BUG: Improve logic for bti

doc/changes/latest.inc

@@ -46,8 +46,8 @@ Bugs
 - Fix bug in :class:`mne.viz.Brain` constructor where the first argument was named ``subject_id`` instead of ``subject`` (:gh:`11049` by `Eric Larson`_)
 - Fix bug in :ref:`mne coreg` where the MEG helmet position was not updated during ICP fitting (:gh:`11084` by `Eric Larson`_)
 - Document ``height`` and ``weight`` keys of  ``subject_info`` entry in :class:`mne.Info` (:gh:`11019` by :newcontrib:`Sena Er`)
-- Fixed bug in :func:`mne.viz.plot_filter` when plotting filters created using ``output='ba'`` mode with ``compensation`` turned on. (by `Marian Dovgialo`_)
 - Fix bug in :func:`mne.viz.plot_filter` when plotting filters created using ``output='ba'`` mode with ``compensation`` turned on. (:gh:`11040` by `Marian Dovgialo`_)
+- Fix bug in :func:`mne.io.read_raw_bti` where EEG, EMG, and H/VEOG channels were not detected properly, and many non-ECG channels were called ECG. The logic has been improved, and any channels of unknown type are now labeled as ``misc`` (:gh:`11102` by `Eric Larson`_)
 - Fix bug in :func:`mne.viz.plot_topomap` when providing ``sphere="eeglab"`` (:gh:`11081` by `Mathieu Scheltienne`_)
 - Applying a montage where EEG locations are not in head space (or unknown space) without fiducials will now raise an error message. (:gh:`11080` by `Marijn van Vliet`_)
 

mne/io/bti/bti.py

@@ -8,6 +8,7 @@
 #
 #          simplified BSD-3 license
 
+import functools
 import os.path as op
 from io import BytesIO
 from itertools import count
@@ -48,7 +49,7 @@ def _instantiate_default_info_chs():
                 unit=FIFF.FIFF_UNIT_V,
                 cal=1.0,
                 scanno=None,
-                kind=FIFF.FIFFV_ECG_CH,
+                kind=FIFF.FIFFV_MISC_CH,
                 logno=None)
 
 
@@ -997,6 +998,23 @@ def _read_segment_file(self, data, idx, fi, start, stop, cals, mult):
                 _mult_cal_one(data_view, one, idx, cals, mult)
 
 
+@functools.lru_cache(1)
+def _1020_names():
+    from mne.channels import make_standard_montage
+    return set(ch_name.lower()
+               for ch_name in make_standard_montage('standard_1005').ch_names)
+
+
+def _eeg_like(ch_name):
+    # Some bti recordigs look like "F4-POz", so let's at least mark them
+    # as EEG
+    if ch_name.count('-') != 1:
+        return
+    ch, ref = ch_name.split('-')
+    eeg_names = _1020_names()
+    return ch.lower() in eeg_names and ref.lower() in eeg_names
+
+
 def _make_bti_digitization(
         info, head_shape_fname, convert, use_hpi, bti_dev_t, dev_ctf_t):
     with info._unlock():
@@ -1184,7 +1202,7 @@ def _get_bti_info(pdf_fname, config_fname, head_shape_fname, rotation_x,
                 chan_info['coil_type'] = \
                     FIFF.FIFFV_COIL_MAGNES_OFFDIAG_REF_GRAD
 
-        elif chan_4d.startswith('EEG'):
+        elif chan_4d.startswith('EEG') or _eeg_like(chan_4d):
             chan_info['kind'] = FIFF.FIFFV_EEG_CH
             chan_info['coil_type'] = FIFF.FIFFV_COIL_EEG
             chan_info['coord_frame'] = eeg_frame
@@ -1194,14 +1212,17 @@ def _get_bti_info(pdf_fname, config_fname, head_shape_fname, rotation_x,
             chan_info['kind'] = FIFF.FIFFV_STIM_CH
         elif chan_4d == 'TRIGGER':
             chan_info['kind'] = FIFF.FIFFV_STIM_CH
-        elif chan_4d.startswith('EOG') or chan_4d in eog_ch:
+        elif chan_4d.startswith('EOG') or \
+                chan_4d[:4] in ('HEOG', 'VEOG') or chan_4d in eog_ch:
             chan_info['kind'] = FIFF.FIFFV_EOG_CH
-        elif chan_4d == ecg_ch:
+        elif chan_4d.startswith('EMG'):
+            chan_info['kind'] = FIFF.FIFFV_EMG_CH
+        elif chan_4d == ecg_ch or chan_4d.startswith('ECG'):
             chan_info['kind'] = FIFF.FIFFV_ECG_CH
-        elif chan_4d.startswith('X'):
-            chan_info['kind'] = FIFF.FIFFV_MISC_CH
-        elif chan_4d == 'UACurrent':
-            chan_info['kind'] = FIFF.FIFFV_MISC_CH
+        # Our default is now misc, but if we ever change that,
+        # we'll need this:
+        # elif chan_4d.startswith('X') or chan_4d == 'UACurrent':
+        #     chan_info['kind'] = FIFF.FIFFV_MISC_CH
 
