in patients with ID revealed a significantly positive correlation between the DAN-FPC FNC and reaction time (RT) of psychomotor vigilance task (PVT). The current study demonstrated that even during the resting state, the task-activated and task-deactivated large-scale brain networks in insomniacs may still maintain a hyperarousal state, looking quite similar to the pattern in a task condition with external stimuli. Those results support the hyperarousal model of insomnia.

Discovering EEG resting state alterations of semantic dementia.

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Grieder, Matthias; Koenig, Thomas; Kinoshita, Toshihiko; Utsunomiya, Keita; Wahlund, Lars-Olof; Dierks, Thomas; Nishida, Keiichiro

2016-05-01

Diagnosis of semantic dementia relies on cost-intensive MRI or PET, although resting EEG markers of other dementias have been reported. Yet the view still holds that resting EEG in patients with semantic dementia is normal. However, studies using increasingly sophisticated EEG analysis methods have demonstrated that slightest alterations of functional brain states can be detected. We analyzed the common four resting EEG microstates (A, B, C, and D) of 8 patients with semantic dementia in comparison with 8 healthy controls and 8 patients with Alzheimer's disease. Topographical differences between the groups were found in microstate classes B and C, while microstate classes A and D were comparable. The data showed that the semantic dementia group had a peculiar microstate E, but the commonly found microstate C was lacking. Furthermore, the presence of microstate E was significantly correlated with lower MMSE and language scores. Alterations in resting EEG can be found in semantic dementia. Topographical shifts in microstate C might be related to semantic memory deficits. This is the first study that discovered resting state EEG abnormality in semantic dementia. The notion that resting EEG in this dementia subtype is normal has to be revised. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

A comparison of resting images from two myocardial perfusion tracers

International Nuclear Information System (INIS)

Anagnostopoulos, C.; Laney, R.; Pennell, D.; Proukakis, H.; Underwood, R.

1995-01-01

We have compared stress-redistribution and delayed rest thallium-201 with rest technetium-99m methoxyisobutylisonitrile (MIBI) tomograms in order to compare the tracers for the assessment of myocardial viability and to validate a rapid protocol combining the two tracers. We studied 30 consecutive patients with known or suspected coronary artery disease [group 1: 16 with normal left ventricular function, mean left ventricular ejection fraction (LVEF) 55%, SD 6%; group 2: 14 with abnormal function, mean LVEF 28%, SD 8%]. 201 Tl was injected during infusion of adenosine followed by acquisition of conventional stress and redistribution tomograms. On a separate day, 201 Tl was injected at rest with imaging 4 h later. 99m Tc-MIBI was then given at rest and imaging was performed. Three images were compared: redistribution 201 Tl, rest 201 Tl, and rest 99m Tc-MIBI. Tracer activity was classified visually and quantitatively in nine segments and segments with>50% activity were defined as containing clinically significant viable myocardium. Mean global tracer uptake as a percentage of maximum was similar in group 1 (rest 201 Tl 69%±12%, redistribution 201 Tl 69%±15%, rest 99m Tc-MIBI 70%±13%), but in group 2 mean tracer uptake was significantly greater in the rest 201 Tl images (59%±16%) than in redistribution 201 Tl images (53%±17%) or rest 99m Tc-MIBI images (53%±19%). Overall agreement for regional uptake score was excellent (κ from 0.79 to 0.84), although there were a significant number of segments with less uptake shown by redistribution 201 Tl and by rest 99m Tc-MIBI than by rest 201 Tl in group 2. The number of segments with significant viable myocardium in group 1 was very similar between the three images but in group 2 rest 201 Tl identified significantly more segments as viable than the other images. (orig./MG) (orig.). With 1 fig., 7 tabs

Rural emergency medical technician pre-hospital electrocardiogram transmission.

Science.gov (United States)

Powell, A M; Halon, J M; Nelson, J

2014-01-01

Emergent care of the acute heart attack patient continues to be at the forefront of quality and cost reduction strategies throughout the healthcare industry. Although the average cardiac door-to-balloon (D2B) times have decreased substantially over the past few years, there are still vast disparities found in D2B times in populations that reside in rural areas. Such disparities are mostly related to prolonged travel time and subsequent delays in cardiac catherization lab team activation. Urban ambulance companies that are routinely staffed with paramedic level providers have been successful in the implementation of pre-hospital 12-lead electrocardiogram (ECG) protocols as a strategy to reduce D2B times. The authors sought to evaluate the evidence related to the risk and benefits associated with the replication of an ECG transmission protocol in a small rural emergency medical service. The latter is staffed with emergency medical technician-basics (EMT-B), emergency medical technician-advanced (EMT-A), and emergency medical technician-intermediate (EMT-I) level. The evidence reviewed was limited to studies with relevant data regarding the challenges and complexities of the ECG transmission process, the difficulties associated with ECG transmission in rural settings, and ECG transmission outcomes by provider level. The evidence supports additional research to further evaluate the feasibility of ECG transmission at the non-paramedic level. Multiple variables must be investigated including equipment cost, utilization, and rural transmission capabilities. Clearly, pre-hospital ECG transmission and early activation of the cardiac catheterization laboratory are critical components to successfully decreasing D2B times.

REST represses a subset of the pancreatic endocrine differentiation program

DEFF Research Database (Denmark)

Martin, David; Kim, Yung-Hae; Sever, Dror

2015-01-01

in neurons and in endocrine cells, which is necessary for their normal function. During development, REST represses a subset of genes in the neuronal differentiation program and Rest is down-regulated as neurons differentiate. Here, we investigate the role of REST in the differentiation of pancreatic...... endocrine cells, which are molecularly close to neurons. We show that Rest is widely expressed in pancreas progenitors and that it is down-regulated in differentiated endocrine cells. Sustained expression of REST in Pdx1(+) progenitors impairs the differentiation of endocrine-committed Neurog3...

Building RESTful web services with Go learn how to build powerful RESTful APIs with Golang that scale gracefully

CERN Document Server

Yellavula, Naren

2017-01-01

REST is an architectural style that tackles the challenges of building scalable web services and in today's connected world, APIs have taken a central role on the web. APIs provide the fabric through which systems interact, and REST has become synonymous with APIs. The depth, breadth, and ease of use of Go, makes it a breeze for developers to ...

Impact of the 12-lead electrocardiogram on ED evaluation and management.

Science.gov (United States)

Benner, John P; Borloz, Matthew P; Adams, Madeline; Brady, William J

2007-10-01

This study was conducted to assess the impact (diagnostic, therapeutic, and disposition) of the 12-lead electrocardiogram (ECG) on emergency department (ED) patient evaluation and management. This project was a prospective study of a convenience sample of 304 ED patients undergoing ECG analysis during their evaluation in the ED of a level 1 trauma center. The data collection for this study was divided into 4 parts. In part I, the treating physicians determined the specific reasons for ECG analysis; categories include complaint-based (eg, chest pain), syndrome-based (eg, overdose/poisoning), and system-based (eg, "requested by consult"). In part II, all treating physicians were surveyed before ECG interpretation regarding the future diagnostic, therapeutic, and disposition plans for the patient based only on history and physical examination. Their comments were recorded on a standardized data sheet. In part III, the physicians were surveyed after their interpretation of the ECG as to whether the results could suggest any further diagnostic information (eg, normal vs abnormal), or provide enough information for the patient care plan to be altered. In part IV of the study period, alterations to the original diagnostic, therapeutic, and disposition plans made by information provided by the ECG were obtained from the treating physician. A total of 304 patients underwent ECG examination and were used for data analysis. The average age of patients, of which 48% were men, was 60 years. The most common complaints that prompted electrocardiographic evaluation were chest pain and dyspnea. The most common reason an ECG was ordered was nursing staff protocol. Physicians determined that they were able to make a diagnosis based primarily on ECG in 33 (10.9%) cases. The total number of ECGs that were determined to be normal was 95 (31.3%), 7 (2.3%) of which allowed a rule-out diagnosis; 209 (68.7%) of total ECGs were determined to be abnormal, 72 (23.6%) of which were considered

REST-MapReduce: An Integrated Interface but Differentiated Service

Directory of Open Access Journals (Sweden)

Jong-Hyuk Park

2014-01-01

Full Text Available With the fast deployment of cloud computing, MapReduce architectures are becoming the major technologies for mobile cloud computing. The concept of MapReduce was first introduced as a novel programming model and implementation for a large set of computing devices. In this research, we propose a novel concept of REST-MapReduce, enabling users to use only the REST interface without using the MapReduce architecture. This approach provides a higher level of abstraction by integration of the two types of access interface, REST API and MapReduce. The motivation of this research stems from the slower response time for accessing simple RDBMS on Hadoop than direct access to RDMBS. This is because there is overhead to job scheduling, initiating, starting, tracking, and management during MapReduce-based parallel execution. Therefore, we provide a good performance for REST Open API service and for MapReduce, respectively. This is very useful for constructing REST Open API services on Hadoop hosting services, for example, Amazon AWS (Macdonald, 2005 or IBM Smart Cloud. For evaluating performance of our REST-MapReduce framework, we conducted experiments with Jersey REST web server and Hadoop. Experimental result shows that our approach outperforms conventional approaches.

The Effect of Exercise Training on Resting Concentrations of Peripheral Brain-Derived Neurotrophic Factor (BDNF: A Meta-Analysis.

Directory of Open Access Journals (Sweden)

Adam Dinoff

Full Text Available The mechanisms through which physical activity supports healthy brain function remain to be elucidated. One hypothesis suggests that increased brain-derived neurotrophic factor (BDNF mediates some cognitive and mood benefits. This meta-analysis sought to determine the effect of exercise training on resting concentrations of BDNF in peripheral blood.MEDLINE, Embase, PsycINFO, SPORTDiscus, Rehabilitation & Sports Medicine Source, and CINAHL databases were searched for original, peer-reviewed reports of peripheral blood BDNF concentrations before and after exercise interventions ≥ 2 weeks. Risk of bias was assessed using standardized criteria. Standardized mean differences (SMDs were generated from random effects models. Risk of publication bias was assessed using funnel plots and Egger's test. Potential sources of heterogeneity were explored in subgroup analyses.In 29 studies that met inclusion criteria, resting concentrations of peripheral blood BDNF were higher after intervention (SMD = 0.39, 95% CI: 0.17-0.60, p < 0.001. Subgroup analyses suggested a significant effect in aerobic (SMD = 0.66, 95% CI: 0.33-0.99, p < 0.001 but not resistance training (SMD = 0.07, 95% CI: -0.15-0.30, p = 0.52 interventions. No significant difference in effect was observed between males and females, nor in serum vs plasma.Aerobic but not resistance training interventions increased resting BDNF concentrations in peripheral blood.

Stress hormones at rest and following exercise testing predict coronary artery disease severity and outcome.

Science.gov (United States)

Popovic, Dejana; Damjanovic, Svetozar; Djordjevic, Tea; Martic, Dejana; Ignjatovic, Svetlana; Milinkovic, Neda; Banovic, Marko; Lasica, Ratko; Petrovic, Milan; Guazzi, Marco; Arena, Ross

2017-09-01

Despite considerable knowledge regarding the importance of stress in coronary artery disease (CAD) pathogenesis, its underestimation persists in routine clinical practice, in part attributable to lack of a standardized, objective assessment. The current study examined the ability of stress hormones to predict CAD severity and prognosis at basal conditions as well as during and following an exertional stimulus. Forty Caucasian subjects with significant coronary artery lesions (≥50%) were included. Within 2 months of coronary angiography, cardiopulmonary exercise testing (CPET) on a recumbent ergometer was performed in conjunction with stress echocardiography (SE). At rest, peak and after 3 min of recovery following CPET, plasma levels of cortisol, adrenocorticotropic hormone (ACTH) and NT-pro-brain natriuretic peptide (NT-pro-BNP) were measured by immunoassay sandwich technique, radioimmunoassay, and radioimmunometric technique, respectively. Subjects were subsequently followed a mean of 32 ± 10 months. Mean ejection fraction was 56.7 ± 9.6%. Subjects with 1-2 stenotic coronary arteries (SCA) demonstrated a significantly lower plasma cortisol levels during CPET compared to those with 3-SCA (p  .05). Among CPET, SE, and hormonal parameters, cortisol at rest and during CPET recovery demonstrated the best predictive value in distinguishing between 1-, 2-, and 3-SCA [area under ROC curve 0.75 and 0.77 (SE = 0.11, 0.10; p = .043, .04) for rest and recovery, respectively]. ΔCortisol peak/rest predicted cumulative cardiac events (area under ROC curve 0.75, SE = 0.10, p = .049). Cortisol at rest and following an exercise test holds predictive value for CAD severity and prognosis, further demonstrating a link between stress and unwanted cardiac events.

"Therapeutic" bed rest in pregnancy: unethical and unsupported by data.

Science.gov (United States)

McCall, Christina A; Grimes, David A; Lyerly, Anne Drapkin

2013-06-01

"Therapeutic" bed rest continues to be used widely, despite evidence of no benefit and known harms. In this commentary, we summarize the Cochrane reviews of bed rest and propose an ethical argument for discontinuing this practice. Cochrane systematic reviews do not support "therapeutic" bed rest for threatened abortion, hypertension, preeclampsia, preterm birth, multiple gestations, or impaired fetal growth. This assessment has been echoed in other comprehensive reviews. Prescribing bed rest is inconsistent with the ethical principles of autonomy, beneficence, and justice. Hence, if bed rest is to be used, it should be only within a formal clinical trial.

Electrocardiogram signal denoising based on a new improved wavelet thresholding

Science.gov (United States)

Han, Guoqiang; Xu, Zhijun

2016-08-01

Good quality electrocardiogram (ECG) is utilized by physicians for the interpretation and identification of physiological and pathological phenomena. In general, ECG signals may mix various noises such as baseline wander, power line interference, and electromagnetic interference in gathering and recording process. As ECG signals are non-stationary physiological signals, wavelet transform is investigated to be an effective tool to discard noises from corrupted signals. A new compromising threshold function called sigmoid function-based thresholding scheme is adopted in processing ECG signals. Compared with other methods such as hard/soft thresholding or other existing thresholding functions, the new algorithm has many advantages in the noise reduction of ECG signals. It perfectly overcomes the discontinuity at ±T of hard thresholding and reduces the fixed deviation of soft thresholding. The improved wavelet thresholding denoising can be proved to be more efficient than existing algorithms in ECG signal denoising. The signal to noise ratio, mean square error, and percent root mean square difference are calculated to verify the denoising performance as quantitative tools. The experimental results reveal that the waves including P, Q, R, and S waves of ECG signals after denoising coincide with the original ECG signals by employing the new proposed method.

A REST-ful interpretation for embedded modular systems based on open architecture

Science.gov (United States)

Lyke, James

2016-05-01

The much-anticipated revolution of the "Internet of things" (IoT) is expected to generate one trillion internet devices within the next 15 years, mostly in the form of simple wireless sensor devices. While this revolution promises to transform silicon markets and drive a number of disruptive changes in society, it is also the case that the protocols, complexity, and security issues of extremely large dynamic, co-mingled networks is still poorly understood. Furthermore, embedded system developers, to include military and aerospace users, have largely ignored the potential (good and bound) of the cloudlike, possibly intermingling networks having variable structure to how future systems might be engineered. In this paper, we consider a new interpretation of IoT inspired modular architecture strategies involving the representational state transfer (REST) model, in which dynamic networks with variable structure employ stateless application programming interface (API) concepts. The power of the method, which extends concepts originally developed for space plug-and-play avionics, is that it allows for the fluid co-mingling of hardware and software in networks whose structure can overlap and evolve. Paradoxically, these systems may have the most stringent determinism and fault-tolerant needs. In this paper we review how RESTful APIs can potentially be used to design, create, test, and deploy systems rapidly while addressing security and referential integrity even when the nodes of many systems might physically co-mingle. We will also explore ways to take advantage of the RESTful paradigm for fault tolerance and what extensions might be necessary to deal with high-performance and determinism.

[Creep of amalgam fillings under clasp rests].

Science.gov (United States)

Borchers, L; Jung, T; West, M

1989-10-01

A clinically realistic experiment was set up to obtain information on the amount of vertical settling of clasp rests in amalgam restorations under functional loading. Mesioocclusal cavities were prepared in 16 lower molar specimens cast in brass. The cavities were filled with amalgam and provided with a mesial rest seat. A constant load of 100 N was applied via a simplified (experimental) saddle to a cobalt-chromium E-clasp cast to the saddle. The duration of the load corresponded to 160 days of clinical function. The chronological course of vertical displacement was analyzed mathematically. According to this result the process can be divided into three components: settling immediately upon load initiation (mean value 96 microns, transition creep (mean value 25 microns) and creep ata constant rate (mean value 15 microns). The mean overall vertical displacement of the rests was 136 microns, the maximum value 287 microns. These findings suggest that vertical settling of a clasp rest into its seat in an amalgam restoration may eventually result in significant changes in occlusion and may almost completely exhaust gingival resilience.

Artifactual ECG changes induced by electrocautery in a patient with coronary artery disease.

Science.gov (United States)

Naik, B Naveen; Luthra, Ankur; Dwivedi, Ashish; Jafra, Anudeep

Continuous monitoring of 5-lead electrocardiogram is a basic standard of care (included under standard ASA monitor) in the operating room and electrocautery interference is a common phenomenon. Clinical signs, along with monitored waveforms from other simultaneously monitored parameters may provide us clues to differentiate artifacts from true changes on the electrocardiogram. An improved understanding of the artifacts generated by electrocautery and their identifying characteristics is important to avoid misinterpretation, misdiagnosis, and hence mismanagement. This case report highlights the artifacts in electrocardiogram induced by electrocautery. Copyright © 2017 Elsevier Inc. All rights reserved.

Structure and Topology Dynamics of Hyper-Frequency Networks during Rest and Auditory Oddball Performance.

Science.gov (United States)

Müller, Viktor; Perdikis, Dionysios; von Oertzen, Timo; Sleimen-Malkoun, Rita; Jirsa, Viktor; Lindenberger, Ulman

2016-01-01

Resting-state and task-related recordings are characterized by oscillatory brain activity and widely distributed networks of synchronized oscillatory circuits. Electroencephalographic recordings (EEG) were used to assess network structure and network dynamics during resting state with eyes open and closed, and auditory oddball performance through phase synchronization between EEG channels. For this assessment, we constructed a hyper-frequency network (HFN) based on within- and cross-frequency coupling (WFC and CFC, respectively) at 10 oscillation frequencies ranging between 2 and 20 Hz. We found that CFC generally differentiates between task conditions better than WFC. CFC was the highest during resting state with eyes open. Using a graph-theoretical approach (GTA), we found that HFNs possess small-world network (SWN) topology with a slight tendency to random network characteristics. Moreover, analysis of the temporal fluctuations of HFNs revealed specific network topology dynamics (NTD), i.e., temporal changes of different graph-theoretical measures such as strength, clustering coefficient, characteristic path length (CPL), local, and global efficiency determined for HFNs at different time windows. The different topology metrics showed significant differences between conditions in the mean and standard deviation of these metrics both across time and nodes. In addition, using an artificial neural network approach, we found stimulus-related dynamics that varied across the different network topology metrics. We conclude that functional connectivity dynamics (FCD), or NTD, which was found using the HFN approach during rest and stimulus processing, reflects temporal and topological changes in the functional organization and reorganization of neuronal cell assemblies.

Cardiac atrophy after bed rest and spaceflight

Science.gov (United States)

Perhonen, M. A.; Franco, F.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.; Zerwekh, J. E.; Peshock, R. M.; Weatherall, P. T.; Levine, B. D.

2001-01-01

Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 (n = 5) and 12 (n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 +/- 2.2% (P = 0.005) after 6 wk with an additional atrophy of 7.6 +/- 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 +/- 12.2 vs. 153.4 +/- 12.1 g, P = 0.81). Mean wall thickness decreased (4 +/- 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 +/- 1.7% (P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 +/- 2.7% (P = 0.06) and RV end-diastolic volume by 16 +/- 7.9% (P = 0.06). After spaceflight, LV mass decreased by 12 +/- 6.9% (P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity

Resting state brain networks in the prairie vole.

Science.gov (United States)

Ortiz, Juan J; Portillo, Wendy; Paredes, Raul G; Young, Larry J; Alcauter, Sarael

2018-01-19

Resting state functional magnetic resonance imaging (rsfMRI) has shown the hierarchical organization of the human brain into large-scale complex networks, referred as resting state networks. This technique has turned into a promising translational research tool after the finding of similar resting state networks in non-human primates, rodents and other animal models of great value for neuroscience. Here, we demonstrate and characterize the presence of resting states networks in Microtus ochrogaster, the prairie vole, an extraordinary animal model to study complex human-like social behavior, with potential implications for the research of normal social development, addiction and neuropsychiatric disorders. Independent component analysis of rsfMRI data from isoflurane-anestethized prairie voles resulted in cortical and subcortical networks, including primary motor and sensory networks, but also included putative salience and default mode networks. We further discuss how future research could help to close the gap between the properties of the large scale functional organization and the underlying neurobiology of several aspects of social cognition. These results contribute to the evidence of preserved resting state brain networks across species and provide the foundations to explore the use of rsfMRI in the prairie vole for basic and translational research.

From "rest" to language task: Task activation selects and prunes from broader resting-state network.

Science.gov (United States)

Doucet, Gaelle E; He, Xiaosong; Sperling, Michael R; Sharan, Ashwini; Tracy, Joseph I

2017-05-01

Resting-state networks (RSNs) show spatial patterns generally consistent with networks revealed during cognitive tasks. However, the exact degree of overlap between these networks has not been clearly quantified. Such an investigation shows promise for decoding altered functional connectivity (FC) related to abnormal language functioning in clinical populations such as temporal lobe epilepsy (TLE). In this context, we investigated the network configurations during a language task and during resting state using FC. Twenty-four healthy controls, 24 right and 24 left TLE patients completed a verb generation (VG) task and a resting-state fMRI scan. We compared the language network revealed by the VG task with three FC-based networks (seeding the left inferior frontal cortex (IFC)/Broca): two from the task (ON, OFF blocks) and one from the resting state. We found that, for both left TLE patients and controls, the RSN recruited regions bilaterally, whereas both VG-on and VG-off conditions produced more left-lateralized FC networks, matching more closely with the activated language network. TLE brings with it variability in both task-dependent and task-independent networks, reflective of atypical language organization. Overall, our findings suggest that our RSN captured bilateral activity, reflecting a set of prepotent language regions. We propose that this relationship can be best understood by the notion of pruning or winnowing down of the larger language-ready RSN to carry out specific task demands. Our data suggest that multiple types of network analyses may be needed to decode the association between language deficits and the underlying functional mechanisms altered by disease. Hum Brain Mapp 38:2540-2552, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Temporal abstraction and inductive logic programming for arrhythmia recognition from electrocardiograms.

Science.gov (United States)

Carrault, G; Cordier, M-O; Quiniou, R; Wang, F

2003-07-01

This paper proposes a novel approach to cardiac arrhythmia recognition from electrocardiograms (ECGs). ECGs record the electrical activity of the heart and are used to diagnose many heart disorders. The numerical ECG is first temporally abstracted into series of time-stamped events. Temporal abstraction makes use of artificial neural networks to extract interesting waves and their features from the input signals. A temporal reasoner called a chronicle recogniser processes such series in order to discover temporal patterns called chronicles which can be related to cardiac arrhythmias. Generally, it is difficult to elicit an accurate set of chronicles from a doctor. Thus, we propose to learn automatically from symbolic ECG examples the chronicles discriminating the arrhythmias belonging to some specific subset. Since temporal relationships are of major importance, inductive logic programming (ILP) is the tool of choice as it enables first-order relational learning. The approach has been evaluated on real ECGs taken from the MIT-BIH database. The performance of the different modules as well as the efficiency of the whole system is presented. The results are rather good and demonstrate that integrating numerical techniques for low level perception and symbolic techniques for high level classification is very valuable.

Quality Aware Compression of Electrocardiogram Using Principal Component Analysis.

Science.gov (United States)

Gupta, Rajarshi

2016-05-01

Electrocardiogram (ECG) compression finds wide application in various patient monitoring purposes. Quality control in ECG compression ensures reconstruction quality and its clinical acceptance for diagnostic decision making. In this paper, a quality aware compression method of single lead ECG is described using principal component analysis (PCA). After pre-processing, beat extraction and PCA decomposition, two independent quality criteria, namely, bit rate control (BRC) or error control (EC) criteria were set to select optimal principal components, eigenvectors and their quantization level to achieve desired bit rate or error measure. The selected principal components and eigenvectors were finally compressed using a modified delta and Huffman encoder. The algorithms were validated with 32 sets of MIT Arrhythmia data and 60 normal and 30 sets of diagnostic ECG data from PTB Diagnostic ECG data ptbdb, all at 1 kHz sampling. For BRC with a CR threshold of 40, an average Compression Ratio (CR), percentage root mean squared difference normalized (PRDN) and maximum absolute error (MAE) of 50.74, 16.22 and 0.243 mV respectively were obtained. For EC with an upper limit of 5 % PRDN and 0.1 mV MAE, the average CR, PRDN and MAE of 9.48, 4.13 and 0.049 mV respectively were obtained. For mitdb data 117, the reconstruction quality could be preserved up to CR of 68.96 by extending the BRC threshold. The proposed method yields better results than recently published works on quality controlled ECG compression.

Singularity detection by wavelet approach: application to electrocardiogram signal

Science.gov (United States)

Jalil, Bushra; Beya, Ouadi; Fauvet, Eric; Laligant, Olivier

2010-01-01

In signal processing, the region of abrupt changes contains the most of the useful information about the nature of the signal. The region or the points where these changes occurred are often termed as singular point or singular region. The singularity is considered to be an important character of the signal, as it refers to the discontinuity and interruption present in the signal and the main purpose of the detection of such singular point is to identify the existence, location and size of those singularities. Electrocardiogram (ECG) signal is used to analyze the cardiovascular activity in the human body. However the presence of noise due to several reasons limits the doctor's decision and prevents accurate identification of different pathologies. In this work we attempt to analyze the ECG signal with energy based approach and some heuristic methods to segment and identify different signatures inside the signal. ECG signal has been initially denoised by empirical wavelet shrinkage approach based on Steins Unbiased Risk Estimate (SURE). At the second stage, the ECG signal has been analyzed by Mallat approach based on modulus maximas and Lipschitz exponent computation. The results from both approaches has been discussed and important aspects has been highlighted. In order to evaluate the algorithm, the analysis has been done on MIT-BIH Arrhythmia database; a set of ECG data records sampled at a rate of 360 Hz with 11 bit resolution over a 10mv range. The results have been examined and approved by medical doctors.

