You are reading a single comment by @adroit and its replies.
Click here to read the full conversation.
-
Every day is a school day. I read a bit more on the subject and found this.
https://circuit.bcit.ca/repository/islandora/object/repository%3A2043/datastream/PDF/download/citation.pdf
adroit
stevep
Whilst this is correct.
This is incorrect.
We know there to be a statistically significant delta in reflectance and absorbance in Photoplethysmography (ie what's used for oxygen saturation and drives the heart-rate data from your garmin/fitbit/Apple Watch) across skin-tones (https://www.nature.com/articles/s41746-021-00408-5 , etc.).
There is also a smaller, but still significant delta in the near-IR and IR bands, up till a wavelength over the 850nm that the IR dispensers use:
(skin color scale: https://en.wikipedia.org/wiki/Fitzpatrick_scale)
(reference: https://opg.optica.org/directpdfaccess/c0a24e54-ec7f-460e-b95000098ac41736_333549/ao-54-35-10559.pdf)
The cause for this is- at least partially- Melanin's absorbance spectra, and so whilst no object can be racist, there is a difference in skin absorptivity, which has been- historically- overlooked.
