Engineers had to calculate the optimal air flow into the chamber to ensure that patients would breathe a full dose each time.

FORBES: Waiting to Inhale

If it loses its hold, much power would flow to the chamber.

ECONOMIST: Democracy, Mexican-style

So Parks borrowed a tool common in the welding of plastic components, which is to gently agitate the hopper so that particles flow like water into a metering chamber.

FORBES: The Impossible Made Possible