Detection of Atrial Fibrillation Using Artifical Neural Network with Power Spectrum Density of RR Interval of Electrocardiogram

Science.gov (United States)

Afdala, Adfal; Nuryani, Nuryani; Satrio Nugroho, Anto

2017-01-01

Atrial fibrillation (AF) is a disorder of the heart with fairly high mortality in adults. AF is a common heart arrythmia which is characterized by a missing or irregular contraction of atria. Therefore, finding a method to detect atrial fibrillation is necessary. In this article a system to detect atrial fibrillation has been proposed. Detection system utilized backpropagation artifical neural network. Data input in this method includes power spectrum density of R-peaks interval of electrocardiogram which is selected by wrapping method. This research uses parameter learning rate, momentum, epoch and hidden layer. System produces good performance with accuracy, sensitivity, and specificity of 83.55%, 86.72 % and 81.47 %, respectively.

Comparison of myocardial perfusion imaging between the new high-speed gamma camera and the standard anger camera

International Nuclear Information System (INIS)

Tanaka, Hirokazu; Chikamori, Taishiro; Hida, Satoshi

2013-01-01

Cadmium-zinc-telluride (CZT) solid-state detectors have been recently introduced into the field of myocardial perfusion imaging. The aim of this study was to prospectively compare the diagnostic performance of the CZT high-speed gamma camera (Discovery NM 530c) with that of the standard 3-head gamma camera in the same group of patients. The study group consisted of 150 consecutive patients who underwent a 1-day stress-rest 99m Tc-sestamibi or tetrofosmin imaging protocol. Image acquisition was performed first on a standard gamma camera with a 15-min scan time each for stress and for rest. All scans were immediately repeated on a CZT camera with a 5-min scan time for stress and a 3-min scan time for rest, using list mode. The correlations between the CZT camera and the standard camera for perfusion and function analyses were strong within narrow Bland-Altman limits of agreement. Using list mode analysis, image quality for stress was rated as good or excellent in 97% of the 3-min scans, and in 100% of the ≥4-min scans. For CZT scans at rest, similarly, image quality was rated as good or excellent in 94% of the 1-min scans, and in 100% of the ≥2-min scans. The novel CZT camera provides excellent image quality, which is equivalent to standard myocardial single-photon emission computed tomography, despite a short scan time of less than half of the standard time. (author)

Computer decision support as a source of interpretation error: the case of electrocardiograms.

Science.gov (United States)

Tsai, Theodore L; Fridsma, Douglas B; Gatti, Guido

2003-01-01

The aim of this study was to determine the effect that the computer interpretation (CI) of electrocardiograms (EKGs) has on the accuracy of resident (noncardiologist) physicians reading EKGs. A randomized, controlled trial was conducted in a laboratory setting from February through June 2001, using a two-period crossover design with matched pairs of subjects randomly assigned to sequencing groups. Subjects' interpretive accuracy of discrete, cardiologist-determined EKG findings were measured as judged by a board-certified internist. Without the CI, subjects interpreted 48.9% (95% confidence interval, 45.0% to 52.8%) of the findings correctly. With the CI, subjects interpreted 55.4% (51.9% to 58.9%) correctly (p EKG 67.7% (57.2% to 76.7%) than when it was not 34.6% (23.8% to 47.3%; p reading EKGs. However, subjects were influenced significantly by incorrect advice, which tempers the overall usefulness of computer-generated advice in this and perhaps other areas.

RESTful web API design with Node.js

CERN Document Server

Bojinov, Valentin

2015-01-01

If you are a web developer wanting to enrich your development skills to create scalable, server-side, RESTful applications based on the Node.js platform, this book is for you. You also need to be aware of HTTP communication concepts and should have a working knowledge of JavaScript. Knowledge of REST would be an added advantage but is definitely not a necessity.

Prevalence of electrocardiographic ST-T changes during acute ischemic stroke in patients without known ischemic heart disease

DEFF Research Database (Denmark)

Jensen, Jesper K; Bak, Søren; Flemming Høilund-Carlsen, Poul

2008-01-01

We evaluated characteristics and prevalence of ST-segment depression and/or T-wave inversion in the resting electrocardiogram of 244 consecutive patients with acute ischemic stroke, but without ischemic heart disease. The prevalence of ST-T changes ranged from 13% to 16% and this is what to expect...

Association between uncoupling protein 2, adiponectin and resting energy expenditure in obese women with normal and low resting energy expenditure.

Science.gov (United States)

Taghadomi Masoumi, Zahra; Eshraghian, Mohammad Reza; Hedayati, Mahdi; Pishva, Hamideh

2018-02-01

Obesity is recognized as the most prevalent metabolic disease worldwide. Decreases in energy expenditure may increase risk of obesity. One of the key regulators of energy balance is uncoupling protein2 (UCP2), a transporter protein presents in mitochondrial inner membrane. Moreover, adiponectin is the most abundant adipocytokine, it may play a role in energy metabolism and gene expression of UCP2. The aim of this study was to investigate potential associations between the level of uncoupling protein 2 and adiponectin and their relationship with REE (Resting Energy Expenditure) in obese women with normal and low resting energy expenditure. A total of 49 subjects (women, 25-50 years old), were included in current study, 16 subjects with BMI > 30 and low resting energy expenditure, 17 subjects with BMI > 30 and normal resting energy expenditure and 16 non-obese subjects as a control group. Anthropometric, body composition parameters and resting energy expenditure were measured. Plasma adiponectin, UCP2 protein and total protein in PBMC were determined. Measured resting energy expenditure in obese subjects with low REE was significantly lower than other groups. Plasma adiponectin in the obese subjects with low REE was significantly lower compared to normal weight group. There was a significant relationship between 'UCP2 protein/Total protein' ratio and plasma adiponectin in obese group with low REE and in three groups when we pooled. There was a significant association between REE and plasma adiponectin in three groups when we pooled. There was a significant association between plasma adiponectin and REE. Moreover, there was a significant relationship between UCP2 and REE.

Long-Term Clinical Impact of Coronary CT Angiography in Patients With Recent Acute-Onset Chest Pain

DEFF Research Database (Denmark)

Linde, Jesper J; Hove, Jens D; Sørgaard, Mathias

2015-01-01

. BACKGROUND: The prognostic implications of a coronary CTA-guided treatment strategy have not been compared in a randomized fashion to standard care in patients referred for acute-onset chest pain. METHODS: Patients with acute chest pain but normal electrocardiograms and troponin values were randomized...... to treatment guided by either coronary CTA or standard care (bicycle exercise electrocardiogram or myocardial perfusion imaging). In the coronary CTA-guided group, a functional test was included in cases of nondiagnostic coronary CTA images or coronary stenoses of borderline severity. The primary endpoint...... electrocardiograms and troponin values compared to standard care with a functional test. (Cardiac-CT in the Treatment of Acute Chest Pain [CATCH]; NCT01534000)....

Resting state functional connectivity changes in adults with developmental stuttering: an initial sLORETA study.

Directory of Open Access Journals (Sweden)

Kathleen eJoos

2014-10-01

Full Text Available Introduction: Stuttering is defined as speech characterized by verbal dysfluencies, but should not be seen as an isolated speech disorder, but as a generalized sensorimotor timing deficit due to impaired communication between speech related brain areas. Therefore we focused on resting state brain activity and functional connectivity.Method: We included 11 patients with developmental stuttering and 11 age matched controls. To objectify stuttering severity and the impact on the quality of life (QoL, we used the Dutch validated Test for Stuttering Severity-Readers (TSS-R and the Overall Assessment of the Speaker’s Experience of Stuttering (OASES, respectively. Furthermore, we used standardized low resolution brain electromagnetic tomography (sLORETA analyses to look at resting state activity and functional connectivity differences and their correlations with the TSS-R and OASES.Results: No resting state activity differences were identified in comparison to fluently speaking controls or in correlation with stuttering severity or QoL measures. Significant alterations in resting state functional connectivity were found, predominantly interhemispheric, i.e. a decreased functional connectivity for high frequency oscillations (beta and gamma between motor speech areas (BA44 and 45 and the contralateral premotor (BA 6 and motor (BA 4 areas. A positive correlation was found between functional connectivity at low frequency oscillations (theta and alpha and stuttering severity, while a mixed increased and decreased functional connectivity at low and high frequency oscillations correlated with QoL.Discussion: PWS are characterized by decreased high frequency interhemispheric functional connectivity between motor speech, premotor and motor areas in the resting state, while higher functional connectivity in the low frequency bands indicates more severe speech disturbances, suggesting that increased interhemispheric and right sided functional connectivity is

A rest period does not affect in vitro storage properties in apheresis platelets collected from the buffy coat layer.

Science.gov (United States)

Wagner, Stephen J; Seetharaman, Shalini; Kurtz, James

2012-11-01

A previous study demonstrated that several in vitro storage properties of apheresis platelets (PLTs) that are isolated by sedimentation against the collection container and subsequently resuspended can benefit from a rest period before continuous agitation. This study examines whether the in vitro storage properties of apheresis PLTs isolated by collection from the buffy coat layer benefit from a rest period before agitation. Freshly collected apheresis PLTs (Trima, GambroBCT) were divided into five 60-mL aliquots. One aliquot was immediately placed on a flat-bed agitator; the other aliquots were held on a laboratory bench for 1, 2, 4, and 6 hours before continuous agitation. Samples were obtained on Days 1, 5, and 7 for standard in vitro PLT assays. The experiment was repeated 12 times. For each sampling day, no significant differences were observed in aliquots held with or without a rest period for any of the following PLT properties: PLT content, mean PLT volume, pH, pCO2, bicarbonate, glucose, lactate, hypotonic shock response, extent of shape change, aggregation, morphology, CD62P, CD63, and CD42b. Although regression analysis identified several in vitro properties whose mean levels appeared to improve with increasing length of the rest period, maximum differences in mean levels were small (coat layer do not benefit from a rest period. © 2012 American Association of Blood Banks.

Longer rest periods for intensive rotational grazing limit diet quality ...

African Journals Online (AJOL)

Longer rest periods for intensive rotational grazing limit diet quality of sheep without enhancing environmental benefits. ... This experiment was established to compare three intensive rotational grazing strategies (fast rotation [FR], average 57-day rest; slow rotation [SR], average 114-day rest; and flexible grazing [FX], based ...

Activity flow over resting-state networks shapes cognitive task activations.

Science.gov (United States)

Cole, Michael W; Ito, Takuya; Bassett, Danielle S; Schultz, Douglas H

2016-12-01

Resting-state functional connectivity (FC) has helped reveal the intrinsic network organization of the human brain, yet its relevance to cognitive task activations has been unclear. Uncertainty remains despite evidence that resting-state FC patterns are highly similar to cognitive task activation patterns. Identifying the distributed processes that shape localized cognitive task activations may help reveal why resting-state FC is so strongly related to cognitive task activations. We found that estimating task-evoked activity flow (the spread of activation amplitudes) over resting-state FC networks allowed prediction of cognitive task activations in a large-scale neural network model. Applying this insight to empirical functional MRI data, we found that cognitive task activations can be predicted in held-out brain regions (and held-out individuals) via estimated activity flow over resting-state FC networks. This suggests that task-evoked activity flow over intrinsic networks is a large-scale mechanism explaining the relevance of resting-state FC to cognitive task activations.

REST based service composition

DEFF Research Database (Denmark)

Grönvall, Erik; Ingstrup, Mads; Pløger, Morten

2011-01-01

This paper presents an ongoing work developing and testing a Service Composition framework based upon the REST architecture named SECREST. A minimalistic approach have been favored instead of a creating a complete infrastructure. One focus has been on the system's interaction model. Indeed, an aim...

Bed rest and increased diuretic treatment in chronic congestive heart failure

DEFF Research Database (Denmark)

Abildgaard, U; Aldershvile, J; Ring-Larsen, H

1985-01-01

To elucidate the effect of bed rest used as an adjunct to increased diuretic treatment, twelve patients with chronic congestive heart failure (CHF) had a 50% increase in loop diuretic dosage and were allocated to either continuous bed rest or bed rest during nights only. The 24-hour bed rest group...... is a reasonable adjunct to diuretic treatment in patients with CHF....

A Bayesian Double Fusion Model for Resting-State Brain Connectivity Using Joint Functional and Structural Data

KAUST Repository

Kang, Hakmook

2017-03-20

Current approaches separately analyze concurrently acquired diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) data. The primary limitation of these approaches is that they do not take advantage of the information from DTI that could potentially enhance estimation of resting-state functional connectivity (FC) between brain regions. To overcome this limitation, we develop a Bayesian hierarchical spatiotemporal model that incorporates structural connectivity (SC) into estimating FC. In our proposed approach, SC based on DTI data is used to construct an informative prior for FC based on resting-state fMRI data through the Cholesky decomposition. Simulation studies showed that incorporating the two data produced significantly reduced mean squared errors compared to the standard approach of separately analyzing the two data from different modalities. We applied our model to analyze the resting state DTI and fMRI data collected to estimate FC between the brain regions that were hypothetically important in the origination and spread of temporal lobe epilepsy seizures. Our analysis concludes that the proposed model achieves smaller false positive rates and is much robust to data decimation compared to the conventional approach.

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students--a pilot study.

Science.gov (United States)

Rubinstein, Jack; Dhoble, Abhijeet; Ferenchick, Gary

2009-01-13

Most medical professionals are expected to possess basic electrocardiogram (EKG) interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9) received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6) received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. The average score after only traditional teaching was 4.07 +/- 2.08 while after only the puzzle session was 4.04 +/- 2.36 (p = 0.97). The average improvement after the traditional session was followed up with a puzzle session was 2.53 +/- 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 +/- 1.73 (p = 0.67). The final EKG exam score for this cohort (n = 15) was 84.1 compared to 86.6 (p = 0.22) for a comparable sample of medical students (n = 15) at a different campus. Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale.

Infraslow Electroencephalographic and Dynamic Resting State Network Activity.

Science.gov (United States)

Grooms, Joshua K; Thompson, Garth J; Pan, Wen-Ju; Billings, Jacob; Schumacher, Eric H; Epstein, Charles M; Keilholz, Shella D

2017-06-01

A number of studies have linked the blood oxygenation level dependent (BOLD) signal to electroencephalographic (EEG) signals in traditional frequency bands (δ, θ, α, β, and γ), but the relationship between BOLD and its direct frequency correlates in the infraslow band (resting state magnetic resonance imaging data were acquired simultaneously. The DC EEG signals were correlated with the BOLD signal in patterns that resembled resting state networks. Subsequent dynamic analysis showed that the correlation between DC EEG and the BOLD signal varied substantially over time, even within individual subjects. The variation in DC EEG appears to reflect the time-varying contribution of different resting state networks. Furthermore, some of the patterns of DC EEG and BOLD correlation are consistent with previous work demonstrating quasiperiodic spatiotemporal patterns of large-scale network activity in resting state. These findings demonstrate that infraslow electrical activity is linked to BOLD fluctuations in humans and that it may provide a basis for large-scale organization comparable to that observed in animal studies.

Effects of electrocardiogram gating on CT pulmonary angiography image quality

International Nuclear Information System (INIS)

Ardley, Nicholas D.; Lau, Ken K.; Troupis, John M.; Buchan, Kevin; Paul, Eldho

2014-01-01

Pulmonary embolism (PE) is the third most common cause of death from cardiovascular disease. Computed-tomographic pulmonary angiography (CTPA) is an accurate and safe test for diagnosing PE. The aim of this retrospective analysis was to evaluate the effects on image quality (IQ) of electrocardiogram (ECG) gating during CTPA. Fifty consecutive patients presenting for CTPA were included in the study. A single acquisition was performed, resulting in two reconstructions: one at 75% of the R–R interval and the other without ECG influence. IQ evaluation was undertaken by two radiologists, focusing on respiratory and cardiac motion, image noise, low-contrast resolution, vessel and lung clarity, contrast media opacification and artefacts. Various regions of the lungs and vasculature were evaluated, and IQ scores were statistically compared. For the ECG-tagged reconstructions, IQ was noted to be better overall with regard to vessel clarity (P<0.05) and cardiac motion (P<0.05), while lung clarity was better only in the left lower zone (P<0.05). IQ was better with regard to image noise (P<0.05) and low-contrast resolution (P<0.05) in the non-ECG-tagged reconstructions. No statistical IQ difference between the two types of reconstruction was noted with regard to respiratory motion, contrast media opacification or presence of artefacts. The two types of reconstruction provide complementary information for evaluating CTPA results.

Rest and the associated benefits in restorative sleep: a concept analysis.

Science.gov (United States)

Helvig, Ashley; Wade, Sonya; Hunter-Eades, Lee

2016-01-01

To report an analysis of the concept of rest. Consistency in the literature to describe the concept and use of rest is limited. Concept analysis may be advantageous in rendering an operational definition in the health care setting. This analysis is important to examine the concept of rest for structure and function to promote an understanding of the phenomenon. Rest is a vital component of restorative sleep which has implications for physical, mental and spiritual well-being. Concept analysis. A literature search was conducted in the following databases: PubMed, CINAHL, Medline, ProQuest and an online Internet search with the majority of articles published between 1995-2015. This concept analysis was implemented using the eight step approach developed by Walker and Avant. In health care, rest incorporates the cessation of activity used to promote physical and mental health. Defining attributes of rest include a pathway to calm, inner tranquillity and mental health; base of support; and stillness. Antecedents for rest are time, suitable environment and willingness. Resulting consequences include renewed physical energy, mental clarity and improved health. Rest is a concept that is used frequently in the discipline of nursing but also in various other disciplines. Rest is a basic necessity for restorative sleep to enhance well-being through the restoration of the body, mind and spirit. Defining the concept of rest in the practice of patient care is necessary for consistent use of the term in the development of holistic, patient-centred therapies. © 2015 John Wiley & Sons Ltd.

The impact of global signal regression on resting state correlations: are anti-correlated networks introduced?

Science.gov (United States)

Murphy, Kevin; Birn, Rasmus M; Handwerker, Daniel A; Jones, Tyler B; Bandettini, Peter A

2009-02-01

Low-frequency fluctuations in fMRI signal have been used to map several consistent resting state networks in the brain. Using the posterior cingulate cortex as a seed region, functional connectivity analyses have found not only positive correlations in the default mode network but negative correlations in another resting state network related to attentional processes. The interpretation is that the human brain is intrinsically organized into dynamic, anti-correlated functional networks. Global variations of the BOLD signal are often considered nuisance effects and are commonly removed using a general linear model (GLM) technique. This global signal regression method has been shown to introduce negative activation measures in standard fMRI analyses. The topic of this paper is whether such a correction technique could be the cause of anti-correlated resting state networks in functional connectivity analyses. Here we show that, after global signal regression, correlation values to a seed voxel must sum to a negative value. Simulations also show that small phase differences between regions can lead to spurious negative correlation values. A combination breath holding and visual task demonstrates that the relative phase of global and local signals can affect connectivity measures and that, experimentally, global signal regression leads to bell-shaped correlation value distributions, centred on zero. Finally, analyses of negatively correlated networks in resting state data show that global signal regression is most likely the cause of anti-correlations. These results call into question the interpretation of negatively correlated regions in the brain when using global signal regression as an initial processing step.

Resting-State Functional Connectivity in the Infant Brain: Methods, Pitfalls, and Potentiality.

Science.gov (United States)

Mongerson, Chandler R L; Jennings, Russell W; Borsook, David; Becerra, Lino; Bajic, Dusica

2017-01-01

Early brain development is characterized by rapid growth and perpetual reconfiguration, driven by a dynamic milieu of heterogeneous processes. Postnatal brain plasticity is associated with increased vulnerability to environmental stimuli. However, little is known regarding the ontogeny and temporal manifestations of inter- and intra-regional functional connectivity that comprise functional brain networks. Resting-state functional magnetic resonance imaging (rs-fMRI) has emerged as a promising non-invasive neuroinvestigative tool, measuring spontaneous fluctuations in blood oxygen level dependent (BOLD) signal at rest that reflect baseline neuronal activity. Over the past decade, its application has expanded to infant populations providing unprecedented insight into functional organization of the developing brain, as well as early biomarkers of abnormal states. However, many methodological issues of rs-fMRI analysis need to be resolved prior to standardization of the technique to infant populations. As a primary goal, this methodological manuscript will (1) present a robust methodological protocol to extract and assess resting-state networks in early infancy using independent component analysis (ICA), such that investigators without previous knowledge in the field can implement the analysis and reliably obtain viable results consistent with previous literature; (2) review the current methodological challenges and ethical considerations associated with emerging field of infant rs-fMRI analysis; and (3) discuss the significance of rs-fMRI application in infants for future investigations of neurodevelopment in the context of early life stressors and pathological processes. The overarching goal is to catalyze efforts toward development of robust, infant-specific acquisition, and preprocessing pipelines, as well as promote greater transparency by researchers regarding methods used.

Characterizing Resting-State Brain Function Using Arterial Spin Labeling

Science.gov (United States)

Jann, Kay; Wang, Danny J.J.

2015-01-01

Abstract Arterial spin labeling (ASL) is an increasingly established magnetic resonance imaging (MRI) technique that is finding broader applications in studying the healthy and diseased brain. This review addresses the use of ASL to assess brain function in the resting state. Following a brief technical description, we discuss the use of ASL in the following main categories: (1) resting-state functional connectivity (FC) measurement: the use of ASL-based cerebral blood flow (CBF) measurements as an alternative to the blood oxygen level-dependent (BOLD) technique to assess resting-state FC; (2) the link between network CBF and FC measurements: the use of network CBF as a surrogate of the metabolic activity within corresponding networks; and (3) the study of resting-state dynamic CBF-BOLD coupling and cerebral metabolism: the use of dynamic CBF information obtained using ASL to assess dynamic CBF-BOLD coupling and oxidative metabolism in the resting state. In addition, we summarize some future challenges and interesting research directions for ASL, including slice-accelerated (multiband) imaging as well as the effects of motion and other physiological confounds on perfusion-based FC measurement. In summary, this work reviews the state-of-the-art of ASL and establishes it as an increasingly viable MRI technique with high translational value in studying resting-state brain function. PMID:26106930

Distinguishing rhythmic from non-rhythmic brain activity during rest in healthy neurocognitive aging.

Science.gov (United States)

Caplan, Jeremy B; Bottomley, Monica; Kang, Pardeep; Dixon, Roger A

2015-05-15

Rhythmic brain activity at low frequencies (healthy neurocognitive aging are mixed. Here we address two reasons conventional spectral analyses may have led to inconsistent results. First, spectral-power measures are compared to a baseline condition; when resting activity is the signal of interest, it is unclear what the baseline should be. Second, conventional methods do not clearly differentiate power due to rhythmic versus non-rhythmic activity. The Better OSCillation detection method (BOSC; Caplan et al., 2001; Whitten et al., 2011) avoids these problems by using the signal's own spectral characteristics as a reference to detect elevations in power lasting a few cycles. We recorded electroencephalographic (EEG) signal during rest, alternating eyes open and closed, in healthy younger (18-25 years) and older (60-74 years) participants. Topographic plots suggested the conventional and BOSC analyses measured different sources of activity, particularly at frequencies, like delta (1-4Hz), at which rhythms are sporadic; topographies were more similar in the 8-12Hz alpha band. There was little theta-band activity meeting the BOSC method's criteria, suggesting prior findings of theta power in healthy aging may reflect non-rhythmic signal. In contrast, delta oscillations were present at higher levels than theta in both age groups. In summary, applying strict and standardized criteria for rhythmicity, slow rhythms appear present in the resting brain at delta and alpha, but not theta frequencies, and appear unchanged in healthy aging. Copyright © 2015 Elsevier Inc. All rights reserved.

Enhanced subject-specific resting-state network detection and extraction with fast fMRI.

Science.gov (United States)

Akin, Burak; Lee, Hsu-Lei; Hennig, Jürgen; LeVan, Pierre

2017-02-01

Resting-state networks have become an important tool for the study of brain function. An ultra-fast imaging technique that allows to measure brain function, called Magnetic Resonance Encephalography (MREG), achieves an order of magnitude higher temporal resolution than standard echo-planar imaging (EPI). This new sequence helps to correct physiological artifacts and improves the sensitivity of the fMRI analysis. In this study, EPI is compared with MREG in terms of capability to extract resting-state networks. Healthy controls underwent two consecutive resting-state scans, one with EPI and the other with MREG. Subject-level independent component analyses (ICA) were performed separately for each of the two datasets. Using Stanford FIND atlas parcels as network templates, the presence of ICA maps corresponding to each network was quantified in each subject. The number of detected individual networks was significantly higher in the MREG data set than for EPI. Moreover, using short time segments of MREG data, such as 50 seconds, one can still detect and track consistent networks. Fast fMRI thus results in an increased capability to extract distinct functional regions at the individual subject level for the same scan times, and also allow the extraction of consistent networks within shorter time intervals than when using EPI, which is notably relevant for the analysis of dynamic functional connectivity fluctuations. Hum Brain Mapp 38:817-830, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

How the knowledge of genetic "makeup" and cellular data can affect the analysis of repolarization in surface electrocardiogram.

