Lung modeling 1

[EcoMan]

Hello,
Left and right lungs are pneumatically in parallel. The compliances of springs in parallel add as reciprocals, so why do lung compliances add directly?

 

[Elabbasi]

Interesting observation. The definition of compliance varies between engineering fields. In pneumatic systems compliance is the volume change (or flow rate) divided by pressure drop, and parallel lungs have the same pressure drop. Mechanical springs are the opposite; compliance is the displacement divided by the force and parallel springs share the same displacement. Electric circuits are similar to pneumatic systems in that regard: compliance is the current divided by the voltage drop and parallel resistors share the same pressure drop.

Nagi Elabbasi
Veryst Engineering

Nagi Elabbasi

http://www.veryst.com