How pulse oximeters work, and why they sometimes do not

Pulse oximeters, which measure oxygen levels in blood, are one of the most widely used medical tools. They are affordable, portable, and easy to use, but they have a major drawback: Numerous studies show they are less accurate for people with darker skin.
Watch this video to understand the technology behind these devices and why they are less accurate in some patients.

[@danieldc4175]

Hi. Have they improved the device? How does having thick callous skin on the fingers affect readings?

[@trileobayu2023]

why the bgm so intense?

[@briank592]

This beat is sick, reminds me of b.o.c.'s : "everything you do is a ballon"

[@daviderickennedy2194]

The pulse oximeters in this video, the 20 buck ones are not even remotely in the same class as the ones at a hospital nursing station (Desktop Models). They have far fewer problems, but they cost $700 - $3000 bucks!