====== Detecting Muscle Onset ====== || Surface EMG signals typically have a frequency content between 50 and 500 Hz. These signals may have a DC bias. It is common to apply a high pass filter with a cutoff frequency of 50 Hz to EMG signals prior to any other processing to remove the DC bias. **Note: Many laboratories assume a frequency content between 20 and 500 Hz** **Note: Applying a high pass filter will effectively remove any DC bias in the signal.** ! By default, Visual3D uses a second order Butterworth Bidirectional Filter (resulting in a ! fourth order filter) for Lowpass/Highpass filtering. ! High pass filter Highpass_Filter /Signal_Types= ANALOG /SIgnal_Names= EMG1+EMG2+EMG3 /Signal_Folder= ORIGINAL ! /Result_Suffix= ! /Result_Folder=PROCESSED ! /Filter_Class=BUTTERWORTH /Frequency_Cutoff= 50 /Num_Reflected= 0 /Total_Buffer_Size=100 /Num_Bidirectional_Passes=1 ;