An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Microchannels form as the result of variations in patient airways. A polyurethane cuff designed to eliminate leakage through these folds is shown. Image used by permission from Nellcor Puritan Bennett LLC, Boulder, Colorado, doing business as Covidien.