Needle placement errors can mitigate the effectiveness of the diagnosis or the therapy, sometimes with catastrophic outcomes. Previous design of a simplified model for needle deflection estimation was motivated by the clinical constraints of ARCS (Abdomino-pelvic Robotic-driven slightly flexible needle insertion performed in CT/MRI-guided Scenario). We present in this work, the validation results for the needle deflection prediction model. Its robustness is evaluated under an unknown context such as a different robotic platform, facing uncertainties conditions not conceived previously in the model's confection. In addition, the work presents the development and validation experiments of an adaptive path planner that uses the model as predictor's strategy. It provides pre-operative planning assistance, as well as intra-operative decision-making support. The experiments results showed average error around 1mm for the pre-operative planning and the intra-operative replanning approach showed to be very robust to correct the initial predictions, showing average error smaller than 1 mm.

In this paper we propose a modeling method for the interaction impedance of a remote soft tissue that contains quasi-periodic physiological motion disturbance. Through this study, it is shown that the interaction with such environment is not passive and its influence should be considered in the teleoperator design. The interaction impedance depends not only on the soft tissue impedance but also on the relationship between the robotic tool motion and the soft tissue motion disturbance. An illustrative case study is presented to demonstrate how to analyze the environment interaction impedance in real application.

Tele-surgery has been more and more popular in robotassisted medical intervention. Most existing teleoperation architectures for medical applications adopt 2-channel architectures. The 2-channel architectures have been evaluated in literature and it is shown that some architectures, e.g. position-force (P-F), are able to provide the surgeon a reliable haptic sense of the working environment (transparency). However, stability of these P-F architecture is still a considerable concern especially when physiological disturbances exist in the remote environment. P-PF architecture is proved to provide a convenient alternative. With one more channel 3-channel teleoperation architectures present promising options due to their augmented design flexibility. This paper evaluates stability and transparency of general 3-channel bilateral teleoperation control architectures and provides a design framework guidelines to improve the architectures' stability robustness and optimize the transparency. Simulation evaluations are provided to illustrate how the optimal 3-channel teleoperation architecture is chosen for medical applications given their dedicated requirements.