Science.gov (United States)

Shimizu, Wataru

2010-01-01

This review article sought to describe patterns of repolarization on the surface electrocardiogram in inherited cardiac arrhythmias and to discuss how the knowledge of genetic makeup and cellular data can affect the analysis based on the data derived from the experimental studies using arterially perfused canine ventricular wedge preparations. Molecular genetic studies have established a link between a number of inherited cardiac arrhythmia syndromes and mutations in genes encoding cardiac ion channels or membrane components during the past 2 decades. Twelve forms of congenital long QT syndrome have been so far identified, and genotype-phenotype correlations have been investigated especially in the 3 major genotypes-LQT1, LQT2, and LQT3. Abnormal T waves are reported in the LQT1, LQT2, and LQT3, and the differences in the time course of repolarization of the epicardial, midmyocardial, and endocardial cells give rise to voltage gradients responsible for the manifestation of phenotypic appearance of abnormal T waves. Brugada syndrome is characterized by ST-segment elevation in leads V1 to V3 and an episode of ventricular fibrillation, in which 7 genotypes have been reported. An intrinsically prominent transient outward current (I(to))-mediated action potential notch and a subsequent loss of action potential dome in the epicardium, but not in the endocardium of the right ventricular outflow tract, give rise to a transmural voltage gradient, resulting in ST-segment elevation, and a subsequent phase 2 reentry-induced ventricular fibrillation. In conclusion, transmural electrical heterogeneity of repolarization across the ventricular wall profoundly affects the phenotypic manifestation of repolarization patterns on the surface electrocardiogram in inherited cardiac arrhythmias. Copyright © 2010 Elsevier Inc. All rights reserved.

The Shortest QRS Duration of an Electrocardiogram Might Be an Optimal Electrocardiographic Predictor for Response to Cardiac Resynchronization Therapy.

Science.gov (United States)

Chen, Jan-Yow; Lin, Kuo-Hung; Chang, Kuan-Cheng; Chou, Che-Yi

2017-08-03

QRS duration has been associated with the response to cardiac resynchronization therapy (CRT). However, the methods for defining QRS duration to predict the outcome of CRT have discrepancies in previous reports. The aim of this study was to determine an optimal measurement of QRS duration to predict the response to CRT.Sixty-one patients who received CRT were analyzed. All patients had class III-IV heart failure, left ventricular ejection fraction not more than 35%, and complete left bundle branch block. The shortest, longest, and average QRS durations from the 12 leads of each electrocardiogram (ECG) were measured. The responses to CRT were determined using the changes in echocardiography after 6 months. Thirty-five (57.4%) patients were responders and 26 (42.6%) patients were non-responders. The pre-procedure shortest, average, and longest QRS durations and the QRS shortening (ΔQRS) of the shortest QRS duration were significantly associated with the response to CRT in a univariate logistic regression analysis (P = 0.002, P = 0.03, P = 0.04 and P = 0.04, respectively). Based on the measurement of the area under curve of the receiver operating characteristic curve, only the pre-procedure shortest QRS duration and the ΔQRS of the shortest QRS duration showed significant discrimination for the response to CRT (P = 0.002 and P = 0.038, respectively). Multivariable logistic regression showed the pre-procedure shortest QRS duration is an independent predictor for the response to CRT.The shortest QRS duration from the 12 leads of the electrocardiogram might be an optimal measurement to predict the response to CRT.

Value of the Electrocardiogram as a Predictor of Right Ventricular Dysfunction in Patients With Chronic Right Ventricular Volume Overload.

Science.gov (United States)

Alonso, Pau; Andrés, Ana; Rueda, Joaquín; Buendía, Francisco; Igual, Begoña; Rodríguez, María; Osa, Ana; Arnau, Miguel A; Salvador, Antonio

2015-05-01

Pulmonary regurgitation is a common complication in patients with repaired tetralogy of Fallot or congenital pulmonary stenosis. Electrocardiographic variables have been correlated with parameters used to evaluate right ventricular function. We aimed to analyze the diagnostic value of the width and fragmentation of the electrocardiogram in the identification of patients with right ventricular dysfunction and/or dilation. We selected 107 consecutive patients diagnosed with severe pulmonary insufficiency after repair of pulmonary stenosis or tetralogy of Fallot. The tests included electrocardiography, echocardiography, and magnetic resonance. Each electrocardiogram was analyzed manually to measure QRS duration. We defined QRS fragmentation as the presence of low-voltage waves in the terminal portion of the QRS complex in at least 2 contiguous leads. We found a significant negative correlation between QRS width and right ventricular function, as well as a positive correlation with right ventricular volume. The receiver operating characteristic curve indicated a cut-off point for QRS width of 140ms, which showed good sensitivity for a diagnosis of right ventricular dilation (> 80%) and dysfunction (> 95%). In logistic regression models, a QRS duration > 140ms was found to be the only independent predictor of right ventricular dilation and dysfunction. Electrocardiography is a rapid, widely available, and reproducible tool. QRS width constitutes an independent predictor of the presence of right ventricular dilation and dysfunction. This study is the first to provide a cutoff value for QRS width to screen for right ventricle involvement. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Cognitive and default-mode resting state networks: do male and female brains "rest" differently?

Science.gov (United States)

Weissman-Fogel, Irit; Moayedi, Massieh; Taylor, Keri S; Pope, Geoff; Davis, Karen D

2010-11-01

Variability in human behavior related to sex is supported by neuroimaging studies showing differences in brain activation patterns during cognitive task performance. An emerging field is examining the human connectome, including networks of brain regions that are not only temporally-correlated during different task conditions, but also networks that show highly correlated spontaneous activity during a task-free state. Both task-related and task-free network activity has been associated with individual task performance and behavior under certain conditions. Therefore, our aim was to determine whether sex differences exist during a task-free resting state for two networks associated with cognitive task performance (executive control network (ECN), salience network (SN)) and the default mode network (DMN). Forty-nine healthy subjects (26 females, 23 males) underwent a 5-min task-free fMRI scan in a 3T MRI. An independent components analysis (ICA) was performed to identify the best-fit IC for each network based on specific spatial nodes defined in previous studies. To determine the consistency of these networks across subjects we performed self-organizing group-level ICA analyses. There were no significant differences between sexes in the functional connectivity of the brain areas within the ECN, SN, or the DMN. These important findings highlight the robustness of intrinsic connectivity of these resting state networks and their similarity between sexes. Furthermore, our findings suggest that resting state fMRI studies do not need to be controlled for sex. © 2010 Wiley-Liss, Inc.

Educational Software Applied in Teaching Electrocardiogram: A Systematic Review

Directory of Open Access Journals (Sweden)

Paulo A. I. Pontes

2018-01-01

Full Text Available Background. The electrocardiogram (ECG is the most used diagnostic tool in medicine; in this sense, it is essential that medical undergraduates learn how to interpret it correctly while they are still on training. Naturally, they go through classic learning (e.g., lectures and speeches. However, they are not often efficiently trained in analyzing ECG results. In this regard, methodologies such as other educational support tools in medical practice, such as educational software, should be considered a valuable approach for medical training purposes. Methods. We performed a literature review in six electronic databases, considering studies published before April 2017. The resulting set comprises 2,467 studies. From this collection, 12 studies have been selected, initially, whereby we carried out a snowballing process to identify other relevant studies through the reference lists of these studies, resulting in five relevant studies, making up a total of 17 articles that passed all stages and criteria. Results. The results show that 52.9% of software types were tutorial and 58.8% were designed to be run locally on a computer. The subjects were discussed together with a greater focus on the teaching of electrophysiology and/or cardiac physiology, identifying patterns of ECG and/or arrhythmias. Conclusions. We found positive results with the introduction of educational software for ECG teaching. However, there is a clear need for using higher quality research methodologies and the inclusion of appropriate controls, in order to obtain more precise conclusions about how beneficial the inclusion of such tools can be for the practices of ECG interpretation.

Compliance and quality of life in patients on prescribed voice rest.

Science.gov (United States)

Rousseau, Bernard; Cohen, Seth M; Zeller, Amy S; Scearce, Leda; Tritter, Andrew G; Garrett, C Gaelyn

2011-01-01

To determine patient compliance with voice rest and the impact of voice rest on quality of life (QOL). Prospective. University hospital. Demographics, self-reported compliance, QOL impact on a 100-mm visual analog scale (VAS), and communication methods were collected from 84 participants from 2 academic voice centers. Of 84 participants, 36.9% were men, 63.1% were women, and 64.3% were singers. The mean age of participants was 47.2 years. The mean duration of voice rest was 8.8 days (range, 3-28), and the median was 7 days. Overall compliance was 34.5%. Postoperative voice rest patients were more compliant than non-postoperative patients (42.4% vs 16.0%, P = .04, χ(2)). Voice rest had an impact on QOL (mean ± SD, 68.5 ± 27.7). Voice rest also had a greater impact on singers than nonsingers (mean VAS 77.2 vs 63.6, P = .03, t test) and on those age <60 years than those age ≥ 60 years (mean VAS 74.4 vs 46.7, P < .001, t test). More talkative patients and those with longer periods of voice rest had worse QOL scores (Spearman correlation = 0.35, P = .001 and Spearman correlation = 0.24, P = .03, respectively). Restrictions in personal and social life were noted in 36.9% of patients, 46.4% were unable to work, 44.0% felt frustrated, and 38.1% reported feeling handicapped while on voice rest. Given poor patient compliance and the significant impact of voice rest on QOL, further studies are warranted to examine the efficacy of voice rest and factors that may contribute to patient noncompliance with treatment.

A Precise Drunk Driving Detection Using Weighted Kernel Based on Electrocardiogram.

Science.gov (United States)

Wu, Chung Kit; Tsang, Kim Fung; Chi, Hao Ran; Hung, Faan Hei

2016-05-09

Globally, 1.2 million people die and 50 million people are injured annually due to traffic accidents. These traffic accidents cost $500 billion dollars. Drunk drivers are found in 40% of the traffic crashes. Existing drunk driving detection (DDD) systems do not provide accurate detection and pre-warning concurrently. Electrocardiogram (ECG) is a proven biosignal that accurately and simultaneously reflects human's biological status. In this letter, a classifier for DDD based on ECG is investigated in an attempt to reduce traffic accidents caused by drunk drivers. At this point, it appears that there is no known research or literature found on ECG classifier for DDD. To identify drunk syndromes, the ECG signals from drunk drivers are studied and analyzed. As such, a precise ECG-based DDD (ECG-DDD) using a weighted kernel is developed. From the measurements, 10 key features of ECG signals were identified. To incorporate the important features, the feature vectors are weighted in the customization of kernel functions. Four commonly adopted kernel functions are studied. Results reveal that weighted feature vectors improve the accuracy by 11% compared to the computation using the prime kernel. Evaluation shows that ECG-DDD improved the accuracy by 8% to 18% compared to prevailing methods.

Case report: an electrocardiogram of spontaneous pneumothorax mimicking arm lead reversal.

Science.gov (United States)

Wieters, J Scott; Carlin, Joseph P; Morris, Andrew

2014-05-01

There are several previously documented findings for electrocardiograms (ECGs) of spontaneous pneumothorax. These findings include axis deviation, T-wave inversion, and right bundle branch block. When an ECG has the arm leads incorrectly placed, the ECG will display right axis deviation and inversion of the P waves in lead I. There have been no previously published ECGs of spontaneous pneumothorax that have shown the same findings as reversal of the limb leads of an ECG. A possible finding of spontaneous pneumothorax is an identical finding to that of an ECG that has been flagged for limb lead reversal. A patient presented in the emergency setting with acute chest pain and shortness of breath caused by a tension pneumothorax. An ECG was administered; findings indicated reversal of the arm leads (right axis deviation and inverted P waves in lead I), but there was no actual limb lead reversal present. ECG findings resolved upon resolution of the pneumothorax. If a patient presents with chest pain and shortness of breath, and the patient's ECG is flagged for limb lead reversal despite being set up correctly, the physician should raise clinical suspicion for a possible spontaneous pneumothorax. Copyright © 2014 Elsevier Inc. All rights reserved.

A Precise Drunk Driving Detection Using Weighted Kernel Based on Electrocardiogram

Directory of Open Access Journals (Sweden)

Chung Kit Wu

2016-05-01

Full Text Available Globally, 1.2 million people die and 50 million people are injured annually due to traffic accidents. These traffic accidents cost $500 billion dollars. Drunk drivers are found in 40% of the traffic crashes. Existing drunk driving detection (DDD systems do not provide accurate detection and pre-warning concurrently. Electrocardiogram (ECG is a proven biosignal that accurately and simultaneously reflects human’s biological status. In this letter, a classifier for DDD based on ECG is investigated in an attempt to reduce traffic accidents caused by drunk drivers. At this point, it appears that there is no known research or literature found on ECG classifier for DDD. To identify drunk syndromes, the ECG signals from drunk drivers are studied and analyzed. As such, a precise ECG-based DDD (ECG-DDD using a weighted kernel is developed. From the measurements, 10 key features of ECG signals were identified. To incorporate the important features, the feature vectors are weighted in the customization of kernel functions. Four commonly adopted kernel functions are studied. Results reveal that weighted feature vectors improve the accuracy by 11% compared to the computation using the prime kernel. Evaluation shows that ECG-DDD improved the accuracy by 8% to 18% compared to prevailing methods.

Reliability and validity of a smartphone pulse rate application for the assessment of resting and elevated pulse rate.

Science.gov (United States)

Mitchell, Katy; Graff, Megan; Hedt, Corbin; Simmons, James

2016-08-01

Purpose/hypothesis: This study was designed to investigate the test-retest reliability, concurrent validity, and the standard error of measurement (SEm) of a pulse rate assessment application (Azumio®'s Instant Heart Rate) on both Android® and iOS® (iphone operating system) smartphones as compared to a FT7 Polar® Heart Rate monitor. Number of subjects: 111. Resting (sitting) pulse rate was assessed twice and then the participants were asked to complete a 1-min standing step test and then immediately re-assessed. The smartphone assessors were blinded to their measurements. Test-retest reliability (intraclass correlation coefficient [ICC 2,1] and 95% confidence interval) for the three tools at rest (time 1/time 2): iOS® (0.76 [0.67-0.83]); Polar® (0.84 [0.78-0.89]); and Android® (0.82 [0.75-0.88]). Concurrent validity at rest time 2 (ICC 2,1) with the Polar® device: IOS® (0.92 [0.88-0.94]) and Android® (0.95 [0.92-0.96]). Concurrent validity post-exercise (time 3) (ICC) with the Polar® device: iOS® (0.90 [0.86-0.93]) and Android® (0.94 [0.91-0.96]). The SEm values for the three devices at rest: iOS® (5.77 beats per minute [BPM]), Polar® (4.56 BPM) and Android® (4.96 BPM). The Android®, iOS®, and Polar® devices showed acceptable test-retest reliability at rest and post-exercise. Both the smartphone platforms demonstrated concurrent validity with the Polar® at rest and post-exercise. The Azumio® Instant Heart Rate application when used by either platform appears to be a reliable and valid tool to assess pulse rate in healthy individuals.

Trend Extraction in Functional Data of Amplitudes of R and T Waves in Exercise Electrocardiogram

Science.gov (United States)

Cammarota, Camillo; Curione, Mario

The amplitudes of R and T waves of the electrocardiogram (ECG) recorded during the exercise test show both large inter- and intra-individual variability in response to stress. We analyze a dataset of 65 normal subjects undergoing ambulatory test. We model the dataset of R and T series in the framework of functional data, assuming that the individual series are realizations of a non-stationary process, centered at the population trend. We test the time variability of this trend computing a simultaneous confidence band and the zero crossing of its derivative. The analysis shows that the amplitudes of the R and T waves have opposite responses to stress, consisting respectively in a bump and a dip at the early recovery stage. Our findings support the existence of a relationship between R and T wave amplitudes and respectively diastolic and systolic ventricular volumes.

Suprathreshold Heat Pain Response Predicts Activity-Related Pain, but Not Rest-Related Pain, in an Exercise-Induced Injury Model

Science.gov (United States)

Coronado, Rogelio A.; Simon, Corey B.; Valencia, Carolina; Parr, Jeffrey J.; Borsa, Paul A.; George, Steven Z.

2014-01-01

Exercise-induced injury models are advantageous for studying pain since the onset of pain is controlled and both pre-injury and post-injury factors can be utilized as explanatory variables or predictors. In these studies, rest-related pain is often considered the primary dependent variable or outcome, as opposed to a measure of activity-related pain. Additionally, few studies include pain sensitivity measures as predictors. In this study, we examined the influence of pre-injury and post-injury factors, including pain sensitivity, for induced rest and activity-related pain following exercise induced muscle injury. The overall goal of this investigation was to determine if there were convergent or divergent predictors of rest and activity-related pain. One hundred forty-three participants provided demographic, psychological, and pain sensitivity information and underwent a standard fatigue trial of resistance exercise to induce injury of the dominant shoulder. Pain at rest and during active and resisted shoulder motion were measured at 48- and 96-hours post-injury. Separate hierarchical models were generated for assessing the influence of pre-injury and post-injury factors on 48- and 96-hour rest-related and activity-related pain. Overall, we did not find a universal predictor of pain across all models. However, pre-injury and post-injury suprathreshold heat pain response (SHPR), a pain sensitivity measure, was a consistent predictor of activity-related pain, even after controlling for known psychological factors. These results suggest there is differential prediction of pain. A measure of pain sensitivity such as SHPR appears more influential for activity-related pain, but not rest-related pain, and may reflect different underlying processes involved during pain appraisal. PMID:25265560

Is myocardial infarction common in the South Sudan?

African Journals Online (AJOL)

2012-06-05

Jun 5, 2012 ... He was not in heart failure and the rest of the examination was unremarkable. There were no nicotine stains in the fingers despite the history of heavy smoking. Random blood sugar on presentation was. 12mmol/litre. The initial 12 lead electrocardiogram (Figure 1) showed hyperacute ST segment elevation ...

The Rest-Activity Rhythm and Physical Activity in Early-Onset Dementia

NARCIS (Netherlands)

Hooghiemstra, A.M.; Eggermont, L.H.P.; Scheltens, P.; van der Flier, W.M.; Scherder, E.J.A.

2015-01-01

Background: A substantial part of elderly persons with dementia show rest-activity rhythm disturbances. The rest-activity rhythm is important to study in people with early-onset dementia (EOD) for rest-activity rhythm disturbances are predictive of institutionalization, and caregivers of young

Changes in resting-state fMRI in vestibular neuritis.

Science.gov (United States)

Helmchen, Christoph; Ye, Zheng; Sprenger, Andreas; Münte, Thomas F

2014-11-01

Vestibular neuritis (VN) is a sudden peripheral unilateral vestibular failure with often persistent head movement-related dizziness and unsteadiness. Compensation of asymmetrical activity in the primary peripheral vestibular afferents is accomplished by restoration of impaired brainstem vestibulo-ocular and vestibulo-spinal reflexes, but presumably also by changing cortical vestibular tone imbalance subserving, e.g., spatial perception and orientation. The aim of this study was to elucidate (i) whether there are changes of cerebral resting-state networks with respect to functional interregional connectivity (resting-state activity) in VN patients and (ii) whether these are related to neurophysiological, perceptual and functional parameters of vestibular-induced disability. Using independent component analysis (ICA), we compared resting-state networks between 20 patients with unilateral VN and 20 age- and gender-matched healthy control subjects. Patients were examined in the acute VN stage and after 3 months. A neural network (component 50) comprising the parietal lobe, medial aspect of the superior parietal lobule, posterior cingulate cortex, middle frontal gyrus, middle temporal gyrus, parahippocampal gyrus, anterior cingulate cortex, insular cortex, caudate nucleus, thalamus and midbrain was modulated between acute VN patients and healthy controls and in patients over time. Within this network, acute VN patients showed decreased resting-state activity (ICA) in the contralateral intraparietal sulcus (IPS), in close vicinity to the supramarginal gyrus (SMG), which increased after 3 months. Resting-state activity in IPS tended to increase over 3 months in VN patients who improved with respect to functional parameters of vestibular-induced disability (VADL). Resting-state activity in the IPS was not related to perceptual (subjective visual vertical) or neurophysiological parameters of vestibular-induced disability (e.g., gain of vestibulo-ocular reflex, caloric

Effect of rest interval on strength recovery in young and old women.

Science.gov (United States)

Theou, Olga; Gareth, Jones R; Brown, Lee E

2008-11-01

This study compares the effects of rest intervals on isokinetic muscle torque recovery between sets of a knee extensor and flexor exercise protocol in physically active younger and older women. Twenty young (22.4 +/- 1.7 years) and 16 older (70.7 +/- 4.3 years) women performed three sets of eight maximum repetitions of knee extension/flexion at 60 degrees x s(-1). The rest interval between sets was 15, 30, and 60 seconds and was randomly assigned across three testing days. No significant interaction of rest by set by age group was observed. There was a significant decline in mean knee extensor torque when 15- and 30-second rest intervals were used between sets, but not when a 60-second rest interval was applied for both the young and the old women. No significant decline for mean knee flexor torque was observed in the older women when a 30-second rest interval was used, whereas a longer 60-second rest interval was required in younger women. Active younger and older women require similar rest intervals between sets of a knee extensor exercise (60 seconds) for complete recovery. However, older women recovered faster (30 seconds) than younger women (60 seconds) between sets of a knee flexor exercise. The exercise-to-rest ratio for knee extensors was similar for young and old women (1:2). Old women required only a 1:1 exercise-to-rest ratio for knee flexor recovery, whereas younger women required a longer 1:2 exercise-to-rest ratio. The results of the present study are specific to isokinetic testing and training and are more applicable in rehabilitation and research settings. Practitioners should consider age and gender when prescribing rest intervals between sets.

Automated processing of the single-lead electrocardiogram for the detection of obstructive sleep apnoea.

Science.gov (United States)

de Chazal, Philip; Heneghan, Conor; Sheridan, Elaine; Reilly, Richard; Nolan, Philip; O'Malley, Mark

2003-06-01

A method for the automatic processing of the electrocardiogram (ECG) for the detection of obstructive apnoea is presented. The method screens nighttime single-lead ECG recordings for the presence of major sleep apnoea and provides a minute-by-minute analysis of disordered breathing. A large independently validated database of 70 ECG recordings acquired from normal subjects and subjects with obstructive and mixed sleep apnoea, each of approximately eight hours in duration, was used throughout the study. Thirty-five of these recordings were used for training and 35 retained for independent testing. A wide variety of features based on heartbeat intervals and an ECG-derived respiratory signal were considered. Classifiers based on linear and quadratic discriminants were compared. Feature selection and regularization of classifier parameters were used to optimize classifier performance. Results show that the normal recordings could be separated from the apnoea recordings with a 100% success rate and a minute-by-minute classification accuracy of over 90% is achievable.

Modelling transport of waste material leachate in soils in support of environmental standards

NARCIS (Netherlands)

van Eijkeren JCH; Aalbers TG; de Wilde PGM

1992-01-01

In the Netherlands a process of defining environmental standards is going on. These standards serve to protect the environment at the one hand, and to stimulate the reuse of rest-materials, e.g. ash from blast-furnaces, as building materials at the other hand. In order to come to an environmental

Resting-State Functional Magnetic Resonance Imaging for Language Preoperative Planning

Science.gov (United States)

Branco, Paulo; Seixas, Daniela; Deprez, Sabine; Kovacs, Silvia; Peeters, Ronald; Castro, São L.; Sunaert, Stefan

2016-01-01

Functional magnetic resonance imaging (fMRI) is a well-known non-invasive technique for the study of brain function. One of its most common clinical applications is preoperative language mapping, essential for the preservation of function in neurosurgical patients. Typically, fMRI is used to track task-related activity, but poor task performance and movement artifacts can be critical limitations in clinical settings. Recent advances in resting-state protocols open new possibilities for pre-surgical mapping of language potentially overcoming these limitations. To test the feasibility of using resting-state fMRI instead of conventional active task-based protocols, we compared results from fifteen patients with brain lesions while performing a verb-to-noun generation task and while at rest. Task-activity was measured using a general linear model analysis and independent component analysis (ICA). Resting-state networks were extracted using ICA and further classified in two ways: manually by an expert and by using an automated template matching procedure. The results revealed that the automated classification procedure correctly identified language networks as compared to the expert manual classification. We found a good overlay between task-related activity and resting-state language maps, particularly within the language regions of interest. Furthermore, resting-state language maps were as sensitive as task-related maps, and had higher specificity. Our findings suggest that resting-state protocols may be suitable to map language networks in a quick and clinically efficient way. PMID:26869899

A resting bottom sodium cooled fast reactor

International Nuclear Information System (INIS)

Costes, D.

2012-01-01

This follows ICAPP 2011 paper 11059 'Fast Reactor with a Cold Bottom Vessel', on sodium cooled reactor vessels in thermal gradient, resting on soil. Sodium is frozen on vessel bottom plate, temperature increasing to the top. The vault cover rests on the safety vessel, the core diagrid welded to a toric collector forms a slab, supported by skirts resting on the bottom plate. Intermediate exchangers and pumps, fixed on the cover, plunge on the collector. At the vessel top, a skirt hanging from the cover plunges into sodium, leaving a thin circular slit partially filled by sodium covered by argon, providing leak-tightness and allowing vessel dilatation, as well as a radial relative holding due to sodium inertia. No 'air conditioning' at 400 deg. C is needed as for hanging vessels, and this allows a large economy. The sodium volume below the slab contains isolating refractory elements, stopping a hypothetical corium flow. The small gas volume around the vessel limits any LOCA. The liner cooling system of the concrete safety vessel may contribute to reactor cooling. The cold resting bottom vessel, proposed by the author for many years, could avoid the complete visual inspection required for hanging vessels. However, a double vessel, containing support skirts, would allow introduction of inspecting devices. Stress limiting thermal gradient is obtained by filling secondary sodium in the intermediate space. (authors)

REST controls self-renewal and tumorigenic competence of human glioblastoma cells.

Directory of Open Access Journals (Sweden)

Luciano Conti

Full Text Available The Repressor Element 1 Silencing Transcription factor (REST/NRSF is a master repressor of neuronal programs in non-neuronal lineages shown to function as a central regulator of developmental programs and stem cell physiology. Aberrant REST function has been associated with a number of pathological conditions. In cancer biology, REST has been shown to play a tumor suppressor activity in epithelial cancers but an oncogenic role in brain childhood malignancies such as neuroblastoma and medulloblastoma. Here we examined REST expression in human glioblastoma multiforme (GBM specimens and its role in GBM cells carrying self-renewal and tumorigenic competence. We found REST to be expressed in GBM specimens, its presence being particularly enriched in tumor cells in the perivascular compartment. Significantly, REST is highly expressed in self-renewing tumorigenic-competent GBM cells and its knock down strongly reduces their self-renewal in vitro and tumor-initiating capacity in vivo and affects levels of miR-124 and its downstream targets. These results indicate that REST contributes to GBM maintenance by affecting its self-renewing and tumorigenic cellular component and that, hence, a better understanding of these circuitries in these cells might lead to new exploitable therapeutic targets.

