Figure 2. Overview of the needle tips produced for this study.

Shown on the left are the side-view projections of the tips, with or without pre-bend or pre-curve. On the right, photographs of the actual needle tips are shown. The tip types are denoted by a B or C, corresponding to a bevel or conical tip, and a number corresponding to the tip angle, θ, which was either 10°, 20°, or 30°. In the side-view projection, all six tips had an equal apex angle, α = 20°. The needle diameters were also equal, d = 10 mm, and the radius of curvature was r = 40 mm.