Integrative Modeling of Liver Organ for Simulation of Flexible Needle Insertion

A straight line needle trajectory is typically used in medical needle insertion for percutaneous intervention. Flexible needle steering may be able to avoid obstacles, and reach regions that are currently inaccessible using straight line trajectory. The success of flexible needle insertion in clinical application, for example, biopsy to obtain a tissue sample from human liver organ is dependent on how accurate the motion path can be planned and simulated. We developed a motion planning algorithm for flexible needle insertion with an integrative model of human liver organ, and finite element models of needle and needle-tissue interaction. The aim of image based integrative modeling is to have a unified organ model of patient comprising finite element and implicit surface models of blood vessels, normal and pathological tissues. The trajectory path can be determined in an interactive manner. The generated trajectory for flexible needles avoids obstacles (vessels) to reach target (tumor) inaccessible to rigid needles. The algorithm can also be used to simulate needle bending due to dynamic contact with tumor