PROPOSED SIMPLE METHOD FOR ELECTROCARDIOGRAM RECORDING IN FREE-RANGING ASIAN ELEPHANTS (ELEPHAS MAXIMUS).

Science.gov (United States)

Chai, Norin; Pouchelon, Jean Louis; Bouvard, Jonathan; Sillero, Leonor Camacho; Huynh, Minh; Segalini, Vincent; Point, Lisa; Croce, Veronica; Rigaux, Goulven; Highwood, Jack; Chetboul, Valérie

2016-03-01

Electrocardiography represents a relevant diagnostic tool for detecting cardiac disease in animals. Elephants can present various congenital and acquired cardiovascular diseases. However, few electrophysiologic studies have been reported in captive elephants, mainly due to challenging technical difficulties in obtaining good-quality electrocardiogram (ECG) tracings, and no data are currently available for free-ranging Asian elephants (Elephas maximus). The purpose of this pilot prospective study was to evaluate the feasibility of using a simple method for recording ECG tracings in wild, apparently healthy, unsedated Asian elephants (n = 7) in the standing position. Successful six-lead recordings (I, II, III, aVR, aVL, and aVF) were obtained, with the aVL lead providing the best-quality tracings in most animals. Variables measured in the aVL lead included heart rate, amplitudes and duration of the P waves, QRS complexes, T and U waves, and duration of the PR, QT, and QU intervals. A negative deflection following positive P waves, representative of an atrial repolarization wave (Ta wave), was observed for five out of the seven elephants.

Thallium-201 myocardial scintigraphy and left ventricular function at rest in patients with rest angina pectoris

International Nuclear Information System (INIS)

Hakki, A.H.; Iskandrian, A.S.; Kane, S.A.; Amenta, A.

1984-01-01

The purpose of this study was to examine the rest thallium-201 perfusion pattern during angina-free periods in 40 patients with rest angina pectoris secondary to coronary artery disease (greater than or equal to 70% diameter narrowing). Seventeen patients had previous Q wave myocardial infarction. The perfusion defects were considered fixed or reversible, depending on the absence or presence of redistribution in the 4-hour delayed images. There were 40 perfusion defects (26 fixed and 14 reversible) in 27 patients whereas 13 patients had normal scans. Reversible perfusion defects were present in 10 patients (25%). Of the 26 fixed perfusion defects, 17 did not have corresponding Q waves. Occluded vessels (63%) had more perfusion defects than vessels with subtotal occlusion (30%) (p less than 0.01). The perfusion defect size was larger in patients with lower ejection fraction than in patients with higher ejection fraction. We conclude: (1) perfusion defects are common in patients with rest angina and are reversible in 25% of patients indicating reduced regional coronary blood flow; (2) the degree of stenosis affects the presence of perfusion defect; (3) fixed defects may be present without corresponding Q waves; and (4) global left ventricular function is related to the size of perfusion defects

Complex network analysis of resting-state fMRI of the brain.

Science.gov (United States)

Anwar, Abdul Rauf; Hashmy, Muhammad Yousaf; Imran, Bilal; Riaz, Muhammad Hussnain; Mehdi, Sabtain Muhammad Muntazir; Muthalib, Makii; Perrey, Stephane; Deuschl, Gunther; Groppa, Sergiu; Muthuraman, Muthuraman

2016-08-01

Due to the fact that the brain activity hardly ever diminishes in healthy individuals, analysis of resting state functionality of the brain seems pertinent. Various resting state networks are active inside the idle brain at any time. Based on various neuro-imaging studies, it is understood that various structurally distant regions of the brain could be functionally connected. Regions of the brain, that are functionally connected, during rest constitutes to the resting state network. In the present study, we employed the complex network measures to estimate the presence of community structures within a network. Such estimate is named as modularity. Instead of using a traditional correlation matrix, we used a coherence matrix taken from the causality measure between different nodes. Our results show that in prolonged resting state the modularity starts to decrease. This decrease was observed in all the resting state networks and on both sides of the brain. Our study highlights the usage of coherence matrix instead of correlation matrix for complex network analysis.

Analysis of Morphological Characteristics and Origins of Idiopathic Premature Ventricular Contractions Under a 12-Lead Electrocardiogram in Children with Structurally Normal Hearts.

Science.gov (United States)

Jiang, Jianbin; He, Yuee; Qiu, Huixian; Zhang, Yuanhai; Chu, Maoping; Li, Yuechun; Chen, Qi

2017-10-21

Up to 40% of healthy children have premature ventricular complexes or contractions (PVCs) detected with 24-hour Holter monitoring. We aimed to investigate the morphological characteristics and origins of idiopathic PVCs under a 12-lead electrocardiogram in children with structurally normal hearts. All asymptomatic monomorphic PVC patients with structurally normal hearts under 18 years of age were included in this retrospective study. Characteristics of PVCs in lead V 1 under a 12-lead electrocardiogram were classified as left bundle branch block (PVC-LBBB) or right bundle branch block (PVC-RBBB). According to limb leads, PVC-LBBB or PVC-RBBB was divided into: PVCs-LBBB type I; PVCs-LBBB type II; PVCs-RBBB type I; PVCs-RBBB type II; and PVCs-RBBB type III. Out of 178 PVC patients, 94 cases of PVCs-LBBB (PVCs-LBBB type I = 60; PVCs-LBBB type II = 34) and 84 cases of PVCs-RBBB (PVCs-RBBB type I = 3; PVCs-RBBB type II = 55; PVCs-RBBB type III = 26) were identified. The frequency of PVCs-LBBB type I increased with age and the frequency of PVCs-RBBB type II and III decreased with age. Among the children monitor tested, from 1 years old to 18 years old, PVCs originating from the left or right ventricular outflow tract gradually increased with age, while PVCs originating from the branch sources decreased with age.

Exclusive channels in bar pp annihilation at rest

International Nuclear Information System (INIS)

Bluem, P.

1992-01-01

Exclusive channels in bar pp annihilation at rest provide a powerful tool for studying the meson spectrum below the bar pp threshold. The mesons can be classified in SU(3) multiplets according to their quantum numbers. The states which do not fit into this classification are candidates for new forms of hadronic matter like glueballs, hybrids, and multi-quark states. Recent results on the search for exotic states in exclusive channels of bar pp annihilation at rest are discussed. No less important is the study of the annihilation mechanism. In particular, high-statistic measurements of bar pp annihilation at rest into two-meson final states are an excellent tool for studying quark dynamics. Examples of two-body reactions are presented. 24 refs., 9 figs., 3 tabs

Memory reactivation during rest supports upcoming learning of related content

Science.gov (United States)

Schlichting, Margaret L.; Preston, Alison R.

2014-01-01

Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face–object associations were scanned during passive rest and during encoding of new related and unrelated pairs of objects. Spontaneous reactivation of established memories and enhanced hippocampal–neocortical functional connectivity during rest was related to better subsequent learning, specifically of related content. Moreover, the degree of functional coupling during rest was predictive of neural engagement during the new learning experience itself. These results suggest that through rest-phase reactivation and hippocampal–neocortical interactions, existing memories may come to facilitate encoding during subsequent related episodes. PMID:25331890

Memory reactivation during rest supports upcoming learning of related content.

Science.gov (United States)

Schlichting, Margaret L; Preston, Alison R

2014-11-04

Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face-object associations were scanned during passive rest and during encoding of new related and unrelated pairs of objects. Spontaneous reactivation of established memories and enhanced hippocampal-neocortical functional connectivity during rest was related to better subsequent learning, specifically of related content. Moreover, the degree of functional coupling during rest was predictive of neural engagement during the new learning experience itself. These results suggest that through rest-phase reactivation and hippocampal-neocortical interactions, existing memories may come to facilitate encoding during subsequent related episodes.

Annihilation of antiproton on deuteron at rest

International Nuclear Information System (INIS)

Grach, I.; Shmatikov, M.

1982-01-01

The system of Faddeev equations for amplitudes of anti pD iteraction at rest accounting for higher partial anti NN waves is derived. From its solution the total and elastic anti pD cross sections are calculated. Predictions for the missing-mass spectrum in the anti pD annihilation are made. The P-wave anti NN states give small contribution to the anti pD cross section at rest, the theoretical value of the latter being less than the experimental cross section extrapolated to the threshold. Let us emphasize that the total anti pD cross section depending weakly on the radii of anti NN interactions is sensitive to the values of the anti NN scattering lengths. Experimental data for anti pD cross sections at rest can be obtained only by extrapolation procedure. Henceforth it is very important to investigate the anti pD interactions at low but non-zero momenta where the direct comparison to the experiment is possible [ru

Thallium-201 exercise myocardial imaging to evaluate myocardial perfusion after coronary artery bypass surgery

International Nuclear Information System (INIS)

Hirzel, H.O.; Nuesch, K.; Sialer, G.; Horst, W.; Krayenbuehl, H.P.

1980-01-01

To assess the usefulness of thallium-201 exercise scintigraphy in evaluating myocardial perfusion after coronary artery bypass surgery, imaging was performed after submaximal bicycle ergometry and at rest in 54 patients before and within 24 +- 10 (SD) weeks after operation. Scintigraphy identified 8 out of 20 patients who were symptom free after operation and showed normal exercise electrocardiograms as still having exercise-induced ischaemia and thus as having not truly benefited from the surgical intervention. In contrast, improvement in perfusion was documented in 17 out of 31 patients despite further complaints of chest pain and persistence of a pathological exercise electrocardiogram in 6 of them. Bypass graft patency rate paralleled the scintigraphic findings in the 35 patients who were restudied arteriographically. It was concluded that thallium-201 exercise scintigraphy is a useful technique to document changes in regional perfusion after surgery and is definitely superior to the clinical evaluation of patients including the exercise electrocardiogram. (author)

Resting-State Functional Connectivity in the Infant Brain: Methods, Pitfalls, and Potentiality

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Chandler R. L. Mongerson

2017-08-01

Full Text Available Early brain development is characterized by rapid growth and perpetual reconfiguration, driven by a dynamic milieu of heterogeneous processes. Postnatal brain plasticity is associated with increased vulnerability to environmental stimuli. However, little is known regarding the ontogeny and temporal manifestations of inter- and intra-regional functional connectivity that comprise functional brain networks. Resting-state functional magnetic resonance imaging (rs-fMRI has emerged as a promising non-invasive neuroinvestigative tool, measuring spontaneous fluctuations in blood oxygen level dependent (BOLD signal at rest that reflect baseline neuronal activity. Over the past decade, its application has expanded to infant populations providing unprecedented insight into functional organization of the developing brain, as well as early biomarkers of abnormal states. However, many methodological issues of rs-fMRI analysis need to be resolved prior to standardization of the technique to infant populations. As a primary goal, this methodological manuscript will (1 present a robust methodological protocol to extract and assess resting-state networks in early infancy using independent component analysis (ICA, such that investigators without previous knowledge in the field can implement the analysis and reliably obtain viable results consistent with previous literature; (2 review the current methodological challenges and ethical considerations associated with emerging field of infant rs-fMRI analysis; and (3 discuss the significance of rs-fMRI application in infants for future investigations of neurodevelopment in the context of early life stressors and pathological processes. The overarching goal is to catalyze efforts toward development of robust, infant-specific acquisition, and preprocessing pipelines, as well as promote greater transparency by researchers regarding methods used.

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students – a pilot study

Science.gov (United States)

Rubinstein, Jack; Dhoble, Abhijeet; Ferenchick, Gary

2009-01-01

Background Most medical professionals are expected to possess basic electrocardiogram (EKG) interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. Methods This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9) received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6) received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. Results The average score after only traditional teaching was 4.07 ± 2.08 while after only the puzzle session was 4.04 ± 2.36 (p = 0.97). The average improvement after the traditional session was followed up with a puzzle session was 2.53 ± 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 ± 1.73 (p = 0.67). The final EKG exam score for this cohort (n = 15) was 84.1 compared to 86.6 (p = 0.22) for a comparable sample of medical students (n = 15) at a different campus. Conclusion Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale. PMID:19144134

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students – a pilot study

Directory of Open Access Journals (Sweden)

Dhoble Abhijeet

2009-01-01

Full Text Available Abstract Background Most medical professionals are expected to possess basic electrocardiogram (EKG interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. Methods This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9 received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6 received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. Results The average score after only traditional teaching was 4.07 ± 2.08 while after only the puzzle session was 4.04 ± 2.36 (p = 0.97. The average improvement after the traditional session was followed up with a puzzle session was 2.53 ± 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 ± 1.73 (p = 0.67. The final EKG exam score for this cohort (n = 15 was 84.1 compared to 86.6 (p = 0.22 for a comparable sample of medical students (n = 15 at a different campus. Conclusion Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale.

Detection of coronary artery disease using 12-lead electrocardiogram and simultaneous dual myocardial imaging with iodine-123-β-methyl iodophenyl-pentadecanoic acid (BMIPP) and thallium-201 in patients with unstable angina

International Nuclear Information System (INIS)

Saitoh, Makoto; Hasegawa, Koh; Hasegawa, Kazuo; Kondoh, Teruo; Yanagawa, Tetsuo.

1995-01-01

We investigated the usefulness of 12-lead electrocardiogram and simultaneous single-photon emission computed tomography (SPECT) with 123 I-β-methyl iodophenyl-pentadecanoic acid (BMIPP) and thallium-201 ( 201 Tl) for detecting coronary artery disease (CAD) in 54 consecutive patients with unstable angina. Discordant BMIPP uptake was defined as less 123 I-BMIPP uptake than 201 Tl uptake in 123 I-BMIPP/ 201 Tl dual SPECT. In the detection of CAD, ischemic electrocardiographic change during anginal attack had high sensitivity and low specificity, while discordant BMIPP finding had low sensitivity and high specificity. In patients showing ST depression during anginal attack, discordant BMIPP uptake showed high sensitivity and high specificity for detecting CAD. In conclusion, both 12-lead electrocardiogram during anginal attack and discordant BMIPP uptake are useful in detecting CAD in patients with unstable angina. (author)

General relativistic fields of an isolated spin-half charged particle near the spin axis with application to the rest-mass of the electron and positron

International Nuclear Information System (INIS)

Lynch, J.T.

1999-01-01

Using a lowest-order approximation, the field equations of a general relativistic spinor-connection theory are solved semi-analytically for the fields of a stable, spin-half changed particle near the spin axis. With the exception of the atomic fine-structure constant, all parameters arising in the solution, including the rest mass of the source particle, are found by imposing the standard junction conditions of general relativity and electromagnetism. Using the empirical value for the fine-structure constant, the value derived for the rest mass gives some reason to identify the source particle with the electron. Moreover, since the rest mass is independent of the sign of the electron charge carried by the source, the solution is equally applicable to the positron

Rest requirements and rest management of personnel in shift work

Energy Technology Data Exchange (ETDEWEB)

Hammell, B.D. [PDG Environmental, Melbourne, FL (United States); Scheuerle, A. [Univ. of Texas, Houston, TX (United States)

1995-12-31

A difficulty-weighted shift assignment scheme is proposed for use in prolonged and strenuous field operations such as emergency response, site testing, and short term hazardous waste remediation projects. The purpose of the work rotation plan is to increase productivity, safety, and moral of workers. Job weighting is accomplished by assigning adjustments to the mental and physical intensity of the task, the protective equipment worn, and the climatic conditions. The plan is based on medical studies of sleep deprivation, the effects of rest adjustments, and programs to reduce sleep deprivation and normalize shift schedules.

Mechanisms for decreased exercise capacity after bed rest in normal middle-aged men

International Nuclear Information System (INIS)

Hung, J.; Goldwater, D.; Convertino, V.A.; McKillop, J.H.; Goris, M.L.; DeBusk, R.F.

1983-01-01

The mechanisms responsible for the decrease in exercise capacity after bed rest were assessed in 12 apparently healthy men aged 50 +/- 4 years who underwent equilibrium gated blood pool scintigraphy during supine and upright multistage bicycle ergometry before and after 10 days of bed rest. After bed rest, echocardiographically measured supine resting left ventricular end-diastolic volume decreased by 16% (p less than 0.05). Peak oxygen uptake during supine effort after bed rest was diminished by 6% (p . not significant [NS]), whereas peak oxygen uptake during upright effort declined by 15% (p less than 0.05). After bed rest, increases in heart rate were also greater during exercise in the upright than in the supine position (p less than 0.05). Values of left ventricular ejection fraction increased normally during both supine and upright effort after bed rest and were higher than corresponding values before bed rest (p less than 0.05). After bed rest, increased left ventricular ejection fraction and heart rate largely compensated for the reduced cardiac volume during supine effort, but these mechanisms were insufficient to maintain oxygen transport capacity at levels during upright effort before bed rest. These results indicate that orthostatically induced cardiac underfilling, not physical deconditioning or left ventricular dysfunction, is the major cause of reduced effort tolerance after 10 days of bed rest in normal middle-aged men

Modifications of resting state networks in spinocerebellar ataxia type 2.

Science.gov (United States)

Cocozza, Sirio; Saccà, Francesco; Cervo, Amedeo; Marsili, Angela; Russo, Cinzia Valeria; Giorgio, Sara Maria Delle Acque; De Michele, Giuseppe; Filla, Alessandro; Brunetti, Arturo; Quarantelli, Mario

2015-09-01

We aimed to investigate the integrity of the Resting State Networks in spinocerebellar ataxia type 2 (SCA2) and the correlations between the modification of these networks and clinical variables. Resting-state functional magnetic resonance imaging (RS-fMRI) data from 19 SCA2 patients and 29 healthy controls were analyzed using an independent component analysis and dual regression, controlling at voxel level for the effect of atrophy by co-varying for gray matter volume. Correlations between the resting state networks alterations and disease duration, age at onset, number of triplets, and clinical score were assessed by Spearman's coefficient, for each cluster which was significantly different in SCA2 patients compared with healthy controls. In SCA2 patients, disruption of the cerebellar components of all major resting state networks was present, with supratentorial involvement only for the default mode network. When controlling at voxel level for gray matter volume, the reduction in functional connectivity in supratentorial regions of the default mode network, and in cerebellar regions within the default mode, executive and right fronto-parietal networks, was still significant. No correlations with clinical variables were found for any of the investigated resting state networks. The SCA2 patients show significant alterations of the resting state networks, only partly explained by the atrophy. The default mode network is the only resting state network that shows also supratentorial changes, which appear unrelated to the cortical gray matter volume. Further studies are needed to assess the clinical significance of these changes. © 2015 International Parkinson and Movement Disorder Society.

A NEW APPROACH TO DETECT CONGESTIVE HEART FAILURE USING DETRENDED FLUCTUATION ANALYSIS OF ELECTROCARDIOGRAM SIGNALS

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CHANDRAKAR KAMATH

2015-02-01

Full Text Available The aim of this study is to evaluate how far the detrended fluctuation analysis (DFA approach helps to characterize the short-term and intermediate-term fractal correlations in the raw electrocardiogram (ECG signals and thereby discriminate between normal and congestive heart failure (CHF subjects. The DFA-1 calculations were performed on normal and CHF short-term ECG segments, of the order of 20 seconds duration. Differences were found in shortterm and intermediate-term correlation properties and the corresponding scaling exponents of the two groups (normal and CHF. The statistical analyses show that short-term fractal scaling exponent alone is sufficient to distinguish between normal and CHF subjects. The receiver operating characteristic curve (ROC analysis confirms the robustness of this new approach and exhibits an average accuracy that exceeds 98.2%, average sensitivity of about 98.4%, positive predictivity of 98.00%, and average specificity of 98.00%.

HORMONAL RESPONSE TO DIFFERENT REST INTERVALS DURING RESISTANCE TRAINING WITH LIGHT LOADS

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Payam Mohamad-Panahi

2014-02-01

Full Text Available Purpose: The purpose of the present study was to determine the appropriate rest time between sets during weight training with light load. Material: Seventeen cadet wrestlers (age =16.7В±0.6 yrs.; height =169.2В±8.2 cm; and weight =51.4В±7.9 kg were recruited from wrestling clubs in the Iranian province of Kurdistan and served as subjects in this study. This study was conducted over seven sessions with 48 hours recovery between sessions. In the first session, the characteristic features of subjects were recorded and the one repetition maximum in the bench press test was determined for each subject. On 6 separate occasions, subjects performed a 4 set of bench press at 60% 1RM with a 90 and 240 seconds rest interval until volitional fatigue. The numbers of repetition performed by the subjects, and also, cortisol and testosterone levels and 1RM were recorded. The results showed that there was a significant difference in the sustainability of repetitions during 4 sets bench press with 60 % load between 90 and 240 seconds rest intervals (rest interval effect (p<0.05 as well as with 90% load. Results: Additionally, there was a significant difference in the sustainability of repetitions during 4 sets bench press in 90 and 240 seconds rest intervals, both, between light and heavy loads (load effect. Plasma cortisol concentrations significantly increased after all bench press trials. Also, the rest interval effect was statistically significant in both 60 % and 90% load trials. But, the load effect was only statistically significant in 90 seconds rest interval trial (p<0.05. In contrast, plasma testosterone concentrations significantly increased after 4 sets bench press only in 90 seconds rest interval with heavy load and 240 seconds rest interval with light load (p<0.05. Accordingly, testosterone to cortisol (T:C ratio were significantly decreased after 4 sets bench press in 90 seconds rest interval with light load and 240 seconds rest interval with

HORMONAL RESPONSE TO DIFFERENT REST INTERVALS DURING RESISTANCE TRAINING WITH LIGHT LOADS

Directory of Open Access Journals (Sweden)

Payam Mohamad-Panahi

2014-02-01

Full Text Available Purpose: The purpose of the present study was to determine the appropriate rest time between sets during weight training with light load. Material: Seventeen cadet wrestlers (age =16.7±0.6 yrs.; height =169.2±8.2 cm; and weight =51.4±7.9 kg were recruited from wrestling clubs in the Iranian province of Kurdistan and served as subjects in this study. This study was conducted over seven sessions with 48 hours recovery between sessions. In the first session, the characteristic features of subjects were recorded and the one repetition maximum in the bench press test was determined for each subject. On 6 separate occasions, subjects performed a 4 set of bench press at 60% 1RM with a 90 and 240 seconds rest interval until volitional fatigue. The numbers of repetition performed by the subjects, and also, cortisol and testosterone levels and 1RM were recorded. The results showed that there was a significant difference in the sustainability of repetitions during 4 sets bench press with 60 % load between 90 and 240 seconds rest intervals (rest interval effect (p<0.05 as well as with 90% load. Results: Additionally, there was a significant difference in the sustainability of repetitions during 4 sets bench press in 90 and 240 seconds rest intervals, both, between light and heavy loads (load effect. Plasma cortisol concentrations significantly increased after all bench press trials. Also, the rest interval effect was statistically significant in both 60 % and 90% load trials. But, the load effect was only statistically significant in 90 seconds rest interval trial (p<0.05. In contrast, plasma testosterone concentrations significantly increased after 4 sets bench press only in 90 seconds rest interval with heavy load and 240 seconds rest interval with light load (p<0.05. Accordingly, testosterone to cortisol (T:C ratio were significantly decreased after 4 sets bench press in 90 seconds rest interval with light load and 240 seconds rest interval with heavy

Hours of work and rest in the rail industry.

Science.gov (United States)

Anderson, C; Grunstein, R R; Rajaratnam, S M W

2013-06-01

Currently, the National Transport Commission is considering four options to form the regulatory framework for rail safety within Australia with respect to fatigue. While the National Transport Commission currently recommends no limitations around hours of work or rest, we provide evidence which suggests regulatory frameworks should incorporate a traditional hours of service regulation over more flexible policies. Our review highlights: Shift durations >12 h are associated with a doubling of risk for accident and injury. Fatigue builds cumulatively with each successive shift where rest in between is inadequate (hours of work and rest, including maximum shift duration and successive number of shifts. Appropriately, validated biomathematical models and technologies may be used as a part of a fatigue management system, to augment the protection afforded by limits on hours of work and rest. A comprehensive sleep disorder screening and management programme should form an essential component of any regulatory framework. © 2013 The Authors; Internal Medicine Journal © 2013 Royal Australasian College of Physicians.

Branched-chain amino acid supplementation during bed rest: effect on recovery

Science.gov (United States)

Stein, T. P.; Donaldson, M. R.; Leskiw, M. J.; Schluter, M. D.; Baggett, D. W.; Boden, G.

2003-01-01

Bed rest is associated with a loss of protein from the weight-bearing muscle. The objectives of this study are to determine whether increasing dietary branched-chain amino acids (BCAAs) during bed rest improves the anabolic response after bed rest. The study consisted of a 1-day ambulatory period, 14 days of bed rest, and a 4-day recovery period. During bed rest, dietary intake was supplemented with either 30 mmol/day each of glycine, serine, and alanine (group 1) or with 30 mmol/day each of the three BCAAs (group 2). Whole body protein synthesis was determined with U-(15)N-labeled amino acids, muscle, and selected plasma protein synthesis with l-[(2)H(5)]phenylalanine. Total glucose production and gluconeogenesis from alanine were determined with l-[U-(13)C(3)]alanine and [6,6-(2)H(2)]glucose. During bed rest, nitrogen (N) retention was greater with BCAA feeding (56 +/- 6 vs. 26 +/- 12 mg N. kg(-1). day(-1), P < 0.05). There was no effect of BCAA supplementation on either whole body, muscle, or plasma protein synthesis or the rate of 3-MeH excretion. Muscle tissue free amino acid concentrations were increased during bed rest with BCAA (0.214 +/- 0.066 vs. 0.088 +/- 0.12 nmol/mg protein, P < 0.05). Total glucose production and gluconeogenesis from alanine were unchanged with bed rest but were significantly reduced (P < 0.05) with the BCAA group in the recovery phase. In conclusion, the improved N retention during bed rest is due, at least in part, to accretion of amino acids in the tissue free amino acid pools. The amount accreted is not enough to impact protein kinetics in the recovery phase but does improve N retention by providing additional essential amino acids in the early recovery phase.

