Table 1.

The test results of the tracking accuracy of the G-arm system

	Measurement
Phantom Movement	Exp. 1 (mm)	Exp. 2 (mm)	Exp. 3 (mm)	Average (mm)	Error (%)
x-axis 20 mm	20.22	20.42	20.27	20.30	1.51
x-axis 15 mm	14.75	14.46	14.45	14.55	2.97
x-axis 10 mm	9.55	9.82	9.80	9.72	2.76
y-axis 20 mm	20.22	20.42	20.27	20.30	1.51
y-axis 15 mm	14.50	14.66	14.50	14.55	2.97
y-axis 10 mm	9.90	9.85	9.84	9.87	1.36
z-axis 20 mm	20.09	19.74	20.63	20.15	0.77
z-axis 15 mm	14.64	14.68	14.38	14.57	2.88
z-axis 10 mm	9.54	9.81	9.79	9.71	2.86

The BrainLAB phantom was moved in the SI, AP and LT directions at 20 mm, 15 mm and 10 mm amplitudes. The experiments were repeated three times.