def BandPower(extractor,signal,band,filtering,reference,samples_segment,noverlap_segment,signal_len):
'Band Power according Absolute, Relative & Reference values'
signal_power = np.zeros(0)
# (1) Signal Filtering
# --- highpass filter
filtered_tempo = filtfilt(band[1][0], band[1][1], signal)
# --- lowpass filter
filtered_tempo = filtfilt(band[2][0], band[2][1], filtered_tempo)
# (2) Signal Power
power = filtered_tempo**2
# (3) Reference Signal Calculation for Relative Values
if extractor == 'relative':
ref_tempo = filtfilt(filtering[10][1][0], filtering[10][1][1], signal)
ref_tempo = filtfilt(filtering[10][2][0], filtering[10][2][1], ref_tempo)
ref_power = ref_tempo**2
# (4) ERD/ERS Power
if extractor == 'ERD/ERS': power = power - reference
# (5) Signal Segmentation & Powering
# --- time window initialization
start, end = 0, samples_segment
while end <= signal_len:
# A- absolute power or ERDS
power_point = np.average(power[start:end])
# B- relative power
if extractor == 'relative':
ref_point = np.average(ref_power[start:end])
power_point = power_point/ref_point
# C- segment power into signal power
#row = np.append(row, np.log10(power_point))
signal_power = np.append(signal_power, power_point)
# D- time window update
start += noverlap_segment
end += noverlap_segment
return signal_power
def ERDSPower_REF(eeg_ref, bandpass_filtering):
'Reference Calculation for ERD/ERS Power'
# ***** Offline Processing *****
if type(eeg_ref) == list:
# (a) Dimension of the eeg_ref matrix
Reference, dimX, dimY, = [], [], []
for idx in range(len(eeg_ref)):
dimX.append(np.size(eeg_ref[idx], axis = 0))
dimY.append(np.size(eeg_ref[idx], axis = 1))
# (b) Feature Extraction
row = np.zeros(0)
for idx in range(len(eeg_ref)):
for tr in range(dimY[idx]):
for ch in range(dimX[idx]):
for band in bandpass_filtering:
if band[0] == 'on':
# -- highpass filtering
tempo = filtfilt(band[1][0], band[1][1], eeg_ref[idx][ch, tr, :])
# -- lowpass filtering + band power
tempo = filtfilt(band[2][0], band[2][1], tempo)
row = np.append(row, np.mean(tempo**2))
# -- matrix creation according to the number of features
if tr == 0:
Reference.append(np.zeros((1, len(row))))
Reference[idx][0, :] = row.copy()
else:
row = np.reshape(row, (1, len(row)))
Reference[idx] = np.append(Reference[idx], row.copy(), axis = 0)
# -- row reset
row = np.zeros(0)
return Reference
# ***** Online Processing *****
else:
# (a) Dimension of the eeg_ref matrix
dimX = np.size(eeg_ref, axis = 0)
# (b) Feature Extraction
row = np.zeros(0)
for ch in range(dimX):
for band in bandpass_filtering:
if band[0] == 'on':
# -- highpass filtering
tempo = filtfilt(band[1][0], band[1][1], eeg_ref[ch, :])
# -- lowpass filtering + band power
tempo = filtfilt(band[2][0], band[2][1], tempo)
row = np.append(row, np.mean(tempo**2))
return row
def ERDS_PreProcessing(eeg_data, eeg_samples, eeg_trials, bandpass_filtering, channels):
'ERD/ERS Maps Preprocessing'
# (a) Local Variables Declaration
# -- number of bands
numbands = 0
for item in bandpass_filtering:
if item[0] == 'on': numbands += 1
# -- returning matrix
Power_ERDS = []
# (b) Time Course of ERD/ERS
for idx in range(len(eeg_data)):
# -- number of samples
Samples = eeg_samples[idx]
Power_ERDS.append(np.zeros((len(channels),numbands,len(Samples))))
