Nevigation Control Of Articulated Needle Based On Heterogeity Tissue

Minimally Invasive Surgery is one of the key projects and important subjects in the development of the 21st century surgery, in which the needle for biopsy and puncture is the most basic and common instruments. The study of the needle has gone through the development from the initial rigid straight needle to pre-curved needle and to steering compliant needle. In the use of the needle, for the surgeon, to control the needle into the deep of the human body accurately is very important. And simultaneously, during inserting, the important tissue like organs and vessels should be avoided for the less iatrogenic injury. So, the navigation of the needle seems to be particularly important.In order to study and improve the passive navigation performance of articulated needle widely, soft tissue model was built to study the relationship between needle and tissue based on the existing research results. Experimental study was achieved to test the forces’ transfer on the articulations and accurate path planning method was chosen to simulate the motion trail of articulated needle effective.The main research works conducted in this thesis are as follows:(1) Heterogeneity tissue model, which material characteristics and property were studied, was built to analysis the interaction between the tissue and needle, so as the Moony-Rivlin energy equation.(2) The path planning method was optimized based on the existing A* algorithm studied by other member and RRT algorithm was presented.(3) Forces’ transfer was studied in articulations, so as the effect of bevel tip’s angle, forces’direction and needle’s length. Hardware circuit and software were designed for the experiment of forces’ transfer.(4) Navigation coordinate of 2D and 3D were studied. Ansys was used to simulate the force acted on Mooney-Rivlin model and FEM analysis. Passive navigation of articulated needle control was achieved.