Table 2.
Summary of normalized amplitude features.
| Feature index | Feature name | Physical meaning |
|---|---|---|
| 1 | m_Amp_SysS1 | mean value of the ratio of the mean absolute amplitude during systole to that during S1 in each heart beat |
| 2 | sd_Amp_SysS1 | SD of m_Amp_SysS1 |
| 3 | m_Amp_DiaS2 | mean value of the ratio of the mean absolute amplitude during diastole to that during S2 in each heart beat |
| 4 | sd_Amp_DiaS2 | SD of m_Amp_DiaS2 |
| 5 | m_Amp_S1S2 | mean value of the ratio of the mean absolute amplitude during S1 to that during S2 in each heart beat |
| 6 | sd_Amp_S1S2 | SD of m_Amp_S1S2 |
| 7 | m_Amp_S1Dia | mean value of the ratio of the mean absolute amplitude during S1 to that during diastole in each heart beat |
| 8 | sd_Amp_S1Dia | SD of m_Amp_S1Dia |
| 9 | m_Amp_SysDia | mean value of the ratio of the mean absolute amplitude during systole to that during diastole in each heart beat |
| 10 | sd_Amp_SysDia | SD of m_Amp_SysDia |
| 11 | m_Amp_S2Sys | mean value of the ratio of the mean absolute amplitude during S2 to that during systole in each heart beat |
| 12 | sd_Amp_S2Sys | SD of m_Amp_S2Sys |