# -- number of trials
Trials = eeg_trials[idx]
# -- processing for one specific band
index_band = -1
for Band in bandpass_filtering:
if Band[0] == 'on':
# -- number of current selected bands
index_band += 1
for index_ch in range(len(channels)):
# -- current bandpass filtering of all trial for the selected channel
filtered_trials = np.zeros((len(Trials),len(Samples)))
for index_tr in Trials:
# signal extraction
signal = eeg_data[idx][channels[index_ch], index_tr, Samples]
# highpass filtering
signal = filtfilt(Band[1][0], Band[1][1], signal)
# lowpass filtering
filtered_trials[index_tr,:] = filtfilt(Band[2][0], Band[2][1], signal)
# -- average calculation over all band-pass filtered trials
mean_trial = np.mean(filtered_trials, axis = 0)
mean_trial = np.reshape(mean_trial, (1,len(mean_trial)))
mean_trial = np.repeat(mean_trial, len(Trials), axis = 0)
# -- substraction of the mean of the data for each sample to avoid that
# the evoked potentials may mask induced activities
filtered_trials = filtered_trials - mean_trial
# -- squaring of the amplitude samples to obtain power samples
filtered_trials = filtered_trials**2
# -- averaging of power samples for all trials
filtered_trials = np.median(filtered_trials, axis = 0)
# -- data storage
Power_ERDS[idx][index_ch, index_band, :] = filtered_trials.copy()
return Power_ERDS
def BandPower(extractor, signal, band, filtering, reference, samples_segment,
noverlap_segment, signal_len):
'Band Power according Absolute, Relative & Reference values'
signal_power = np.zeros(0)
# (1) Signal Filtering
# --- highpass filter
filtered_tempo = filtfilt(band[1][0], band[1][1], signal)
# --- lowpass filter
filtered_tempo = filtfilt(band[2][0], band[2][1], filtered_tempo)
# (2) Signal Power
power = filtered_tempo**2
# (3) Reference Signal Calculation for Relative Values
if extractor == 'relative':
ref_tempo = filtfilt(filtering[10][1][0], filtering[10][1][1], signal)
ref_tempo = filtfilt(filtering[10][2][0], filtering[10][2][1],
ref_tempo)
ref_power = ref_tempo**2
# (4) ERD/ERS Power
if extractor == 'ERD/ERS': power = power - reference
# (5) Signal Segmentation & Powering
# --- time window initialization
start, end = 0, samples_segment
while end <= signal_len:
# A- absolute power or ERDS
power_point = np.average(power[start:end])
# B- relative power
if extractor == 'relative':
ref_point = np.average(ref_power[start:end])
power_point = power_point / ref_point
# C- segment power into signal power
#row = np.append(row, np.log10(power_point))
signal_power = np.append(signal_power, power_point)
# D- time window update
start += noverlap_segment
end += noverlap_segment
return signal_power
def SiGCoN(ch,eeg_data,new_layout,reference,bandwidth,bandrejection,DCband,downsample_rate,mode,bad_chs):
'reference = [Ref_Type, ch_neg]\
bandwidth = [BW, (Bhp,Ahp),(Blp,Alp)]\
bandrejection = [Rej50,(B,A)]\
DCband = [DCremove, (B,A)]'
num_channels= np.size(eeg_data, axis = 0)
# ------------------------------------------------------
if mode == 'spectral':
# ***** Offline Processing *****
if eeg_data.ndim == 3:
num_trials = np.size(eeg_data, axis = 1)
for tr in range(num_trials):
# (a) Spectral Filtering
# --- DC removal
if DCband[0] == 'on':
eeg_data[ch,tr,:] = eeg_data[ch,tr,:] - np.mean(eeg_data[ch,tr,:])
