Guiding Medical Needles Using Single-Point Tissue Manipulation
Meysam Torabi, Kris Hauser, Ron Alterovitz, Vincent Duindam and Ken Goldberg
National Institute of Health
This topic addresses the use of robotic tissue manipulation in medical needle insertion procedures to improve targeting accuracy and to help avoid damaging sensitive tissues. To control these multiple, potentially competing objectives, we present a phased controller that operates one manipulator at a time using closed-loop imaging feedback. We remark that it may be beneficial to use unilateral manipulators with a large, rounded region of manipulator/tissue contact. We present an automated procedure planning technique that uses tissue geometry to select the needle insertion location, manipulation locations, and controller parameters. The planner uses a stochastic optimization of a cost function that includes tissue stress and robustness to disturbances. We demonstrate the system on 2D tissues simulated with a mass-spring model, including a simulation of a prostate brachytherapy procedure. It can reduce targeting errors from more than 2cm to less than 1mm, and can also shift obstacles by over 1cm to clear them away from the needle path. An immediate goal for future work is to evaluate our technique with more sophisticated 3D tissue models and needle-tissue interaction models. We would also like to test the automated procedure planner with various medical applications, including multiple-seed prostate brachytherapy treatments. And finally a long-term goal is to move from simulations to clinical settings.
Figure 1: Simulation of a prostate needle insertion. Image is an oblique slice from The Virtual Human Project dataset.
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