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  • A microgravity isolation mount

    Paper ID



    • D.I. Jones
    • A.R. Owens
    • R.G. Owen


    School of Electronic Engineering Science, University College of North Wales


    United Kingdom




    The large aplco-basal gradients In alveolar size, ventilation, capillary distension, and blood flow that exist In the erect human I ung cause readl ly measureable gradients In regional ltung function (West, 1977). There are also gradients in the ratio of airflow (V^) and bloodflow (Qc>, and thus In gas exchange and local alveolar gas concentration. Gradients In gas concentration also occur when a foreign gas Is Inhaled, because the ventilation per unit volume differs topographically (M11Ic-Em 11 1, 1977). These gradients In gas concentration can be seen during single, slow vital capacity exhalations, when we use a rapidly responding gas analyzer to sample gas concentrations at the lips. The heart causes pulsatile flow from the dependent lung regions, and thus there are 'cardIogen!c' oscillations In C02 and Oj concentration due to the topographic gradients In gas exchange. SI m I I ar I y there are ose 11 rations of N2 (the res I dent gas) if a breath of a di I uent foreign gas has just been Inhaled (Fowler and Read, 1963). The lungs static mechanical properties cause the dependent regions to stop emptying first during exhalation, and this can be seen as a terminal inflection In gas concentration as flow from the upper regions predominates (Anthonisen, 1977).