An Ultrasound Imaging-Guided Robotic HIFU Ablation Experimental System and Accuracy Evaluations

Table 1

The distance error of three peak points (of the calibration template) (unit: mm).

Number of point	Coordinates of the target point			Number of image	Coordinates of the guided pinpoint			Distance error
	x	y	z		x	y	z
Case A: 3 cm
1	26.7	8.9	−46.5	I	26.6	8.6	−46.8	0.44
				II	27.4	8.4	−46.4	0.87
				III	27.1	8.4	−46.7	0.70
2	6.2	−5.4	−45.2	I	5.3	−4.5	−44.9	1.31
				II	6.0	−5.2	−44.8	0.49
				III	6.3	−5.0	−44.6	0.73
3	1.8	−19.1	−61.5	I	2.0	−19.3	−62.0	0.57
				II	1.9	−19.6	−61.9	0.65
				III	1.8	−19.4	−61.6	0.31
Max error: 1.31; average error: 0.67; standard deviation 0.27
Case B: 7 cm
1	38.9	27.9	−89.6	I	39.2	28.1	−90.5	0.97
				II	39.1	28.0	−90.7	1.12
				III	39.6	27.8	−90.5	1.14
2	18.3	14.0	−87.7	I	17.5	13.8	−88.5	1.15
				II	18.0	13.6	−88.1	0.64
				III	18.1	13.9	−88.2	0.55
3	13.7	−0.1	−104.5	I	14.1	−0.5	−105.4	1.06
				II	14.0	0.0	−105.9	1.43
				III	14.2	−0.2	−105.5	1.12
Max error: 1.43; average error 1.02; standard deviation: 0.26
Case C: 12 cm
1	54.1	46.8	−136.3	I	55.4	46.7	−136.2	1.31
				II	53.5	47.5	−137.6	1.59
				III	53.9	47.3	−137.3	1.14
2	33.2	32.9	−134.6	I	34.5	32.8	−134.2	1.36
				II	32.7	33.4	−135.3	0.99
				III	32.8	32.9	−135.4	0.89
3	28.9	19.0	−151.6	I	29.8	19.4	−151.4	1.00
				II	28.6	20.1	−152.1	1.24
				III	28.0	19.2	−152.9	1.59
Max error: 1.59; average error: 1.24; standard deviation: 0.24