1. Estimation of pulmonary blood flow fromsinusoidal gas exchange during anaesthesia: a theoreticalstudy 
M.J. Turner, D. Weismann, G.G. Jâros, A.B. Baker 
British Journal of Anaesthesia 
Volume 85, Issue 3, Pages (September 2000)
DOI: /bja/
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Diagrammatic representation of thecomputer model of the respiratory system. V ˙ I, V ˙ E: total inspiratory and expiratory flows,respectively; V ˙ AI, V ˙ AE:alveolar inspiratory and expiratory flows, respectively;PI, PE,P E ¯ : partial pressure ofindicator in inspiratory, alveolar and mixed expired gases, respectively; Q ˙ p: PBF.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Systematic errors in PBF estimates when a low-concentration insolubletracer gas (N2) is used to monitor alveolar volume, and variousmean concentrations of N2O with O2 as balance areused to monitor Q ˙ p. (i) Equations (A9), (A8) and(A6) evaluated sequentially. (ii) Equations (A9), (A8) and (A10) evaluatedsequentially. PBF, pulmonary blood flow.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
Systematic errors in estimated values of alveolar volume when the meanFiO2 was 0.20, 0.25 and 0.30, andPBF was 1, 5 and 10 l min−1. Equations (A9) and(A7) were evaluated sequentially to estimateVa.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

5. Fig 4
Systematic errors in PBF estimates when O2 (meanFiO2 0.25) is used as theinsoluble tracer gas and N2O as the soluble gas withN2 as balance using: (i) equations (A9), (A8) and (A6) evaluatedsequentially; (ii) equations (A9), (A8) and (A10) evaluated sequentially;and (iii) evaluation of equation (A9) followed by simultaneous solution ofequations (A10) and (A13) by interval bisection.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

6. Fig 5
Perunit sensitivity of estimated PBF (using simultaneous equation (A10) toerrors in alveolar volume calculated using a forward difference techniquefor FiO2 = 0.25 andbalance N2).
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

7. Fig 6
Per unit sensitivity of estimatedPBF (using simultaneous equations (A10) and (A13)) to errors in the ratiosof the magnitudes of the partial pressure of the indicator gases calculatedusing a forward difference technique forFiO2 = 0.25and balance N2. The sensitivities to O2 andN2O are almost identical, therefore only one curve is plotted ateach PBF.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions

8. Fig 7
Per unit sensitivity of estimatedalveolar volume (using simultaneous equations (A10) and (A13)) to errors inthe ratios of the magnitudes of the partial pressures of the indicatorgases calculated using a forward difference technique forFiO2&  = 0.25and balance N2.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2000 British Journal of Anaesthesia Terms and Conditions