# [1991] Proceedings Computers in Cardiology

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Displaying Results 1 - 25 of 189
• ### Proceedings. Computers in Cardiology (Cat. No.91CH3116-1)

Publication Year: 1991
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• ### DEKG-Manager: formative evaluation in teaching dynamic electrocardiography

Publication Year: 1991
| | PDF (47 KB)

Summary form only given. The DEKG-Trainer system is an instructional aid oriented toward environmental simulation and summative evaluation in the field of dynamic electrocardiography teaching. The clinic arrhythmia database holds a teaching-oriented version of arrhythmia knowledge. The integration presented is the DEKG-Manager system. It is intended for formative evaluation of a student who has ma... View full abstract»

• ### A new integrated system for three-dimensional echocardiographic reconstruction and ventricular volume measurement

Publication Year: 1991, Page(s):113 - 116
Cited by:  Papers (4)
| | PDF (448 KB)

A system has been developed which automatically integrates, a real time, the two-dimensional ultrasound images, electrocardiogram (ECG), and positional data necessary for 3-D reconstruction, with time and storage requirements that are no more than those for an ordinary 2-D echocardiographic study. This system was validated by reconstructing and measuring the volumes of a series of gel-filled ventr... View full abstract»

• ### Development of a conceptual reference model for digital ECG data storage

Publication Year: 1991, Page(s):109 - 112
Cited by:  Papers (3)
| | PDF (356 KB)

A conceptual reference model has been developed for storage and retrieval of electrocardiogram (ECG) data. The general principles of the model are outlined, and the external models for data acquisition and preprocessing are presented. The model has been designed around the concept of the entity-relationship data model, and includes as many as 38 different entities, 22 relationships with attributes... View full abstract»

• ### Compression and encoding of ECG data within the European standard communications protocol

Publication Year: 1991, Page(s):105 - 108
Cited by:  Papers (12)
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The European Community has launched a project to develop a standard communications protocol for computerized electrocardiography (SCP-ECG). Within this project, compression and encoding of ECG data for transmission and storage has been investigated. A compression scheme with well-specified error limits was developed. Compression ratios for resting ECGs achieved by this method are as high as 20. Th... View full abstract»

• ### Texture analysis for discrimination of tissues in MRI data

Publication Year: 1991, Page(s):481 - 484
Cited by:  Papers (5)
| | PDF (296 KB)

The authors investigate an approach based on texture analysis and pattern recognition for the differentiation of tissues in images produced by magnetic resonance. A set of masks with minimal spatial extent is used with the purpose of providing a set of texture measures by creating a feature vector to be associated to each pixel. Automatic segmentation is achieved by applying a fuzzy C-means cluste... View full abstract»

• ### Time-scale analysis of high-resolution signal-averaged surface ECG using wavelet transformation

Publication Year: 1991, Page(s):393 - 396
Cited by:  Papers (19)
| | PDF (240 KB)

The authors investigate the contribution to the prediction of ventricular tachycardia (VT) of a new time-scale technique suited to transient signal detection: wavelet analysis (WA). Wavelet Transformation (WT) is obtained by expanding the signal on a set of functions resulting from the translation (time) and the dilatation (scale) of a so-called analyzing wavelet'. It provides a bidimensional rep... View full abstract»

• ### Fast FIR filters for a stress test system

Publication Year: 1991, Page(s):129 - 132
Cited by:  Papers (1)
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The authors describe a technique for design of fast finite-impulse-response (FIR) filters with a flat frequency response for certain frequencies. Such filters are well suited for stress test electrocardiograms (ECGs). A 0.5 Hz high-pass and a 30 Hz low-pass filter were designed. To evaluate the design method and computing time of the fast filter and of an equivalent traditional filter were compare... View full abstract»

• ### A knowledge-based system for qualitative ECG simulation and ECG analysis

Publication Year: 1991, Page(s):733 - 736
Cited by:  Papers (3)  |  Patents (1)
| | PDF (300 KB)

A qualitative electrocardiogram (ECG) simulation is investigated. Qualitative ECGs are viewed as the synthesis of qualitative projections of cardiac vectors on ECG leads. The projections of vectors are described in linguistic terms, the meanings of which are represented by using fuzzy sets. The simulated qualitative ECGs are compared with measured ECGs by means of similarity measures. The simulati... View full abstract»

