Table 1.

Experimentally determined mean ± standard deviation for user target error, trajectory and duration quantities for the first phantom

System	Error (mm)	Trajectory (cm)	Duration (s)
IGS	$1.60\pm 0.82$	$134\pm 98$	$59\pm 54$
VG	$1.27\pm 0.{90}^{\ast }$	$97\pm 49$	$33\pm {27}^{\ast }$
IGS+VG	$1.31\pm 0.{81}^{\ast }$	$89\pm 43$	$28\pm {21}^{\ast }$

*The asterisk identifies the p-values that are significant at the 0.01 level