Design and evaluation of a robotic needle steering manipulator for image-guided breast biopsy

Breast cancer is one of the leading causes of cancer death in women. First signs of breast cancer are often found during the screening phase. In this phase, the breast is examined using screening techniques such as manual palpation, mammography, ultrasound and Magnetic Resonance Imaging (MRI). Suspected regions are further investigated by inserting a biopsy needle where imaging modalities such as MRI and ultrasound are used for guidance to target the lesion to acquire tissue samples for pathology assessment. As needle biopsy under MRI guidance is difficult due to the limited amount of space inside the MRI scanner and sensitivity to ferro-magnetic materials, ultrasound-guided biopsy is often the method of choice, due realtime, availability and lower cost advantages. However, ultrasound detectability of tumors is still lower than that of MRI.

This study is part of a project aiming to combine both MRI and ultrasound imaging worlds for precise robotic-assisted needle biopsy. An off-the-shelf robotic arm from KUKA (Munich, Germany) is used to steer an ultrasound probe [1][2] and needle guide end-effector. After localization of targeted lesion with the ultrasound transducer and merged MRI data, a needle guide is placed into the target position with the use of mechatronics. For Safety reasons, a biopsy needle is manually inserted through the guide into the breast by a radiologist [3].

The aim of this research is to design and evaluate an end-effector (Figure 1) to be mounted on a robotic arm. This end-effector is composed of an ultrasound probe holder and the needleguide. The base of the end-effector interconnects motors, probe holder and robot interface to each other, Six set screws are used to clamp and align an ultrasound probe with the needle guide so that the controlled planar movement of the needle is visible in the ultrasound image plane. The needle guide is mechatronically manipulated through a parallel mechanism that is laser cut out of delrin parts. With the help of magnetic joints, the biopsy needle is released from its holder for safety when applied forces are higher than 1.5N. This was validated with spring scale measurements. Workspace analysis showed that the needle and guiding mechanism can handle breast sizes with diameters up to 200mm, measured from the base of the breast. A preliminary hazard analysis was performed and the design evaluation on a breast phantom showed that the end-effector is expected to provide safe insertion of the biopsy needle. The robotic arm provides more precise positioning of the needle on the breast surface. This helps in reducing the needle insertion path length in breast tissue and consequently minimizes the patient’s trauma. Based on the obtained results, further development of the current end-effector (prototype) is expected to result in a functional product. Validation of the end-effector developed in current study showed promising results for biopsy procedures.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 688188.

References

[1] K. Mathiassen, J.E. Fjellin, K. Glette, P.K. Hol, O.J. Elle, An Ultrasound Robotic System Using the Commercial Robot UR5, Frontiers in Robotics and AI, 3(1) p.1-16, 2016.
[2] P. Chatelain, A. Krupa, N. Navab, 3D ultrasound-guided robotic steering of a flexible needle via visual servoing., IEEE International Conference on Robotics and automation (ICRA), p. 2250-2255, 2015.
[3] J. Hong, T. Dohi, M. Hashizume, K. Konishi, N. Hata, An ultrasound-driven needle insertion robot for percutaneous cholecystostomy, Physics in Medicine and Biology, 49(3), 411-451, 2004.