Profiling of REST-dependent microRNAs reveals dynamic modes of expression

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Zhengliang eGao

2012-05-01

Full Text Available Multipotent neural stem cells (NSCs possess the ability to self-renew and differentiate into both neurons and glia. However, the detailed mechanisms underlying NSC fate decisions are not well understood. Recent work suggest that the interaction between cell-type specific transcription factors and microRNAs (miRNAs is important as resident neural stem/progenitor cells give rise to functionally mature neurons. Recently, we demonstrated that the transcriptional repressor REST (RE1-silencing transcription factor is essential to prevent precocious neuronal differentiation and maintain NSC self-renewal in the adult hippocampus. Here we show that REST is required for orchestrating the expression of distinct subsets of miRNAs in primary mouse NSC cultures, a physiologically relevant cell type. Using miRNA array profiling, we identified known REST-regulated miRNA genes, as well as previously uncharacterized REST-dependent miRNAs. Interestingly, REST-regulated miRNAs undergo dynamic expression changes under differentiation conditions over time, but not under proliferation conditions. These results suggest that REST functions in a context-dependent manner through its target miRNAs for mediating neuronal production.

Sex Differences in the Relationship Between Depressive Symptoms and Actigraphic Assessments of Sleep and Rest-Activity Rhythms in a Population-Based Sample.

Science.gov (United States)

White, Kaitlin Hanley; Rumble, Meredith E; Benca, Ruth M

2017-05-01

Depression is often associated with disruptions in sleep and circadian rhythms. We aimed to confirm these relationships via actigraphic assessment in a large, population-based sample and test whether sex moderates these relationships. A total of 418 participants (age = 35-85 years, mean [standard deviation] = 57.04 [11.47]) completed questionnaires and 1 week of actigraphy, used to calculate sleep and rest-activity statistics including mesor (mean activity level), amplitude (height of rhythm), and acrophase (time of day that rhythm peaks). Depressive symptoms, assessed via Center for Epidemiologic Studies Depression Scale, were associated with disrupted sleep and rest-activity rhythms. Furthermore, men demonstrated longer sleep onset latency (SOL, B = -13.28, p continuity and rest-activity rhythms in this population-based sample; however, these relationships differed by sex. Women with greater depressive symptoms exhibited difficulty with sleep continuity, whereas men with greater depressive symptoms demonstrated disruption throughout the 24-hour rhythm.

Addition of the electrocardiogram to the preparticipation examination of college athletes.

Science.gov (United States)

Le, Vy-Van; Wheeler, Matthew T; Mandic, Sandra; Dewey, Frederick; Fonda, Holly; Perez, Marco; Sungar, Gannon; Garza, Daniel; Ashley, Euan A; Matheson, Gordon; Froelicher, Victor

2010-03-01

Although the use of standardized cardiovascular (CV) system-focused history and physical examination is recommended for the preparticipation examination (PPE) of athletes, the addition of the electrocardiogram (ECG) has been controversial. Because the impact of ECG screening on college athletes has rarely been reported, we analyzed the findings of adding the ECG to the PPE of Stanford athletes. For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database. Although the use of standardized CV-focused history and physical examination are recommended for the PPE of athletes, the addition of the ECG has been controversial. Because the feasibility and outcomes of ECG screening on college athletes have rarely been reported, we present findings derived from the addition of the ECG to the PPE of Stanford athletes. For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database. Six hundred fifty-eight recordings were obtained (54% men, 10% African-American, mean age 20 years) representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete right bundle branch block (RBBB) (13%), right axis deviation (RAD) (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for left ventricular hypertrophy (LVH) were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7%, and only 5 men had abnormal Q-waves. Sixty-three athletes (10%) were judged to have distinctly abnormal ECG findings

Tremor pattern differentiates drug-induced resting tremor from Parkinson disease.

Science.gov (United States)

Nisticò, R; Fratto, A; Vescio, B; Arabia, G; Sciacca, G; Morelli, M; Labate, A; Salsone, M; Novellino, F; Nicoletti, A; Petralia, A; Gambardella, A; Zappia, M; Quattrone, A

2016-04-01

DAT-SPECT, is a well-established procedure for distinguishing drug-induced parkinsonism from Parkinson's disease (PD). We investigated the usefulness of blink reflex recovery cycle (BRrc) and of electromyographic parameters of resting tremor for the differentiation of patients with drug-induced parkinsonism with resting tremor (rDIP) from those with resting tremor due to PD. This was a cross-sectional study. In 16 patients with rDIP and 18 patients with PD we analysed electrophysiological parameters (amplitude, duration, burst and pattern) of resting tremor. BRrc at interstimulus intervals (ISI) of 100, 150, 200, 300, 400, 500 and 750 msec was also analysed in patients with rDIP, patients with PD and healthy controls. All patients and controls underwent DAT-SPECT. Rest tremor amplitude was higher in PD patients than in rDIP patients (p tremor showed a synchronous pattern in all patients with rDIP, whereas it had an alternating pattern in all PD patients (p tremor can be considered a useful investigation for differentiating rDIP from PD. Copyright © 2016. Published by Elsevier Ltd.

REST in practice Hypermedia and systems architecture

CERN Document Server

Webber, Jim; Robinson, Ian

2010-01-01

Why don't typical enterprise projects go as smoothly as projects you develop for the Web? Does the REST architectural style really present a viable alternative for building distributed systems and enterprise-class applications? In this insightful book, three SOA experts provide a down-to-earth explanation of REST and demonstrate how you can develop simple and elegant distributed hypermedia systems by applying the Web's guiding principles to common enterprise computing problems. You'll learn techniques for implementing specific Web technologies and patterns to solve the needs of a typical com

Experimental evaluation of the influence of various rests on task performance

International Nuclear Information System (INIS)

Nagasaka, Akihiko; Hirose, Ayako

2000-01-01

This report deals with the result of the experiment that 8 subjects had executed adding task and search task. They executed each task in 80 minutes under 5 conditions: (1) with no rest, and with 4 kinds of 20 minutes rests, in which they (2) opened eyes, (3) closed eyes, (4) closed eyes with listening classic music and (5) closed eyes with feet massage, in the middle of the task. The results of analysis of variance with the task performance in the latter half, there were significant differences between each condition with every subject in adding task, and with 6 subjects in search task. However, the orders of the task performance with each condition were not the same by each subject. It was suggested that transition of the arousal levels under the rest was related to the effects of the rest rather than the subjects' taste in rests. In the rest, the percentage of α wave of electroencephalogram and the coefficient of variation of R-R interval (time interval of heart beats) were increased than in executing task. The mean Kendall's rank correlation of coefficient with the order of increase rate of α/β wave and the task performance in the latter half was slightly negative in adding task, but was about 0.4 in search task. From these results, about six requirements for 'an effective rest' were able to be mentioned, for example, 'the devices that raises the arousal levels is carried out just before a rest end'. (author)

Experimental evaluation of the influence of various rests on task performance

Energy Technology Data Exchange (ETDEWEB)

Nagasaka, Akihiko; Hirose, Ayako [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

2000-01-01

This report deals with the result of the experiment that 8 subjects had executed adding task and search task. They executed each task in 80 minutes under 5 conditions: (1) with no rest, and with 4 kinds of 20 minutes rests, in which they (2) opened eyes, (3) closed eyes, (4) closed eyes with listening classic music and (5) closed eyes with feet massage, in the middle of the task. The results of analysis of variance with the task performance in the latter half, there were significant differences between each condition with every subject in adding task, and with 6 subjects in search task. However, the orders of the task performance with each condition were not the same by each subject. It was suggested that transition of the arousal levels under the rest was related to the effects of the rest rather than the subjects' taste in rests. In the rest, the percentage of {alpha} wave of electroencephalogram and the coefficient of variation of R-R interval (time interval of heart beats) were increased than in executing task. The mean Kendall's rank correlation of coefficient with the order of increase rate of {alpha}/{beta} wave and the task performance in the latter half was slightly negative in adding task, but was about 0.4 in search task. From these results, about six requirements for 'an effective rest' were able to be mentioned, for example, 'the devices that raises the arousal levels is carried out just before a rest end'. (author)

Petechiae: reproducible pattern of distribution and increased appearance after bed rest.

Science.gov (United States)

Ganse, Bergita; Limper, Ulrich; Bühlmeier, Judith; Rittweger, Jörn

2013-08-01

Exposure to acceleration can cause petechial hemorrhages, called G measles. Petechiae usually start to develop between 5 and 9 G with a high interindividual variance. Centrifuge training delays the onset to higher G levels. One might expect onset at lower G levels after bed rest; however, there is no evidence in the literature. A case of petechiae formation after bed rest is presented here. Orthostatic tolerance was tested using a tilt table and lower body negative pressure before and after bed rest in both campaigns of a 2 x 21-d bed rest study with 6 degrees head-down tilt. A 42-yr-old male Caucasian without any history of thrombosis, venous disease, hemorrhage, or petechiae, and with a negative thrombophilia screening, took part in the bed rest study as 1 out of 10 subjects. He was the only one to develop petechiae during the orthostatic tests after, but not before, bed rest in both campaigns. Petechiae were distributed throughout the lower legs and most pronounced at the shin in a stocking-like fashion, surprisingly reoccurring in an identical pattern of distribution. Petechiae appeared slowly over minutes during hyperemia. This case indicates that prolonged bed rest decreases the threshold for petechiae formation. A reproducible distribution pattern suggests that factors predisposing to petechiae formation keep their local distribution over time (possibly due to local vessel structures). Mechanisms of adaptation and interindividual variance are unclear. Findings are of clinical relevance as such cases might occur after prolonged bed rest in patients without need of expensive testing.

Temporal reliability and lateralization of the resting-state language network.

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Zhu, Linlin; Fan, Yang; Zou, Qihong; Wang, Jue; Gao, Jia-Hong; Niu, Zhendong

2014-01-01

The neural processing loop of language is complex but highly associated with Broca's and Wernicke's areas. The left dominance of these two areas was the earliest observation of brain asymmetry. It was demonstrated that the language network and its functional asymmetry during resting state were reproducible across institutions. However, the temporal reliability of resting-state language network and its functional asymmetry are still short of knowledge. In this study, we established a seed-based resting-state functional connectivity analysis of language network with seed regions located at Broca's and Wernicke's areas, and investigated temporal reliability of language network and its functional asymmetry. The language network was found to be temporally reliable in both short- and long-term. In the aspect of functional asymmetry, the Broca's area was found to be left lateralized, while the Wernicke's area is mainly right lateralized. Functional asymmetry of these two areas revealed high short- and long-term reliability as well. In addition, the impact of global signal regression (GSR) on reliability of the resting-state language network was investigated, and our results demonstrated that GSR had negligible effect on the temporal reliability of the resting-state language network. Our study provided methodology basis for future cross-culture and clinical researches of resting-state language network and suggested priority of adopting seed-based functional connectivity for its high reliability.

Temporal reliability and lateralization of the resting-state language network.

Directory of Open Access Journals (Sweden)

Linlin Zhu

Full Text Available The neural processing loop of language is complex but highly associated with Broca's and Wernicke's areas. The left dominance of these two areas was the earliest observation of brain asymmetry. It was demonstrated that the language network and its functional asymmetry during resting state were reproducible across institutions. However, the temporal reliability of resting-state language network and its functional asymmetry are still short of knowledge. In this study, we established a seed-based resting-state functional connectivity analysis of language network with seed regions located at Broca's and Wernicke's areas, and investigated temporal reliability of language network and its functional asymmetry. The language network was found to be temporally reliable in both short- and long-term. In the aspect of functional asymmetry, the Broca's area was found to be left lateralized, while the Wernicke's area is mainly right lateralized. Functional asymmetry of these two areas revealed high short- and long-term reliability as well. In addition, the impact of global signal regression (GSR on reliability of the resting-state language network was investigated, and our results demonstrated that GSR had negligible effect on the temporal reliability of the resting-state language network. Our study provided methodology basis for future cross-culture and clinical researches of resting-state language network and suggested priority of adopting seed-based functional connectivity for its high reliability.

Temporal Reliability and Lateralization of the Resting-State Language Network

Science.gov (United States)

Zou, Qihong; Wang, Jue; Gao, Jia-Hong; Niu, Zhendong

2014-01-01

The neural processing loop of language is complex but highly associated with Broca's and Wernicke's areas. The left dominance of these two areas was the earliest observation of brain asymmetry. It was demonstrated that the language network and its functional asymmetry during resting state were reproducible across institutions. However, the temporal reliability of resting-state language network and its functional asymmetry are still short of knowledge. In this study, we established a seed-based resting-state functional connectivity analysis of language network with seed regions located at Broca's and Wernicke's areas, and investigated temporal reliability of language network and its functional asymmetry. The language network was found to be temporally reliable in both short- and long-term. In the aspect of functional asymmetry, the Broca's area was found to be left lateralized, while the Wernicke's area is mainly right lateralized. Functional asymmetry of these two areas revealed high short- and long-term reliability as well. In addition, the impact of global signal regression (GSR) on reliability of the resting-state language network was investigated, and our results demonstrated that GSR had negligible effect on the temporal reliability of the resting-state language network. Our study provided methodology basis for future cross-culture and clinical researches of resting-state language network and suggested priority of adopting seed-based functional connectivity for its high reliability. PMID:24475058

Real-Time Monitoring and Analysis of Zebrafish Electrocardiogram with Anomaly Detection

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Michael Lenning

2017-12-01

Full Text Available Heart disease is the leading cause of mortality in the U.S. with approximately 610,000 people dying every year. Effective therapies for many cardiac diseases are lacking, largely due to an incomplete understanding of their genetic basis and underlying molecular mechanisms. Zebrafish (Danio rerio are an excellent model system for studying heart disease as they enable a forward genetic approach to tackle this unmet medical need. In recent years, our team has been employing electrocardiogram (ECG as an efficient tool to study the zebrafish heart along with conventional approaches, such as immunohistochemistry, DNA and protein analyses. We have overcome various challenges in the small size and aquatic environment of zebrafish in order to obtain ECG signals with favorable signal-to-noise ratio (SNR, and high spatial and temporal resolution. In this paper, we highlight our recent efforts in zebrafish ECG acquisition with a cost-effective simplified microelectrode array (MEA membrane providing multi-channel recording, a novel multi-chamber apparatus for simultaneous screening, and a LabVIEW program to facilitate recording and processing. We also demonstrate the use of machine learning-based programs to recognize specific ECG patterns, yielding promising results with our current limited amount of zebrafish data. Our solutions hold promise to carry out numerous studies of heart diseases, drug screening, stem cell-based therapy validation, and regenerative medicine.

Towards a Process Calculus for Rest: Current State of the Art

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Dwornikowski Dariusz

2015-12-01

Full Text Available SOA is a popular paradigm for building distributed systems that has gained a great recognition over past years. There are two main approaches to implementing SOA: SOAP-based and RESTful Web services. In order to address problems of modeling and verification of Web services, several process calculi have been proposed for SOAP-based Web services but none for the RESTful Web services based systems. This article is a comparative survey on existing process calculi for SOA systems, also the existing attempts to formalize REST systems are discussed. The aim of the article is to see how process calculi for SOAP-based systems deal with different aspects of their modeling domain, and whether their approaches can be used to model RESTful and ROA systems. Finally, basing on the survey, requirements for a new process calculus specific for REST are defined.

Classic electrocardiogram-based and mobile technology derived approaches to heart rate variability are not equivalent.

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Guzik, Przemyslaw; Piekos, Caroline; Pierog, Olivia; Fenech, Naiman; Krauze, Tomasz; Piskorski, Jaroslaw; Wykretowicz, Andrzej

2018-05-01

We compared classic ECG-derived versus a mobile approach to heart rate variability (HRV) measurement. 29 young adult healthy volunteers underwent a simultaneous recording of heart rate using an ECG and a chest heart rate monitor at supine rest, during mental stress and active standing. Mean RR interval, Standard Deviation of Normal-to-Normal (SDNN) of RR intervals, and Root Mean Square of the Successive Differences (RMSSD) between RR intervals were computed in 168 pairs of 5-minute epochs by in-house software on a PC (only sinus beats) and by mobile application "ELITEHRV" on a smartphone (no beat type identification). ECG analysis showed that 33.9% of the recordings contained at least one non-sinus beat or artefact, the mobile app did not report this. The mean RR intervals were significantly longer (p = 0.0378), while SDNN (p = 0.0001) and RMSSD (p = 0.0199) were smaller for the mobile approach. Measures of identical HRV parameters by ECG-based and mobile approaches are not equivalent. Copyright © 2018 Elsevier B.V. All rights reserved.

Ciliates from ancient permafrost: Assessment of cold resistance of the resting cysts.

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Shatilovich, Anastasia; Stoupin, Daniel; Rivkina, Elizaveta

2015-06-01

There is evidence that resting cysts of soil ciliates and numerous taxa of other protists can survive in permafrost for thousands of years at subzero temperatures; however, our knowledge about mechanisms of long term cryobiosis remains incomplete. In order to better understand the means by which ancient cysts survive, we investigated resistance to cyclical supercooling stress of resting cysts of the soil ciliate Colpoda steinii (Colpodida, Ciliophora). Three clonal strains were used for comparison, isolated from Siberian tundra soil, ancient Holocene (5-7,000 y) and late Pleistocene (32-35,000 y) permafrost sediments. To determine the viability of the ancient and contemporary ciliate cysts we improved and validated a cultivation-independent method of vital fluorescent staining with a combination of two nucleic acid binding dyes, acridine orange and propidium iodide. The viability of Colpoda steinii cysts during low-temperature experiments was measured using both the proposed vital fluorescent staining method and standard germination test. Our results indicate that the dual-fluorescence technique is a more accurate, rapid, and efficient method for estimating cyst viability. We found that cysts of ancient ciliates display lower tolerance to the impact of cyclical cold compared to cysts of contemporary ciliates from Siberian permafrost affected soils. Copyright © 2015 Elsevier GmbH. All rights reserved.

An ontological analysis of the electrocardiogram - DOI: 10.3395/reciis.v3i1.242en

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Bernardo Gonçalves

2009-04-01

Full Text Available Bioinformatics has been a fertile field for the application of the discipline of formal ontology. The principled representation of biomedical entities has increasingly supported biological research, with direct benefits ranging from the reformulation of medical terminologies to the introduction of new perspectives for enhanced models of Electronic Health Records (EHR. This paper introduces an application-independent ontological analysis of the electrocardiogram (ECG grounded in the Unified Foundational Ontology. With the objective of investigating the phenomena underlying this cardiological exam, we deal with the sub-domains of human heart electrophysiology and anatomy. We then outline an ECG Ontology built upon the OBO Relation Ontology. In addition, the domain ontology sketched here takes inspiration both in the Foundational Model of Anatomy and in the Ontology of Functions proposed under the auspices of the General Formal Ontology (GFO research program.

Diagnosis of silent myocardial ischemia in type 2 diabetic patients by electrocardiogram, ergometry and Gated-SPECT

International Nuclear Information System (INIS)

Penna Quian, Yamile; Fernandez-Britto Rodriguez, Jose; Bacallao Gallestey, Jorge; Batista Cuellar, Juan Felipe; Coca Perez, Marco Antonio; Toirac Garcia, Noresma; Penna Coego, Andria

2008-01-01

31 asymptomatic type 2 diabetic patients were studied by lab tests, electrocardiogram, ergometry, Gated-SPECT and coronariography to determine the relation between the atherosclerotic risk factors and the silent myocardial ischemia. Patients were classified into two groups: positive SPECT and negative SPECT. Association tests were made for each variable and ROC curves were constructed to identify risk markers. In 35.5% of the patients silent myocardial ischemia was detected with a good angiographic correlation. A significant association was evidenced between positive SPECT and the atherosclerotic risk factors, namely, low values of HDLc, family pathological history of ischemic heart disease and peripheral vascular disease. The logistic regression models showed that low values of HDLc together with family pathological history of ischemic heart disease may be strong predictors of silent myocardial ischemia in asymptomatic type 2 diabetic patients

Comparison of resting β-methyl-iodophenyl pentadecanoic acid (BMIPP) and thallium-201 tomography using quantitative polar maps in patients with unstable angina

International Nuclear Information System (INIS)

Suzuki, Akio; Takada, Yasuo; Nagasaka, Makoto; Kato, Rinya; Watanabe, Toshiya; Shimokata, Keiko; Yasui, Shoji

1997-01-01

We compared resting β-methyl-iodophenyl pentadecanoic acid (BMIPP) tomography with resting thallium-201 tomography in 28 patients with unstable angina. Tracer distribution was displayed on a polar map and compared with a normal standard deviation map obtained from a group of 12 normal subjects. The extent scores and severity scores obtained by BMIPP were significantly greater than those obtained by thallium-201. Confirmation by coronary angiography revealed the sensitivity of the methods in identifying patients to be 89% for BMIPP and 54% for thallium-201. There were significant differences between BMIPP and thallium-201 in the sensitivities of detecting postischemic jeopardized myocardium in the area supplied by the right coronary artery (RCA; 53% vs 18%, p<0.05), left circumflex artery (LCX; 78% vs 39%, p<0.025) and all 3 vessels combined (71% vs 35%, p<0.001) but no significant differences in specificity (RCA: 82% vs 64%; LCX: 70% vs 90%; and total 3 vessels combined: 75% vs 79%). In conclusion, resting BMIPP tomography is more sensitive than resting thallium-201 tomography in detecting postischemic myocardial damage in patients with unstable angina. (author)

Intensive Exercise Training During Bed Rest Attenuates Deconditioning

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Greenleaf, John E.

1997-01-01

Intensive exercise training during bed rest attenuates deconditioning. Med. Sci. Sports Exerc., Vol. 29, No. 2, pp. 207-215, 1997. A 30-d 6 deg head-down bed rest project was conducted to evaluate variable high-intensity, short-duration, isotonic cycle ergometer exercise (ITE) training and high-intensity intermittent resistive isokinetic exercise (IKE) training regimens designed to maintain peak VO2 and muscle mass, strength, and endurance at ambulatory control levels throughout prolonged bed rest. Other elements of the deconditioning (adaptive) syndrome, such as proprioception, psychological performance, hypovolemia, water balance, body composition, and orthostatic tolerance, were also measured. Major findings are summarized in this paper. Compared with response during bed rest of the no exercise (NOE) control group: the ITE training regimen (a) maintained work capacity (peak VO2), (b) maintained plasma and red cell volumes, (c) induced positive body water balance, (d) decreased quality of sleep and mental concentration, and (e) had no effect on the decrease in orthostatic tolerance; the IKE training regimen (f) attenuated the decrease in peak VO2 by 50%, (g) attenuated loss of red cell volume by 40% but had no effect on loss of plasma volume, (b) induced positive body water balance, (i) had no adverse effect on quality of sleep or concentration, and 0) had no effect on the decrease in orthostatic tolerance. These findings suggest that various elements of the deconditioning syndrome can be manipulated by duration and intensity of ITE or IKE training regimens and that several different training protocols will be required to maintain or restore physiological and psychological performance of individuals confined to prolonged bed rest.

The impacts of multiple rest-break periods on commercial truck driver's crash risk.

Science.gov (United States)

Chen, Chen; Xie, Yuanchang

2014-02-01

Driver fatigue has been a major contributing factor to fatal commercial truck crashes, which accounted for about 10% of all fatal motor vehicle crashes that happened between 2009 and 2011. Commercial truck drivers' safety performance can deteriorate easily due to fatigue caused by long driving hours and irregular working schedules. To ensure safety, truck drivers often use off-duty time and short rest breaks during a trip to recover from fatigue. This study thoroughly investigates the impacts of off-duty time prior to a trip and short rest breaks on commercial truck safety by using Cox proportional hazards model and Andersen-Gill model. It is found that increasing total rest-break duration can consistently reduce fatigue-related crash risk. Similarly, taking more rest breaks can help to reduce crash risk. The results suggest that two rest breaks are generally considered enough for a 10-hour trip, as three or more rest breaks may not further reduce crash risk substantially. Also, the length of each rest break does not need to be very long and 30min is usually adequate. In addition, this study investigates the safety impacts of when to take rest breaks. It is found that taking rest breaks too soon after a trip starts will cause the rest breaks to be less effective. The findings of this research can help policy makers and trucking companies better understand the impacts of multiple rest-break periods and develop more effective rules to improve the safety of truck drivers. Copyright © 2014 Elsevier Ltd and National Safety Council. All rights reserved.

Diagnostic Accuracy of a New Cardiac Electrical Biomarker for Detection of Electrocardiogram Changes Suggestive of Acute Myocardial Ischemic Injury

Science.gov (United States)

Schreck, David M; Fishberg, Robert D

2014-01-01

Objective A new cardiac “electrical” biomarker (CEB) for detection of 12-lead electrocardiogram (ECG) changes indicative of acute myocardial ischemic injury has been identified. Objective was to test CEB diagnostic accuracy. Methods This is a blinded, observational retrospective case-control, noninferiority study. A total of 508 ECGs obtained from archived digital databases were interpreted by cardiologist and emergency physician (EP) blinded reference standards for presence of acute myocardial ischemic injury. CEB was constructed from three ECG cardiac monitoring leads using nonlinear modeling. Comparative active controls included ST voltage changes (J-point, ST area under curve) and a computerized ECG interpretive algorithm (ECGI). Training set of 141 ECGs identified CEB cutoffs by receiver-operating-characteristic (ROC) analysis. Test set of 367 ECGs was analyzed for validation. Poor-quality ECGs were excluded. Sensitivity, specificity, and negative and positive predictive values were calculated with 95% confidence intervals. Adjudication was performed by consensus. Results CEB demonstrated noninferiority to all active controls by hypothesis testing. CEB adjudication demonstrated 85.3–94.4% sensitivity, 92.5–93.0% specificity, 93.8–98.6% negative predictive value, and 74.6–83.5% positive predictive value. CEB was superior against all active controls in EP analysis, and against ST area under curve and ECGI by cardiologist. Conclusion CEB detects acute myocardial ischemic injury with high diagnostic accuracy. CEB is instantly constructed from three ECG leads on the cardiac monitor and displayed instantly allowing immediate cost-effective identification of patients with acute ischemic injury during cardiac rhythm monitoring. PMID:24118724

Resting Pd/Pa and haemodynamic relevance of coronary stenosis as evaluated by fractional flow reserve.

