polarofficial / polar-ble-sdk

Repository includes SDK and code examples. More info https://polar.com/en/developers
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INVERSION OF PPG SIGNAL #472

Open PChiericoUPV opened 4 months ago

PChiericoUPV commented 4 months ago

Platform your question concerns:

Device:

Description: I would like to understand if the PPG signal is inverted, as the systolic phase seems to align with the literature only when I invert the signal on the Y-axis.

Regarding the three PPG channels, does Ch0 represent the photodiode of two opposite LEDs?

Additionally, concerning ambient light, is there an Automatic Light Control (ALC) in the device? Does anyone have advice for effectively using raw ambient light data? For me, averaging the three channels and subtracting the ambient light is not robust enough. Is there a method o subtract, perhaps using the median or an alternative average of the ambient light?

FinalScreenshot 2024-07-08 110312