Ideas & Stuff:

This is a collection of a few images and files that I have created to help us in our exploration of understanding mechanical ventilation.

Endotracheal Tube Resistance:

Comparison of endotracheal resistance as measure in our lab with precision. Note that the resistance is not a constant. I speculate that this is due to the turbulent flow of air through the endotracheal tube.

Exploration of Time Constants:

Below are two diagrams that demonstrate the effects of compliance and resistance variations on inspiratory flow during pressure control ventilation.

Here are two links to videos that help explain the interactions between time constants, inspiratory flow, and the relationships between ventilator settings and patient lung characteristics: 

• https://www.youtube.com/watch?v=LucvWmw27M4

• https://www.youtube.com/watch?v=_s4o5h1kbdE

Time Constant = Resistance X Compliance

Ti dynamic = Time Constants X 5

Attached below are the original image files so you may download and examine in detail.