Table 3.
Heart sound classification techniques
| References | Classification method | Normal HS | AR | AS | MR | MS | |
|---|---|---|---|---|---|---|---|
| [81] | Markov Blanket Random Forests (multiple binary classification) | Analyzed sound/disorder | Y | Y | Y | Y | Y |
| No. of cases | 38 | 38 | 41 | 43 | 38 | ||
| Sensitivity | Accuracy of 90.22% for distinguishing between normal and abnormal; accuracies of 92.45 and 90.34% for distinguishing between AR-MS and AS-MR | ||||||
| Specificity | |||||||
| [82] | ANN (multi-class classification) | Analyzed sound/disorder | Y | Y | Y | Y | – |
| No. of cases | 31 | 26 | 28 | 26 | – | ||
| Sensitivity | – | 89.7 ± 5.9% | – | ||||
| Specificity | – | – | – | – | – | ||
| [83] | SVM (multiple binary classification) | Analyzed sound/disorder | Y | Y | Y | Y | – |
| No. of cases | 15 | 51 in total | |||||
| Sensitivity | – | 95.37% | 94.02% | 95.20% | – | ||
| Specificity | – | 95.49% | 96.68% | 96.33% | – | ||
| [84] | ANN, GMM, SVM (multiple binary classification) | Analyzed sound/disorder | Y | Y | Y | Y | – |
| No. of cases | 15 | 51 in total | |||||
| Sensitivity | – | 93.20% | 92.63% | 96.88% | – | ||
| Specificity | – | 95.87% | 95.80% | 92.78% | – | ||
| [85] | HMM, SVM (multi-class classification) | Analyzed sound/disorder | Y | Y | Y | Y | Y |
| No. of cases | 80 | 6 | 9 | 9 | 12 | ||
| Sensitivity | – | 67% | 67% | 67% | 83% | ||
| Specificity | 99% | – | – | – | – | ||
| [86] | ANN (multi-class classification) | Analyzed sound/disorder | Y | Y | Y | Y | Y |
| No. of cases | 4 | 4 | 4 | 4 | 4 | ||
| Sensitivity | – | 100% | 98% | 100% | 100% | ||
| Specificity | 100% | – | – | – | – | ||
| [87] | SVM (binary hierarchical classification) | Analyzed sound/disorder | Y | – | Y | – | Y |
| No. of cases | 225 | – | 60 | – | 60 | ||
| Sensitivity | – | – | 85% | – | 95% | ||
| Specificity | 98.67% | – | – | – | – | ||
| [88] | SVM (multiple binary classification) | Analyzed sound/disorder | Y | Y | Y | Y | Y |
| No. of cases | 38 | 38 | 41 | 43 | 38 | ||
| Sensitivity | Accuracy of 91.43% for distinguishing between normal and abnormal; accuracies of 92.11 and 91.67% for distinguishing between AR-MS and AS-MR | ||||||
| Specificity | |||||||
| [89] | SVM (binary hierarchical classification) | Analyzed sound/disorder | Y | Y | Y | Y | Y |
| No. of cases | 6 | 6 | 4 | 6 | 9 | ||
| Sensitivity | – | 93.75% | 92.31% | 96.97% | 90.63% | ||
| Specificity | 99.49% | – | – | – | – | ||
Y yes.