LXDeviceAPI

Definition

 

int GetFilterFrequency_LXDeviceAPI(int device_handling_id,int signal_source, float * freq_hpf, float * freq_lpf, float * freq_notch);

Parameters

Parameter Available Value Description
int device_handling_id
  • return value of OpenDevice
int signal_source
  • 0 : EEG
  • 1 : EOG
  • 2 : ECG
Select bio signal type to retrieve the applied filter information.
float * freq_hpf
  • output
High Pass Filter cut frequency. unit : Hz. The value -100 means  No HPF applied.
float * freq_lpf
  •  output
Low Pass Filter cut frequency. unit : Hz. The value -100 means  no LPF applied.
float * freq_notch
  •  output
Notch Filter frequency. uint : Hz. The value -100 means  no notch filter applied.

Return Values

Return  meaning Description
 1  Success
 -3  Fail. No device(correspond to int device_handling_id).
 -10  Fail. Wrong calling order. GetFilterFrequency should be called after OpenApi.

Code Example

void CLXDeviceAPI_Sample1View::OnMenuGetfilterfrequency()
{
  float f_hpf, f_lpf, f_notch;
  CString cst_hpf, cst_lpf, cst_notch;
  // Get EEG Filter info 
  if (GetFilterFrequency_LXDeviceAPI(m_iDeviceHandlingID,0, &f_hpf, &f_lpf, &f_notch) == 1) 
  {
    if (f_hpf < -1.f) 	cst_hpf = _T("HPF=off, ");
    else		cst_hpf.Format(_T("HPF=%.1fHz, "), f_hpf); 

    if (f_lpf < -1.f)	cst_lpf = _T("LPF=off, ");
    else		cst_lpf.Format(_T("LPF=%.1fHz, "), f_lpf);

    if (f_notch < -1.f)	cst_notch = _T("Notch=off");
    else		cst_notch.Format(_T("Notch=%.1fHz"), f_notch);

    AfxMessageBox(_T("EEG Filter : ") + cst_hpf + cst_lpf + cst_notch);
  }
}

Result

Signal Filter Frequencies

Signal Filter Frequencies