Long-term quasi-continuous oxygen saturation levels obtained from sternal photoplethysmography on patients with obstructive lung diseases.

Calculation of long-term quasi-continuous oxygen saturation (SpO2) levels is highly relevant for critically ill patients. The purpose of this study is therefore to conduct a preliminary investigation of the clinical reliability of long-term photoplethysmography (PPG) recordings obtained from the sternum of patients admitted to the hospital with obstructive lung diseases. Due to the lack of a gold standard reference that is suitable for long-term monitoring without interfering with the patient's activity level, we extracted reliable segments based on knowledge from the basic pulse oximeter theory as well as knowledge about the inherent physiological regulation of the SpO2 levels.

A clinical study of short-term sternal photoplethysmography: Recordings from patients with obstructive airways diseases.

Traditionally, measurements of the oxygen saturation (SO) has been confound to the extremities. In this study, we therefore investigated the possibility for reliable estimation of clinically relevant SO levels from photoplethysmography (PPG) obtained on the sternum of patients with obstructive airway diseases. We initiated the study with a calibration of a prototype sternal PPG sensor.