Why use remote guidance to steer catheters and guide wires?

A Novel Remote-Controlled Vascular Interventional Robotic System Based on Hollow Ultrasonic Motor

Cardiovascular diseases (CVDs) are the deadliest diseases worldwide. Master-slave robotic systems have been widely used in vascular interventional surgery with the benefit of high safety, efficient operation, and procedural facilitation. This paper introduces a remote-controlled vascular interventional robot (RVIR) that aims to enable surgeons to perform complex vascular interventions reliably and accurately under a magnetic resonance imaging (MRI) environment. The slave robot includes a guidewire manipulator (GM) and catheter manipulator (CM) that are mainly composed of a hollow driving mechanism and a linear motion platform. The hollow driving mechanism is based on a traveling wave-type hollow ultrasonic motor (HUM) which has high positional precision, fast response, and magnetic interference resistance and realizes the cooperation of the guidewire and catheter by omitting the redundant transmission mechanism and maintaining good coaxiality. The HUM stator, the core part of the RVIR, is optimized by an adaptive genetic algorithm for better quality and greater amplitude of traveling waves, which are beneficial to the drive efficiency and precision. The robot system features great cooperating performance, small hysteresis, and high kinematic accuracy and has been experimentally verified for its capability to precisely manipulate the guidewire and catheter.

Design and Development of Surgeon Augmented Endovascular Robotic System

OBJECTIVE

Inadequate visual and force feedback while navigating surgical tools elevate the risk of endovascular procedures. It also poses occupational hazard due to repeated exposure to X-rays. A teleoperated robotic system that augments surgeon's actions is a solution.

METHOD

We have designed and developed an endovascular robotic system that augments surgeon's actions using conventional surgical tools, as well as generates feedback in order to ensure safety during the procedure. The reaction force from vasculature is estimated from motor current that drives the surgical tool. Calibration required for force estimation is based on bilevel optimization. Input shaping is used in conjunction with a cascaded controller to avoid large responses due to faster inputs and to track tool position. The design, realization, and testing of our system are presented.

RESULTS

The responses of the system in comparison with the dynamics model is similar vis-à-vis the same input commands. Any error in the position tracking is reduced by the cascaded controller. Phase-portrait analysis of the system showed that the system is stable. The reaction force estimation is validated against load cell measurements. The safety mechanism in the events of excessive reaction forces while interacting with vasculature is demonstrated.

CONCLUSION AND SIGNIFICANCE

Our system is a step toward intelligent robots that can assist surgeons during endovascular procedures by monitoring and alerting the surgeons regarding detrimental parameters. It arrests any unintended excursions of the surgical tools or surgeon's actions. This will also eliminate the need for surgeons to be in radiation environment.

Magnetic guide-wire navigation in pulmonary and systemic arterial catheterization: initial experience in pigs

PURPOSE

Cardiovascular catheterization can be challenging whenever a stenosis or an abnormal vascular course interferes with probing the target vessel. This study addresses the feasibility of navigating a guide wire with a magnetic tip by an external magnetic field through pulmonary and systemic arteries in an experimental porcine model.

MATERIALS AND METHODS

We investigated six piglets using magnetic guide-wire navigation. Two pulmonary arteriograms were taken from different angles in order to reconstruct the three-dimensional vessel anatomy. A computer interface then calculated three-dimensional coordinates for the vessel in space. Using these coordinates, two external magnets were positioned to create magnetic vectors along the expected vessel course. Magnetically enabled guide wires were then navigated into the vessels using the magnetic field to orient the guide-wire tips. Aortic and renal branches were addressed in a similar fashion. Difficulty in reaching the target vessel was reflected by the number of attempts that were necessary. After 10 failed attempts, the maneuver was recorded to have failed.

RESULTS

Thirty-five of 37 (94.6%) arteries with branches at acute angles were reached successfully using magnetic navigation. In two pigs, the left upper lobe artery could not be probed. Peripheral arteries of small diameter were easier to reach than large central arteries, requiring less attempts.

CONCLUSIONS

Magnetic guide-wire navigation is feasible in the arteries of the lungs, the head and neck, and the kidneys. It is particularly useful in entering small arterial branches at acute angles and may facilitate interventional therapy in a variety of vascular diseases in children and adults.

Performance of magnetic field-guided navigation system for interventional neurosurgical and cardiac procedures

A hospital-based magnetic guidance system (MGS) was installed to assist a physician in navigating catheters and guide wires during interventional cardiac and neurosurgical procedures. The objective of this study is to examine the performance of this magnetic field-guided navigation system. Our results show that the system's radiological imaging components produce images with quality similar to that produced by other modern fluoroscopic devices. The system's magnetic navigation components also deflect the wire and catheter tips toward the intended direction. The physician, however, will have to oversteer the wire or catheter when defining the steering angle during the procedure. The MGS could be clinically useful in device navigation deflection and vessel access.