Science.gov (United States)

De Luca, Giuseppe; Verdoia, Monica; Barbieri, Lucia; Marino, Paolo; Suryapranata, Harry

2018-03-01

Fractional flow reserve (FFR) currently represents the gold standard in the evaluation of the haemodynamic relevance of coronary stenoses. However, both intracoronary and intravenous adenosine may be tolerated poorly by some patients. Therefore, considerable interest had been focused in the last few years on new adenosine-free indexes to define the haemodynamic relevance of coronary stenoses. So far, few data have been reported on resting Pd/Pa and its correlation with FFR as evaluated with high-dose intracoronary adenosine administration, which is the aim of the current study. FFR was assessed in 120 patients with 137 intermediate lesions during cardiac catheterization by a pressure-recording guidewire (PrimeWire). FFR was calculated as the ratio of the distal coronary pressure to the aortic pressure at hyperaemia. Intracoronary doses of adenosine were administered up to 720 μg as intracoronary boli. Exclusion criteria were as follows: (a) allergy to adenosine; (b) baseline bradycardia (heart rate values and increased the percentage of patients showing an FFR less than 0.80. Resting Pd/Pa showed good accuracy in the identification of patients with significant FFR values (value in the prediction of a positive FFR value. A value up to 0.88 was associated with a 100% positive predictive value, whereas a value of at least 0.95 was associated with a 95% negative predictive value. This study showed that in intermediate lesions, resting Pd/Pa was related linearly to FFR. We identified 0.93 as the best cut-off value in the prediction of haemodynamically significant coronary stenosis as evaluated by FFR. However, cut-off values of 0.88 and 0.95 could provide the maximal predictive positive and negative values, suggesting the additional use of FFR only in patients with resting values within this range.

Branched-chain amino acid supplementation during bed rest: effect on recovery

Science.gov (United States)

Stein, T. P.; Donaldson, M. R.; Leskiw, M. J.; Schluter, M. D.; Baggett, D. W.; Boden, G.

2003-01-01

Bed rest is associated with a loss of protein from the weight-bearing muscle. The objectives of this study are to determine whether increasing dietary branched-chain amino acids (BCAAs) during bed rest improves the anabolic response after bed rest. The study consisted of a 1-day ambulatory period, 14 days of bed rest, and a 4-day recovery period. During bed rest, dietary intake was supplemented with either 30 mmol/day each of glycine, serine, and alanine (group 1) or with 30 mmol/day each of the three BCAAs (group 2). Whole body protein synthesis was determined with U-(15)N-labeled amino acids, muscle, and selected plasma protein synthesis with l-[(2)H(5)]phenylalanine. Total glucose production and gluconeogenesis from alanine were determined with l-[U-(13)C(3)]alanine and [6,6-(2)H(2)]glucose. During bed rest, nitrogen (N) retention was greater with BCAA feeding (56 +/- 6 vs. 26 +/- 12 mg N. kg(-1). day(-1), P BCAA supplementation on either whole body, muscle, or plasma protein synthesis or the rate of 3-MeH excretion. Muscle tissue free amino acid concentrations were increased during bed rest with BCAA (0.214 +/- 0.066 vs. 0.088 +/- 0.12 nmol/mg protein, P BCAA group in the recovery phase. In conclusion, the improved N retention during bed rest is due, at least in part, to accretion of amino acids in the tissue free amino acid pools. The amount accreted is not enough to impact protein kinetics in the recovery phase but does improve N retention by providing additional essential amino acids in the early recovery phase.

The influence of rest period instructions on the default mode network

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Christopher eBenjamin

2010-12-01

Full Text Available The default mode network (DMN refers to regional brain activity that is greater during rest periods than during attention-demanding tasks and many studies have reported DMN alterations in patient populations. It has also been shown that the DMN is suppressed by scanner background noise (SBN, which is the noise produced by functional magnetic resonance imaging (fMRI. However, it is unclear whether different approaches to rest in the noisy MR environment can alter the DMN and constitute a confound in studies investigating the DMN in particular patient populations (e.g., individuals with schizophrenia, Alzheimer’s disease. We examined twenty-seven healthy adult volunteers who completed an fMRI experiment with 3 different instructions for rest: (1 relax and be still, (2 attend to SBN, or (3 ignore SBN. Region of interest (ROI analyses were performed to determine the influence of rest period instructions on core regions of the DMN and DMN regions previously reported to be altered in patients with or at risk for Alzheimer’s disease or schizophrenia. The dorsal medial prefrontal cortex (dmPFC exhibited greater activity when specific resting instructions were given (i.e. attend to or ignore SBN compared to when non-specific resting instructions were given. Condition-related differences in connectivity were also observed between regions of the dmPFC and inferior parietal/posterior superior temporal cortex. We conclude that rest period instructions and SBN levels should be carefully considered for fMRI studies on the DMN, especially studies on clinical populations and groups that may have different approaches to rest, such as first-time research participants and children.

Structural connectivity allows for multi-threading during rest: the structure of the cortex leads to efficient alternation between resting state exploratory behavior and default mode processing.

Science.gov (United States)

Senden, Mario; Goebel, Rainer; Deco, Gustavo

2012-05-01

Despite the absence of stimulation or task conditions the cortex exhibits highly structured spatio-temporal activity patterns. These patterns are known as resting state networks (RSNs) and emerge as low-frequency fluctuations (rest. We are interested in the relationship between structural connectivity of the cortex and the fluctuations exhibited during resting conditions. We are especially interested in the effect of degree of connectivity on resting state dynamics as the default mode network (DMN) is highly connected. We find in experimental resting fMRI data that the DMN is the functional network that is most frequently active and for the longest time. In large-scale computational simulations of the cortex based on the corresponding underlying DTI/DSI based neuroanatomical connectivity matrix, we additionally find a strong correlation between the mean degree of functional networks and the proportion of time they are active. By artificially modifying different types of neuroanatomical connectivity matrices in the model, we were able to demonstrate that only models based on structural connectivity containing hubs give rise to this relationship. We conclude that, during rest, the cortex alternates efficiently between explorations of its externally oriented functional repertoire and internally oriented processing as a consequence of the DMN's high degree of connectivity. Copyright © 2012 Elsevier Inc. All rights reserved.

Variations in resting energy expenditure: impact on gestational weight gain.

Science.gov (United States)

Berggren, E K; O'Tierney-Ginn, P; Lewis, S; Presley, L; De-Mouzon, S Hauguel; Catalano, P M

2017-10-01

There are significant variations in gestational weight gain, with many women gaining in excess of the Institute of Medicine guidelines. Unfortunately, efforts to improve appropriate gestational weight gain have had only limited success. To date, interventions have focused primarily on decreasing energy intake and/or increasing physical activity. Maternal resting energy expenditure, which comprises ∼60% of total energy expenditure compared with the ∼20% that comes from physical activity, may be an important consideration in understanding variations in gestational weight gain. Our objective was to quantify the changes in resting energy expenditure during pregnancy and their relationship to gestational weight gain and body composition changes among healthy women. We hypothesized that greater gestational weight gain, and fat mass accrual in particular, are inversely related to variations in resting energy expenditure. We conducted a secondary analysis of a prospective cohort studied before conception and late pregnancy (34-36 weeks). Body composition (estimated using hydrodensitometry) and resting energy expenditure (estimated using indirect calorimetry) were measured. The relationship between the changes in resting energy expenditure and gestational weight gain and the change in fat mass and fat-free mass were quantified. Resting energy expenditure was expressed as kilocalories per kilogram of fat-free mass per day (kilocalories per kilogram of fat-free mass -1 /day -1 ) and kilocalories per day. Correlations are reported as r. Among 51 women, preconception body mass index was 23.0 (4.7) kg/m 2 ; gestational weight gain was 12.8 (4.7) kg. Preconception and late pregnancy resting energy expenditure (kilocalories per day) correlated positively with the change in fat-free mass (r = 0.37, P = .008; r = 0.51, P = .001). Late-pregnancy resting energy expenditure (kilocalories per kilogram of fat-free mass -1 /day -1 ) was inversely associated with the change in fat

Physiological and Functional Alterations after Spaceflight and Bed Rest.

Science.gov (United States)

Mulavara, Ajitkumar P; Peters, Brian T; Miller, Chris A; Kofman, Igor S; Reschke, Millard F; Taylor, Laura C; Lawrence, Emily L; Wood, Scott J; Laurie, Steven S; Lee, Stuart M C; Buxton, Roxanne E; May-Phillips, Tiffany R; Stenger, Michael B; Ploutz-Snyder, Lori L; Ryder, Jeffrey W; Feiveson, Alan H; Bloomberg, Jacob J

2018-04-03

Exposure to microgravity causes alterations in multiple physiological systems, potentially impacting the ability of astronauts to perform critical mission tasks. The goal of this study was to determine the effects of spaceflight on functional task performance and to identify the key physiological factors contributing to their deficits. A test battery comprised of 7 functional tests and 15 physiological measures was used to investigate the sensorimotor, cardiovascular and neuromuscular adaptations to spaceflight. Astronauts were tested before and after 6-month spaceflights. Subjects were also tested before and after 70 days of 6° head-down bed rest, a spaceflight analog, to examine the role of axial body unloading on the spaceflight results. These subjects included Control and Exercise groups to examine the effects of exercise during bed rest. Spaceflight subjects showed the greatest decrement in performance during functional tasks that required the greatest demand for dynamic control of postural equilibrium which was paralleled by similar decrements in sensorimotor tests that assessed postural and dynamic gait control. Other changes included reduced lower limb muscle performance and increased heart rate to maintain blood pressure. Exercise performed during bed rest prevented detrimental change in neuromuscular and cardiovascular function, however, both bed rest groups experienced functional and balance deficits similar to spaceflight subjects. Bed rest data indicates that body support unloading experienced during spaceflight contributes to postflight postural control dysfunction. Further, the bed rest results in the Exercise group of subjects confirm that resistance and aerobic exercises performed during spaceflight can play an integral role in maintaining neuromuscular and cardiovascular function, which can help in reducing decrements in functional performance. These results indicate that a countermeasure to mitigate postflight postural control dysfunction is

Normalization of aberrant resting state functional connectivity in fibromyalgia patients following a three month physical exercise therapy

OpenAIRE

P. Flodin; S. Martinsen; K. Mannerkorpi; M. Löfgren; I. Bileviciute-Ljungar; E. Kosek; P. Fransson

2015-01-01

Physical exercise is one of the most efficient interventions to mitigate chronic pain symptoms in fibromyalgia (FM). However, little is known about the neurophysiological mechanisms mediating these effects. In this study we investigated resting-state connectivity using functional magnetic resonance imaging (fMRI) before and after a 15 week standardized exercise program supervised by physical therapists. Our aim was to gain an understanding of how physical exercise influences previously shown ...

Resting state brain dynamics and its transients: a combined TMS-EEG study.

Science.gov (United States)

Bonnard, Mireille; Chen, Sophie; Gaychet, Jérôme; Carrere, Marcel; Woodman, Marmaduke; Giusiano, Bernard; Jirsa, Viktor

2016-08-04

The brain at rest exhibits a spatio-temporally rich dynamics which adheres to systematic behaviours that persist in task paradigms but appear altered in disease. Despite this hypothesis, many rest state paradigms do not act directly upon the rest state and therefore cannot confirm hypotheses about its mechanisms. To address this challenge, we combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to study brain's relaxation toward rest following a transient perturbation. Specifically, TMS targeted either the medial prefrontal cortex (MPFC), i.e. part of the Default Mode Network (DMN) or the superior parietal lobule (SPL), involved in the Dorsal Attention Network. TMS was triggered by a given brain state, namely an increase in occipital alpha rhythm power. Following the initial TMS-Evoked Potential, TMS at MPFC enhances the induced occipital alpha rhythm, called Event Related Synchronisation, with a longer transient lifetime than TMS at SPL, and a higher amplitude. Our findings show a strong coupling between MPFC and the occipital alpha power. Although the rest state is organized around a core of resting state networks, the DMN functionally takes a special role among these resting state networks.

Resting state functional connectivity magnetic resonance imaging integrated with intraoperative neuronavigation for functional mapping after aborted awake craniotomy

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Batra, Prag; Bandt, S. Kathleen; Leuthardt, Eric C.

2016-01-01

Background: Awake craniotomy is currently the gold standard for aggressive tumor resections in eloquent cortex. However, a significant subset of patients is unable to tolerate this procedure, particularly the very young or old or those with psychiatric comorbidities, cardiopulmonary comorbidities, or obesity, among other conditions. In these cases, typical alternative procedures include biopsy alone or subtotal resection, both of which are associated with diminished surgical outcomes. Case Description: Here, we report the successful use of a preoperatively obtained resting state functional connectivity magnetic resonance imaging (MRI) integrated with intraoperative neuronavigation software in order to perform functional cortical mapping in the setting of an aborted awake craniotomy due to loss of airway. Conclusion: Resting state functional connectivity MRI integrated with intraoperative neuronavigation software can provide an alternative option for functional cortical mapping in the setting of an aborted awake craniotomy. PMID:26958419

The effect of inter-set rest intervals on resistance exercise-induced muscle hypertrophy.

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Henselmans, Menno; Schoenfeld, Brad J

2014-12-01

Due to a scarcity of longitudinal trials directly measuring changes in muscle girth, previous recommendations for inter-set rest intervals in resistance training programs designed to stimulate muscular hypertrophy were primarily based on the post-exercise endocrinological response and other mechanisms theoretically related to muscle growth. New research regarding the effects of inter-set rest interval manipulation on resistance training-induced muscular hypertrophy is reviewed here to evaluate current practices and provide directions for future research. Of the studies measuring long-term muscle hypertrophy in groups employing different rest intervals, none have found superior muscle growth in the shorter compared with the longer rest interval group and one study has found the opposite. Rest intervals less than 1 minute can result in acute increases in serum growth hormone levels and these rest intervals also decrease the serum testosterone to cortisol ratio. Long-term adaptations may abate the post-exercise endocrinological response and the relationship between the transient change in hormonal production and chronic muscular hypertrophy is highly contentious and appears to be weak. The relationship between the rest interval-mediated effect on immune system response, muscle damage, metabolic stress, or energy production capacity and muscle hypertrophy is still ambiguous and largely theoretical. In conclusion, the literature does not support the hypothesis that training for muscle hypertrophy requires shorter rest intervals than training for strength development or that predetermined rest intervals are preferable to auto-regulated rest periods in this regard.

Sparse dictionary learning of resting state fMRI networks.

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Eavani, Harini; Filipovych, Roman; Davatzikos, Christos; Satterthwaite, Theodore D; Gur, Raquel E; Gur, Ruben C

2012-07-02

Research in resting state fMRI (rsfMRI) has revealed the presence of stable, anti-correlated functional subnetworks in the brain. Task-positive networks are active during a cognitive process and are anti-correlated with task-negative networks, which are active during rest. In this paper, based on the assumption that the structure of the resting state functional brain connectivity is sparse, we utilize sparse dictionary modeling to identify distinct functional sub-networks. We propose two ways of formulating the sparse functional network learning problem that characterize the underlying functional connectivity from different perspectives. Our results show that the whole-brain functional connectivity can be concisely represented with highly modular, overlapping task-positive/negative pairs of sub-networks.

Rest and action tremor in Parkinson's disease: effects of Deep Brain Stimulation

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Heida, Tjitske; Wentink, E.C.

2010-01-01

One of the cardinal symptoms of Parkinson’s disease is rest tremor. While rest tremor generally disappears during sleep and voluntary movement, action tremor may be triggered by voluntary movement, and may even be more disabling than rest tremor. Deep brain stimulation (DBS) in the subthalamic

Rapid computation of single PET scan rest-stress myocardial blood flow parametric images by table look up.

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Guehl, Nicolas J; Normandin, Marc D; Wooten, Dustin W; Rozen, Guy; Ruskin, Jeremy N; Shoup, Timothy M; Woo, Jonghye; Ptaszek, Leon M; Fakhri, Georges El; Alpert, Nathaniel M

2017-09-01

We have recently reported a method for measuring rest-stress myocardial blood flow (MBF) using a single, relatively short, PET scan session. The method requires two IV tracer injections, one to initiate rest imaging and one at peak stress. We previously validated absolute flow quantitation in ml/min/cc for standard bull's eye, segmental analysis. In this work, we extend the method for fast computation of rest-stress MBF parametric images. We provide an analytic solution to the single-scan rest-stress flow model which is then solved using a two-dimensional table lookup method (LM). Simulations were performed to compare the accuracy and precision of the lookup method with the original nonlinear method (NLM). Then the method was applied to 16 single scan rest/stress measurements made in 12 pigs: seven studied after infarction of the left anterior descending artery (LAD) territory, and nine imaged in the native state. Parametric maps of rest and stress MBF as well as maps of left (f LV ) and right (f RV ) ventricular spill-over fractions were generated. Regions of interest (ROIs) for 17 myocardial segments were defined in bull's eye fashion on the parametric maps. The mean of each ROI was then compared to the rest (K 1r ) and stress (K 1s ) MBF estimates obtained from fitting the 17 regional TACs with the NLM. In simulation, the LM performed as well as the NLM in terms of precision and accuracy. The simulation did not show that bias was introduced by the use of a predefined two-dimensional lookup table. In experimental data, parametric maps demonstrated good statistical quality and the LM was computationally much more efficient than the original NLM. Very good agreement was obtained between the mean MBF calculated on the parametric maps for each of the 17 ROIs and the regional MBF values estimated by the NLM (K 1map LM  = 1.019 × K 1 ROI NLM  + 0.019, R 2  = 0.986; mean difference = 0.034 ± 0.036 mL/min/cc). We developed a table lookup method for fast

Learning electrocardiogram on YouTube: how useful is it?

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Akgun, Taylan; Karabay, Can Yucel; Kocabay, Gonenc; Kalayci, Arzu; Oduncu, Vecih; Guler, Ahmet; Pala, Selcuk; Kirma, Cevat

2014-01-01

YouTube has become a useful resource for knowledge and is widely used by medical students as an e-learning source. The purpose of this study was to assess the videos relating electrocardiogram (ECG) on YouTube. YouTube was searched on May 28, 2013 for the search terms "AF ecg" for atrial fibrillation, "AVNRT" for atrioventricular nodal reentrant tachycardia, "AVRT" for atrioventricular reentrant tachycardia, "AV block or heart block" for atrioventricular block, "LBBB, RBBB" for bundle branch block, "left anterior fascicular block or left posterior fascicular block" for fascicular blocks, "VT ecg" for ventricular tachycardia, "long QT" and "Brugada ecg". Non-English language, unrelated and non-educational videos were excluded. Remaining videos were assessed for usefulness, source and characteristics. Usefulness was assessed with using a checklist developed by the authors. One hundred nineteen videos were included in the analysis. Sources of the videos were as follows: individuals n=70, 58.8%, universities/hospitals n=10, 8.4% and medical organizations n=3, 2.5%, health ads n=10 8.4%, health websites n=26, 21.8%. Fifty-six (47.1%) videos were classified as very useful and 16 (13.4%) videos were misleading. 90% of the videos uploaded by universities/hospitals were grouped as very useful videos, the same ratio was 45% for the individual uploads. There were statistically significant differences in ECG diagnosis among the groups (for very useful, useful and misleading, pYouTube has a substantial amount of videos on ECG with a wide diversity from useful to misleading content. The lack of quality content relating to ECG on YouTube necessitates that videos should be selected with utmost care. © 2013 Elsevier Inc. All rights reserved.

The differences in electrocardiogram interpretation in top-level athletes.

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Jakubiak, Agnieszka A; Burkhard-Jagodzińska, Krystyna; Król, Wojciech; Konopka, Marcin; Bursa, Dominik; Sitkowski, Dariusz; Kuch, Marek; Braksator, Wojciech

2017-01-01

The Ministry of Health in Poland recommends electrocardiogram (ECG)-based cardiovascular screening in athletes, but so far there has been a lack of guidelines on preparticipation assessment. We compared different criteria of ECG screening assessment in a group of top-level athletes. The aims were to evaluate the prevalence of ECG changes in athletes that necessitate further cardiological work-up according to three criteria in various age groups as well as to identify factors determining the occurrence of changes related and unrelated to the training. 262 high-dynamic, high-static Polish athletes (rowers, cyclists, canoeists) were divided into two age categories: young (≤ 18 years of age; n = 177, mean age 16.9 ± 0.8; 15-18 years) and elite (> 18 years of age; n = 85, mean age 22.9 ± 3.4; 19-34 years). All sports persons had a 12-lead ECG performed and evaluated according to 2010 European Society of Cardiology (ESC) recommendations, 2012 Seattle criteria, and 2014 Refined criteria. The Refined criteria reduced (p < 0.001) the number of training-unrelated ECG findings to 8.0% vs. 12.6% (Seattle criteria) and 30.5% (ESC recommendations). All three criteria revealed more training-related changes in the group of older athletes (76.5% vs. 55.9%, p = 0.001). Predictors that significantly (p < 0.005) affected the occurrence of adaptive changes were the age of the athlete, training duration (in years), and male gender. 1. The ESC criteria identified a group of athletes that was unacceptably large, as for the screening test, requiring verification with other methods (every fourth athlete). 2. The use of the Refined criteria helps to significantly reduce the frequency and necessity for additional tests. 3. The dependence of adaptive changes on training duration and athletes' age confirms the benign nature of those ECG findings.

Standard Setting as Psychometric Due Process: Going a Little Further Down an Uncertain Road.

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Cizek, Gregory J.

The concept of due process provides an analogy for the process of standard setting that emphasizes many of the procedural and substantive elements of the process over technical and statistical concerns. Surely such concerns can and should continue to be addressed. However, a sound rationale for standard setting does not rest on this foundation.…

Induction of Inflammation In Vivo by Electrocardiogram Sensor Operation Using Wireless Power Transmission.

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Heo, Jin-Chul; Kim, Beomjoon; Kim, Yoon-Nyun; Kim, Dae-Kwang; Lee, Jong-Ha

2017-12-14

Prolonged monitoring by cardiac electrocardiogram (ECG) sensors is useful for patients with emergency heart conditions. However, implant monitoring systems are limited by lack of tissue biocompatibility. Here, we developed an implantable ECG sensor for real-time monitoring of ventricular fibrillation and evaluated its biocompatibility using an animal model. The implantable sensor comprised transplant sensors with two electrodes, a wireless power transmission system, and a monitoring system. The sensor was inserted into the subcutaneous tissue of the abdominal area and operated for 1 h/day for 5 days using a wireless power system. Importantly, the sensor was encapsulated by subcutaneous tissue and induced angiogenesis, inflammation, and phagocytosis. In addition, we observed that the levels of inflammation-related markers increased with wireless-powered transmission via the ECG sensor; in particular, levels of the Th-1 cytokine interleukin-12 were significantly increased. The results showed that induced tissue damage was associated with the use of wireless-powered sensors. We also investigated research strategies for the prevention of adverse effects caused by lack of tissue biocompatibility of a wireless-powered ECG monitoring system and provided information on the clinical applications of inflammatory reactions in implant treatment using the wireless-powered transmission system.

Corrected Integral Shape Averaging Applied to Obstructive Sleep Apnea Detection from the Electrocardiogram

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C. O'Brien

2007-01-01

Full Text Available We present a technique called corrected integral shape averaging (CISA for quantifying shape and shape differences in a set of signals. CISA can be used to account for signal differences which are purely due to affine time warping (jitter and dilation/compression, and hence provide access to intrinsic shape fluctuations. CISA can also be used to define a distance between shapes which has useful mathematical properties; a mean shape signal for a set of signals can be defined, which minimizes the sum of squared shape distances of the set from the mean. The CISA procedure also allows joint estimation of the affine time parameters. Numerical simulations are presented to support the algorithm for obtaining the CISA mean and parameters. Since CISA provides a well-defined shape distance, it can be used in shape clustering applications based on distance measures such as k-means. We present an application in which CISA shape clustering is applied to P-waves extracted from the electrocardiogram of subjects suffering from sleep apnea. The resulting shape clustering distinguishes ECG segments recorded during apnea from those recorded during normal breathing with a sensitivity of 81% and specificity of 84%.

Comparison of Electrocardiogram Signals in Men and Women during Creativity with Classification Approaches

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Sahar ZAKERI

2016-07-01

Full Text Available Electrocardiogram (ECG analysis is mostly used as a valuable tool in the evaluation of cognitive tasks. By taking and analyzing measurements in vast quantities, researchers are working toward a better understanding of how human physiological systems work. For the first time, this study investigated the function of the cardiovascular system during creative thinking. In addition, the difference between male/female and normal/creativity states from ECG signals was investigated. Overall, the purpose of this paper was to illustrate the heart working during the creativity, and discover the creative men or women subjects. For these goals, six nonlinear features of the ECG signal were extracted to detect creativity states. During the three tasks of the Torrance Tests of Creative Thinking (TTCT- Figural B, ECG signals were recorded from 52 participants (26 men and 26 women. Then, the proficiency of two kinds of classification approaches was evaluated: Artificial Neural Network (ANN and Support Vector Machine (SVM. The results indicated the high accuracy rate of discriminations between male/female (96.09% and normal/creativity states (95.84% using ANN classifier. Therefore, the proposed method can be useful to detect the creativity states.

The Classic: On Rest and Pain: Lecture XIV.

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Hilton, John

2009-09-01

This Classic article is a reprint of the original work by John Hilton, On Rest and Pain: Lecture XIV. An accompanying biographical sketch on John Hilton, MD, is available at DOI 10.1007/s11999-009-0927-2 . The Classic Article is reprinted with courtesy from Hilton J. On The Influence of Mechanical and Physiological Rest in the Treatment of Accidents and Surgical Diseases, and the Diagnostic Value of Pain. London, England: Bell and Daldy; 1863.

Sequential Markov chain Monte Carlo filter with simultaneous model selection for electrocardiogram signal modeling.

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Edla, Shwetha; Kovvali, Narayan; Papandreou-Suppappola, Antonia

2012-01-01

Constructing statistical models of electrocardiogram (ECG) signals, whose parameters can be used for automated disease classification, is of great importance in precluding manual annotation and providing prompt diagnosis of cardiac diseases. ECG signals consist of several segments with different morphologies (namely the P wave, QRS complex and the T wave) in a single heart beat, which can vary across individuals and diseases. Also, existing statistical ECG models exhibit a reliance upon obtaining a priori information from the ECG data by using preprocessing algorithms to initialize the filter parameters, or to define the user-specified model parameters. In this paper, we propose an ECG modeling technique using the sequential Markov chain Monte Carlo (SMCMC) filter that can perform simultaneous model selection, by adaptively choosing from different representations depending upon the nature of the data. Our results demonstrate the ability of the algorithm to track various types of ECG morphologies, including intermittently occurring ECG beats. In addition, we use the estimated model parameters as the feature set to classify between ECG signals with normal sinus rhythm and four different types of arrhythmia.

