A New Approach to Photoelectric Plethysmography

Photoelectric plethysmography has already been used for a very long time to monitor the circulation during anaesthesia, because it is a non-invasive method which can be applied easily and rapidly. Because of the accessibility during anaesthesia it is almost exclusively applied to the skin of the fingers, toes or ears. During the past few years much more knowledge has been acquired about the background of the method and in this paper we intend to present a review of our research with this method in approximately 500 patients. In particular the difference between the plethysmograms recorded from finger and earshell will be discussed. The review is preceded by an explanation of the basic principles.