Pulse oxygenation devices use several LEDs to measure pulse rate and blood oxygen content. The LEDs are tuned to specific wavelengths corresponding to the absorbance band of oxygenated blood; by cycling through the LEDs rapidly the device compensates for skin and ambient light.
## Background
- high-level overview of pulse oxymetry from 1989: Tremper, Kevin K., and Steven J. Barker. "Pulse oximetry." Anesthesiology: The Journal of the American Society of Anesthesiologists 70.1 (1989): 98-108.