Comparison of continuously acquired resting state and extracted analogues from active tasks.

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Ganger, Sebastian; Hahn, Andreas; Küblböck, Martin; Kranz, Georg S; Spies, Marie; Vanicek, Thomas; Seiger, René; Sladky, Ronald; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

2015-10-01

Functional connectivity analysis of brain networks has become an important tool for investigation of human brain function. Although functional connectivity computations are usually based on resting-state data, the application to task-specific fMRI has received growing attention. Three major methods for extraction of resting-state data from task-related signal have been proposed (1) usage of unmanipulated task data for functional connectivity; (2) regression against task effects, subsequently using the residuals; and (3) concatenation of baseline blocks located in-between task blocks. Despite widespread application in current research, consensus on which method best resembles resting-state seems to be missing. We, therefore, evaluated these techniques in a sample of 26 healthy controls measured at 7 Tesla. In addition to continuous resting-state, two different task paradigms were assessed (emotion discrimination and right finger-tapping) and five well-described networks were analyzed (default mode, thalamus, cuneus, sensorimotor, and auditory). Investigating the similarity to continuous resting-state (Dice, Intraclass correlation coefficient (ICC), R(2) ) showed that regression against task effects yields functional connectivity networks most alike to resting-state. However, all methods exhibited significant differences when compared to continuous resting-state and similarity metrics were lower than test-retest of two resting-state scans. Omitting global signal regression did not change these findings. Visually, the networks are highly similar, but through further investigation marked differences can be found. Therefore, our data does not support referring to resting-state when extracting signals from task designs, although functional connectivity computed from task-specific data may indeed yield interesting information. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

RESTful Java patterns and best practices

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Mehta, Bhakti

2014-01-01

This book is aimed at novice developers who want to gain insights into building RESTful services and improve productivity, as well as for advanced developers who want to delve into more complicated topics.

Construction and use of a zebrafish heart voltage and calcium optical mapping system, with integrated electrocardiogram and programmable electrical stimulation

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Lin, Eric; Craig, Calvin; Lamothe, Marcel; Sarunic, Marinko V.; Beg, Mirza Faisal

2015-01-01

Zebrafish are increasingly being used as a model of vertebrate cardiology due to mammalian-like cardiac properties in many respects. The size and fecundity of zebrafish make them suitable for large-scale genetic and pharmacological screening. In larger mammalian hearts, optical mapping is often used to investigate the interplay between voltage and calcium dynamics and to investigate their respective roles in arrhythmogenesis. This report outlines the construction of an optical mapping system for use with zebrafish hearts, using the voltage-sensitive dye RH 237 and the calcium indicator dye Rhod-2 using two industrial-level CCD cameras. With the use of economical cameras and a common 532-nm diode laser for excitation, the rate dependence of voltage and calcium dynamics within the atrial and ventricular compartments can be simultaneously determined. At 140 beats/min, the atrial action potential duration was 36 ms and the transient duration was 53 ms. With the use of a programmable electrical stimulator, a shallow rate dependence of 3 and 4 ms per 100 beats/min was observed, respectively. In the ventricle the action potential duration was 109 ms and the transient duration was 124 ms, with a steeper rate dependence of 12 and 16 ms per 100 beats/min. Synchronous electrocardiograms and optical mapping recordings were recorded, in which the P-wave aligns with the atrial voltage peak and R-wave aligns with the ventricular peak. A simple optical pathway and imaging chamber are detailed along with schematics for the in-house construction of the electrocardiogram amplifier and electrical stimulator. Laboratory procedures necessary for zebrafish heart isolation, cannulation, and loading are also presented. PMID:25740339

Proposed clinical scale for the diagnosis of acute coronary syndrome in patients with an inconclusive electrocardiogram and myocardial injury biomarkers.

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Montero-Pérez, F J; Quero-Espinosa, F B; Clemente-Millán, M J; Castro-Giménez, J A; de Burgos-Marín, J; Romero-Moreno, M Á

2018-03-01

Acute coronary syndrome (ACS) requires improved diagnostic accuracy through useful, safe and easy-to-apply tools. To obtain an assessment scale for the diagnosis of ACS in patients with chest pain and nondiagnostic electrocardiogram and troponin concentrations. A prospective cohort study included 286 patients treated in the emergency department for chest pain, with normal electrocardiogram and troponin levels. Using multiple logistic regression, we obtained the independent predictors for the diagnosis of ACS. The assessment scale's discriminative power was assessed with the area under the ROC curve. The diagnosis of ACS was confirmed in 103 patients (36%). The final predictive model included 3 endpoints: a history of coronary artery disease, hyperlipidaemia and a score≥6 points on the Geleijnse scale. The area under the ROC curve for the final model was 0.90 (95% confidence interval [95% CI] 0.85-0.93). A threshold of 5 points achieved a sensitivity of 76.7% (95% CI 68-84), a specificity of 91.8% (95% CI 87-95), a positive likelihood ratio of 9.36 (95% CI 5.70-15.40), a negative likelihood ratio of 0.25 (95% CI 18.00-36.00) and an overall diagnostic accuracy of 86.4% (95% CI 82-90). The predictive model was superior to the Geleijnse scale alone. The final scale showed good discriminative capacity for diagnosing ACS and could therefore be of interest for identifying ACS in emergency departments. Nevertheless, the scale needs to be validated in larger multicentre studies. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Time interval between maternal electrocardiogram and venous Doppler waves in normal pregnancy and preeclampsia: a pilot study.

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Tomsin, K; Mesens, T; Molenberghs, G; Peeters, L; Gyselaers, W

2012-12-01

To evaluate the time interval between maternal electrocardiogram (ECG) and venous Doppler waves at different stages of uncomplicated pregnancy (UP) and in preeclampsia (PE). Cross-sectional pilot study in 40 uncomplicated singleton pregnancies, categorized in four groups of ten according to gestational age: 10 - 14 weeks (UP1), 18 - 23 weeks (UP2), 28 - 33 weeks (UP3) and ≥ 37 weeks (UP4) of gestation. A fifth group of ten women with PE was also included. A Doppler flow examination at the level of renal interlobar veins (RIV) and hepatic veins (HV) was performed according to a standard protocol, in association with a maternal ECG. The time interval between the ECG P-wave and the corresponding A-deflection of the venous Doppler waves was measured (PA), and expressed relative to the duration of the cardiac cycle (RR), and labeled PA/RR. In hepatic veins, the PA/RR is longer in UP 4 than in UP 1 (0.48 ± 0.15 versus 0.29 ± 0.09, p ≤ 0.001). When all UP groups were compared, the PA/RR increased gradually with gestational age. In PE, the HV PA/RR is shorter than in UP 3 (0.25 ± 0.09 versus 0.42 ± 0.14, p advanced gestational stages are consistent with known features of maternal cardiovascular adaptation. Shorter values in preeclampsia are consistent with maternal cardiovascular maladaptation mechanisms. Our pilot study invites more research of the relevance of the time interval between maternal ECG and venous Doppler waves as a new parameter for studying the gestational cardiovascular (patho)physiology of the maternal venous compartment by duplex sonography. © Georg Thieme Verlag KG Stuttgart · New York.

Exploring resting-state EEG brain oscillatory activity in relation to cognitive functioning in multiple sclerosis.

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Keune, Philipp M; Hansen, Sascha; Weber, Emily; Zapf, Franziska; Habich, Juliane; Muenssinger, Jana; Wolf, Sebastian; Schönenberg, Michael; Oschmann, Patrick

2017-09-01

Neurophysiologic monitoring parameters related to cognition in Multiple Sclerosis (MS) are sparse. Previous work reported an association between magnetoencephalographic (MEG) alpha-1 activity and information processing speed. While this remains to be replicated by more available electroencephalographic (EEG) methods, also other established EEG markers, e.g. the slow-wave/fast-wave ratio (theta/beta ratio), remain to be explored in this context. Performance on standard tests addressing information processing speed and attention (Symbol-Digit Modalities Test, SDMT; Test of Attention Performance, TAP) was examined in relation to resting-state EEG alpha-1 and alpha-2 activity and the theta/beta ratio in 25MS patients. Increased global alpha-1 and alpha-2 activity and an increased frontal theta/beta ratio (pronounced slow-wave relative to fast-wave activity) were associated with lower SDMT processing speed. In an exploratory analysis, clinically impaired attention was associated with a significantly increased frontal theta/beta ratio whereas alpha power did not show sensitivity to clinical impairment. EEG global alpha power and the frontal theta/beta ratio were both associated with attention. The theta/beta ratio involved potential clinical sensitivity. Resting-state EEG recordings can be obtained during the routine clinical process. The examined resting-state measures may represent feasible monitoring parameters in MS. This notion should be explored in future intervention studies. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Reliability of fully automated versus visually controlled pre- and post-processing of resting-state EEG.

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Hatz, F; Hardmeier, M; Bousleiman, H; Rüegg, S; Schindler, C; Fuhr, P

2015-02-01

To compare the reliability of a newly developed Matlab® toolbox for the fully automated, pre- and post-processing of resting state EEG (automated analysis, AA) with the reliability of analysis involving visually controlled pre- and post-processing (VA). 34 healthy volunteers (age: median 38.2 (20-49), 82% female) had three consecutive 256-channel resting-state EEG at one year intervals. Results of frequency analysis of AA and VA were compared with Pearson correlation coefficients, and reliability over time was assessed with intraclass correlation coefficients (ICC). Mean correlation coefficient between AA and VA was 0.94±0.07, mean ICC for AA 0.83±0.05 and for VA 0.84±0.07. AA and VA yield very similar results for spectral EEG analysis and are equally reliable. AA is less time-consuming, completely standardized, and independent of raters and their training. Automated processing of EEG facilitates workflow in quantitative EEG analysis. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Information Flow Between Resting-State Networks.

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Diez, Ibai; Erramuzpe, Asier; Escudero, Iñaki; Mateos, Beatriz; Cabrera, Alberto; Marinazzo, Daniele; Sanz-Arigita, Ernesto J; Stramaglia, Sebastiano; Cortes Diaz, Jesus M

2015-11-01

The resting brain dynamics self-organize into a finite number of correlated patterns known as resting-state networks (RSNs). It is well known that techniques such as independent component analysis can separate the brain activity at rest to provide such RSNs, but the specific pattern of interaction between RSNs is not yet fully understood. To this aim, we propose here a novel method to compute the information flow (IF) between different RSNs from resting-state magnetic resonance imaging. After hemodynamic response function blind deconvolution of all voxel signals, and under the hypothesis that RSNs define regions of interest, our method first uses principal component analysis to reduce dimensionality in each RSN to next compute IF (estimated here in terms of transfer entropy) between the different RSNs by systematically increasing k (the number of principal components used in the calculation). When k=1, this method is equivalent to computing IF using the average of all voxel activities in each RSN. For k≥1, our method calculates the k multivariate IF between the different RSNs. We find that the average IF among RSNs is dimension dependent, increasing from k=1 (i.e., the average voxel activity) up to a maximum occurring at k=5 and to finally decay to zero for k≥10. This suggests that a small number of components (close to five) is sufficient to describe the IF pattern between RSNs. Our method--addressing differences in IF between RSNs for any generic data--can be used for group comparison in health or disease. To illustrate this, we have calculated the inter-RSN IF in a data set of Alzheimer's disease (AD) to find that the most significant differences between AD and controls occurred for k=2, in addition to AD showing increased IF w.r.t. The spatial localization of the k=2 component, within RSNs, allows the characterization of IF differences between AD and controls.

Effects of Flotation-REST on Muscle Tension Pain

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Anette Kjellgren

2001-01-01

Full Text Available The purpose of the present study was to investigate whether the floating form of the restricted environmental stimulation technique (REST may be applied within the field of pain relief. Flotation-REST consists of a procedure whereby an individual is immersed in a tank filled with water of an extremely high salt concentration. Thirty-seven patients (14 men and 23 women suffering from chronic pain consisting of aching muscles in the neck and back area participated in the study. They were randomly assigned to either a control group (17 participants or an experimental group (20 participants. The experimental group received nine opportunities to use the flotation-REST technique in the water tank over a three-week period. The results indicated that the most severe perceived pain intensity was significantly reduced, whereas low perceived pain intensity was not influenced by the floating technique. Further, the results indicated that circulating levels of the noradrenaline metabolite 3-methoxy-4-hydroxyphenylethyleneglycol were reduced significantly in the experimental group but not in the control group following treatment, whereas endorphin levels were not affected by flotation. Flotation-REST treatment also elevated the participants' optimism and reduced the degree of anxiety or depression; at nighttime, patients who underwent flotation fell asleep more easily. The present findings describe possible changes, for the better, in patients presenting with chronic pain complaints.

Effects of flotation-REST on muscle tension pain.

Science.gov (United States)

Kjellgren, A; Sundequist, U; Norlander, T; Archer, T

2001-01-01

The purpose of the present study was to investigate whether the floating form of the restricted environmental stimulation technique (REST) may be applied within the field of pain relief. Flotation-REST consists of a procedure whereby an individual is immersed in a tank filled with water of an extremely high salt concentration. Thirty-seven patients (14 men and 23 women) suffering from chronic pain consisting of aching muscles in the neck and back area participated in the study. They were randomly assigned to either a control group (17 participants) or an experimental group (20 participants). The experimental group received nine opportunities to use the flotation-REST technique in the water tank over a three-week period. The results indicated that the most severe perceived pain intensity was significantly reduced, whereas low perceived pain intensity was not influenced by the floating technique. Further, the results indicated that circulating levels of the noradrenaline metabolite 3-methoxy-4-hydroxyphenylethyleneglycol were reduced significantly in the experimental group but not in the control group following treatment, whereas endorphin levels were not affected by flotation. Flotation-REST treatment also elevated the participants' optimism and reduced the degree of anxiety or depression; at nighttime, patients who underwent flotation fell asleep more easily. The present findings describe possible changes, for the better, in patients presenting with chronic pain complaints.

Aerobic exercise deconditioning and countermeasures during bed rest.

Science.gov (United States)

Lee, Stuart M C; Moore, Alan D; Everett, Meghan E; Stenger, Michael B; Platts, Steven H

2010-01-01

Bed rest is a well-accepted model for spaceflight in which the physiologic adaptations, particularly in the cardiovascular system, are studied and potential countermeasures can be tested. Bed rest without countermeasures results in reduced aerobic capacity and altered submaximal exercise responses. Aerobic endurance and factors which may impact prolonged exercise, however, have not been well studied. The initial loss of aerobic capacity is rapid, occurring in parallel with the loss of plasma volume. Thereafter, the reduction in maximal aerobic capacity proceeds more slowly and is influenced by central and peripheral adaptation. Exercise capacity can be maintained during bed rest and may be improved during recovery with appropriate countermeasures. Plasma volume restoration, resistive exercise, orthostatic stress, aerobic exercise, and aerobic exercise plus orthostatic stress all have been tested with varying levels of success. However, the optimal combination of elements-exercise modality, intensity, duration, muscle groups exercised and frequency of aerobic exercise, orthostatic stress, and supplementary resistive or anaerobic exercise training-has not been systematically evaluated. Currently, frequent (at least 3 days per week) bouts of intense exercise (interval-style and near maximal) with orthostatic stress appears to be the most efficacious method to protect aerobic capacity during bed rest. Further refinement of protocols and countermeasure hardware may be necessary to insure the success of countermeasures in the unique environment of space.

Quantitative performance of E-Scribe warehouse in detecting quality issues with digital annotated ECG data from healthy subjects.

Science.gov (United States)

Sarapa, Nenad; Mortara, Justin L; Brown, Barry D; Isola, Lamberto; Badilini, Fabio

2008-05-01

The US Food and Drug Administration recommends submission of digital electrocardiograms in the standard HL7 XML format into the electrocardiogram warehouse to support preapproval review of new drug applications. The Food and Drug Administration scrutinizes electrocardiogram quality by viewing the annotated waveforms and scoring electrocardiogram quality by the warehouse algorithms. Part of the Food and Drug Administration warehouse is commercially available to sponsors as the E-Scribe Warehouse. The authors tested the performance of E-Scribe Warehouse algorithms by quantifying electrocardiogram acquisition quality, adherence to QT annotation protocol, and T-wave signal strength in 2 data sets: "reference" (104 digital electrocardiograms from a phase I study with sotalol in 26 healthy subjects with QT annotations by computer-assisted manual adjustment) and "test" (the same electrocardiograms with an intentionally introduced predefined number of quality issues). The E-Scribe Warehouse correctly detected differences between the 2 sets expected from the number and pattern of errors in the "test" set (except for 1 subject with QT misannotated in different leads of serial electrocardiograms) and confirmed the absence of differences where none was expected. E-Scribe Warehouse scores below the threshold value identified individual electrocardiograms with questionable T-wave signal strength. The E-Scribe Warehouse showed satisfactory performance in detecting electrocardiogram quality issues that may impair reliability of QTc assessment in clinical trials in healthy subjects.

Genetic variablilities of body temperature and resting behaviour in ...

African Journals Online (AJOL)

This implies that neither progeny nor generation had effect on body temperature. The Alpha strain exhibited more resting behaviour than did the exotic and the pure native types. Majority of the birds rested in the afternoon at 2.00 pm. This could be attributed to the fact that at 2.00 pm the weather is hot and birds search for a ...

Are particle rest masses variable: Theory and constraints from solar system experiments

International Nuclear Information System (INIS)

Bekenstein, J.D.

1977-01-01

Particle rest mass variation in spacetime is considered. According to Dicke, if this is the case various null experiments indicate that all masses vary in the same way. Their variation relative to the Planck-Wheeler mass defines a universal scalar rest-mass field. We construct the relativistic dynamics for this field based on very general assumptions. In addition, we assume Einstein's equations to be valid in Planck-Wheeler units. A special case of the theory coincides with Dicke's reformulation of Brans-Dicke theory as general relativity with variable rest masses. In the general case the rest-mass field is some power r of a scalar field which obeys an ordinary scalar equation with coupling to the curvature of strength q. The r and q are the only parameters of the theory. Comparison with experiment is facilitated by recasting the theory into units in which rest masses are constant, the Planck-Wheeler mass varies, and the metric satisfies the equations of a small subset of the scalar-tensor theories of gravitation. The results of solar system experiments, usually used to test general relativity, are here used to delimit the acceptable values of r and q. We conclude that if cosmological considerations are not invoked, then the solar system experiments do not rule out the possibility of rest-mass variability. That is, there are theories which agree with all null and solar system experiments, and yet contradict the strong equivalence principle by allowing rest masses to vary relative to the Planck-Wheeler mass. We show that the field theory of the rest-mass field can be quantized and interpreted in terms of massless scalar quanta which interact very weakly with matter. This explains why they have not turned up in high-energy experiments. In future reports we shall investigate the implications of various cosmological and astrophysical data for the theory of variable rest masses. The ultimate goal is a firm decision on whether rest masses vary or not

Increased interhemispheric resting-state functional connectivity after sleep deprivation: a resting-state fMRI study.

Science.gov (United States)

Zhu, Yuanqiang; Feng, Zhiyan; Xu, Junling; Fu, Chang; Sun, Jinbo; Yang, Xuejuan; Shi, Dapeng; Qin, Wei

2016-09-01

Several functional imaging studies have investigated the regional effects of sleep deprivation (SD) on impaired brain function; however, potential changes in the functional interactions between the cerebral hemispheres after SD are not well understood. In this study, we used a recently validated approach, voxel-mirrored homotopic connectivity (VMHC), to directly examine the changes in interhemispheric homotopic resting-state functional connectivity (RSFC) after SD. Resting-state functional MRI (fMRI) was performed in 28 participants both after rest wakefulness (RW) and a total night of SD. An interhemispheric RSFC map was obtained by calculating the Pearson correlation (Fisher Z transformed) between each pair of homotopic voxel time series for each subject in each condition. The between-condition differences in interhemispheric RSFC were then examined at global and voxelwise levels separately. Significantly increased global VMHC was found after sleep deprivation; specifically, a significant increase in VMHC was found in specific brain regions, including the thalamus, paracentral lobule, supplementary motor area, postcentral gyrus and lingual gyrus. No regions showed significantly reduced VMHC after sleep deprivation. Further analysis indicates that these findings did not depend on the various sizes of smoothing kernels that were adopted in the preprocessing steps and that the differences in these regions were still significant with or without global signal regression. Our data suggest that the increased VMHC might reflect the compensatory involvement of bilateral brain areas, especially the bilateral thalamus, to prevent cognitive performance deterioration when sleep pressure is elevated after sleep deprivation. Our findings provide preliminary evidence of interhemispheric correlation changes after SD and contribute to a better understanding of the neural mechanisms of SD.

Resting-state networks in healthy adult subjects: a comparison between a 32-element and an 8-element phased array head coil at 3.0 Tesla.

Science.gov (United States)

Paolini, Marco; Keeser, Daniel; Ingrisch, Michael; Werner, Natalie; Kindermann, Nicole; Reiser, Maximilian; Blautzik, Janusch

2015-05-01

Little research exists on the influence of a magnetic resonance imaging (MRI) head coil's channel count on measured resting-state functional connectivity. To compare a 32-element (32ch) and an 8-element (8ch) phased array head coil with respect to their potential to detect functional connectivity within resting-state networks. Twenty-six healthy adults (mean age, 21.7 years; SD, 2.1 years) underwent resting-state functional MRI at 3.0 Tesla with both coils using equal standard imaging parameters and a counterbalanced design. Independent component analysis (ICA) at different model orders and a dual regression approach were performed. Voxel-wise non-parametric statistical between-group contrasts were determined using permutation-based non-parametric inference. Phantom measurements demonstrated a generally higher image signal-to-noise ratio using the 32ch head coil. However, the results showed no significant differences between corresponding resting-state networks derived from both coils (p coil does not offer any significant advantages in detecting ICA-based functional connectivity within RSNs. © The Foundation Acta Radiologica 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Continuous ECG Monitoring in Patients With Acute Coronary Syndrome or Heart Failure: EASI Versus Gold Standard.

Science.gov (United States)

Lancia, Loreto; Toccaceli, Andrea; Petrucci, Cristina; Romano, Silvio; Penco, Maria

2018-05-01

The purpose of the study was to compare the EASI system with the standard 12-lead surface electrocardiogram (ECG) for the accuracy in detecting the main electrocardiographic parameters (J point, PR, QT, and QRS) commonly monitored in patients with acute coronary syndromes or heart failure. In this observational comparative study, 253 patients who were consecutively admitted to the coronary care unit with acute coronary syndrome or heart failure were evaluated. In all patients, two complete 12-lead ECGs were acquired simultaneously. A total of 6,072 electrocardiographic leads were compared (3,036 standard and 3,036 EASI). No significant differences were found between the investigate parameters of the two measurement methods, either in patients with acute coronary syndrome or in those with heart failure. This study confirmed the accuracy of the EASI system in monitoring the main ECG parameters in patients admitted to the coronary care unit with acute coronary syndrome or heart failure.

Electrocardiogram Pattern Recognition and Analysis Based on Artificial Neural Networks and Support Vector Machines: A Review

Directory of Open Access Journals (Sweden)

Mario Sansone

2013-01-01

Full Text Available Computer systems for Electrocardiogram (ECG analysis support the clinician in tedious tasks (e.g., Holter ECG monitored in Intensive Care Units or in prompt detection of dangerous events (e.g., ventricular fibrillation. Together with clinical applications (arrhythmia detection and heart rate variability analysis, ECG is currently being investigated in biometrics (human identification, an emerging area receiving increasing attention. Methodologies for clinical applications can have both differences and similarities with respect to biometrics. This paper reviews methods of ECG processing from a pattern recognition perspective. In particular, we focus on features commonly used for heartbeat classification. Considering the vast literature in the field and the limited space of this review, we dedicated a detailed discussion only to a few classifiers (Artificial Neural Networks and Support Vector Machines because of their popularity; however, other techniques such as Hidden Markov Models and Kalman Filtering will be also mentioned.

Analysis of Arterial Mechanics During Head-Down-Tilt Bed Rest

Science.gov (United States)

Elliott, Morgan B.; Martin, David S.; Westby, Christian M.; Stenger, Michael B.; Platts, Steven H.

2014-01-01

Carotid, brachial, and tibial arteries reacted differently to HDTBR. Previous studies have not analyzed the mechanical properties of the human brachial or anterior tibial arteries. After slight variations during bed-rest, arterial mechanical properties and IMT returned to pre-bed rest values, with the exception of tibial stiffness and PSE, which continued to be reduced post-bed rest while the DC remained elevated. The tibial artery remodeling was probably due to decreased pressure and volume. Resulting implications for longer duration spaceflight are unclear. Arterial health may be affected by microgravity, as shown by increased thoracic aorta stiffness in other ground based simulations (Aubert).

Long Rest Interval Promotes Durable Testosterone Responses in High-Intensity Bench Press.

Science.gov (United States)

Scudese, Estevão; Simão, Roberto; Senna, Gilmar; Vingren, Jakob L; Willardson, Jeffrey M; Baffi, Matheus; Miranda, Humberto

2016-05-01

The purpose of this study was to examine the influence of rest period duration (1 vs. 3 minute between sets) on acute hormone responses to a high-intensity and equal volume bench press workout. Ten resistance-trained men (25.2 ± 5.6 years; 78.2 ± 5.7 kg; 176.7 ± 5.4 cm; bench press relative strength: 1.3 ± 0.1 kg per kilogram of body mass) performed 2 bench press workouts separated by 1 week. Each workout consisted of 5 sets of 3 repetitions performed at 85% of 1 repetition maximum, with either 1- or 3-minute rest between sets. Circulating concentrations of total testosterone (TT), free testosterone (FT), cortisol (C), testosterone/cortisol ratio (TT/C), and growth hormone (GH) were measured at preworkout (PRE), and immediately (T0), 15 minutes (T15), and 30 minutes (T30) postworkout. Rating of perceived exertion was recorded before and after each set. For TT, both rest lengths enhanced all postexercise verifications (T0, T15, and T30) compared with PRE, with 1 minute showing decreases on T15 and T30 compared with T0. For FT, both 1- and 3-minute rest protocols triggered augmentations on distinct postexercise moments (T0 and T15 for 1 minute; T15 and T30 for 3-minute) compared with PRE. The C values did not change throughout any postexercise verification for either rests. The TT/C ratio was significantly elevated for both rests in all postexercise moments compared with PRE. Finally, GH values did not change for both rest lengths. In conclusion, although both short and long rest periods enhanced acute testosterone values, the longer rest promoted a long-lasting elevation for both TT and FT.

Serial thallium-201 imaging at rest in patients with unstable and stable angina pectoris: relationship of myocardial perfusion at rest to presenting clinical syndrome

International Nuclear Information System (INIS)

Brown, K.A.; Okada, R.D.; Boucher, C.A.; Phillips, H.R.; Strauss, H.W.; Pohost, G.M.

1983-01-01

In order to determine whether there are differences in myocardial perfusion at rest among patients with various unstable and stable angina syndromes, serial thallium-201 imaging was performed at rest in 19 patients presenting with rapidly worsening exertional angina (unstable angina, group A), 12 patients with rest angina alone without exertional symptoms (unstable angina, group B), and 34 patients with chronic stable angina. No patient had an episode of angina within 4 hours of study. Nineteen of 19 (100%) patients in group A demonstrated transient defects compared to only 3 of 12 (25%) patients in group B (p less than 0.0001) and 4 of 34 (12%) stable angina patients (p less than 0.0001). The majority of zones demonstrating transient defects in group A were associated with hypokinesis of the corresponding left ventriculogram segment without associated ECG evidence of previous infarction. There were no significant differences in the frequency of persistent thallium defects, severity of angiographic coronary artery disease, or frequency of regional wall motion abnormalities of myocardial segments supplied by stenotic coronary arteries among the three groups of patients. Transient defects have been shown to reflect reduction in regional coronary blood flow to viable myocardium. Therefore, we conclude that regional resting hypoperfusion of viable myocardium is far more common in patients with exertional unstable angina symptoms than in patients with rest angina alone or chronic stable angina

Improved sensitivity and specificity for resting state and task fMRI with multiband multi-echo EPI compared to multi-echo EPI at 7T.

NARCIS (Netherlands)

Boyacioglu, R.; Schulz, J.; Koopmans, P.J.; Barth, M.; Norris, David Gordon

2015-01-01

A multiband multi-echo (MBME) sequence is implemented and compared to a matched standard multi-echo (ME) protocol to investigate the potential improvement in sensitivity and spatial specificity at 7 T for resting state and task fMRI. ME acquisition is attractive because BOLD sensitivity is less

Dosimetry requirements derived from the sterilization standards

DEFF Research Database (Denmark)

Miller, A.

1998-01-01

The main standards for radiation sterilization, ISO 11137 and EN 552, rest the documentation for the properly executed sterilization process on dosimetry. Both standards describe general requirements to the dosimetry system: The dose measurements must be traceable to national standards...... and documented uncertainty limits of the dose measurements can be used to specify process control limits. This is also useful, for example, when dose setting experiments are carried out according to the methods described in ISO 11137, where product samples shall be irradiated within narrow limits......., the uncertainty of the dose measurement and the environmental influences must be known. This paper discusses how to obtain and maintain traceability and how to document measurement uncertainty. The implications of these requirements in the process control of radiation sterilization are further discussed. Known...

Correlation of Respiratory Signals and Electrocardiogram Signals via Empirical Mode Decomposition

KAUST Repository

El Fiky, Ahmed Osama

2011-05-24

Recently Electrocardiogram (ECG) signals are being broadly used as an essential diagnosing tool in different clinical applications as they carry a reliable representation not only for cardiac activities, but also for other associated biological processes, like respiration. However, the process of recording and collecting them has usually suffered from the presence of some undesired noises, which in turn affects the reliability of such representations.Therefore, de-noising ECG signals became a hot research field for signal processing experts to ensure better and clear representation of the different cardiac activities. Given the nonlinear and non-stationary properties of ECGs, it is not a simple task to cancel the undesired noise terms without affecting the biological physics of them. In this study, we are interested in correlating the ECG signals with respiratory parameters, specifically the lung volume and lung pressure. We have focused on the concept of de-noising ECG signals by means of signal decomposition using an algorithm called the Empirical Mode Decomposition (EMD) where the original ECG signals are being decomposed into a set of intrinsic mode functions (IMF). Then, we have provided criteria based on which some of these IMFs have been adapted to reconstruct de-noised ECG version. Finally, we have utilized de-noised ECGs as well as IMFs for to study the correlation with lung volume and lung pressure. These correlation studies have showed some clear resemblance especially between the oscillations of ECGs and lung pressures.

The effect of sport on computerized electrocardiogram measurements in college athletes.

Science.gov (United States)

Gademan, Maaike G J; Uberoi, Abhimanyu; Le, Vy-Van; Mandic, Sandra; van Oort, Eddy R; Myers, Jonathan; Froelicher, Victor F

2012-02-01

Broad criteria for abnormal electrocardiogram (ECG) findings, requiring additional testing, have been recommended for preparticipation exams (PPE) of athletes. As these criteria have not considered the sport in which athletes participate, we examined the effect of sports on the computerized ECG measurements obtained in college athletes. During the Stanford 2007 PPE, computerized 12-lead ECGs (Schiller AG) were obtained in 641 athletes (350 male/291 female, age 19.5 ± 2 years). Athletes were engaged in 22 different sports and were grouped into 16 categories: baseball/softball, basketball, crew, crosscountry, fencing, field events, football linemen, football other positions, golf, gymnastics, racquet sports, sailing, track/field, volleyball, water sports, and wrestling. The analysis focused on ECG leads V2, aVF and V5 which provide a three-dimensional representation of the heart's electrical activity. As marked ECG differences exist between males and females, the data are presented by gender. In males, ANOVA analysis yielded significant ECG differences between sports for heart rate, QRS duration, QTc, J-amplitude in V2 and V5, spatial vector length (SVL) of the P wave, SVL R wave, and SVL T wave, and RS(sum) (p sports were found for heart rate, QRS duration, QRS axis and SVL T wave (p sports, and these differences were more apparent in males than females. Therefore, sport-specific ECG criteria for abnormal ECG findings should be developed to obtain a more useful approach to ECG screening in athletes.

Application of artificial neural networks for versatile preprocessing of electrocardiogram recordings.

Science.gov (United States)

Mateo, J; Rieta, J J

2012-02-01

The electrocardiogram (ECG) is the most widely used method for diagnosis of heart diseases, where a good quality of recordings allows the proper interpretation and identification of physiological and pathological phenomena. However, ECG recordings often have interference from noises including thermal, muscle, baseline and powerline noises. These signals severely limit ECG recording utility and, hence, have to be removed. To deal with this problem, the present paper proposes an artificial neural network (ANN) as a filter to remove all kinds of noise in just one step. The method is based on a growing ANN which optimizes both the number of nodes in the hidden layer and the coefficient matrices, which are optimized by means of the Widrow-Hoff delta algorithm. The ANN has been trained with a database comprising all kinds of noise, both from synthesized and real ECG recordings, in order to handle any noise signal present in the ECG. The proposed system improves results yielded by conventional techniques of ECG filtering, such as FIR-based systems, adaptive filtering and wavelet filtering. Therefore, the algorithm could serve as an effective framework to substantially reduce noise in ECG recordings. In addition, the resulting ECG signal distortion is notably more reduced in comparison with conventional methodologies. In summary, the current contribution introduces a new method which is able to suppress all ECG interference signals in only one step with low ECG distortion and a high noise reduction.

ST-segment deviation on the admission electrocardiogram, treatment strategy, and outcome in non-ST-elevation acute coronary syndromes - A substudy of the Invasive versus Conservative Treatment in Unstable coronary Syndromes (ICTUS) Trial

NARCIS (Netherlands)

Windhausen, Fons; Hirsch, Alexander; Tijssen, Jan G. P.; Cornel, Jan Hein; Verheugt, Freek W. A.; Klees, Margriet I.; de Winter, Robbert J.

2007-01-01

Background: We assessed the prognostic significance of the presence of cumulative (Sigma) ST-segment deviation on the admission electrocardiogram (ECG) in patients with non-ST-elevation acute coronary syndrome and an elevated troponin T randomized to a selective invasive (SI) or an early invasive

Intrinsic resting-state activity predicts working memory brain activation and behavioral performance.

Science.gov (United States)

Zou, Qihong; Ross, Thomas J; Gu, Hong; Geng, Xiujuan; Zuo, Xi-Nian; Hong, L Elliot; Gao, Jia-Hong; Stein, Elliot A; Zang, Yu-Feng; Yang, Yihong

2013-12-01

Although resting-state brain activity has been demonstrated to correspond with task-evoked brain activation, the relationship between intrinsic and evoked brain activity has not been fully characterized. For example, it is unclear whether intrinsic activity can also predict task-evoked deactivation and whether the rest-task relationship is dependent on task load. In this study, we addressed these issues on 40 healthy control subjects using resting-state and task-driven [N-back working memory (WM) task] functional magnetic resonance imaging data collected in the same session. Using amplitude of low-frequency fluctuation (ALFF) as an index of intrinsic resting-state activity, we found that ALFF in the middle frontal gyrus and inferior/superior parietal lobules was positively correlated with WM task-evoked activation, while ALFF in the medial prefrontal cortex, posterior cingulate cortex, superior frontal gyrus, superior temporal gyrus, and fusiform gyrus was negatively correlated with WM task-evoked deactivation. Further, the relationship between the intrinsic resting-state activity and task-evoked activation in lateral/superior frontal gyri, inferior/superior parietal lobules, superior temporal gyrus, and midline regions was stronger at higher WM task loads. In addition, both resting-state activity and the task-evoked activation in the superior parietal lobule/precuneus were significantly correlated with the WM task behavioral performance, explaining similar portions of intersubject performance variance. Together, these findings suggest that intrinsic resting-state activity facilitates or is permissive of specific brain circuit engagement to perform a cognitive task, and that resting activity can predict subsequent task-evoked brain responses and behavioral performance. Copyright © 2012 Wiley Periodicals, Inc.

Resting-state connectivity of pre-motor cortex reflects disability in multiple sclerosis.

Science.gov (United States)

Dogonowski, A-M; Siebner, H R; Soelberg Sørensen, P; Paulson, O B; Dyrby, T B; Blinkenberg, M; Madsen, K H

2013-11-01

To characterize the relationship between motor resting-state connectivity of the dorsal pre-motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS). A total of 27 patients with relapsing-remitting MS (RR-MS) and 15 patients with secondary progressive MS (SP-MS) underwent functional resting-state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting-state connectivity. Multiple regression analysis was performed in SPM8 between the individual expression of motor resting-state connectivity in PMd and EDSS scores including age as covariate. Separate post hoc analyses were performed for patients with RR-MS and SP-MS. The EDSS scores ranged from 0 to 7 with a median score of 4.3. Motor resting-state connectivity of left PMd showed a positive linear relation with clinical disability in patients with MS. This effect was stronger when considering the group of patients with RR-MS alone, whereas patients with SP-MS showed no increase in coupling strength between left PMd and the motor resting-state network with increasing clinical disability. No significant relation between motor resting-state connectivity of the right PMd and clinical disability was detected in MS. The increase in functional coupling between left PMd and the motor resting-state network with increasing clinical disability can be interpreted as adaptive reorganization of the motor system to maintain motor function, which appears to be limited to the relapsing-remitting stage of the disease. © 2013 John Wiley & Sons A/S.

Resting-State Connectivity Predicts Levodopa-Induced Dyskinesias in Parkinson's Disease

DEFF Research Database (Denmark)

Herz, Damian M.; Haagensen, Brian N.; Nielsen, Silas H.

2016-01-01

Background: Levodopa-induced dyskinesias are a common side effect of dopaminergic therapy in PD, but their neural correlates remain poorly understood. Objectives: This study examines whether dyskinesias are associated with abnormal dopaminergic modulation of resting-state cortico-striatal connect......Background: Levodopa-induced dyskinesias are a common side effect of dopaminergic therapy in PD, but their neural correlates remain poorly understood. Objectives: This study examines whether dyskinesias are associated with abnormal dopaminergic modulation of resting-state cortico......-striatal connectivity. Methods: Twelve PD patients with peak-of-dose dyskinesias and 12 patients without dyskinesias were withdrawn from dopaminergic medication. All patients received a single dose of fast-acting soluble levodopa and then underwent resting-state functional magnetic resonance imaging before any...... dyskinesias emerged. Levodopa-induced modulation of cortico-striatal resting-state connectivity was assessed between the putamen and the following 3 cortical regions of interest: supplementary motor area, primary sensorimotor cortex, and right inferior frontal gyrus. These functional connectivity measures...

Resting release of acetylcholine at the motor endplate

International Nuclear Information System (INIS)

Molenaar, P.C.; Polak, R.L.

1986-01-01

This paper reviews recent work on resting release of ACh in frog, rat and mouse skeletal muscle. Because of the effect of Ca 2+ on resting release it was of interest to know whether non-quantal release of ACh is increased under conditions of increased Ca 2+ influx, viz. during depolarization of the nerve terminals. It is shown that depolarization of the motor nerve terminals by K + ions led to an increase of both min.e.p.c. frequency and chemically detectable ACh release

Hemifacial Display of Emotion in the Resting State

Directory of Open Access Journals (Sweden)

M. K. Mandal

1992-01-01

Full Text Available The human face at rest displays distinguishable asymmetries with some lateralization of emotion or expression. The asymmetrical nature of the resting face was examined by preparing hemifacial composites, left–left, right–right, along with normal facial orientation. The left side and right side composites were constructed by using the lateral half of one side of the face and its mirror-reversal. The left side facial composites were found to be more emotional than the right side or normal facial orientations of neutral expressions.

Non-invasive prediction of catheter ablation outcome in persistent atrial fibrillation by fibrillatory wave amplitude computation in multiple electrocardiogram leads.

Science.gov (United States)

Zarzoso, Vicente; Latcu, Decebal G; Hidalgo-Muñoz, Antonio R; Meo, Marianna; Meste, Olivier; Popescu, Irina; Saoudi, Nadir

2016-12-01

Catheter ablation (CA) of persistent atrial fibrillation (AF) is challenging, and reported results are capable of improvement. A better patient selection for the procedure could enhance its success rate while avoiding the risks associated with ablation, especially for patients with low odds of favorable outcome. CA outcome can be predicted non-invasively by atrial fibrillatory wave (f-wave) amplitude, but previous works focused mostly on manual measures in single electrocardiogram (ECG) leads only. To assess the long-term prediction ability of f-wave amplitude when computed in multiple ECG leads. Sixty-two patients with persistent AF (52 men; mean age 61.5±10.4years) referred for CA were enrolled. A standard 1-minute 12-lead ECG was acquired before the ablation procedure for each patient. F-wave amplitudes in different ECG leads were computed by a non-invasive signal processing algorithm, and combined into a mutivariate prediction model based on logistic regression. During an average follow-up of 13.9±8.3months, 47 patients had no AF recurrence after ablation. A lead selection approach relying on the Wald index pointed to I, V1, V2 and V5 as the most relevant ECG leads to predict jointly CA outcome using f-wave amplitudes, reaching an area under the curve of 0.854, and improving on single-lead amplitude-based predictors. Analysing the f-wave amplitude in several ECG leads simultaneously can significantly improve CA long-term outcome prediction in persistent AF compared with predictors based on single-lead measures. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Learning a common dictionary for subject-transfer decoding with resting calibration.

Science.gov (United States)

Morioka, Hiroshi; Kanemura, Atsunori; Hirayama, Jun-ichiro; Shikauchi, Manabu; Ogawa, Takeshi; Ikeda, Shigeyuki; Kawanabe, Motoaki; Ishii, Shin

2015-05-01

Brain signals measured over a series of experiments have inherent variability because of different physical and mental conditions among multiple subjects and sessions. Such variability complicates the analysis of data from multiple subjects and sessions in a consistent way, and degrades the performance of subject-transfer decoding in a brain-machine interface (BMI). To accommodate the variability in brain signals, we propose 1) a method for extracting spatial bases (or a dictionary) shared by multiple subjects, by employing a signal-processing technique of dictionary learning modified to compensate for variations between subjects and sessions, and 2) an approach to subject-transfer decoding that uses the resting-state activity of a previously unseen target subject as calibration data for compensating for variations, eliminating the need for a standard calibration based on task sessions. Applying our methodology to a dataset of electroencephalography (EEG) recordings during a selective visual-spatial attention task from multiple subjects and sessions, where the variability compensation was essential for reducing the redundancy of the dictionary, we found that the extracted common brain activities were reasonable in the light of neuroscience knowledge. The applicability to subject-transfer decoding was confirmed by improved performance over existing decoding methods. These results suggest that analyzing multisubject brain activities on common bases by the proposed method enables information sharing across subjects with low-burden resting calibration, and is effective for practical use of BMI in variable environments. Copyright © 2015 Elsevier Inc. All rights reserved.

Earth-Base: A Free And Open Source, RESTful Earth Sciences Platform

Science.gov (United States)

Kishor, P.; Heim, N. A.; Peters, S. E.; McClennen, M.

2012-12-01

This presentation describes the motivation, concept, and architecture behind Earth-Base, a web-based, RESTful data-management, analysis and visualization platform for earth sciences data. Traditionally web applications have been built directly accessing data from a database using a scripting language. While such applications are great at bring results to a wide audience, they are limited in scope to the imagination and capabilities of the application developer. Earth-Base decouples the data store from the web application by introducing an intermediate "data application" tier. The data application's job is to query the data store using self-documented, RESTful URIs, and send the results back formatted as JavaScript Object Notation (JSON). Decoupling the data store from the application allows virtually limitless flexibility in developing applications, both web-based for human consumption or programmatic for machine consumption. It also allows outside developers to use the data in their own applications, potentially creating applications that the original data creator and app developer may not have even thought of. Standardized specifications for URI-based querying and JSON-formatted results make querying and developing applications easy. URI-based querying also allows utilizing distributed datasets easily. Companion mechanisms for querying data snapshots aka time-travel, usage tracking and license management, and verification of semantic equivalence of data are also described. The latter promotes the "What You Expect Is What You Get" (WYEIWYG) principle that can aid in data citation and verification.

Diagnostic value of stress-rest myocardial perfusion imaging in detection of coronary disease in elderly patients

International Nuclear Information System (INIS)

Han Pingping; Tian Yueqin; Fang Wei; Shen Rui; Yang Minfu; Wei Hongxing; Guo Xinhua; He Zuoxiang

2009-01-01

Objective: Coronary artery disease is one of the most common causes of death in elderly people. Yet, definite diagnosis is a dilemma due to the variety of symptoms and signs. The aim of this study was to evaluate the diagnostic value of nuclear stress-rest myocardial perfusion imaging(MPI) in detection of coronary disease in the elderly. Methods: Two hundred and five elderly subjects (≥60 years old, average of 67 ± 5) who were suspected to have coronary disease, underwent both stress-rest myocardial perfusion imaging (185 with exercise stress and 20 with adenosine stress) and coronary angiography (CAG). All had no pereutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Coronary angiography was used as a 'golden standard' to evaluate the sensitivity, specificity and accuracy of the stress-rest myocardial perfusion imaging. χ 2 -test was used in data analysis with SPSS 15.0. Results: Among 205 patients. there were 57 patients with an abnormal CAG result and 148 patients with a normal result. Of the 57 patients, there were 30 one-, 19 two-, and 8 three-vessel stenosis. Fifteen were mild-, 17 were moderate-, 17 were severe stenosis, and 8 were totally occluded.About 63% (36/57) had positive stress-rest MPI. Of the 148 subjects who had a normal CAG, 135 had negative MPL. The sensitivity.specificity and accuracy of stress MPI were 63% (36/57), 91% (135/148) and 83% (171/205) in patient level.respectively. The di-agnostic sensitivities of stress-rest MPI for detection of one-, two-, and three-vessel stenosis were 57%(17/30), 58% (11/19) and 8/8, respectively. All 185 patients who underwent exemise stress MPI were divided into 2 groups according to whether the patients reached the target heart rate or not at the peak of the test. And 53 patients (29%) were group 1 (reached the target heart rate)and 132 patients (71%) were group 2 (did not reach the target heart rate). The sensitivity of group 1 wag higher than that of group 2, but with no

Mach's principle and the rest mass of the graviton

International Nuclear Information System (INIS)

Woodward, J.F.; Crowley, R.J.; Yourgrau, W.

1975-01-01

The question of the graviton rest mass is briefly discussed and then it is shown that the Sciama-Dicke formulation of Mach's principle admits, in the linear approximation, the calculation of the graviton rest mass. One finds that the value of the graviton rest mass depends on the cosmological model adopted, the mean matter density in the universe, the speed of light, and the constant of gravitation. The value obtained for an infinite, stationary universe is 7.6 times 10 -67 g. The value for evolutionary cosmological models is found to depend critically on the mass and ''radius'' of the universe, both null and non-null values occurring only for certain values of these parameters. Problems that arise as a consequence of the linear approximation are pointed out

Focal Gray Matter Plasticity as a Function of Long Duration Head Down Tilted Bed Rest: Preliminary Results

Science.gov (United States)

Koppelmans, V.; Erdeniz, B.; DeDios, Y. E.; Wood, S. J.; Reuter-Lorenz, P. A.; Kofman, I.; Bloomberg, J. J.; Mulavara, A. P.; Seidler, R. D.

2014-01-01

. Longitudinal processing in VBM8 includes linear registration of each scan to the mean of the subject and subsequently transforming all scans in to MNI space by applying the warp from the mean subject to MNI to the individual gray matter segmentations. Modulation was applied so that all images represented the volume of the original structure in native space. Voxel wise analysis was carried out on the gray matter images after smoothing, using a flexible factorial design with family wise error correction. Focal changes in white matter microstructural integrity were assessed using tract based spatial statistics (TBSS) as part of FMRIB software library (FSL). TBSS registers all DTI scans to standard space. It subsequently creates a study specific white matter skeleton of the major white matter tracts. For each subject, for each DTI metric (i.e. fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD)), the maximum value in a line perpendicular to the skeleton tract is projected to the skeleton. Non-parametric permutation based t-tests and ANOVA's were used for voxel-wise comparison of the skeletons. For both VBM and TBSS, comparison of pre bed rest measurements did not show significant differences. VBM analysis revealed decreased gray matter density in bilateral areas including the frontal medial cortex, the insular cortex and the caudate (see Figure) from 'pre to in bed rest'. Over the same time period, there was an increase in gray matter density in the cerebellum, occipital-, and parietal cortex, including the precuneus (see Figure). The majority of these changes did not recover from 'during to post bed rest'. TBSS analysis did not reveal significant changes in white matter microstructural integrity after correction for multiple comparisons. Uncorrected analyses (p<.015) revealed an increase in RD in the cerebellum and brainstem from pre bed rest to the first week in bed rest that did not recover post bed rest. Extended bed rest

REST/NRSF Knockdown Alters Survival, Lineage Differentiation and Signaling in Human Embryonic Stem Cells.

Directory of Open Access Journals (Sweden)

Kaushali Thakore-Shah

Full Text Available REST (RE1 silencing transcription factor, also known as NRSF (neuron-restrictive silencer factor, is a well-known transcriptional repressor of neural genes in non-neural tissues and stem cells. Dysregulation of REST activity is thought to play a role in diverse diseases including epilepsy, cancer, Down's syndrome and Huntington's disease. The role of REST/NRSF in control of human embryonic stem cell (hESC fate has never been examined. To evaluate the role of REST in hESCs we developed an inducible REST knockdown system and examined both growth and differentiation over short and long term culture. Interestingly, we have found that altering REST levels in multiple hESC lines does not result in loss of self-renewal but instead leads to increased survival. During differentiation, REST knockdown resulted in increased MAPK/ERK and WNT signaling and increased expression of mesendoderm differentiation markers. Therefore we have uncovered a new role for REST in regulation of growth and early differentiation decisions in human embryonic stem cells.

Detection of Acute Myocardial Infarction in a Pig Model Using the SAN-Atrial-AVN-His (SAAH) Electrocardiogram (ECG), Model PHS-A10, an Automated and Integrated Signals Recognition System.

Science.gov (United States)

Zhao, Wenjiao; Lu, Guihua; Liu, Li; Sun, Zhishan; Wu, Mingxin; Yi, Wenyan; Chen, Haiyan; Li, Yanhui; Tang, Lilong; Zeng, Jianping

2018-03-04

BACKGROUND The aim of this study was to compare the use of the standard 12-lead electrocardiogram (ECG) with the SAN-Atrial-AVN-His (SAAH) ECG (Model PHS-A10), a new automated and integrated signals recognition system that detects micro-waveforms within the P, QRS, and T-wave, in a pig model of acute myocardial infarction (MI). MATERIAL AND METHODS Six medium-sized domestic Chinese pigs underwent general anesthesia, and an angioplasty balloon was placed and dilated for 120 minutes in the first diagonal coronary artery arising from the left anterior descending (LAD) coronary artery. A standard ECG and a SAAH ECG (Model PHS-A10) were used to evaluate: 1) the number of wavelets in ST-T segment in lead V5; 2) the duration of the repolarization initial (Ri), or duration of the wavelets starting from the J-point to the endpoint of the wavelets in the ST interval; 3) the duration of the repolarization terminal (Rt), of the wavelets, starting from the endpoint of the wavelets in the ST interval to the cross-point of the T-wave and baseline; 4) the ratio Ri: Rt. RESULTS Following coronary artery occlusion, duration of Ri and Ri/Rt increased, and Rt decreased, which was detected by the SAAH ECG (Model PHS-A10) within 12 seconds, compared with standard ECG that detected ST segment depression at 24 seconds following coronary artery occlusion. CONCLUSIONS The findings from this preliminary study in a pig model of acute MI support the need for clinical studies to evaluate the SAAH ECG (Model PHS-A10) for the early detection of acute MI.