Evaluation of the influence of movement on saturation readings from pulse oximeters.

This study aimed to develop a protocol for assessing the influence of movement on oxyhaemoglobin saturation readings from pulse oximeters. Thirty-six volunteers took part in the study. In each volunteer, each hand was monitored by both a Nellcor N200 oximeter using a disposable probe and by a Datex Satlite DS103 oximeter using a clip-on finger probe. Volunteers made five standardised movements during which output was recorded from all four oximeters. All movements were associated with apparent decreases in oxyhaemoglobin saturation which were statistically significant for two movements with the Nellcor equipment and for four movements with the Datex equipment. Movement was associated with increases in the magnitude of pulse amplitude, but this was not quantitatively associated with magnitude of artefactual changes in saturation. Use of this standardised movement protocol allows quantification of movement artefact from pulse oximeters and should facilitate the development of equipment less affected by movement.