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A pneumatic analogue for predicting the occurrence of decompression sickness

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Abstract

A pneumatic analogue has been constructed, as a mathematical instrument for predicting the occurrence of marginal symptoms of decompression sickness. It is designed to analyse diving data according to the concept of phase equilibration, in preference to the conventional criterion of limited supersaturation. This ‘thermodynamic’ approach display a better correlation with experimental data fed to the instrument than that afforded by conventional calculation methods.

By considering the worst possible case, in preference to the statistical average, the transport model is one of radial diffusion of inert gas into cytoplasm. The immediate, availability of information enables the analogue to be readily converted to an instrument for use on board ship for the automatic decompression of a diver.

Sommaire

Un modèle pneumatique a été construit comme instrument mathématique servant à prévoir la possibilité de symptomes marginaux de maux de décompression. Il est destiné à analyser les données de la plongée conformément au concept d'équilibration de phase, de préférence au critère habituel de supersaturation limitée. Cette approche “thermodynamique” fait paraître une corrélation meilleure avec les données expérimentales fournies à l'instrument que celle offerte par les méthodes de calcul classiques. Dans l'hypothèse la plus défavorable, de préférence à la moyenne statistique, le mode de transport est celui d'une diffusion radiale de gaz inerte dans le cytoplasme. La disponibilité immédiate de l'information permet de convertir facilement le modèle en un instrument utilisé à bord d'un bateau pour la décompression automatique d'un scaphandrier.

Zusammenfassung

Ein Lungenanalogon wurde als mathematisches Instrument zur Vorhersage des Auftretens von Randsymptomen der Dekompressionskrankheit konstruiert. Es wurde zur Analyse von Tauchdaten angelegt nach dem Prinzip der Phasenäquilibrierung und nicht nach dem üblichen Kriterium der begrenzten Übersättigung. Diese ‘thermodynamische’ Betrachtungsweise zeigt eine bessere Korrelation mit den experimentellen in das Gerät gegebenen Daten als die üblichen Berechnungsmethoden. Um den Extremfall in Abweichung vom statistischen Mittel zu betrachten: Das Transportmodell besteht in der Radialdiffusion eines inerten Gases in das Zytoplasma. Die sofortige Erreichbarkeit der Information macht eine schnelle Wandlung des Instruments zum Gebrauch an Bord zur automatischen Dekompression des Tauchers möglich.

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Abbreviations

a :

capillary radius

2b :

intercapillary distance

D :

diffusion coefficient of inert gas in cytoplasm

G :

gas eliminated from analogue

G ∞ :

gas eliminated from analogue after infinite time

J 0,J 1,Y 0,Y 1 :

Bessel and Neumann functions as defined byWatson (1944)

k n :

n th time constant of tissue

P :

absolute pressure of diver

P o :

initial absolute pressure

p :

inert gas tension at a point

P CO 2,P O 2,P HO 2 :

tissue tensions of CO2, O2 and H2O respectively

r :

radial co-ordinate from capillary axis

S :

net solubility of inert gas in tissue

t :

time

V n :

volume of then th chamber

x :

mole fraction of inert gas in inhaled gas

λn :

nth time constant of analogue response

A:

pressure applied to backs of transducer pistons

ρ:

design factor defined in text

References

  • Behnke, A. R. (1951) InDecompression Sickness. (Edited byJ. F. Fulton). Chap. 3, Saunders, Philadelphia.

    Google Scholar 

  • Boycott, A. E., Damant, G. C. G. andHaldane, J. S. (1908) The prevention of compressed air illness,J. Hyg. Camb. 8, 343–443.

    Google Scholar 

  • Crocker, W. E. (1957) Investigation into the decompression tables—revised tables, Royal Navy rep. R.N.P. 58/902, U.P.S. 171.

  • Crump, S. F. (1949)Determination of critical pressures for the inception of cavitation in fresh and sea water,David Taylor Model Basin rep. 575.

  • Dick, D. A. T. (1959) The rate of diffusion of water in the protoplasm of living cells,Expl Cell. Res. 17, 5–12.

    Article  Google Scholar 

  • Eisenberg, P. (1961) InHandbook of Fluid Mechanics. (Edited byV. L. Streeter). McGraw-Hill, New York.

    Google Scholar 

  • Fenichel, I. R. andHorowitz, S. B. (1963), The transport of nonelectrolytes in muscle as a diffusional process in cytoplasm,Acta Physiol. Scand. 60, suppl. 221.

    Google Scholar 

  • Fine, M. E. (1964)Phase Transformations in Condensed Systems. Macmillan, New York.

    Google Scholar 

  • Forster, R. E. (1964) InThe Uptake and Distribution of Anesthetic Agents. (Edited byE. M. Papper andR. J. Kitz). McGraw-Hill, New York.

    Google Scholar 

  • Harvey, E. N. (1951) InDecompression Sickness. (Edited byJ. F. Fulton). Saunders, Philadelphia.

    Google Scholar 

  • Hawkins, J. A., Shilling, C. W. andHansen, R. A. (1935). Suggested change in calculating decompression tables for diving,Nav. Med. Bull., Wash. 33, 327–38.

    Google Scholar 

  • Hempleman, H. V. (1952) Investigation into the decompression tables—a new, theoretical basis, Royal Navy rep. R.N.P. 52/708, U.P.S. 131.

  • Hills, B. A. (1966)A Thermodynamic and Kinetic Approach to Decompression Sickness, S. Australian Pub. Libr., Adelaide.

    Google Scholar 

  • Hills, B. A. (1967) Diffusion versus blood perfusion in limiting the rate of uptake of inert non-polar gases by skeletal rabbit muscle,Clin. Sci. 33.

  • Hills, B. A. andLeMessurier, D. H. (1966), Driving force for tissue desaturation following decompression,Proc. Int. Aerospace Med. Meeting, Sydney, paper No. 17.

  • Jones, H. B. (1951) InDecompression Sickness, (Edited byJ. F. Fulton). Chap. 9 (Part II) Saunders, Philadelphia.

    Google Scholar 

  • Krogh, A. (1918) The rate of diffusion of gases through animal tissues with some remarks on the coefficient of invasion,J. Physiol., Lond. 52, 391.

    Google Scholar 

  • LeMessurier, D. H. andHills, B. A. (1965) Decompression sickness: a thermodynamic hypothesis arising from a study of Torres Strait diving techniques,Hvalradets Skrifter,48, 54–84.

    Google Scholar 

  • Ostwald, W. (1911)Z. Phys. Chem. 22, 148.

    Google Scholar 

  • Rashbass, C. (1954) Investigation into the decompression tables—consideration of basic theories of decompression sickness, Royal Navy rep. R.N.P.L. 2/62, U.P.S. 151.

  • Watson, G. N. (1944)Theory of Bessel Functions, 2nd ed., Cambridge University Press, London.

    Google Scholar 

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Author notes

  1. B. A. Hills

    Present address: Division of Medical and Biological Sciences, Brown University, Providence, R.I., U.S.A.

Authors and Affiliations

  1. Department of Chemical Engineering, The University of Adelaide, South Australia

    B. A. Hills

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  1. B. A. Hills
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Hills, B.A. A pneumatic analogue for predicting the occurrence of decompression sickness. Med. & biol. Engng. 5, 421–432 (1967). https://doi.org/10.1007/BF02479136

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  • DOI: https://doi.org/10.1007/BF02479136

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