Pulse Oximetry Flashcards
What is the purpose of pulse oximetry?
Measure arterial blood oxygenation and efficiency of ventilation
What range of wavelength is pulse oximetry performed?
NIR (~700-900nm)
Where is the isobestic point?
802nm
When is Hb absorption of O2 greater than HbO2 absorption of O2?
Below the isobestic point
When is deoxygenated tissue most transparent?
At wavelength above the isobestic point
What is the principle of regional oxygenation monitoring of thick tissue?
Optical scattering means light can be collected from the same side as the source
Losses in the received light are due to absorption in the tissue
What does regional oxygenation monitoring measure?
The continuous, non-pulsating absorption of IR light relating to local tissue
When is regional oxygenation monitoring used?
Brain O2 during surgery
Muscle O2 during sport
