Development of a Signal Processing Library for Extraction of SpO2, HR, HRV, and RR from Photoplethysmographic Waveforms

Non-invasive remote physiological monitoring of soldiers on the battlefield has the potential to provide fast, accurate status assessments that are key to improving the survivability of critical injuries. The development of WPI’s wearable wireless pulse oximeter, designed for field-based applications, has allowed for the optimization of important hardware features such as physical size and power management. However, software-based digital signal processing (DSP) methods are still required to perform physiological assessments. This research evaluated DSP methods that were capable of providing arterial oxygen saturation (SpO2), heart rate (HR), heart rate variability (HRV), and respiration rate (RR) measurements derived from data acquired using a single optical sensor. In vivo experiments were conducted to evaluate the accuracies of the processing methods across ranges of physiological conditions. Of the algorithms assessed, 13 SpO2 methods, 1 HR method, 6 HRV indices, and 4 RR methods were identified that provided clinically acceptable measurement accuracies and could potentially be employed in a wearable pulse oximeter.

[1]  T. L. Rusch,et al.  Signal processing methods for pulse oximetry , 1996, Comput. Biol. Medicine.

[2]  P. King,et al.  Design Of Pulse Oximeters , 1998, IEEE Engineering in Medicine and Biology Magazine.

[3]  Y. Mendelson Pulse oximetry: theory and applications for noninvasive monitoring. , 1992, Clinical chemistry.

[4]  T. L. Rusch,et al.  Optimization of portable pulse oximetry through Fourier analysis , 1993, [1993] Proceedings of the Twelfth Southern Biomedical Engineering Conference.

[5]  Professor P. Å. Öberg,et al.  Estimation of respiratory volumes from the photoplethysmographic signal. Part 2: a model study , 2006, Medical & Biological Engineering & Computing.

[6]  Y. Shimada,et al.  Spectrophotometric monitoring of arterial oxygen saturation in the fingertip , 2006, Medical and Biological Engineering and Computing.

[7]  M. Akay,et al.  Using a forehead reflectance pulse oximeter to detect changes in sympathetic tone , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[8]  F. Flack,et al.  Comparative Review of Techniques for Recording Respiratory Events at Rest and during Deglutition , 1997, Dysphagia.

[9]  H V Huikuri,et al.  Measurement of heart rate variability: a clinical tool or a research toy? , 1999, Journal of the American College of Cardiology.

[10]  A. Tura,et al.  A Medical Wearable Device with Wireless Bluetooth-based Data Transmission , 2003 .

[11]  R.I. Kitney,et al.  Real-time heart rate variability extraction using the Kaiser window , 1997, IEEE Transactions on Biomedical Engineering.

[12]  G. Blike,et al.  Investigating respiratory variation using a forehead reflectance pulse oximeter to identify airway obstruction for automated remote triage , 2005, Proceedings of the IEEE 31st Annual Northeast Bioengineering Conference, 2005..

[13]  Charles L. Britton,et al.  Medical telesensors , 1998, Photonics West - Biomedical Optics.

[14]  A Calciati,et al.  Autonomic control of skin microvessels: assessment by power spectrum of photoplethysmographic waves. , 1996, Clinical science.

[15]  Michael V. Scanlon Acoustic sensor pad for physiological monitoring , 1997, Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 'Magnificent Milestones and Emerging Opportunities in Medical Engineering' (Cat. No.97CH36136).

[16]  A. Malliani,et al.  Heart rate variability. Standards of measurement, physiological interpretation, and clinical use , 1996 .

[17]  R. Mccraty,et al.  The effects of emotions on short-term power spectrum analysis of heart rate variability . , 1995, The American journal of cardiology.

[18]  Abdulnasir Hossen,et al.  Subband decomposition soft-decision algorithm for heart rate variability analysis in patients with obstructive sleep apnea and normal controls , 2005, Signal Process..

