ENERGY BASED MODEL TO PREDICT THE TISSUE-NEEDLE INTERACTION MECHANICS OF ACTIVE SURGICAL NEEDLES

摘要

Needle insertion is a common surgical technique used in diagnosis (e.g. biopsy) and prognosis (e.g. brachytherapy) of several diseases. The success of such procedures highly depends on the accuracy of needle placement to target locations. Accuracy of the needle placement is presently limited due to movement of tissue, inability to control needle deflection, and inaccessibility of image monitoring techniques. These limitations are being addressed by using active (or smart) needles (e.g. see Fig. 1) that can maneuver within the tissue with the aid of actuators attached to the needle body [1-3]. However, in these studies, active needles were studied in air but not inside the tissue where they are supposed to be used. Therefore, to develop active needles that are feasible for clinical applications, it is necessary to understand the mechanics of active needles within the tissue. Interaction mechanics of tissue-needle has been reported in literature [4], but they are limited to passive needles where only insertion forces are considered on the needle. However, to the best of author's knowledge the interaction mechanics with active needle (where actuation forces are being applied) has not been studied. Therefore, in this study actuation forces acting on the needle were included in the tissue-needle interaction studies. A numerical model has been developed to predict the active needle behavior within the tissue, which has been validated with needle insertion experiments.