Abstract
The measurement of oxygen saturation using pulse oximeters requires clean photoplethysmograph (PPG) signals, as motion artifacts often lead to a significant degree of error in the computation. This paper proposes a method for reducing motion artifacts from corrupted PPG signals by applying a normalized least mean squares (NLMS) algorithm, using an isobestic point wavelength (800nm) as a noise reference signal for the adaptive filter. A finger ring type sensor was demonstrated to be more comfortable than a clip type sensor. Experimental results indicate that the proposed method is suitable for reconstructing PPG signals and improving the accuracy of measuring oxygen saturation in the blood. © 2011 IEEE.