PT  - JOURNAL ARTICLE
AU  - P Leonard
AU  - T F Beattie
AU  - P S Addison
AU  - J N Watson
TI  - Standard pulse oximeters can be used to monitor respiratory rate
AID  - 10.1136/emj.20.6.524
DP  - 2003 Nov 01
TA  - Emergency Medicine Journal
PG  - 524--525
VI  - 20
IP  - 6
4099  - http://emj.bmj.com/content/20/6/524.short
4100  - http://emj.bmj.com/content/20/6/524.full
SO  - Emerg Med J2003 Nov 01; 20
AB  - Background: One of the most important limitations of standard pulse oximeters is the inability to detect changes in respiratory rate until oxygenation is affected. This study sought to determine if analysis of the plethysmogram by wavelet transforms would enable the determination of changes in respiratory rate at an earlier stage. Methods: Ten healthy adult volunteers were monitored, breathing at baseline and predetermined respiratory rates, using a standard pulse oximeter. Photo-plethysmograms captured in an attached lap top computer were then analysed using wavelet transforms. Results: Determination of baseline respiratory rate and subsequent changes including apnoea were easily identified. Comment: Wavelet transforms permit the accurate determination of respiratory rate by a standard pulse oximeter.