Quincke's test is done to determine whether there is an
increase in pulse pressure.
A bright light is placed against the pad
of a finger. Gentle pressure is then applied to the tip
of the nail, compressing the capillary bed. The
pressure is gradually reduced while one looks for
pulsation of the capillary bed. This resembles a neon
light flashing on and off.
Relative darkness is required from optimal
testing. This can be accomplished by having a helper
shield the test finger with their hands.