Not yet investigated
What we have so far
Melanin absorbs the red light the device relies on. Occult hypoxaemia is roughly three times more common in Black patients, and it changed who got treated in 2020.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.