Table 8.
Features according to the domain.
| Time-Domain Features | Mean absolute value (MAV), root mean square (RMS), waveform length (WL), zero crossings (ZC), fourth-order autoregressive coefficients (AR-Coeff), standard deviation (SD), variance (VAR), slope sign changes (SSC), mean, median, integrated EMG (iEMG), sample entropy (SampEn), mean absolute value ratio (MAVR), modified mean absolute value (MMAV), simple square integral (SSI), Log detector (LOG), average amplitude change (AAC), maximum fractal length (MFL), minimum (MIN), maximum (MAX), Hjorth parameters (HJP), peak value (PK), energy ratio (ER), histogram (HISTG), willison amplitude (WAMP), kurtosis (KURT), skewness (SKEW), non-negative matrix factorization (NMF), natural logarithm of the variance (ln-VAR), root sum square (RSS), logarithm of the root mean square (log-RMS), logarithm of the integrated EMG (log-iEMG), logarithm of the variance (log-VAR), logarithmic band power (LBP), first derivation (DIFF), detrended fluctuation analysis (DFA), modified mean absolute values (MAV1-MAV2), V-order, difference absolute standard deviation value (DASDV), max-min, autoregressive model intercept (Inpt), cardinality (CARD) |
| Frequency-Domain Features | Amplitude spectrum (AmpSpec), mean frequency (MNF), median frequency (MDF), modified median frequency (MMDF), modified mean frequency (MMNF), mean power (MNP), cepstral coefficients (Cep-Coeff), circulant matrix structure for eigenvalue decomposition (CMSED), fast Fourier transform (FFT), median amplitude spectrum (MAS), peak frequency (PKF), total power (TTP), power spectrum ratio (PSR) |
| Time-Frequency-Domain Features | Discrete wavelet transform (DWT), continuous wavelet transform (CWT), mean of the absolute wavelet coefficients (MOAC), average power of the wavelet coefficients (APOC), standard deviation of the wavelet coefficients (STDOC), MOAC-ratio |
| Space-Domain Features | Scaled mean absolute value (SMAV), mean absolute difference of the normalized values (MADN) |
| Fractal-Domain Features | De-trended fluctuation analysis (DFA), Higuchi fractal dimension (HFD) |