A Magnetorheological Fluids-Based Robot-Assisted Catheter/Guidewire Surgery System for Endovascular Catheterization.

A teleoperated robotic catheter operating system is a solution to avoid occupational hazards caused by repeated exposure radiation of the surgeon to X-ray during the endovascular procedures. However, inadequate force feedback and collision detection while teleoperating surgical tools elevate the risk of endovascular procedures. Moreover, surgeons cannot control the force of the catheter/guidewire within a proper range, and thus the risk of blood vessel damage will increase. In this paper, a magnetorheological fluid (MR)-based robot-assisted catheter/guidewire surgery system has been developed, which uses the surgeon's natural manipulation skills acquired through experience and uses haptic cues to generate collision detection to ensure surgical safety. We present tests for the performance evaluation regarding the teleoperation, the force measurement, and the collision detection with haptic cues. Results show that the system can track the desired position of the surgical tool and detect the relevant force event at the catheter. In addition, this method can more readily enable surgeons to distinguish whether the proximal force exceeds or meets the safety threshold of blood vessels.

Performance evaluation of a robot-assisted catheter operating system with haptic feedback.

In this paper, a novel robot-assisted catheter operating system (RCOS) has been proposed as a method to reduce physical stress and X-ray exposure time to physicians during endovascular procedures. The unique design of this system allows the physician to apply conventional bedside catheterization skills (advance, retreat and rotate) to an input catheter, which is placed at the master side to control another patient catheter placed at the slave side. For this purpose, a magnetorheological (MR) fluids-based master haptic interface has been developed to measure the axial and radial motions of an input catheter, as well as to provide the haptic feedback to the physician during the operation. In order to achieve a quick response of the haptic force in the master haptic interface, a hall sensor-based closed-loop control strategy is employed. In slave side, a catheter manipulator is presented to deliver the patient catheter, according to position commands received from the master haptic interface. The contact forces between the patient catheter and blood vessel system can be measured by designed force sensor unit of catheter manipulator. Four levels of haptic force are provided to make the operator aware of the resistance encountered by the patient catheter during the insertion procedure. The catheter manipulator was evaluated for precision positioning. The time lag from the sensed motion to replicated motion is tested. To verify the efficacy of the proposed haptic feedback method, the evaluation experiments in vitro are carried out. The results demonstrate that the proposed system has the ability to enable decreasing the contact forces between the catheter and vasculature.

Design and performance evaluation of collision protection-based safety operation for a haptic robot-assisted catheter operating system.

The robot-assisted catheter system can increase operating distance thus preventing the exposure radiation of the surgeon to X-ray for endovascular catheterization. However, few designs have considered the collision protection between the catheter tip and the vessel wall. This paper presents a novel catheter operating system based on tissue protection to prevent vessel puncture caused by collision. The integrated haptic interface not only allows the operator to feel the real force feedback, but also combines with the newly proposed collision protection mechanism (CPM) to mitigate the collision trauma. The CPM can release the catheter quickly when the measured force exceeds a certain threshold, so as to avoid the vessel puncture. A significant advantage is that the proposed mechanism can adjust the protection threshold in real time by the current according to the actual characteristics of the blood vessel. To verify the effectiveness of the tissue protection by the system, the evaluation experiments in vitro were carried out. The results show that the further collision damage can be effectively prevented by the CPM, which implies the realization of relative safe catheterization. This research provides some insights into the functional improvements of safe and reliable robot-assisted catheter systems.