75da Vinci-ProMIS interface as well as proposing that ProMIS be instated as a regular
form of robotic training at the institution [ 26 ].
ProMIS was found to have known-groups validity again by Jonsson et al., by
comparison of novice and experts during four tasks [ 28 ]. Required exercises included
stretching rubber bands, dissecting a shape, suturing and knot tying, and an anasto-
mosis. Researchers compared path length, duration, and evenness in movement. Path
length did not exhibit statistical significance, but the other two factors did [ 28 ].
ProMIS is advantageous to box trainers in that it generates objectively measured
metrics such as time, efficiency of motion, and path length. Blatant errors, such as
instrument collisions or incorrect cuts, were added in as a penalty by an observer.
Together, these metrics cover most of what is assessed using a VR simulator.
Motion Tracking Sensors
Another means of collecting data on tool paths and economy of motion includes the
use of electromagnetic or optical monitoring systems. Generally, a small marker is
placed on the tool tip that needs to be monitored, while a larger device generates an
electromagnetic field. There are several brands available.
One such device is the trakSTAR Tool Tip Trackers, by Ascension Technology
Corporation in Burlington, VT, visualized in Fig. 5.22. Utilization of three-
dimensional electromagnetic transponder and trackers allows for generation of a
complete Cartesian position. Tausch et al. showed that novice, and expert surgeon’s
Fig. 5.22 da Vinci
training instrument fitted
with trakSTAR tool tip
tracker [ 27 ]
5 Performance Assessment in Minimally Invasive Surgery