An admittance-controlled amplified force tracking scheme for collaborative lumbar puncture surgical robot system.

Background: The accurate sensing and display of the delicate needle-tissue interaction force to the operator is desirable for needle insertion procedures. It not only plays a significant role in the surgical treatment effect, but also has a great significance in improving surgical safety and reducing the incidence of complications. However, the direct detection of the interaction force between the tissue and needle tip by placement of a force sensor is challenging owing to the constraints of miniaturisation, cost, and sterilisation.

Methods: In this study, a new position-based force-to-motion controller with magnified force feedback is presented to provide augmented force perception to the operator during needle insertion on the soft tissue. Furthermore, the demonstration to the position-based low level motion controller is more suitable for needle insertion surgical requirements in the cooperative robotic system.

Results: The proposed controller was experimentally validated by a collaborative lumbar puncture robotics system. Additionally, to provide hand tremor rejection for the stable manipulation of the puncture needle, it was demonstrated that the proposed amplified feedback force controller allowed a safer object interaction with the robotic needle insertion assistance.

Conclusions: The results of the experiment show that a desirable interaction force profile is perceived by the operator during the overall insertion task operation. The admittance gain for the simplified admittance controller has a significant impact on the operator's ability to accurately control the applied force.