Table 1.
Values of Signal Quality Index, S1, S2, and S3 corresponding to different signal quality.
| Signal Quality Index | Signal Quality | S1 | S2 | S3 | Signal-to-Noise Ratio SNR (dB) | Signal-to-Motion Ratio SMR (dB) |
|---|---|---|---|---|---|---|
| >10 | Good signal, higher values were less contaminated. | >1 | +1 | 10 | >15 | >12 |
| <0 | Contaminated with low frequency artifacts. | >0 | −1 | >0.1 and <10 | >15 | <12 |
| <0 | Contaminated with high frequency noise. | >0 | −1 | >0.1 and <10 | <15 | >12 |
| >0 and <1 | Contaminated with both low frequency artifacts and high frequency noise, lower values were more contaminated. | >0 and <1 | +1 | 0.1 | <15 | <12 |