The lymphatic system is not well understood and tools to quantify aspects of its behavior are needed. A technique to
monitor lymph velocity that can lead to flow, the main determinant of transport, in a near real time manner can be
extremely valuable. We recently built a new system that measures lymph velocity, vessel diameter and contractions
using optical microscopy digital imaging with a high speed camera (500fps) and a complex processing algorithm.
The processing time for a typical data period was significantly reduced to less than 3 minutes in comparison to our
previous system in which readings were available 30 minutes after the vessels were imaged. The processing was
based on a correlation algorithm in the frequency domain, which, along with new triggering methods, reduced the
processing and acquisition time significantly. In addition, the use of a new data filtering technique allowed us to
acquire results from recordings that were irresolvable by the previous algorithm due to their high noise level. The
algorithm was tested by measuring velocities and diameter changes in rat mesenteric micro-lymphatics. We recorded
velocities of 0.25mm/s on average in vessels of diameter ranging from 54um to 140um with phasic contraction
strengths of about 6 to 40%. In the future, this system will be used to monitor acute effects that are too fast for
previous systems and will also increase the statistical power when dealing with chronic changes. Furthermore, we
plan on expanding its functionality to measure the propagation of the contractile activity.