Figure 5. Performance results of the four (I–IV) subjects present in our dataset, where the dotted lines indicate the beginning of the breath-holding events.

It can be observed that the RR-based method achieves satisfactory results in the first static part of the recordings, but completely fails in the presence of motion artifacts. The proposed APBV method is capable to estimate SpO₂ during motion, although a decrease in accuracy can be identified compared to the static part.