Related Experiment Video
Updated: Aug 16, 2025

Semi-automated Optical Heartbeat Analysis of Small Hearts
Published on: September 16, 2009
Classification of Heart Sounds Using Chaogram Transform and Deep Convolutional Neural Network Transfer Learning
Ali Harimi1, Yahya Majd2, Abdorreza Alavi Gharahbagh3
1Department of Electrical Engineering, Shahrood Branch, Islamic Azad University, Shahrood 43189-36199, Iran.
This study introduces chaogram, a novel image conversion technique for heart sound analysis. This method enables advanced machine learning models to classify cardiac pathologies from phonocardiogram (PCG) signals with high accuracy.
Area of Science:
- Cardiology
- Biomedical Engineering
- Machine Learning
Background:
- Heart sounds offer critical diagnostic information for cardiac conditions.
- Current heart sound classification methods are explored in telemedicine, digital signal processing, and machine learning for rapid cardiac pathology identification.
Purpose of the Study:
- To introduce chaogram, a new transform for converting heart sound signals into color images.
- To enable the application of deep convolutional neural networks and transfer learning to phonocardiogram (PCG) signal analysis.
Main Methods:
- The chaogram transform projects the phase space representation of PCG signals onto three coordinate planes, creating color images.
- The InceptionV3 model was utilized for classification on the PhysioNet dataset.
Main Results:
- The chaogram method successfully converted heart sound signals into images suitable for deep learning models.
- The InceptionV3 model achieved a classification score of 88.06% on the imbalanced PhysioNet dataset, using the average of sensitivity and specificity.
Conclusions:
- Chaogram is a viable method for transforming PCG signals into image data for machine learning.
- This approach facilitates the use of advanced deep learning techniques, like InceptionV3, for improved cardiac pathology detection.
Related Concept Videos
Heart Sounds
Auscultation is the process of listening to these internal body sounds using a stethoscope. The heart produces four types of sounds, but only two—S1 and S2—can usually be heard with a stethoscope.
S1, also known as the "lub" sound, is caused by the closure of atrioventricular (A-V)...
Classification of Signals
A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where...
Heart Failure IV: Classification and Diagnostic Evaluation
Force Classification
Contact and non-contact forces are two of the most widely used categories of forces. As the name suggests, contact forces require physical contact between two objects to act upon each other. Examples of contact forces include frictional,...
Chambers of the Heart
Deoxygenated blood from the body is received in the right...
Classification of Systems-I
Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as:

