APPENDIX A: PRINCIPLES OF OPERATION
KTMED Inc. Model OXYPALM
Operator’s Manual 21
Principles of Pulse Oximeter
The principle of pulse oximeter is based on the red and infrared light absorption characteristics of
oxygenated and deoxygenated hemoglobin. Oxygenated hemoglobin absorbs more infrared light and allows
more red lights to pass through. Deoxygenated (or reduced) hemoglobin absorbs more red light and allows
more infrared light to pass through. Red light is in the 600-750 nm wavelength light band. Infrared light is in
the 850-1000 nm wavelength light band.
Pulse oximeter uses a light emitter with red and infrared LEDs that shines through a reasonably
translucent site with good blood flow. Typical adult/pediatric sites are the finger, toe, pinna (top) or lobe of the
ear. Infant sites are the foot or palm of the hand and the big toe or thumb. Opposite the emitter is a photo-
detector that receives the light that passes through the measuring site.
