Navigating Sensitive Soft Tissues Using Robotically Steered Flexible Needles

UNIVERSITY OF TWENTE, ENSCHEDE, NETHERLANDS. Robotically steering flexible needles have been produced to reach tissues with sub-millimeter accuracy. These flexible needles can easily avoid sensitive tissues, obstacles and can reorient their path in real time as they  are being inserted.

PhD candidate, Momen Abayazid who is affiliated with the research institute MIRA of the University of Twente, demonstrated his doctoral research on these robotically steered flexible needles. Therapeutic and diagnostic procedures require the insertion of a needle into soft tissues during biopsies. In some cases, the insertion of radioactive seeds in combating prostate cancer requires this procedure. Such operations entail accuracy especially in the positioning of the needle.

Currently, needles with a large diameter are used in these procedures. The main drawback of this is that large needles cannot be maneuvered when inserted into tissues. They cannot avoid any obstacles and result in tissue or organ deformation. There is also a higher percentage that the needle misses its target.

A robot-assisted system for steering flexible needles with asymmetric tips was developed by this research. These needles bend naturally when inserted into soft tissues. One can steer the needle in intricate 3D paths by doing a sequence of rotations and insertions. A robot controls the needle and ultrasound images are used to track in real time. The entire system makes it possible to attain a sub-millimeter level of accuracy. The development of the robotic test-bed, the control that guides the needle and the ultrasound images through the 3D needle localization algorithm, were successfully achieved in this research.

The importance of acceptance in clinical practice is important so Mr. Abayazid developed a system that permits a clinician to have control. This resulted in the combination of clinical expertise with the robotic system’s accuracy. In this system, the clinician inserts the needle while the robotic system provides cues and guidance via visual feedback and vibrations. In addition to that, the shared-controlled system makes it possible to have a needle be remotely guided by a clinician who is in a totally different location from the patient. The research has successfully demonstrated this when the clinician based in Netherlands successfully guided the needle in a patient based in Sienna, Italy.

The developed system has been incorporated with an ultrasound-based, automated breast volume scanner (ABVS). The combination of this proposed system with a robotic, clinically approved ABVS system has made it possible to bring robotic needle guidance from the research lab to an operating room. The system is technically ready for human application. Clinical trials are expected to commence within 3 years.

Image courtesy of pixabay.com

Learn more about PreScouter at www.prescouter.com