Here is a link to the paper in PDF format
Study 2- Oct 2014
A study on 15 subjects has been conducted to compare the heart rate and the heart rate variability obtained from the E3 with the one obtained from a gold standard, the Biopac MP150 equipped with and ECG100C transducer.
The experiment has been performed under low movement conditions.
The comparison is documented in the following presentation: ECGvsE3-BVP_20141029.pdf
Over 9287 peaks were detected from 15 participants’ ground truth ECG. In our analysis data was analyzed from 9 subjects with clean ground-truth ECG:
For heart rate variability computation and vagal tone estimation, it is important to compute the high frequency (HF) component. Sometimes people are also interested in the ratio of the Low Frequency (LF) to HF, as an estimate of sympathovagal balance.
| Mean PP intervals | r=1 | p< 0.0001 |
| SD PP intervals | r=0.997 | p< 0.0001 |
| LF | r=0.991 | p< 0.0001 |
| HF | r=0.981 | p< 0.0001 |
| LF/HF | r=0.965 | p< 0.0001 |
Totalerror = 2.1% = (FP+FN+MD)/ECG peaks
Formal evaluations of the continuous heart-rate are in progress in order to evaluate the signal quality under strong movement conditions