Table 1.

The failure rate, axis error, angle error and tip error results obtained by the proposed method for 18G needles inserted in three types of animal tissues as a function of the needle insertion angle.

Range of Needle Insertion Angles	Tissue Type	Failure Rate	Angel Error (${}^{\circ }$)	Axis Error (mm)	Tip Error (mm)
Shallow angles ($0^{\circ }$–${20}^{\circ }$)	Bovine muscle	$0.0\%$	0.2 ± 0.1	0.3 ± 0.1	0.3 ± 0.1
	Bovine liver	$0.0\%$	0.2 ± 0.1	0.2 ± 0.1	0.3 ± 0.1
	Porcine muscle	$0.0\%$	0.2 ± 0.1	0.2 ± 0.1	0.3 ± 0.1
Moderate angles (${20}^{\circ }$–${40}^{\circ }$)	Bovine muscle	$0.0\%$	0.4 ± 0.2	0.4 ± 0.1	0.5 ± 0.1
	Bovine liver	$0.0\%$	0.3 ± 0.2	0.3 ± 0.1	0.4 ± 0.1
	Porcine muscle	$0.0\%$	0.3 ± 0.2	0.4 ± 0.1	0.4 ± 0.1
Steep angles (${40}^{\circ }$–${65}^{\circ }$)	Bovine muscle	$0.0\%$	0.8 ± 0.2	0.5 ± 0.1	0.6 ± 0.1
	Bovine liver	$0.0\%$	0.7 ± 0.2	0.5 ± 0.1	0.5 ± 0.1
	Porcine muscle	$0.0\%$	0.8 ± 0.2	0.6 ± 0.1	0.5 ± 0.1
All angles ($0^{\circ }$–${65}^{\circ }$)	Bovine muscle	$0.0\%$	0.5 ± 0.3	0.4 ± 0.1	0.5 ± 0.1
	Bovine liver	$0.0\%$	0.4 ± 0.3	0.3 ± 0.2	0.4 ± 0.1
	Porcine muscle	$0.0\%$	0.5 ± 0.3	0.4 ± 0.2	0.4 ± 0.1