Model number

Oxyhemoglobin dissociation curve calculated using a simple Hill equation and Kelman's equation which is a modified Adair equation to take into account temperature, CO2 and pH.


  The simple Hill equation can be used for estimating HbO2 saturation while the more detailed
  Kelman equation is for the conversion of oxygen tension to saturation at various temperatures,
  carbon dioxide tensions, and hydrogen ion concentrations. It is based on a mathematical 
  model of the dissociation curve, similar to that proposed by Adair, applicable to a 
  temperature of 37 C and normal acid-base state, and corrections which make this model 
  applicable to other temperatures and acid-base states. 
  Compare and contrast to other HbO2 dissociation calculations such as 
  Severinghaus (#0027), Adair (#0238), Buerk (#0278), and 
  Dash (#0032).


The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.

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  Adair GS. The hemoglobin system.  VI.  The oxygen dissociation curve of 
  hemoglobin. J Biol Chem 63: 529-545, 1925.   

  Buerk DG, Bridges EW, A simpified algorithm for computing the variation in oxyhemoglobin
  saturation with pH, PCO2, T and DPG, Chem Eng Commun, 1985, Vol 47, 113-124 

  Kelman GR, Digital computer subroutine for the conversion of oxygen tension into saturation.
  Journal of Applied Physiology, July 1966 21(4), 1375-1376

  Keener J and Sneyd J. Mathematical Physiology. New York, NY: 
  Springer-Verlag, 1998, 766 pp.

  Hill R. Oxygen dissociation curves of muscle hemoglobin. Proc Roy Soc Lond B 
  120: 472-480, 1936.

  Roughton FJW, Deland EC, Kernohan JC, and Severinghaus JW. Some recent studies of the
  oxyhemoglobin dissociation curve of human blood under physiological conditions and the
  fitting of the Adair equation to the standard curve. In: Oxygen Affinity of Hemoglobin and
  Red Cell Acid Base Status. Proceedings of the Alfred Benzon Symposium IV Held at the
  Premises of the Royal Danish Academy of Sciences and Letters, Copenhagen 17-22 May,
  1971, edited by Rorth M and Astrup P. Copenhagen: Munksgaard, 1972, p. 73-81.

  Severinghaus, JW. Simple, accurate equations for human blood 02 dissociation computations. 
  J. Appl. Physiol.:Respirat. Environ. Exercise Physiol. 46(3): 599-602, 1979.

  Winslow RM, Swenberg M-L, Berger RL, Shrager RI, Luzzana M, Samaja M,and
  Rossi-Bernardi L. Oxygen equilibrium curve of normal human blood and its evaluation by
  Adair's equation. J Biol Chem 252: 2331-2337, 1977.

Key terms
dissociation curve
blood gases
Hill equation

Please cite in any publication for which this software is used and send one reprint to the address given below:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

Model development and archiving support at provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.