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Use of Symmetrized-Dot Patterns in the Characterization and Detection of Cardiac Abnormalities

IP.com Disclosure Number: IPCOM000062455D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 4 page(s) / 43K

Publishing Venue

IBM

Related People

Evangelisti, CJ: AUTHOR [+2]

Abstract

Nearly a million Americans die each year of cardiovascular disease, according to the American Heart Association. The traditional diagnostic methods for cardiac disease--listening with a stethoscope ("auscultation"), examination of graphic records of the audible sounds ("phonocardiography"), or electrocardiogram (ECG) analysis--have been used for years by physicians and other medical personnel to detect abnormalities of the heart. These and related techniques are also used in research to study and compare cardiac activity. While such methods have been invaluable in guiding the physician, a great deal of training is required for proper evaluation, particularly for certain subtle or complicated anomalies.

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Use of Symmetrized-Dot Patterns in the Characterization and Detection of Cardiac Abnormalities

Nearly a million Americans die each year of cardiovascular disease, according to the American Heart Association. The traditional diagnostic methods for cardiac disease--listening with a stethoscope ("auscultation"), examination of graphic records of the audible sounds ("phonocardiography"), or electrocardiogram (ECG) analysis--have been used for years by physicians and other medical personnel to detect abnormalities of the heart. These and related techniques are also used in research to study and compare cardiac activity. While such methods have been invaluable in guiding the physician, a great deal of training is required for proper evaluation, particularly for certain subtle or complicated anomalies. Also, in general, it is difficult to rigorously compare and characterize sounds by ear alone since the listening process is subject to the limitation and artifacts of both memory and perception, as well as an individual variation in the listener's ability to localize (in time) and describe acoustic features. Today the use of computer ECG systems has become widespread. A flexible and sensitive computer graphics representation and analysis is described herein as an adjunct to the more traditional medical detection techniques. This representation, a "symmetrized dot-pattern" (SDP), has been useful in speech analysis to make subtle differences obvious to the human analyst in a visual manner. Three new features: (1) the medical application, (2) mathematical theory for enhanced sensitivity and flexibility for low frequencies, and (3) the design of hardware for realtime function are added to such an SDP system to render it more suitable for audio vascular diagnosis. Unlike the ECG which measures electrical activity of the heart, the SDP described here operates on acoustic input. The symmetrized dot-pattern (SDP) characterizes waveforms using patterns of dots and requires very limited computational time as a prerequisite. Previous studies in texture discrimination and pattern recognition have shown that symmetry elements can make features more obvious to the human observer [1], and for this reason the SDPs have a high degree of induced symmetry (and redundancy) to aid the human analyst in recognizing and remembering patterns. A particular algorithm for the creation of these forms has been introduced previously [2] to characterize speech sounds. In brief summary, the algorithm which maps the normalized time-waveform (in this disclosure, a digitized heart sound) into symmetrized-dot space creates a probability distribution of neighbor amplitudes on a polar graph. A point in the time waveform is mapped into a radial component, and the adjacent point is mapped to an angular component. The transformation L from waveform to symmetrized- dot space can be written as: L F(t) T S(rj,rij,Dij) where F(t) is the digitized time waveform, and S is the symmetrize...