Document Type: Original Research


1 PhD, Department of Biomedical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran

2 MSc, Department of Biomedical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran


Background: The importance of continuous monitoring along with rapid and accurate notification of changes in blood components such as hemoglobin concentration, especially in acute situations, encourages researchers to use non-invasive methods for measuring.
Objective: This study was aimed to investigate the correlation between hemoglobin concentration and photoplethysmogram (PPG) and the possibility of measuring it by an optical method.
Material and Methods: In this applied study, a PPG signal was simultaneously recorded at four different wavelengths for thirty subjects who were referred to the laboratory for a hemoglobin concentration test. After calibrating the special recording probe with a standard pulse oximeter system and applying the required preprocessing on the obtained signals, the peak-to-peak value of PPG signals was extracted. Finally, the correlation between the peak-to-peak value of the signal at a certain wavelength and hemoglobin concentration was analyzed using Spearman and Pearson correlation for determining the process of changes in the data.
Results: The results demonstrated that based on the normal distribution of data at 590 nm wavelength, there is a significantly negative correlation between a function of the signal peak slope and the hemoglobin concentration, with a Pearson coefficient of -0.787 (p<0.01). In addition, the investigation of rank correlation indicated a significantly negative correlation of -0.842 (p<0.01) using Spearman correlation analysis.


  1. Timm U, Lewis E, McGrath D, Kraitl J, Ewald H, editors. LED based sensor system for non-invasive measurement of the hemoglobin concentration in human blood. 13th International Conference on Biomedical Engineering; 2009: Springer.
  2. Doshi R, Panditrao A. Non-invasive optical sensor for hemoglobin determination. Measurement. 2013;3(2).
  3. Timm U, Lewis E, McGrath D, Kraitl J, Ewald H. Sensor System Concept for Non-Invasive Blood Diagnosis. Procedia Chemistry. 2009;1:493-6.
  4. Ahrens T, Rutherford K, Basham KAR. Essentials of oxygenation: implication for clinical practice: Jones & Bartlett Learning; 1993.
  5. Matcher S, Cope M, Delpy D. Use of the water absorption spectrum to quantify tissue chromophore concentration changes in near-infrared spectroscopy. Phys Med Biol. 1994;39:177-96. PubMed PMID: 7651995.
  6. Kraitl J, Ewald H, Gehring H. An optical device to measure blood components by a photoplethysmographic method. Journal of Optics A: Pure and Applied Optics. 2005;7:S318.
  7. Roggan A, Friebel M, Do Rschel K, Hahn A, Mu Ller G. Optical Properties of Circulating Human Blood in the Wavelength Range 400-2500 nm. J Biomed Opt. 1999;4:36-46. PubMed PMID: 23015168.
  8. Schmitt JM, Guan-Xiong Z, Miller J, editors. Measurement of blood hematocrit by dual-wavelength near-IR photoplethysmography. Proc. Spie; 1992.
  9. Kratil J, Ewald H, editors. Results of hemoglobin concentration measurements in whole blood with an optical non-invasive method”. Photon08, Optics and Photonics, IOP Conference; 2008.
  10. Aldrich TK, Moosikasuwan M, Shah SD, Deshpande KS. Length-normalized pulse photoplethysmography: a noninvasive method to measure blood hemoglobin. Ann Biomed Eng. 2002;30:1291-8. PubMed PMID: 12540205.
  11. Jeon KJ, Kim SJ, Park KK, Kim JW, Yoon G. Noninvasive total hemoglobin measurement. J Biomed Opt. 2002;7:45-50. PubMed PMID: 11818011.
  12. Schmitt JM. Method and apparatus for improving the accuracy of noninvasive hematocrit measurements. Google Patents; 2003.
  13. Jawahar Y. Design of an Infrared based Blood Oxygen Saturation and Heart Rate Monitoring Device. 2009.
  14. Fang S-C, Chan H-L. Human identification by quantifying similarity and dissimilarity in electrocardiogram phase space. Pattern Recognition. 2009;42:1824-31.
  15. Doostdar H, Khalilzadeh M. Quantification the effect of ageing on characteristics of the photoplethysmogram using an optimized windkessel model. J Biomed Phys Eng. 2014;4:103-10. PubMed PMID: 25505777. PubMed PMCID: 4258866.
  16. Nadeau RG, Groner W. The role of a new noninvasive imaging technology in the diagnosis of anemia. J Nutr. 2001;131:1610S-4S. PubMed PMID: 11340126.
  17. Kinoshita Y, Yamane T, Takubo T, Kanashima H, Kamitani T, Tatsumi N, et al. Measurement of Hemoglobin Concentrations Using the AstrimTM Noninvasive Blood Vessel Monitoring Apparatus. Acta haematologica. 2002;108:109-10.
  18. Edrich T, Flaig M, Knitza R, Rall G. Pulse oximetry: an improved in vitro model that reduces blood flow-related artifacts. IEEE Trans Biomed Eng. 2000;47:338-43. PubMed PMID: 10743775.
  19. Steinke JM, Shepherd AP. Role of light scattering in whole blood oximetry. IEEE Trans Biomed Eng. 1986;33:294-301. PubMed PMID: 3957382.
  20. Brunelle JA, Degtiarov AM, Moran RF, Race LA. Simultaneous measurement of total hemoglobin and its derivatives in blood using CO-oximeters: analytical principles; their application in selecting analytical wavelengths and reference methods; a comparison of the results of the choices made. Scandinavian Journal of Clinical and Laboratory Investigation. 1996;56:47-69.
  21. Frojmovic MM, Panjwani R. Blood cell structure-function studies: light transmission and attenuation coefficients of suspensions of blood cells and model particles at rest and with stirring. J Lab Clin Med. 1975;86:326-43. PubMed PMID: 1151155.