Table 2.

Radius of curvature for needle path segments, ρ̄ is the mean of ρ₁, ρ₂, and ρ₃. Percentage deviation is calculated as $\left(\frac{{\rho }_{exp}-\overline{\rho }}{{\rho }_{exp}}\right)\times 100$.

Gel	Needle Ø (mm)	Radius of curvature (mm)					Deviation (ρ̄ and ρexp)
		0–50 mm ρ1	50–100 mm ρ2	100–150 mm ρ3	Mean ρ̄	0–150 mm ρexp
Plastisol A (least stiff)	0.36	399.4	310.4	252.7	320.8	318.1	0.9%
	0.46	314.2	349.9	319.6	327.9	377.9	13.2%
	0.54	543.0	440.0	234.9	406.0	477.3	14.9%
Plastisol B	0.36	302.5	240.5	210.7	251.2	242.8	3.5%
	0.46	195.8	328.3	285.1	269.7	305.9	11.8%
	0.54	203.4	291.8	276.5	257.2	287.8	10.6%
Plastisol C (most stiff)	0.36	105.8	194.8	165.3	155.3	206.7	24.9%
	0.46	276.3	212.8	212.3	233.8	234.6	0.3%
	0.54	324.3	231.0	224.4	259.9	240.0	8.3%
Porcine	0.36	242.0	214.8	263.1	240.0	231.9	3.5%
	0.46	294.9	266.4	239.7	267.0	275.5	3.1%
	0.54	347.4	337.4	314.3	333.0	339.8	2.0%