Evaluating performance of a novel developed robotic catheter manipulating system

An advanced robotic system incorporating haptic feedback for precision cardiac ablation procedures

This study introduces an innovative master-slave cardiac ablation catheter robot system that employs magnetorheological fluids. The system incorporates magnetorheological fluid to enable collision detection through haptic feedback, thereby enhancing the operator's situational awareness. A modular clamping and propulsion mechanism has been engineered for the ablation catheter, facilitating omnidirectional operation and force feedback within the cardiac cavity. To evaluate the proposed system, an in vitro experiment was performed. Results from the experiment indicate that the system demonstrates high motion transmission accuracy. Furthermore, the system effectively alerts operators to potential collisions, enabling swift catheter position adjustments, minimizing the risk of vascular perforation, and ultimately enhancing the overall safety and efficiency of the procedure.

An Intravascular Catheter Bending Recognition Method for Interventional Surgical Robots

Robot-assisted interventional surgery can greatly reduce the radiation received by surgeons during the operation, but the lack of force detection and force feedback is still a risk in the operation which may harm the patient. In those robotic surgeries, the traditional force detection methods may have measurement losses and errors caused by mechanical transmission and cannot identify the direction of the force. In this paper, an interventional surgery robot system with a force detection device is designed and a new force detection method based on strain gauges is proposed to detect the force and infer the bending direction of the catheter in the vessel by using BP neural network. In addition, genetic algorithm is used to optimize the BP neural network, and the error between the calculated results and the actual results is reduced by 37%, which improves the accuracy of catheter bending recognition. Combining this new method with traditional force sensors not only reduces the error caused by the traditional mechanical transmission, but also can detect the bending direction of the catheter in the blood vessel, which greatly improves the safety of the operation.

Design of a New Catheter Operating System for the Surgical Robot

In interventional surgery, the manual operation of the catheter is not accurate. It is necessary to operate the catheter skillfully and effectively to protect the surgeon from radiation injury. The purpose of this paper is to design a new robot catheter operating system, which can help surgeons to complete the operation with high mechanical precision. On the basis of the original mechanical structure-real catheter, the operation information of the main end operator is collected. After the information is collected, the control algorithm of the system is improved, and the BP neural network is combined with the traditional PID controller to adjust the PID control parameters more effectively and intelligently so that the motor can reflect the output of the controller better and faster. The feasibility and superiority of the BP neural network PID controller are verified by simulation experiments.

Analysis of Interventionalists' Natural Behaviors for Recognizing Motion Patterns of Endovascular Tools During Percutaneous Coronary Interventions

Many robotic platforms can indeed reduce radiation exposure to clinicians during percutaneous coronary intervention (PCI), however, interventionalists' natural manipulations are rarely involved in robot-assisted PCI. This requires more attention to analyze interventionalists' natural behaviors during conventional PCI. In this study, four types of natural behavior (i.e., muscle activity, hand motion, proximal force, and finger motion) were synchronously acquired from ten subjects while performing six typical types of guidewire manipulation. These behaviors are evaluated by a hidden Markov model (HMM) based analysis framework for relevant behavior selection. Relevant behaviors are further used as the input of two HMM-based classification frameworks to recognize guidewire motion patterns. Experimental results show that under the basic classification framework (BCF), 91.01% and 93.32% recognition accuracies can be achieved by using all behaviors and relevant behaviors, respectively. Furthermore, the hierarchical classification framework can significantly enhance the recognition ability of relevant behaviors with an accuracy of 96.39%. These promising results demonstrate great potential of proposed methods for promoting the future design of human-robot interfaces in robot-assisted PCI.

A marker-based contactless catheter-sensing method to detect surgeons' operations for catheterization training systems

It is challenging to position a catheter or a guidewire within a patient's complicated and delicate vascular structure due to the lack of intuitive visual feedback by only manipulating the proximal part of the surgical instruments. Training is therefore critical before an actual surgery because any mistake due to the surgeon's inexperience can be fatal for the patient. The catheter manipulation skills of experienced surgeons can be useful as input for training novice surgeons. However, few research groups focused on designs with consideration of the contactless catheter motion measurement, which allows obtaining expert surgeons' catheter manipulation trajectories whilst still allowing them to employ an actual catheter and apply conventional pull, push and twist of the catheter as used in bedside intravascular interventional surgeries. In this paper, a novel contactless catheter-sensing method is proposed to measure the catheter motions by detecting and tracking a passive marker with four feature-point groups. The passive marker is designed to allow simultaneously sensing the translational and rotational motions of the input catheter. Finally, the effectiveness of the proposed contactless catheter-sensing method is validated by conducting a series of comparison experiments. The accuracy and error analysis are quantified based on the absolute error, relative error, mean absolute error, and the success rate of the detection.

