How the clip on your finger sees through you.

Question on this card

Why does a pulse oximeter use only the pulsating part of the signal?

1. To save battery
2. To subtract skin, bone and veins
3. Because light only passes during a pulse
4. To determine heart rhythm

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This card belongs to the topic Body & Health. Every card is short, cites a source and can be saved – due ones come back by themselves later.

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