Table 3. Four N-Localizer system is analyzed using Monte Carlo (MC) simulations of Root Mean Square Errors (RMS-e) of different target locations using four, eight, and twelve rods. Using an overdetermined system of equations improves the RMS-e from four equations to twelve. One also observes good stability throughout the stereotactic volume given the low standard deviation. These errors may be compared to the error shown in Table 1 for the Micromar (Micromar Ind. Com. Ltda, Diadema, Sao Paulo, Brazil) (140x140 mm) three N-localizer system. Using maximum data for the overdetermined systems, the RMS-e for the three N-localizer Micromar and the four N-localizer systems that have comparative geometry are 0.58 (+/- 0.12) and 0.36 (+/- 0.018), respectively.

Millimeter (mm)

Micromar Ind. Com. Ltda, Diadema, Sao Paulo, Brazil

4 N-Localizer System
140x140 mm	4 Rods (RMS-e)	8 Rods (RMS-e)	12 Rods (RMS-e)
Center	0.379	0.337	0.328
Lateral 50 mm	0.427	0.378	0.368
Frontal 50 mm	0.427	0.378	0.368
Posterior 50 mm	0.427	0.378	0.368
Average	0.415	0.368	0.358
Standard Deviation	0.021	0.018	0.018