Table 2.
Readings from all four sensors (A–D) tested in the same position on the left wrist; photoplethysmogram (PPG) peak to peak average (P-Pave), Perfusion Index (PI) average and signal to noise ratio (SNR) for both wavelengths, and the average calculated oxygen saturation (SpO2) was obtained over a 1.5 s window.
| Sensor | Signal | P-Pave (nW) | PI (%) |
SNR | SpO2 (%) |
|---|---|---|---|---|---|
| A | Red | 0.3 | 0.08 | 5.27 | 98.2 |
| IR | 0.15 | 0.07 | 6.28 | ||
| B | Red | 0.32 | 0.07 | 6.50 | 99 |
| IR | 0.16 | 0.08 | 6.52 | ||
| C | Red | 0.31 | 0.06 | 5.95 | 98.5 |
| IR | 0.15 | 0.07 | 6.34 | ||
| D | Red | 0.3 | 0.08 | 6.18 | 98.3 |
| IR | 0.17 | 0.09 | 6.77 |