A novel highly articulated robotic surgical system for epicardial ablation

Continuum Robots for Medical Interventions

Continuum robots are not constructed with discrete joints but, instead, change shape and position their tip by flexing along their entire length. Their narrow curvilinear shape makes them well suited to passing through body lumens, natural orifices, or small surgical incisions to perform minimally invasive procedures. Modeling and controlling these robots are, however, substantially more complex than traditional robots comprised of rigid links connected by discrete joints. Furthermore, there are many approaches to achieving robot flexure. Each presents its own design and modeling challenges, and to date, each has been pursued largely independently of the others. This article attempts to provide a unified summary of the state of the art of continuum robot architectures with respect to design for specific clinical applications. It also describes a unifying framework for modeling and controlling these systems while additionally explaining the elements unique to each architecture. The major research accomplishments are described for each topic and directions for the future progress needed to achieve widespread clinical use are identified.

Evaluation of a novel multi-articulated endoscope: proof of concept through a virtual simulation

PURPOSE

In endoscopic surgery such as video-assisted thoracoscopic surgery and laparoscopic surgery, providing the surgeon a good view of the target is important. Rigid endoscope has for years been the go-to tool for this purpose, but it has certain limitations like the inability to work around obstacles. To improve on current tools, a novel multi-articulated endoscope (MAE) is currently under development. To investigate its feasibility and possible value, we performed a user test using virtual prototype of the MAE with the intent to show that it outperforms the conventional endoscope while bringing minimal additional burden to the operator.

METHODS

To evaluate the prototype, we built a virtual model of the MAE and a rigid oblique-viewing endoscope. Through a comparative user study we evaluate the ability of each device to visualize certain targets placed inside the virtual chest cavity by the angle between the visual axis of the scope and the normal of the plane of the target, while accounting for the usability of each endoscope by recording the time taken for each task. In addition, we collected a questionnaire from each participant to obtain feedback.

RESULTS

The angles obtained using the MAE were smaller on average ([Formula: see text]), indicating that better visualization can be achieved through the proposed method. A nonsignificant difference in mean time taken for each task in favor of the rigid endoscope was also found ([Formula: see text]).

CONCLUSIONS

We have demonstrated that better visualization for endoscopic surgery can be achieved through our novel MAE. The scope may bring about a paradigm shift in the field of minimally invasive surgery by providing more freedom in viewpoint selection, enabling surgeons to perform more elaborate procedures in minimally invasive settings.

A Filtering Approach for Image-Guided Surgery With a Highly Articulated Surgical Snake Robot

GOAL

The objective of this paper is to introduce a probabilistic filtering approach to estimate the pose and internal shape of a highly flexible surgical snake robot during minimally invasive surgery.

METHODS

Our approach renders a depiction of the robot that is registered to preoperatively reconstructed organ models to produce a 3-D visualization that can be used for surgical feedback. Our filtering method estimates the robot shape using an extended Kalman filter that fuses magnetic tracker data with kinematic models that define the motion of the robot. Using Lie derivative analysis, we show that this estimation problem is observable, and thus, the shape and configuration of the robot can be successfully recovered with a sufficient number of magnetic tracker measurements.

RESULTS

We validate this study with benchtop and in-vivo image-guidance experiments in which the surgical robot was driven along the epicardial surface of a porcine heart.

CONCLUSION

This paper introduces a filtering approach for shape estimation that can be used for image guidance during minimally invasive surgery.

SIGNIFICANCE

The methods being introduced in this paper enable informative image guidance for highly articulated surgical robots, which benefits the advancement of robotic surgery.

Active printed materials for complex self-evolving deformations

We propose a new design of complex self-evolving structures that vary over time due to environmental interaction. In conventional 3D printing systems, materials are meant to be stable rather than active and fabricated models are designed and printed as static objects. Here, we introduce a novel approach for simulating and fabricating self-evolving structures that transform into a predetermined shape, changing property and function after fabrication. The new locally coordinated bending primitives combine into a single system, allowing for a global deformation which can stretch, fold and bend given environmental stimulus.

Single-site access robot-assisted epicardial mapping with a snake robot: preparation and first clinical experience

CardioARM, a highly flexible “snakelike” medical robotic system (Medrobotics, Raynham, MA), has been developed to allow physicians to view, access, and perform complex procedures intrapericardially on the beating heart through a single-access port. Transthoracic epicardial catheter mapping and ablation has emerged as a strategy to treat arrhythmias, particularly ventricular arrhythmias, originating from the epicardial surface. The aim of our investigation was to determine whether the CardioARM could be used to diagnose and treat ventricular tachycardia (VT) of epicardial origin. Animal and clinical studies of the CardioARM flexible robot were performed in hybrid surgical–electrophysiology settings. In a porcine model study, single-port pericardial access, navigation, mapping, and ablation were performed in nine animals. The device was then used in a small, single-center feasibility clinical study. Three patients, all with drug-refractory VT and multiple failed endocardial ablation attempts, underwent epicardial mapping with the flexible robot. In all nine animals, navigation, mapping, and ablation were successful without hemodynamic compromise. In the human study, all three patients demonstrated a favorable safety profile, with no major adverse events through a 30-day follow-up. Two cases achieved technical success, in which an electroanatomic map of the epicardial ventricle surface was created; in the third case, blood obscured visualization. These results, although based on a limited number of experimental animals and patients, show promise and suggest that further clinical investigation on the use of the flexible robot in patients requiring epicardial mapping of VT is warranted.