Chest wall maps of heart sounds and murmurs

✍ Scribed by Masahiko Okada

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 756 KB
• Volume: 15
• Category: Article
• ISSN: 0010-4809
• DOI: 10.1016/0010-4809(82)90063-5

✦ Synopsis

An image of a sound distribution during one heart cycle is produced from a phonocardiogram recorded on the chest wall. The cardiac sounds are recorded on 6 x 6 positions of the chest surface concurrently with the electrocardiogram. The recorded phonocardiogram is synchronized to the time reference point of the R wave peak of the ECG for input to the computer. The sound envelope is calculated from the input, being defined as the standard deviation of the values at every 16 points of digitized sound data. The calculation works as a kind of high-pass filter. The envelope thus calculated is correlated by a linear interpolation and is transformed into the eight brightness level picture image which consists of 41 x 41 points. The method is applied to normal subjects as well as a cardiac patient and the results show varying distribution patterns of heart sounds and murmurs over the passage of time.