• ### A computerized system for the analysis of cardiac rhythm and conduction

Publication Year: 1991, Page(s):441 - 443
Cited by:  Patents (1)
| | PDF (160 KB)

An effective system for monitoring of cardiac rhythm and conduction disturbances is discussed. The system permits: diagnosis of 8 types of rhythm disturbances and 4 types of conduction disturbances; performance of parallel around-the-clock monitoring of 8 patients; emitting alarms for asystole, bradycardia and tachycardia; prediction and prevention of the development of acute disturbances; and it ... View full abstract»

• ### A universal set of statement codes for the exchange and storage of diagnostic ECG interpretation results

Publication Year: 1991, Page(s):101 - 104
Cited by:  Papers (1)
| | PDF (336 KB)

A standard communications protocol was developed for computerized electrocardiography (SCP-ECG), consisting of standards for the interchange, encoding, and storage of digital ECG data. This work was performed in three distinct, but closely related, workpackages. As part of Workpackage 1, consisting of standardization of the data contents, format, and messaging, a set of universal ECG statement cod... View full abstract»

• ### Assessing LV wall motion by frame-to-frame curvature matching and optical flow estimation

Publication Year: 1991, Page(s):477 - 480
Cited by:  Papers (1)  |  Patents (1)
| | PDF (344 KB)

This work seeks to describe left ventricle (LV) shape by optimizing the curvature computation. A method based on adaptive Fourier series approximation was developed and compared with three known methods. The authors also wish to assess wall motion by applying both the optical flow method and an improved shape matching algorithm, as well as to compare their results with each other and with the cent... View full abstract»

• ### The effect of varying filter techniques on late potential parameters of signal averaged electrocardiographic records

Publication Year: 1991, Page(s):389 - 391
| | PDF (144 KB)

Signal average electrocardiographic parameters were obtained in 54 patients and 128 normal subjects using two filtering techniques and lead systems. Filtered QRS duration (TQRS), root mean voltage in the terminal filtered QRS (RMS), and terminal QRS duration under 40 microvolts (LAD) were compared. TQRS was significantly different for all subjects. RMS values were different for normal subjects and... View full abstract»

• ### Analysis of high frequency QRS potentials during exercise testing

Publication Year: 1991, Page(s):33 - 35
Cited by:  Papers (1)  |  Patents (1)
| | PDF (192 KB)

The authors examine the feasibility of analyzing high fidelity electrocardiograms (ECGs) recorded during exercise tests to study changes that occur in the high frequency region (150 Hz-250 Hz) of the QRS complex. High fidelity ECGs from the V3, V4, V5, and V6 chest leads were analyzed before, during, and after exercise tests from five patients with arteriographically proven coronary artery disease... View full abstract»

• ### Influence of arterial wall thickening on the blood velocity profiles shape

Publication Year: 1991, Page(s):717 - 720
| | PDF (236 KB)

The influence of the arterial wall thickening on time patterns of blood velocity profiles was theoretically investigated. Spatial distribution of velocity during a cardiac cycle was calculated by means of an original mathematical model of blood motion in the arterial vessel. A slight and local increase in wall thickness due to atherosclerotic plaque was simulated. The results confirm that the pres... View full abstract»

• ### Spectral analysis of heart rate variability as a measure of sympathico-vagal influence after sublingual nitroglycerin: comparison of the quantitative analysis with FFT and autoregressive model

Publication Year: 1991, Page(s):425 - 428
Cited by:  Papers (1)
| | PDF (252 KB)

Short-acting vasodilating drugs like nitroglycerin sublingual (NTG) change sympathico-vagal balance as long as central systolic blood pressure is lowered. To calculate power spectral density (PSD) estimation of heart rate variability (HRV) stationary conditions in the time domain are required. In order to study time course of HRV after administration of NTG, two different methods were used. One me... View full abstract»

• ### Computer model of ANP-hemodynamic interactions

Publication Year: 1991, Page(s):697 - 700
Cited by:  Papers (1)
| | PDF (204 KB)

