Figure 2. Penumbra device.33 Available in the public domain: http://www.ajnr.org/content/29/7/1409/F1.expansion.html.
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.