Like other bevel tip needles that move inside bodies,\cite{okamura2006} the morphing shape of our active-cannula-based pre-curved stylet is also coupled to its insertion speed. By carefully analyzing the obtained data, it is found that the higher insertion speed is, the larger force is exerted on the sub-electrode by the tissue phantom and thus yields a lower deflection angle in a reasonable range, Figure 7E. Meanwhile, the impact of speed-relevant force is more obvious in state 2 than that in state 3, and the higher the speed is, the stronger the impact is, Figure 7F. The quantitively analysis of the sub-electrode provides a useful guidance for the shape morphing and trajectory control of our electrode in the tissue phantom.