RESPIRATORY RATE ESTIMATION IN POSTOPERATIVE CARE—STATE OF THE ART AND PERSPECTIVES

In this work, respiratory rate computation based on the respiratory sinus arrhythmia is described. Based on ECG and PPG signals acquired from standard monitoring, heart rate variability was computed. After that, the respiratory sinus arrhythmia was computed filtering heart rate variability. Finally, the respiratory rate was estimated using a simple peak detection algorithm. The benefit of the presented method is that standard monitoring, available in the recovery room, intensive care, and intermediate care, can be used. No additional sensors, such as capnography, respiration belts, or thermistors, are necessary. In future PPG imaging, a method for image-based PPG assessment, can be used as a source for the presented methods. This could permit a contactless estimation of heart rate, heart rate variability, and therefore also estimated respiratory rate. Combining with other methods for respiratory rate estimation, such as PPG amplitude analysis or frequency analysis, can make assessment of respiratory rate more reliable. Furthermore, a combination with respiratory sinus arrhythmia based analgesia assessment can be implemented to improve pain therapy in postoperative care