Table 2.

The failure rate, axis error, angle error and tip error results obtained by the previous method introduced in [12] 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	$0.0\%$	0.9 ± 0.6	1.1 ± 0.3	1.1 ± 0.4
	Bovine liver	$0.0\%$	1.3 ± 0.5	1.2 ± 0.5	1.3 ± 0.5
	Porcine muscle	$0.0\%$	1.1 ± 0.4	1.1 ± 0.3	1.2 ± 0.3
Moderate angles (${20}^{\circ }$–${40}^{\circ }$)	Bovine muscle	$0.0\%$	1.9 ± 0.4	1.7 ± 0.2	1.6 ± 0.2
	Bovine liver	$0.0\%$	2.5 ± 1.2	1.8 ± 0.5	1.8 ± 0.7
	Porcine muscle	$0.0\%$	2.2 ± 1.2	1.5 ± 0.4	1.6 ± 0.6
Steep angles (${40}^{\circ }$–${65}^{\circ }$)	Bovine muscle	$40.0\%$	2.9 ± 0.6	2.3 ± 0.3	2.2 ± 0.4
	Bovine liver	$33.3\%$	2.9 ± 1.2	2.4 ± 0.4	2.5 ± 0.5
	Porcine muscle	$40.0\%$	2.7 ± 1.1	2.0 ± 0.5	2.1 ± 0.5
All angles ($0^{\circ }$–${65}^{\circ }$)	Bovine muscle	$15.4\%$	1.8 ± 1.0	1.7 ± 0.5	1.6 ± 0.5
	Bovine liver	$12.8\%$	2.2 ± 1.2	1.7 ± 0.7	1.8 ± 0.7
	Porcine muscle	$15.4\%$	1.9 ± 1.2	1.5 ± 0.5	1.6 ± 0.6