Feedforward Coordinate Control of a Robotic Cell Injection Catheter

Remote and robotically actuated catheters are the stepping-stones toward autonomous catheters, where complex intravascular procedures may be performed with minimal intervention from a physician. This article proposes a concept for the positional, feedforward control of a robotically actuated cell injection catheter used for the injection of myogenic or undifferentiated stem cells into the myocardial infarct boundary zones of the left ventricle. The prototype for the catheter system was built upon a needle-based catheter with a single degree of deflection, a 3-D printed handle combined with actuators, and the Arduino microcontroller platform. A bench setup was used to mimic a left ventricle catheter procedure starting from the femoral artery. Using Matlab and the open-source video modeling tool Tracker, the planar coordinates (y, z) of the catheter position were analyzed, and a feedforward control system was developed based on empirical models. Using the Student’s t test with a sample size of 26, it was determined that for both the y- and z-axes, the mean discrepancy between the calibrated and theoretical coordinate values had no significant difference compared to the hypothetical value of µ = 0. The root mean square error of the calibrated coordinates also showed an 88% improvement in the z-axis and 31% improvement in the y-axis compared to the unmodified trial run. This proof of concept investigation leads to the possibility of further developing a feedfoward control system in vivo using catheters with omnidirectional deflection. Feedforward positional control allows for more flexibility in the design of an automated catheter system where problems such as systemic time delay may be a hindrance in instances requiring an immediate reaction.

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.

Preliminary study for motion scaling based control in minimally invasive vascular interventional robot

Robot-assisted vascular interventions present promising trend for reducing the X-ray radiation to the surgeon during the operation. However, the control methods in the current vascular interventional robots only repeat the manipulation of the surgeon. While under certain circumstances, it is necessary to scale the manipulation of the surgeon to obtain a higher precision or a shorter manipulation time. A novel control method based on motion scaling for vascular interventional robot is proposed in this paper. The main idea of the method is to change the motion speed ratios between the master and the slave side. The motion scaling based control method is implemented in the vascular interventional robot we've developed before, so the operator can deliver the interventional devices under different motion scaling factors. Experiment studies verify the effectiveness of the motion scaling based control.

Design and performance evaluation of a master controller for endovascular catheterization

PURPOSE

It is difficult to manipulate a flexible catheter to target a position within a patient's complicated and delicate vessels. However, few researchers focused on the controller designs with much consideration of the natural catheter manipulation skills obtained from manual catheterization. Also, the existing catheter motion measurement methods probably lead to the difficulties in designing the force feedback device. Additionally, the commercially available systems are too expensive which makes them cost prohibitive to most hospitals. This paper presents a simple and cost-effective master controller for endovascular catheterization that can allow the interventionalists to apply the conventional pull, push and twist of the catheter used in current practice.

METHODS

A catheter-sensing unit (used to measure the motion of the catheter) and a force feedback unit (used to provide a sense of resistance force) are both presented. A camera was used to allow a contactless measurement avoiding additional friction, and the force feedback in the axial direction was provided by the magnetic force generated between the permanent magnets and the powered coil.

RESULTS

Performance evaluation of the controller was evaluated by first conducting comparison experiments to quantify the accuracy of the catheter-sensing unit, and then conducting several experiments to evaluate the force feedback unit. From the experimental results, the minimum and the maximum errors of translational displacement were 0.003 mm (0.01 %) and 0.425 mm (1.06 %), respectively. The average error was 0.113 mm (0.28 %). In terms of rotational angles, the minimum and the maximum errors were 0.39°(0.33 %) and 7.2°(6 %), respectively. The average error was 3.61°(3.01 %). The force resolution was approximately 25 mN and a maximum current of 3A generated an approximately 1.5 N force.

CONCLUSION

Based on analysis of requirements and state-of-the-art computer-assisted and robot-assisted training systems for endovascular catheterization, a new master controller with force feedback interface was proposed to maintain the natural endovascular catheterization skills of the interventionalists.