Figure 5
From: Steerable needles for radio-frequency ablation in cirrhotic livers
Pseudo-rigid body diagram of the steerable needles, showing two stylet members (1), as in needle v1. Cannula (2) guidance is illustrated with roller supports, and compliant segments are denoted by joints with torsional springs. The transmission wheel (3) enables relative stylet member translations and articulation of the trocar tip (4). Internal (Fint) and external (Fext) forces are illustrated by arrows. The v2 needle contains four stylet members (circle quadrants), of which opposing pairs are linked by the transmission wheel. This wheel can rotate along the needle’s long axis to interlock with different opposing pairs. The rotation option is shown in Fig. 1, but not in this diagram to maintain the same 2D view.
