A<unk>  measures the absorption of light passing through blood from few as two or three wavelengths of light to several dozens of wavelengths, in order to distinguish oxyhemoglobin, and deoxyhemoglobin (formerly called 'reduced' hemoglobin), and thus determine the oxyhemoglobin saturation (the percentage of oxygenated hemoglobin<unk> mpared to the total amount of available hemoglobin (Hb)). Measurement of greater numbers of wavelengths enables the instrument to distinguish between these and carboxyhemoglobin,-COHb, methemoglobin -metHb, other hemoglobin moieties and 'background' light-absorbing species. Traditionally, measurement is made from arterial blood processed in a specific device designed to be able to measure proportions of multiple<unk> mponents of several hemoglobin moieties using multi-wavelength spectrophotometry and<unk> mplex, but straightforward internal<unk> mputations. While these units still are in wide use, blood gas analyzers with integral<unk> y modules have also been developed and successfully marketed by several manufacturers. More recently, some 'pulse' or more precisely 'peripheral'<unk> s have made it possible to estimate carboxyhemoglobin with non-invasive technology similar to a simple (peripheral) pulse<unk> . In<unk> ntrast, the use of a standard or simple pulse<unk>  is not effective in the diagnosis of<unk>  poisoning as patients suffering from carbon monoxide poisoning may have a normal oxygen saturation reading on a pulse<unk> .
CO-oximeter
Hyperoxia test
Pulse oximetry
Plethysmograph
Carbon monoxide detector
Respiratory pressure meter
Hemoximetry
Oxygenation index