Installation Instructions

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TM
VOS SYSTEMS LLC
not capture contacts at 6 ½ or greater feet. The system’s distance accuracy is very
precise.
 The contact tracing system generates a very precise and accurate report, looking
back over the past two weeks, showing that Alice has had only 12 minutes of
contact with John.
Case 2: The contact tracing system records the duration of contact in instances where
the workers are between 7 to 10 feet from one another.
 Although this is less “precise”, the system will generate a report showing Alice
was within 7-10 feet of John for 50-60 hours.
Which would you view as the most valuable report in terms of knowing the potential risk of
infection for Alice? Clearly 50-60 hours of indoor exposure within 7-9 feet presents a much
higher risk of infection than does 12 minutes of under-6 feet of exposure.
Adjusting the Range/Distance of Mini-to-Mini Detection
The AlertTrace Dashboard allows Admins to adjust the range that the Minis/wearables “see” each
other. This allows an organization to avail itself of the most current information from medical
authorities in determining how near or far to set the range. But in general, less “precision” in terms of
proximity/distance measurement can be more helpful than precision and perfect accuracy, as
demonstrated by the example above. The AlertTrace system provides the most meaningful data when
the range/distance settings are wider rather than shorter, because the system aggregates data hour-
by-hour, day-by-day and week-by-week, and in the long run the “wider” range of distance will provide
more actionable information, as demonstrated in the example of Alice and John above.
An Historical Example of “Fuzziness”
Another example from an historical perspective is the challenges that were experienced with optical
bomb-sighting from aircraft platforms in the early days of aerial bombing. The British found that
inaccuracies in optics and alignment of the optics with the airframe resulted in bombs missing their
target, but doing so consistently to one side of the target. Attempting to make the targeting systems
more precise didn’t resolve the problem. British mathematicians came up with a solution: they
introduced random vibration into the targeting mechanism, resulting in a “fuzzy” targeting path. After
this, statistically, the bombs came much closer to their mark, with uniformly distributed error.
Cumulative Durations of Exposure Provide the Best Data
As described above, the AlertTrace system will provide the most statistically useful data if the
range/distance settings are set to wider rather than closer. The system is also designed to aggregate
cumulative contact data rather than provide simply contacts over a certain duration.
The CDC’s current guidance can be challenging to interpret. They say “Data are insufficient to
precisely define the duration of time that constitutes a prolonged exposure. Recommendations vary on
the length of time of exposure, but 15 minutes of close exposure can be used as an operational