A Novel Approach Using Time-Frequency Analysis of Pulse-Oximeter Data to Detect Progressive Hypovolemia in Spontaneously Breathing Healthy Subjects

• Published in: IEEE transactions on biomedical engineering Vol. 58; no. 8; pp. 2272 - 2279
• Main Authors: Selvaraj, Nandakumar, Shelley, Kirk H., Silverman, David G., Stachenfeld, Nina, Galante, Nicholas, Florian, John P., Mendelson, Yitzhak, Chon, Ki H.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2011; Institute of Electrical and Electronics Engineers
• Subjects: Algorithms; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Blood; Blood loss; Blood Volume; Blood Volume Determination - methods; Diagnosis, Computer-Assisted - methods; Ear; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency and intensive care: techniques, logistics; Fingers; Forehead; Frequency modulation; Heart rate; Humans; hypovolemia; Hypovolemia - diagnosis; Hypovolemia - physiopathology; Intensive care medicine; lower body negative pressure (LBNP); Medical sciences; Monitoring; Oximetry - methods; photoplethysmogram (PPG); Photoplethysmography - methods; Protocols; pulse oximeter; Reproducibility of Results; Respiratory Mechanics; Sensitivity and Specificity; time-frequency analysis; trauma care; Human; trauma care; Blood gas; Intensive care; Pulse oxymetry; Hypovolemia; Hemorrhage; Trauma; lower body negative pressure (LBNP); Heart rate; Blood volume; time-frequency analysis; Blood loss; Respiratory frequency; Signal processing; Photoplethysmography; photoplethysmogram (PPG); pulse oximeter; Diagnosis; Measurement method; Biomedical engineering
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2011.2144981

Accurate and early detection of blood volume loss would greatly improve intraoperative and trauma care. This study has attempted to determine early diagnostic and quantitative markers for blood volume loss by analyzing photoplethysmogram (PPG) data from ear, finger, and forehead sites with our high-resolution time-frequency spectral (TFS) technique in spontaneously breathing healthy subjects (n=11) subjected to lower body negative pressure (LBNP). The instantaneous amplitude modulations (AM) present in heart rate (AM HR ) and breathing rate (AM BR ) band frequencies of PPG signals were calculated from the high-resolution TFS. Results suggested that the changes (P <; 0.05) in AM BR and especially in AM HR values can be used to detect the blood volume loss at an early stage of 20% LBNP tolerance when compared to the baseline values. The mean percent decrease in AM HR values at 100% LBNP tolerance was 78.3%, 72.5%, and 33.9% for ear, finger, and forehead PPG signals, respectively. The mean percent increase in AM BR values at 100% LBNP tolerance was 99.4% and 19.6% for ear and finger sites, respectively; AM BR values were not attainable for forehead PPG signal. Even without baseline AM HR values, our results suggest that hypovolemia detection is possible with specificity and sensitivity greater than 90% for the ear and forehead locations when LBNP tolerance is 100%. Therefore, the TFS analysis of noninvasive PPG waveforms is promising for early diagnosis and quantification of hypovolemia at levels not identified by vital signs in spontaneously breathing subjects.