[19]  T. Strömberg,et al.  Influence of Tidal Volume and THoraco-abdominal Separation on the Respiratory Induced Variation of the Photoplethysmogram , 2004, Journal of Clinical Monitoring and Computing.

[20]  Keith R. Godfrey,et al.  Comparison of methods for harmonic wavelet analysis of heart rate variability , 1998 .

[21]  Suzanne Wendelken,et al.  A medical assessment algorithm for automated remote triage , 2003, Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439).

[22]  Paul Lukowicz,et al.  AMON: a wearable multiparameter medical monitoring and alert system , 2004, IEEE Transactions on Information Technology in Biomedicine.

[23]  V. S. Murthy,et al.  Analysis of photoplethysmographic signals of cardiovascular patients , 2001, 2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[24]  M. Petterson,et al.  Adaptive filtering and alternative calculations revolutionizes pulse oximetry sensitivity and specificity during motion and low perfusion , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[25]  Paul Lukowicz,et al.  AMON: a wearable medical computer for high risk patients , 2002, Proceedings. Sixth International Symposium on Wearable Computers,.

[26]  J. Lebak,et al.  Implementation of a standards-based pulse oximeter on a wearable, embedded platform , 2003, Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439).

[27]  K. Nakajima,et al.  Monitoring of heart and respiratory rates by photoplethysmography using a digital filtering technique. , 1996, Medical engineering & physics.

[28]  S. A. Atapattu,et al.  A telemedicine application utilizing DataSocket(R) to remotely track the heart rate variability of patients in a clinical research environment , 2000, Proceedings 2000 IEEE EMBS International Conference on Information Technology Applications in Biomedicine. ITAB-ITIS 2000. Joint Meeting Third IEEE EMBS International Conference on Information Technol.

[29]  J.M. Kim,et al.  Signal processing using Fourier & wavelet transform for pulse oximetry , 2001, Technical Digest. CLEO/Pacific Rim 2001. 4th Pacific Rim Conference on Lasers and Electro-Optics (Cat. No.01TH8557).

[30]  W J Tompkins,et al.  Design of an inductive plethysmograph for ventilation measurement. , 1994, Physiological measurement.

[31]  Jianchu Yao,et al.  Design of a plug-and-play pulse oximeter , 2002, Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and Biology.

[32]  Suzanne Wendelken,et al.  ARTEMIS : A Vision for Remote Triage and Emergency Management Information Integration , 2003 .

[33]  J. E. Scharf,et al.  Pulse oximetry through spectral analysis , 1993, [1993] Proceedings of the Twelfth Southern Biomedical Engineering Conference.

[34]  Kalju Meigas,et al.  Waveform Analysis of Peripheral Pulse Wave Detected in the Fingertip with Photoplethysmograph , 2003 .

[35]  T. Wisborg,et al.  Respiratory rate as a prehospital triage tool in rural trauma. , 2003, The Journal of trauma.

[36]  M. Akay,et al.  The feasibility of using a forehead reflectance pulse oximeter for automated remote triage , 2004, IEEE 30th Annual Northeast Bioengineering Conference, 2004. Proceedings of the.

[37]  P.D. Mannheimer,et al.  Wavelength selection for low-saturation pulse oximetry , 1997, IEEE Transactions on Biomedical Engineering.

[38]  J. Lauter,et al.  Wearable approach for continuous ECG - and activity patient-monitoring , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[39]  W. B. Murray,et al.  The peripheral pulse wave: Information overlooked , 1996, Journal of clinical monitoring.

[40]  Farid U. Dowla,et al.  Neural networks and wavelet analysis in the computer interpretation of pulse oximetry data , 1996, Neural Networks for Signal Processing VI. Proceedings of the 1996 IEEE Signal Processing Society Workshop.

[41]  Michael L. Jacobson,et al.  Time-frequency analysis of heart rate variability , 2007, 2007 9th International Symposium on Signal Processing and Its Applications.

