ACTIVITY MONITOR - Vanderbilt Kennedy Center

MED ASSOCIATES INC. ACTIVITY MONITOR
Only the distance from X to 6 (the dashed line) is used to determine the Distance
Traveled. In this manner, movements within the Box are eliminated, thus providing a
"filtered" Distance Traveled measure. At 6 above, the Box re-centers on the subject. If
the subject moves through the next Box in less than the Resting Delay, the ambulatory
Distance Traveled is the distance from X to 6 + the distance to 7. The number of X + Y
photo beam breaks that occurred is the Ambulatory Count. Ambulatory Time is defined
as the time from leaving the first Box, until the time that the subject enters the last Box
and does not leave in less than the Resting Delay. And this all occurs in one Ambulatory
Episode.
If data are parsed into time blocks, an Ambulatory Episode and its associated velocity is
only logged in the block in which it ends. Ambulatory Distance Traveled is logged across
time blocks, however.
Distance Traveled is modified if Include Resting Delay is activated. If the animal moves
from X to 1, 2, 3, 4, 5 and then 6 before the Resting Delay has elapsed, the sum of all
movements (distances) from X through 6 is used to determine the Distance Traveled. If
the Resting Delay times-out prior to the subject leaving the Box, then the distance from
X to 6 is used to determine the Distance Traveled. This measure has been included to
allow for consistency with other systems that do not have this "filtering."
The Ambulatory Trigger number adds an additional variable. This number represents the
minimum total X + Y beam breaks that must occur to be considered an Ambulatory
Episode. The beams must be broken before the Box times-out in order for the
Ambulatory Episode and velocity for that given episode to be acquired.
In Figure A4.1, A - D and AA are the beams broken after leaving the box and during a
continuous movement of two user-defined sample times (resolution). An Ambulatory
Trigger of 4 or less would enable measures 1 and 2 (above) to be determined.
The Ambulatory Trigger is useful if trying to generate a velocity measure that enables the
user to determine a Box Size and Resting Delay to differentiate between large/quick and
small/slow movements (below). The Ambulatory Trigger can also be used to further
define the onset of an ambulatory episode, beyond Box Size and Resting Delay, as
continuous.
Differentiating Between Large/Quick and Small/Slow Movements
Given the Box Size, Resting Delay, and Ambulatory Trigger functions described above, it
is possible to differentiate groups of subjects based upon their types of movements. The
defining measures would be Ambulatory Time, Ambulatory Counts, Ambulatory Episodes,
Average Velocity, and Distance Traveled.
Let's assume that we have two groups of subjects, one control group (C) and one
locomotor impaired group. The locomotor impaired group is a Parkinsonian animal model
(P), for example. If we were to measure Distance Traveled between the two groups, C's
may move 1000 cm in 20 minutes with periods of quick movements (high velocity) and
periods of minimal movements (resting or stereotypic). Within a 20-minute period, P's
may also move 1000 cm with few, if any, fast movements but continuous slow
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