Flexible liver-needle navigation using fish-like robotic elements

This paper proposes a new method for steering a flexible needle in soft tissue according to an analogy of the swimming wave motion of fish locomotion. Assuming small deflection, the flexible needle is modeled as a linear beam. The governing equation for cantilever deflection is used to minimize the strain energy of the needle. Our simulation demonstrated that the repetitive motion has presented a more flexible agility to avoid obstacles, and possess better ability to find the appropriate path according to the external forces applied on the tissue during navigation. The motion of the needle can be tracked by comparing the desired deflection with needle position from x-ray images. Point-to-point algorithm is used to achieve real time control of the flexible needle.