|
| 1 | +""" |
| 2 | +BMI/OpenBMI dataset (Motor Imagery). |
| 3 | +""" |
| 4 | + |
| 5 | +import numpy as np |
| 6 | +from mne import create_info |
| 7 | +from mne.channels import make_standard_montage |
| 8 | +from mne.io import RawArray |
| 9 | +from scipy.io import loadmat |
| 10 | + |
| 11 | +from moabb.datasets import download as dl |
| 12 | +from moabb.datasets.base import BaseDataset |
| 13 | + |
| 14 | + |
| 15 | +Lee2019_URL = "ftp://parrot.genomics.cn/gigadb/pub/10.5524/100001_101000/100542/" |
| 16 | + |
| 17 | + |
| 18 | +class Lee2019_MI(BaseDataset): |
| 19 | + """Motor Imagery BMI/OpenBMI dataset from BMI/OpenBMI dataset. |
| 20 | +
|
| 21 | + Dataset from Lee et al 2019 [1]_. |
| 22 | +
|
| 23 | + **Dataset Description** |
| 24 | +
|
| 25 | + EEG signals were recorded with a sampling rate of 1,000 Hz and |
| 26 | + collected with 62 Ag/AgCl electrodes. The EEG amplifier used |
| 27 | + in the experiment was a BrainAmp (Brain Products; Munich, |
| 28 | + Germany). The channels were nasion-referenced and grounded |
| 29 | + to electrode AFz. Additionally, an EMG electrode recorded from |
| 30 | + each flexor digitorum profundus muscle with the olecranon |
| 31 | + used as reference. The EEG/EMG channel configuration and |
| 32 | + indexing numbers are described in Fig. 1. The impedances of the |
| 33 | + EEG electrodes were maintained below 10 k during the entire |
| 34 | + experiment. |
| 35 | +
|
| 36 | + MI paradigm |
| 37 | + The MI paradigm was designed following a well-established system protocol. |
| 38 | + For all blocks, the first 3 s of each trial began |
| 39 | + with a black fixation cross that appeared at the center of the |
| 40 | + monitor to prepare subjects for the MI task. Afterwards, the subject |
| 41 | + performed the imagery task of grasping with the appropriate |
| 42 | + hand for 4 s when the right or left arrow appeared as a visual cue. |
| 43 | + After each task, the screen remained blank for 6 s (± 1.5 s). The |
| 44 | + experiment consisted of training and test phases; each phase |
| 45 | + had 100 trials with balanced right and left hand imagery tasks. |
| 46 | + During the online test phase, the fixation cross appeared at the |
| 47 | + center of the monitor and moved right or left, according to the |
| 48 | + real-time classifier output of the EEG signal. |
| 49 | +
|
| 50 | + References |
| 51 | + ---------- |
| 52 | + .. [1] Lee, M. H., Kwon, O. Y., Kim, Y. J., Kim, H. K., Lee, Y. E., |
| 53 | + Williamson, J., … Lee, S. W. (2019). EEG dataset and OpenBMI |
| 54 | + toolbox for three BCI paradigms: An investigation into BCI |
| 55 | + illiteracy. GigaScience, 8(5), 1–16. |
| 56 | + https://doi.org/10.1093/gigascience/giz002 |
| 57 | + """ |
| 58 | + |
| 59 | + def __init__(self): |
| 60 | + super().__init__( |
| 61 | + subjects=list(range(1, 55)), |
| 62 | + sessions_per_subject=2, |
| 63 | + events=dict(left_hand=2, right_hand=1), |
| 64 | + code="Lee2019_MI", |
| 65 | + interval=[0, 4], |
| 66 | + paradigm="imagery", |
| 67 | + doi="10.5524/100542", |
| 68 | + ) |
| 69 | + |
| 70 | + def _get_single_subject_data(self, subject): |
| 71 | + """return data for a single subejct""" |
| 72 | + |
| 73 | + sessions = {} |
| 74 | + file_path_list = self.data_path(subject) |
| 75 | + |
| 76 | + for session in range(1, 3): |
| 77 | + data = loadmat(file_path_list[session - 1]) |
| 78 | + |
| 79 | + # Create channel info and montage |
| 80 | + eeg_ch_names = data["EEG_MI_train"][0, 0][8][0] |
| 81 | + ch_names = [elem[0] for elem in eeg_ch_names] + ["stim"] |
| 82 | + ch_types = ["eeg"] * 62 + ["stim"] |
| 83 | + sfreq = data["EEG_MI_train"][0, 0][3][0, 0] |
| 84 | + info = create_info(ch_names=ch_names, ch_types=ch_types, sfreq=sfreq) |
| 85 | + montage = make_standard_montage("standard_1005") |
| 86 | + |
| 87 | + # Create raw_data |
| 88 | + raw_train_data = np.transpose(data["EEG_MI_train"][0, 0][0], (1, 2, 0)) |
| 89 | + raw_test_data = np.transpose(data["EEG_MI_test"][0, 0][0], (1, 2, 0)) |
| 90 | + raw_data = np.concatenate([raw_train_data, raw_test_data], axis=0) |
| 91 | + |
| 92 | + # Create raw_event |
| 93 | + train_event_id = data["EEG_MI_train"][0, 0][4].ravel() |
| 94 | + test_event_id = data["EEG_MI_test"][0, 0][4].ravel() |
| 95 | + event_id = np.concatenate([train_event_id, test_event_id], axis=0) |
| 96 | + raw_events = np.zeros((raw_data.shape[0], 1, raw_data.shape[2])) |
| 97 | + raw_events[:, 0, 0] = event_id |
| 98 | + |
| 99 | + # Zero pad the data |
| 100 | + data = np.concatenate([raw_data, raw_events], axis=1) |
| 101 | + zeroshape = (data.shape[0], data.shape[1], 50) |
| 102 | + data = np.concatenate( |
| 103 | + [np.zeros(zeroshape), data, np.zeros(zeroshape)], axis=2 |
| 104 | + ) |
| 105 | + |
| 106 | + # Create RawArray |
| 107 | + raw = RawArray( |
| 108 | + data=np.concatenate(list(data), axis=1), info=info, verbose=False |
| 109 | + ) |
| 110 | + raw.set_montage(montage) |
| 111 | + |
| 112 | + # add the data to sessions |
| 113 | + session_name = "session_{}".format(session) |
| 114 | + sessions[session_name] = {"run_1": raw} |
| 115 | + |
| 116 | + return sessions |
| 117 | + |
| 118 | + def data_path( |
| 119 | + self, subject, path=None, force_update=False, update_path=None, verbose=None |
| 120 | + ): |
| 121 | + |
| 122 | + if subject not in self.subject_list: |
| 123 | + raise (ValueError("Invalid subject number")) |
| 124 | + |
| 125 | + subject_paths = [] |
| 126 | + for session in range(1, 3): |
| 127 | + url = "{0}session{1}/s{2}/sess{1:02d}_subj{2:02d}_EEG_MI.mat".format( |
| 128 | + Lee2019_URL, session, subject |
| 129 | + ) |
| 130 | + |
| 131 | + data_path = dl.data_path( |
| 132 | + url, "Lee2019_MI", path, force_update, update_path, verbose |
| 133 | + ) |
| 134 | + subject_paths.append(data_path) |
| 135 | + |
| 136 | + return subject_paths |
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