Allen test

n.
  1. A test for occlusion of the radial or ulnar artery, in which one of these arteries is compressed after blood has been forced out of the hand by clenching it into a fist; failure of the blood to diffuse into the hand when opened indicates that the artery not compressed is occluded.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.