  The use of needles to access sites within organs is fundamental to many
interventional medical procedures both for diagnosis and treatment. Safe and
accurate navigation of a needle through living tissue to an intra-tissue target
is currently often challenging or infeasible due to the presence of anatomical
obstacles in the tissue, high levels of uncertainty, and natural tissue motion
(e.g., due to breathing). Medical robots capable of automating needle-based
procedures in vivo have the potential to overcome these challenges and enable
an enhanced level of patient care and safety. In this paper, we show the first
medical robot that autonomously navigates a needle inside living tissue around
anatomical obstacles to an intra-tissue target. Our system leverages an aiming
device and a laser-patterned highly flexible steerable needle, a type of needle
capable of maneuvering along curvilinear trajectories to avoid obstacles. The
autonomous robot accounts for anatomical obstacles and uncertainty in living
tissue/needle interaction with replanning and control and accounts for
respiratory motion by defining safe insertion time windows during the breathing
cycle. We apply the system to lung biopsy, which is critical in the diagnosis
of lung cancer, the leading cause of cancer-related death in the United States.
We demonstrate successful performance of our system in multiple in vivo porcine
studies and also demonstrate that our approach leveraging autonomous needle
steering outperforms a standard manual clinical technique for lung nodule
access.
