-
Notifications
You must be signed in to change notification settings - Fork 0
/
EEGNet.py
136 lines (109 loc) · 6.67 KB
/
EEGNet.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
from tensorflow.keras.models import Model
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense, Activation, Permute, Dropout
from tensorflow.keras.layers import Conv2D, MaxPooling2D, AveragePooling2D
from tensorflow.keras.layers import Conv1D, MaxPooling1D, AveragePooling1D
from tensorflow.keras.layers import SeparableConv2D, DepthwiseConv2D
from tensorflow.keras.layers import BatchNormalization
from tensorflow.keras.layers import SpatialDropout2D
from tensorflow.keras.regularizers import l1_l2
from tensorflow.keras.layers import Input, Flatten
from tensorflow.keras.constraints import max_norm
from tensorflow.keras import backend as K
def EEGNet(nb_classes, Chans = 64, Samples = 128,
dropoutRate = 0.5, kernLength = 64, F1 = 8,
D = 2, F2 = 16, norm_rate = 0.25, dropoutType = 'Dropout'):
""" Keras Implementation of EEGNet
http://iopscience.iop.org/article/10.1088/1741-2552/aace8c/meta
Note that this implements the newest version of EEGNet and NOT the earlier
version (version v1 and v2 on arxiv). We strongly recommend using this
architecture as it performs much better and has nicer properties than
our earlier version. For example:
1. Depthwise Convolutions to learn spatial filters within a
temporal convolution. The use of the depth_multiplier option maps
exactly to the number of spatial filters learned within a temporal
filter. This matches the setup of algorithms like FBCSP which learn
spatial filters within each filter in a filter-bank. This also limits
the number of free parameters to fit when compared to a fully-connected
convolution.
2. Separable Convolutions to learn how to optimally combine spatial
filters across temporal bands. Separable Convolutions are Depthwise
Convolutions followed by (1x1) Pointwise Convolutions.
While the original paper used Dropout, we found that SpatialDropout2D
sometimes produced slightly better results for classification of ERP
signals. However, SpatialDropout2D significantly reduced performance
on the Oscillatory dataset (SMR, BCI-IV Dataset 2A). We recommend using
the default Dropout in most cases.
Assumes the input signal is sampled at 128Hz. If you want to use this model
for any other sampling rate you will need to modify the lengths of temporal
kernels and average pooling size in blocks 1 and 2 as needed (double the
kernel lengths for double the sampling rate, etc). Note that we haven't
tested the model performance with this rule so this may not work well.
The model with default parameters gives the EEGNet-8,2 model as discussed
in the paper. This model should do pretty well in general, although it is
advised to do some model searching to get optimal performance on your
particular dataset.
We set F2 = F1 * D (number of input filters = number of output filters) for
the SeparableConv2D layer. We haven't extensively tested other values of this
parameter (say, F2 < F1 * D for compressed learning, and F2 > F1 * D for
overcomplete). We believe the main parameters to focus on are F1 and D.
Inputs:
nb_classes : int, number of classes to classify
Chans, Samples : number of channels and time points in the EEG data
dropoutRate : dropout fraction
kernLength : length of temporal convolution in first layer. We found
that setting this to be half the sampling rate worked
well in practice. For the SMR dataset in particular
since the data was high-passed at 4Hz we used a kernel
length of 32.
F1, F2 : number of temporal filters (F1) and number of pointwise
filters (F2) to learn. Default: F1 = 8, F2 = F1 * D.
D : number of spatial filters to learn within each temporal
convolution. Default: D = 2
dropoutType : Either SpatialDropout2D or Dropout, passed as a string.
"""
if dropoutType == 'SpatialDropout2D':
dropoutType = SpatialDropout2D
elif dropoutType == 'Dropout':
dropoutType = Dropout
else:
raise ValueError('dropoutType must be one of SpatialDropout2D '
'or Dropout, passed as a string.')
input1 = Input(shape = (1, Chans, Samples))
##################################################################
block1 = Conv2D(F1, (1, kernLength), padding = 'same', input_shape = (1, Chans, Samples), use_bias = False, data_format='channels_first')(input1)
block1 = BatchNormalization(axis = 1)(block1)
block1 = DepthwiseConv2D((Chans, 1), use_bias = False, depth_multiplier = D, data_format='channels_first', depthwise_constraint = max_norm(1.))(block1)
block1 = BatchNormalization(axis = 1)(block1)
block1 = Activation('elu')(block1)
block1 = AveragePooling2D((1, 4), data_format='channels_first')(block1)
block1 = dropoutType(dropoutRate)(block1)
block2 = SeparableConv2D(F2, (1, 16), use_bias = False, padding = 'same')(block1)
block2 = BatchNormalization(axis = 1)(block2)
block2 = Activation('elu')(block2)
block2 = AveragePooling2D((1, 8), data_format='channels_first')(block2)
block2 = dropoutType(dropoutRate)(block2)
flatten = Flatten(name = 'flatten')(block2)
dense = Dense(nb_classes, name = 'dense', kernel_constraint = max_norm(norm_rate))(flatten)
softmax = Activation('softmax', name = 'softmax')(dense)
return Model(inputs=input1, outputs=softmax)
def my_EEGNet(input_shape, batch_size=1, n_classes=2):
"""
My Special EEGNet
Arguments:
input_shape: (n_channels, sequence)
batch_size : number of batches
n_classes : number of output classes
"""
model = Sequential()
# model.add(Input(input_shape, batch_size=batch_size, name='input'))
model.add(Conv1D(60, 15, input_shape=input_shape, batch_size=batch_size, activation='relu', name='Conv1_1'))
model.add(Conv1D(40, 15, activation='relu', name='Conv1_2'))
model.add(MaxPooling1D(name='pooling1_1'))
model.add(Conv1D(10, 10, input_shape=input_shape, batch_size=batch_size, activation='relu', name='Conv2_1'))
model.add(Conv1D(15, 5, activation='relu', name='Conv2_2'))
model.add(MaxPooling1D(name='pooling2_1'))
model.add(Flatten())
model.add(Dense(30 , activation='relu', name='Dense1'))
model.add(Dense(1,activation='sigmoid', name='output'))
return model