Where does “peripheral oxygen saturation” come from?

peripheral oxygen saturation (English) comes from English peripheral, from English periphery, from Old French peripherie, from Latin peripherīa, from Ancient Greek περιφέρεια, from Ancient Greek περιφερής, from Ancient Greek περιφέρω, from Ancient Greek περῐ- — to push, to hit.

peripheral oxygen saturation (English): An estimation of the oxygen saturation level usually measured with a pulse oximeter device