 Philip Drinker

Philip Drinker coauthored the 1929 tank-respirator report with Louis A. Shaw. Its apparatus enclosed the body in a sheet-metal tank with a rubber collar at the neck, leaving the head outside at atmospheric pressure. Changing the tank pressure could then expand and compress the chest wall.^[ref]

The scientific principle is a driving pressure difference across the respiratory system. In an original passive linear model, let $v$ be added lung volume, $R$ total resistive coefficient, $C$ total respiratory-system compliance, $P_{\mathrm{ao}}$ airway-opening pressure and $P_b$ body-surface pressure. About a specified mechanical equilibrium,A negative change at the body surface can create a positive filling drive even when the airway remains open to room air. The pump acts on the enclosure; the resulting boundary-condition difference drives air through the airway.

For a stipulated step $P_{\mathrm{ao}}-P_b=10$ cm H${}_2$O, $R=10\mathrm{cm}{\mathrm{H}}_2\mathrm{O}\mathrm{s}{\mathrm{L}}^{-1}$ and $C=0.05\mathrm{L}(\mathrm{cm}{\mathrm{H}}_2\mathrm{O}{)}^{-1}$, the time constant is $RC=0.50$ s andThe initial volumetric flow rate is 1 L/s; after 0.50 s the added volume is about 0.316 L, still below the mechanical equilibrium increment 0.50 L. These are original model values, not measurements from Drinker's apparatus.

The equation also explains a limited equivalence: lowering body-surface pressure by a given amount or raising airway-opening pressure by that amount gives the same driving term in this model. It does not establish identical physiological effects in every respect. Upper-airway behavior, active muscles and departures from linear mechanics are absent from the calculation.

The report's importance lies in connecting an external mechanical apparatus to a sustained respiratory task with explicit pressure boundaries. The neck seal, accessible head and changing enclosure pressure describe how the intervention acts; independently observed gas movement and physiological responses establish what it achieves. The joint byline supports the coauthored contribution without assigning every construction or experimental step to one collaborator.