Most during surgery best measurement of oxygen saturation in anaesthesia is

(Pulse Oximetry): Ref: (1503, 1585 -H) (291,883-B &L 25th) (1590-H 17th)PULSE OXIMETRY: - Most commonly utilized noninvasive monitor of respiratory function. The technique takes advantage of differences in the absorptive properties of oxygenated and deoxygenated hemoglobin (1583-H)* Pulse oximeter calculates oxygen saturation (rather than Pa02) based on measurement of absorption of two wavelengths of light by hemoglobin in pulsatile, cutaneous arterial blood, Because of differential absorption of the two wave lengths of light by oxygenated and nonoxygenated hemoglobin, the percentage of hemoglobin that is saturated with oxygen i.e. Sa02 can be calculated and displayed, instaneously (1503-H)