A mathematical model of ANP (atrial natriuretic peptide)-cardiovascular interactions was developed based on the Guytonian concepts of cardiac output control and data from the literature concerning ANP functioning. The model was used in a series of computer simulation studies to explore the possible mechanisms of acute hemodynamic control by ANP (a potent in vitro vasodilator). These studies provid... View full abstract»

• ### Prototype system for timely image distribution in support of a cardiology outpatient clinic

Publication Year: 1991, Page(s):85 - 88
| | PDF (320 KB)

In order to allow radiographs to be in two locations at once without the waste of duplicating each film, a commercially available sheet film digitizer and an image storage and display system were combined with a custom-tailored fiber-optic clinical imaging network, which was installed throughout a research hospital. The clinical trials indicate that it appears to be technically feasible to transmi... View full abstract»

• ### CAVIAR, a serial ECG processing and management system for pharmacological drug trials

Publication Year: 1991, Page(s):301 - 304
Cited by:  Papers (2)  |  Patents (1)
| | PDF (332 KB)

The authors present a specific implementation of the CAVIAR serial analysis program which is intended to support the processing and the management of serial electrocardiograms (ECGs) from pharmacological drug studies. This system includes bedside, PC-based ECG data acquisition units, computerized unitary and serial ECG analysis software, and a ECG database management system which partly implements... View full abstract»

• ### Source consistency filtering-a new tool for ECG noise reduction

Publication Year: 1991, Page(s):125 - 128
Cited by:  Papers (4)  |  Patents (6)
| | PDF (236 KB)

A novel filter, called SCF (source consistency filtering), is introduced. In its spatial form, SCF uses the constraints provided by the redundancy of leads of multichannel recordings to distinguish noise from signal. Quantitatively, each lead is predicted using least-squares-method-derived coefficients, and a multichannel coherence of leads and their respective predictions results in an effective ... View full abstract»

• ### Extrapolation and filtering of incomplete marker tracks by singular value decomposition [heart motion measurement]

Publication Year: 1991, Page(s):45 - 48
| | PDF (264 KB)

The authors investigate whether the singular value decomposition (SVD) method can be modified to handle incomplete tracks such that appropriate extrapolations for incomplete marker tracks are obtained in an animal experiment were made incomplete by obscuring a part varying in length from 3% up to 44% of the observation time. Comparison of extrapolations with measurements results in a root mean squ... View full abstract»

Publication Year: 1991, Page(s):729 - 732
Cited by:  Patents (3)
| | PDF (280 KB)

A knowledge-based system which allows access to results of clinical studies for an individual patient with acute cardiac ischemia is described. The knowledge base contains 20 recent studies applicable to three periods of time in the hospital. An abstract model for the representation of the studies and a facility for consultations have been developed. The inference process includes the determinatio... View full abstract»

• ### Heart rate variability during dynamic exercise in supine position in sedentary subjects

Publication Year: 1991, Page(s):437 - 440
Cited by:  Papers (1)
| | PDF (248 KB)

The power spectral analysis of heart rate variability (HRV) was assessed during dynamic exercises at different intensities while pedaling in both the orthostatic (O) and clinostatic (C) positions. In addition to a decrease in HRV, with increasing work load high-frequency (HF) peak shifts to higher frequencies in both the O and C positions, reflecting increased ventilation. With increasing exercise... View full abstract»

• ### Testing results and derivation of minimum performance criteria for computerized ECG-analysis

Publication Year: 1991, Page(s):97 - 100
Cited by:  Papers (2)
| | PDF (272 KB)

The authors describe a method for evaluation of performance testing results from the Common Standards for Quantitative Electrocardiography (CSE) studies. It allows derivation of minimum performance requirements which consider the present state of the art by referencing them to the results of all existing systems tested. Based upon these minimum requirements, equipment with pure performance can be ... View full abstract»

• ### A neural network expert system for computer-assisted analysis of blood-pressure data

Publication Year: 1991, Page(s):473 - 476
Cited by:  Patents (3)
| | PDF (324 KB)

The expert system described, based on a neural network architecture, analyzes a subject's anamnesis and 24-hour blood-pressure monitoring, to diagnose hypertension and give advice about choice, timing, and dosage of the most appropriate treatment. It also includes a set of explanation tools, such as the why?' and the `what if . . .' functions, which emulate the ones that are typical of symbolic e... View full abstract»