         chs.append(chan_info)
 

mne/io/bti/tests/test_bti.py

@@ -2,6 +2,7 @@
 #
 # License: BSD-3-Clause
 
+from collections import Counter
 from io import BytesIO
 import os
 import os.path as op
@@ -38,12 +39,10 @@
                    for a in archs]
 tmp_raw_fname = op.join(base_dir, 'tmp_raw.fif')
 
-fname_2500 = op.join(testing.data_path(download=False), 'BTi', 'erm_HFH',
-                     'c,rfDC')
-fname_sim = op.join(testing.data_path(download=False), 'BTi', '4Dsim',
-                    'c,rfDC')
-fname_sim_filt = op.join(testing.data_path(download=False), 'BTi', '4Dsim',
-                         'c,rfDC,fn50,o')
+testing_path_bti = testing.data_path(download=False) / 'BTi'
+fname_2500 = testing_path_bti / 'erm_HFH' / 'c,rfDC'
+fname_sim = testing_path_bti / '4Dsim' / 'c,rfDC'
+fname_sim_filt = testing_path_bti / '4Dsim' / 'c,rfDC,fn50,o'
 
 # the 4D exporter doesn't export all channels, so we confine our comparison
 NCH = 248
@@ -383,3 +382,61 @@ def test_bti_set_eog():
                        preload=False,
                        eog_ch=('X65', 'X67', 'X69', 'X66', 'X68'))
     assert_equal(len(pick_types(raw.info, eog=True)), 5)
+
+
+@testing.requires_testing_data
+def test_bti_ecg_eog_emg(monkeypatch):
+    """Test that EOG/ECG/EMG are set properly in BTi."""
+    kwargs = dict(rename_channels=False, head_shape_fname=None)
+    raw = read_raw_bti(fname_2500, **kwargs)
+    ch_types = raw.get_channel_types()
+    got = Counter(ch_types)
+    # Before improving the triaging in gh-, these values were:
+    # want = dict(mag=148, ref_meg=11, ecg=32, stim=2, misc=1)
+    want = dict(mag=148, ref_meg=11, ecg=1, stim=2, misc=1, eeg=31)
+    assert set(want) == set(got)
+    for key in want:
+        assert want[key] == got[key], key
+
+    # replace channel names with some from HCP (starting from the end)
+    # not including UACurrent (misc) or TRIGGER/RESPONSE (stim) b/c they
+    # already exist
+    got_map = dict(zip(raw.ch_names, ch_types))
+    kind_map = dict(
+        stim=['TRIGGER', 'RESPONSE'],
+        misc=['UACurrent'],
+    )
+    for kind, ch_names in kind_map.items():
+        for ch_name in ch_names:
+            assert got_map[ch_name] == kind
+    kind_map = dict(
+        misc=['SA1', 'SA2', 'SA3'],
+        ecg=['ECG+', 'ECG-'],
+        eog=['VEOG+', 'HEOG+', 'VEOG-', 'HEOG-'],
+        emg=['EMG_LF', 'EMG_LH', 'EMG_RF', 'EMG_RH'],
+    )
+    new_names = sum(kind_map.values(), list())
+    assert len(new_names) == 13
+    assert set(new_names).intersection(set(raw.ch_names)) == set()
+
+    def _read_bti_header_2(*args, **kwargs):
+        bti_info = _read_bti_header(*args, **kwargs)
+        for ch_name, ch in zip(new_names, bti_info['chs'][::-1]):
+            ch['chan_label'] = ch_name
+        return bti_info
+
+    monkeypatch.setattr(mne.io.bti.bti, '_read_bti_header', _read_bti_header_2)
+    raw = read_raw_bti(fname_2500, **kwargs)
+    got_map = dict(zip(raw.ch_names, raw.get_channel_types()))
+    got = Counter(got_map.values())
+    want = dict(mag=148, ref_meg=11, misc=1, stim=2, eeg=19)
+    for kind, ch_names in kind_map.items():
+        want[kind] = want.get(kind, 0) + len(ch_names)
+    assert set(want) == set(got)
+    for key in want:
+        assert want[key] == got[key], key
+    for kind, ch_names in kind_map.items():
+        for ch_name in ch_names:
+            assert ch_name in raw.ch_names
+            err_msg = f'{ch_name} type {got_map[ch_name]} !+ {kind}'
+            assert got_map[ch_name] == kind, err_msg