Atracsys fusionTrack 500 - The Accuracy Verification Tool (AVT); General Concept; Running the Procedure; The Accuracy Verification Tool from Atracsys

13 The accuracy verication tool (AVT)
Accuracy verication must be implemented by the integra-
tor. They can optionnaly purchase the required software and
hardware at Atracsys.
The operator performing accuracy verication must be cor-
rectly trained.
The accuracy verication method is a procedure which checks that the fusionTrack device is able to per-
form accurate measurements in the whole working volume. A failure of this test indicates that the fusionTrack
device must not be used and must be returned to Atracsys.
13.1 General concept
The principle of this test is to verify that a given rigid body keeps its xed geometry wherever the measure-
ment is performed. For a marker, the distance between two ducials is determined and cannot change,
independently of the marker’s position in the working volume. The test consists of moving a marker in the
whole working volume, the best way to ensure repeatability being to dene 3D positions at which the marker
should stay for a while (e.g. for 500 frames) and monitor the marker’s registration error as well as the dis-
tances between the marker’s ducials. If the used marker is accuratly calibrated, it may be enough to look
at the width of the distribution of the registration error. The integrator must specify an upper bound on this
width, above which the test is considered to fail. In general, monitoring the distance between two ducials
of the marker is a suitable way to perform this test: again the width of the distribution of the measured length
must not be larger than a threshold specied by the integrator.
13.2 Running the procedure
This procedure is not part of the usual running of the navigation system: it must be run by a trained techni-
cian, on a regular basis. For instance the integrator can choose to run this procedure once every week or
every 5 surgeries, whatever comes rst.
13.3 The accuracy verication tool from Atracsys
Atracsys offers as an aditional accessory a rigid body designed to perform accuracy verication on the
fusionTrack. Along with this rigid body, Atracsys provides the required software to perform the capture of
data and the accuracy analysis. Please contact the Atracsys after sale service for further information (See
Section 1.6).
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