Mosquito-Inspired Cannula to Improve Control of Active Surgical Needle in Soft Tissue

Abstract

Abstract Active needles obtain more significant tip deflection and improved accuracy over passive needles for percutaneous procedures. However, their ability to navigate through tissues to reach targets depends upon the actuation mechanism, the tip shape, and the surface geometry of the shaft. In this study, we investigate the benefits of changing the surface geometry of the active needle shaft in a) needle tip deflection and b) trajectory tracking during tissue insertion. The modifications in passive needle surface geometry have been proven to reduce friction force, tissue displacement, and tissue damage. This study incorporates the effect of modifying the regular smooth cannula with a mosquito proboscis-inspired design in the active needles. The changes in insertion force, tip deflection, and trajectory tracking control during insertion into a prostate-mimicking phantom are measured. Results show that insertion force is reduced by up to 10.67% in passive bevel-tip needles. In active needles, tip deflection increased by 12.91% at 150mm when the cannula is modified. The bioinspired cannula improved trajectory tracking error in the active needle by 39% while utilizing up to 17.65% lower control duty cycle. Improving tip deflection and tracking control would lead to better patient outcomes and reduced risk of complications during percutaneous procedures.