Predicting Depth of Cut of Water-jet in Soft Tissue Simulants based on Finite Element Analysis with the Application to Fracture-directed Water-jet Steerable Needles

Abstract

Water-jet technology has been used recently in medical applications including surgery, soft tissue resection, bone cutting, and wound debridement. The ability to measure the depth of cut of water-jet is important in these applications to selectively cut the desired tissue, and avoid damage to deeper layers. For fracture-directed water-jet steerable needles, one should be able to predict the depth of cut of water-jet in order to model the motion of the steerable needle. In this paper, the effect of tissue stiffness, water-jet flow rate, and nozzle diameter on depth of cut is studied experimentally and verified by finite element modeling. It is found that the depth of cut of waterjet has a direct relationship with flow rate, and an inverse relationship with elastic modulus of the tissue, and diameter of the needle. The proposed finite element model can predict the depth of cut with acceptable accuracy.