Modeling and control of tissue compression and temperature for automation in robot-assisted surgery

Abstract

Robotic surgery is being used widely due to its various benefits that includes reduced patient trauma and increased dexterity and ergonomics for the operating surgeon. Making the whole or part of the surgical procedure autonomous increases patient safety and will enable the robotic surgery platform to be used in telesurgery. In this work, an Electrosurgery procedure that involves tissue compression and application of heat such as the coaptic vessel closure has been automated. A MIMO nonlinear model characterizing the tissue stiffness and conductance under compression was feedback linearized and tuned PID controllers were used to control the system to achieve both the displacement and temperature constraints. A reference input for both the constraints were chosen as a ramp and hold trajectory which reflect the real constraints that exist in an actual surgical procedure. Our simulations showed that the controllers successfully tracked the reference trajectories with minimal deviation and in finite time horizon. The MIMO system with controllers developed in this work can be used to drive a surgical robot autonomously and perform electrosurgical procedures such as coaptic vessel closures.

Robust shape estimation for 3D deformable object manipulation

“…When provided with sufficient prior knowledge about these two models, modern physically-based simulators such as [10]- [12] can provide a long-horizon prediction about the shape state of the underlying deformable object. As a result, recent work such as [1], [9], [13], [14] embedded a physically-based engine into their pipeline and designed or learned a manipulation control according to the shape feedbacks provided by the simulator. The resulting model-based control could be robust to noise and occlusion, if the simulator has been carefully calibrated to be consistent with the real-world physics, which unfortunately is difficult in practice.…”

Modelling and control of non-linear tissue compression and heating using an LQG controller for automation in robotic surgery

“…However, the system models of surgical tasks, especially the temperature model, are rarely seen in the control design in these references. Our preliminary work on designing a PID controller for tissue compression and heating was the first work of its kind in automation of a surgical task (Sinha et al, 2014). Although some optimal control algorithms have been used in automatic control design (Lewis et al, 2012), they have rarely been seen in surgical robot design to obtain a more effective, robust and accurate controller.…”