Non-Invasive measurement of arterial oxygen saturation in the blood.

Continuous Monitoring

Electrical Safe

R = Log10 (I1/Iin1) / Log10 (I2/Iin2) arn is the absorption coefficient of HbO2 at

wavelength n aon is the absorption coefficient of Hb at wavelength n

R = Log10 (Idc + ac/Idc) 1 / Log10 (Idc + ac/Idc) 2

Look-up Tables up to 85%

I=V/R1 Using feedback comparator

Need ?

Ra=56kOhm, Rb=3.3kOhm C=22nF

F=1/2RC

Accuracy Versus Saturation (up to 85%)

Saturation Versus Perfusion

Saturation Versus Motion Artifacts

Accuracy Versus Optical Artifacts

Effect of Temperature

Alarms

Proteus Simulation Studied

Understood Development Process

Possible Sources of Biases Identified