Powers and limitations of noninvasive measurements implemented in pulse oximetry

The subject of the paper is devoted to pulse oximetry which is one of the most modern diagnostic technique in the field of noninvasive biomedical measurements. A brief review of principles and status of pulse oximetry is presented. The impressive advantages of this diagnostic technique as well as serious problems still connected with reliability of instruments indications are discussed. Tendency to development and major directions in future of pulse oximetry are outlined. On the background of data reported in the literature, the author of this paper describes results collected by her during comparative studies. In these studies, well-known commercial pulse oximeters and a specially designed measuring system, which allows to control components of optical signals acquired from living tissues and to trace sources of errors, were used.