Figure 1. SpO2versus time for three test pulse oximeters compared with stationary N-200 control (thin line) on opposite hands during normoxemia followed by gradual desaturation. (a) Motion oximeter = N-200;(b) N-3000;(c) Masimo SET. Rubbing and tapping motions begin and stop when indicated by bars. The notch in the motion bar indicates time when oximeter sensors (except control) are disconnected and reconnected during motion.