Experimental evaluation of co-manipulated ultrasound-guided flexible needle steering

Background: A teleoperation system for bevel-tipped flexible needle steering has been evaluated. Robotic systems have been exploited as the main tool to achieve high accuracy and reliability. However, for reasons of safety and acceptance by the surgical community, keeping the physician tightly in the loop is preferable. Methods: The system uses ultrasound imaging, path planning, and control to compute the desired needle orientation during the insertion and intuitively passes this information to the operator, who teleoperates the motion of the needle's tip. Navigation cues about the computed orientation are provided through haptic and visual feedback to the operator to steer the needle. Results: The targeting accuracy of several co-manipulation strategies were studied in four sets of experiments involving human subjects with clinical backgrounds. Conclusions: Experimental results show that receiving feedback regarding the desired needle orientation improves the targeting accuracy by a factor of 9 with respect to manual insertions.