# --- Bandpass filter performance
if bandwidth[0] == 'on':
# highpass filtering
eeg_data[ch,tr,:] = filtfilt(bandwidth[1][0], bandwidth[1][1], eeg_data[ch,tr,:])
# lowpass filtering
eeg_data[ch,tr,:] = filtfilt(bandwidth[2][0], bandwidth[2][1], eeg_data[ch,tr,:])
# --- Bandstop filter performance
if bandrejection[0] == 'on':
eeg_data[ch,tr,:] = filtfilt(bandrejection[1][0],bandrejection[1][1], eeg_data[ch,tr,:])
return eeg_data[ch,:,:]
# ***** Online Processing *****
else:
# (a) Spectral Filtering
# --- DC removal
if DCband[0] == 'on':
eeg_data[ch,:] = eeg_data[ch,:] - np.mean(eeg_data[ch,:])
# --- Bandpass filter performance
if bandwidth[0] == 'on':
# highpass filtering
eeg_data[ch,:] = filtfilt(bandwidth[1][0],bandwidth[1][1], eeg_data[ch,:])
# lowpass filtering
eeg_data[ch,:] = filtfilt(bandwidth[2][0],bandwidth[2][1], eeg_data[ch,:])
# --- Bandstop filter performance
if bandrejection[0] == 'on':
eeg_data[ch,:] = filtfilt(bandrejection[1][0],bandrejection[1][1], eeg_data[ch,:])
return eeg_data[ch,:]
# ------------------------------------------------------
if mode == 'spatial':
# (b) DownSampling (previous requirements)
# ***** Offline Processing *****
if eeg_data.ndim == 3:
num_trials = np.size(eeg_data, axis = 1)
num_samples = np.size(eeg_data, axis = 2)//downsample_rate
dsp_ch = np.zeros((1,num_trials,num_samples))
# **** Online Processing *****
else:
num_samples = np.size(eeg_data, axis = 1)//downsample_rate
dsp_ch = np.zeros((1,num_samples))
# (c) Spatial Filtering (previous requirements)
# --- monopolar referencing
if reference[0] == 'Monopolar':
ref_idx = replace_refIDX(reference[1], bad_chs, num_channels)
# --- bipolar referencing
elif reference[0] == 'Bipolar':
ref_idx = replace_refIDX(reference[1], bad_chs, num_channels)
# --- common average referencing
elif reference[0] == 'CAR':
ref_idx = replace_refIDX(range(num_channels), bad_chs, num_channels)
# --- laplacian referencing
else:
(i, j) = np.where(new_layout == (ch+1))
ref_ch = np.zeros(0, dtype = int)
# small laplacian referencing
if reference[0] == 'SmallLaplacian':
if i != 0: ref_ch = np.append(ref_ch, new_layout[i-1,j])
if j != 0: ref_ch = np.append(ref_ch, new_layout[i,j-1])
if j+1 < 9: ref_ch = np.append(ref_ch, new_layout[i,j+1])
if i+1 < 9: ref_ch = np.append(ref_ch, new_layout[i+1,j])
# large laplacian referencing
elif reference[0] == 'LargeLaplacian':
if i-1 > 0: ref_ch = np.append(ref_ch, new_layout[i-2,j])
if j-1 > 0: ref_ch = np.append(ref_ch, new_layout[i,j-2])
if j+2 < 9: ref_ch = np.append(ref_ch, new_layout[i,j+2])
if i+2 < 9: ref_ch = np.append(ref_ch, new_layout[i+2,j])
# remove the zero values & re-assign the channel values (for python processing)
ref_idx = np.nonzero(ref_ch)
if ref_idx[0].tolist() != []:
ref_ch = ref_ch[ref_idx[0]]
ref_ch -= 1
else:
ref_ch = np.zeros(0, dtype = int)
ref_idx = replace_refIDX(ref_ch, bad_chs, num_channels)
# (d) Execution of steps b and c
# ***** Offline Processing *****
if eeg_data.ndim == 3:
for tr in range(num_trials):
eeg_tempo = eeg_data[ch,tr,:] - np.mean(eeg_data[ref_idx,tr,:], axis = 0)
dsp_ch[0,tr,:] = eeg_tempo[0::downsample_rate]
# ***** Online Processing *****
else:
eeg_tempo = eeg_data[ch,:] - np.mean(eeg_data[ref_idx,:], axis = 0)
dsp_ch[0,:] = eeg_tempo[0::downsample_rate]
return dsp_ch
