Independent Component Analysis of Pulse Oximetry Signals Based on Derivative Skew

This paper describes the application of ICA to signals from a pulse oximeter, a device for measuring arterial blood oxygen content. Since the arterial pulse signal resembles a sawtooth wave, taking the time derivative enhances the skew of this component relative to that of the interference. Third-order ICA techniques can take advantage of this to aid the separation. This paper shows an example of ICA used on pulse oximetry signals and then presents simulations to demonstrate that, for pulse oximetry signals, ICA based on third-order statistics of the derivative is indeed superior to fourth-order ICA.