Table 6 Functional neuroimaging systems. Neuroimaging hardware and related signal processing and analysis. ‘–’ indicates that the authors gave no information on the respective matter
From: A review of combined functional neuroimaging and motion capture for motor rehabilitation
Hardware | Signal processing | References | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Technology | Sensor number | Sensor position | Sensor type | Sample rate | Feature domain | Filter | Segmentation | Artifact correction/rejection | Feature extraction | Features | |
EEG | 3 | Prefrontal | Passive dry | – | – | – | – | – | – | Attention level | [45] |
Central | Dry foam | 512 Hz | Frequency | – | – | – | – | Theta/Beta ratio | [46] | ||
≤ 16 | Frontal, central | Active | 256 Hz | Frequency | – | Moving window (1 s) | – | CPS for 8–24 Hz SVM classification | Rest/movement intention maximum joint jerk Kinematics | [43] | |
– | 500 Hz | Time | Band-pass [0.15–20 Hz] | Movement onset [− 2.5 s, 1 s] | Statistical trial rejection Baseline correction Inclusion of C3 or C4 | – | MRCP | [50] | |||
Whole | Active wet | – | (1) Time; (2) Time-frequency | Band-pass [0.5–40 Hz] | Movment onset [− 5 s, 1 s] | 1,2) ICA artifact correction Manual artifact rejection Inclusion of C3 or C4 | – | (1) MP (2) Maximum ERD | [41] | ||
≤ 32 | Frontal, central, parietal, occpitial | Active wet | 256 Hz | (1) Time (2) Time-frequency | (1) Low-Pass [1 Hz] (2) Band-pass [6 - 32 Hz] | (1) Movement onset [− 3 s, − 2 s] (2) Movement onset [− 3 s, − 0.5 s] | – | (1) Dominant channel selection, matched filter (2) Welch’s method, channel/frequency pairs selection, classification (Naive Bayes) (1,2) Logistic regression of 1() and (2) | Movement intention | [40] | |
Whole | Passive wet | 500 Hz | Time-frequency | – | Movment onset [− 5 s, 18 s] | EOG-based artifact correction Manual trial rejection Baseline correction | (1) Band-pass filter [Dominant alpha frequency − 1 Hz/+ 1 Hz] (2) Band-pass filter [14.5 Hz, 24,5 Hz] Rectification | (1) Alpha-ERD (2) Beta-ERD | [39] | ||
250 Hz | Frequency | Band-pass [0.5 Hz–100 Hz] | – | Inclusion of central and front-central areas EOG-based artifact correction | – | Spatial distrubution of beta-band and mu-rythmn | [55] | ||||
≤ 64 | Whole | Active wet | 5000 Hz | Time | Band-pass [0.05 Hz–2 Hz] | Force onset [− 2.5 s, 0.5 s] | Inclusion of frontal, central, and parietal areas Manual artifact rejection | – | MRCP | [47] | |
100 Hz | Non-Linear | Band-pass [0.1–3 Hz] | – | EOG-based artifact correction Exclusion of peripheral channels | Standardize UKF decoder | Predicted joint angles | [48] | ||||
1024 Hz | Time | High-pass [0.1 Hz] | Visual stimulus [− 0.4 s, 1.4 s] | Statistical channel rejection Manual artifact rejection ICA artifact rejection DIPFIT Baseline correction | Downsampling ERP microstate extraction Microstate selection LORETA | Microstate | [54] | ||||
Active | 1000 Hz | Non-Linear | Band-pass [0.1 Hz–3 Hz] | Walking stop/start (between 6 s to 6 min) | ASR Exclusion of peripheral channels Detrend | Standardize PCA UKF decoder | Predicted joint angles and velocity | [44] | |||
500 Hz | Time-frequency | Band-pass [1–40 Hz] | – | Manual channel correction Manual artifact rejection | SVD Morlet wavelet for each SVD topography Coefficient variation for delta, theta, alpha, and beta band | Resting-state SVD components for delta, theta, alpha and beta band | [52] | ||||
≤ 128 | Whole | Active wet | 500 Hz | Frequency | – | Trail start [7.5 s, 17.5 s] | Manual channel rejection ICA artifact rejection | – | Band power | [49] | |
1000 Hz | Time | High-pass [1 Hz] Low-pass [40 Hz] | Heel strike [− 0.5 s, 1.2 s] | Statistical trial/channel rejection | – | ERPs | [42] | ||||
Passive wet | 1024 Hz | Time-frequency | Notch-filter [50 Hz] Band-pass [0.5 Hz–200 Hz] | Movement onset [− 2 s, 4 s] | Manual artifact rejection Statistical channel rejection InfoMax artifact rejection | Co-registration of EEG sensors and anatomical landmarks Source estimation Morelet projections | Volume-based and intentsity-based lateralisation index | [53] | |||
5000 Hz | Time | Low-pass [45 Hz] | Visual stimulus [− 2.5 s, 2.5 s] | Manual trial/channel rejection Baseline correction Manual ICA artifact rejection | (1) Spatiotemporal representation vector, PCA (2) Standardize,FastICA | (1) Spatiotemporal vectors (2) ICA components mean and variance | [51] | ||||
Wet | 2048 Hz | (1) Frequency (2) Time-Frequency | Band-pass [2–200 Hz] | Movement onset [− 2 s, 3 s] | Statistcal channel rejection Manual trial rejection ICA artifact rejection | – | GED topography Time-frequency plot Theta z-score | [57] | |||
fNIRS | 8 | Prefrontal, frontal | Optodes | – | Time | Band-pass [0.005 Hz–0.03 Hz] | – | Statistical channel/trial rejection Wavelet filtering Baseline correction | Correlation-based signal improvement Averaged HBo and HbR | Hdiff | [56] |