[42]  Y. Mendelson,et al.  Extracting heart rate variability from a wearable reflectance pulse oximeter , 2005, Proceedings of the IEEE 31st Annual Northeast Bioengineering Conference, 2005..

[43]  James M. Ecklund,et al.  In search of technological solutions to battlefield management of combat casualties , 1999, Defense, Security, and Sensing.

[44]  Y. Y. Gu,et al.  Reducing the influence of contacting force applied on photoplethysmographic sensor on heart rate variability estimation , 2003, Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439).

[45]  D. Hoyt,et al.  Analysis of heart-rate variability: a noninvasive predictor of death and poor outcome in patients with severe head injury. , 1997, The Journal of trauma.

[46]  P.Z. Zhang,et al.  Respiration response curve analysis of heart rate variability , 1997, IEEE Transactions on Biomedical Engineering.

[47]  J. Taylor,et al.  Continuous assessment of hemodynamic control by complex demodulation of cardiovascular variability. , 1993, The American journal of physiology.

[48]  L. Nilsson,et al.  Macrocirculation is not the sole determinant of respiratory induced variations in the reflection mode photoplethysmographic signal. , 2003, Physiological measurement.

[49]  James E. Whitney,et al.  Respiration rate signal extraction from heart rate , 2001, SPIE Defense + Commercial Sensing.

[50]  Michael V. Scanlon Acoustic Sensor for Health Status Monitoring , 1998 .

[51]  X. Wang,et al.  Time-frequency distribution technique in biological signal processing. , 1995, Biomedical instrumentation & technology.

[52]  Period domain analysis in fetal pulse oximetry , 2002, Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and Biology.

[53]  T. Aldrich,et al.  Length-Normalized Pulse Photoplethysmography: A Noninvasive Method to Measure Blood Hemoglobin, Bronx, NY , 2004, Annals of Biomedical Engineering.

[54]  Ravi Sankar,et al.  Alternate pulse oximetry algorithms for SpO/sub 2/ computation , 1994, Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[55]  H Harry Asada,et al.  Mobile monitoring with wearable photoplethysmographic biosensors. , 2003, IEEE engineering in medicine and biology magazine : the quarterly magazine of the Engineering in Medicine & Biology Society.

[56]  L. Sörnmo Chapter 8 – ECG Signal Processing: Heart Rate Variability , 2005 .

[57]  Steve Warren,et al.  Wearable telemonitoring systems designed with interoperability in mind , 2003, Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439).

[58]  S. A. Atapattu,et al.  A computer program to acquire, analyze and track the heart rate variability of patients in a clinical research environment , 2000, Proceedings of the 22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (Cat. No.00CH37143).

[59]  D. Sapoznikov,et al.  POWER SPECTRUM ANALYSIS OF SPONTANEOUS FLUCTUATIONS IN THE PHOTOPLETHYSMOGRAPHIC SIGNAL , 1994, Journal of basic and clinical physiology and pharmacology.

[60]  Y. Mendelson,et al.  Extracting breathing rate information from a wearable reflectance pulse oximeter sensor , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[61]  A. Johansson,et al.  Estimation of respiratory volumes from the photoplethysmographic signal. Part I: experimental results , 2006, Medical & Biological Engineering & Computing.

[62]  J. Schesser,et al.  Are the results correct? - An application of wavelets to analyze heart rate variability , 2005, Proceedings of the IEEE 31st Annual Northeast Bioengineering Conference, 2005..

[63]  H.C. Kim,et al.  Development of novel algorithm and real-time monitoring ambulatory system using Bluetooth module for fall detection in the elderly , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[64]  Steve Warren,et al.  A wearable standards-based point-of-care system for home use , 2003, Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439).

[65]  D. Barschdorff,et al.  Respiratory rhythm detection with photoplethysmographic methods , 1994, Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[66]  C. Ahlstrom,et al.  A respiration monitor based on electrocardiographic and photoplethysmographic sensor fusion , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.