A minimally invasive surgical system for 3D ultrasound guided robotic retrieval of foreign bodies from a beating heart

The result of various medical conditions and trauma, foreign bodies in the heart pose a serious health risk as they may interfere with cardiovascular function. Particles such as thrombi, bullet fragments, and shrapnel can become trapped in a person's heart after migrating through the venous system, or by direct penetration. The severity of disruption can range from benign to fatal, with associated symptoms including anxiety, fever, cardiac tamponade, hemorrhage, infection, embolism, arrhythmia, and valve dysfunction. Injuries of this nature are common in both civilian and military populations. For symptomatic cases, conventional treatment is removal of the foreign body through open surgery via a median sternotomy, the use of cardiopulmonary bypass, and a wide incision in the heart muscle; these methods incur pronounced perioperative risks and long recovery periods. In order to improve upon the standard of care, we propose an image guided robotic system and a corresponding minimally invasive surgical approach. The system employs a dexterous robotic capture device that can maneuver inside the heart through a small incision. Visualization and guidance within the otherwise occluded internal regions are provided by 3D transesophageal echocardiography (TEE), an emerging form of intraoperative medical imaging used in interventions such as mitral valve repair and device implantation. A robotic approach, as opposed to a manual procedure using rigid instruments, is motivated by the various challenges inherent in minimally invasive surgery, which arise from attempts to perform skilled surgical tasks through small incisions without direct vision. Challenges include reduced dexterity, constrained workspace, limited visualization, and difficult hand-eye coordination, which ultimately lead to poor manipulability. A dexterous robotic end effector with real-time image guidance can help overcome these challenges and potentially improve surgical performance. However promising, such a system and approach require that several technical hurdles be resolved. The foreign body must be automatically tracked as it travels about the dynamic environment of the heart. The erratically moving particle must then be captured using a dexterous robot that moves much more slowly in comparison. Furthermore, retrieval must be performed under 3D ultrasound guidance, amidst the uncertainties presented by both the turbulent flow and by the imaging modality itself. In addressing such barriers, this thesis explores the development of a prototype system capable of retrieving a foreign body from a beating heart, culminating in a set of demonstrative in vitro experiments

Environment-aware Interactive Movement Primitives for Object Reaching in Clutter

The majority of motion planning strategies developed over the literature for reaching an object in clutter are applied to two dimensional (2-d) space where the state space of the environment is constrained in one direction. Fewer works have been investigated to reach a target in 3-d cluttered space, and when so, they have limited performance when applied to complex cases. In this work, we propose a constrained multi-objective optimization framework (OptI-ProMP) to approach the problem of reaching a target in a compact clutter with a case study on soft fruits grown in clusters, leveraging the local optimisation-based planner CHOMP. OptI-ProMP features costs related to both static, dynamic and pushable objects in the target neighborhood, and it relies on probabilistic primitives for problem initialisation. We tested, in a simulated poly-tunnel, both ProMP-based planners from literature and the OptI-ProMP, on low (3-dofs) and high (7-dofs) dexterity robot body, respectively. Results show collision and pushing costs minimisation with 7-dofs robot kinematics, in addition to successful static obstacles avoidance and systematic drifting from the pushable objects center of mass

Control of a hybrid robotic system for computer-assisted interventions in dynamic environments

International audiencePurpose Minimally invasive surgery is becoming the standard treatment of care for a variety of procedures. Surgeons need to display a high level of proficiency to overcome the challenges imposed by the minimal access. Especially when operating on a dynamic organ, it becomes very difficult to align instruments reliably and precisely. In this paper, a hybrid ro-botic system and a dedicated robotic control approach are proposed to assist the surgeon performing complex surgical gestures in a dynamic environment. Methods The proposed hybrid robotic system consists of a rigid robot arm on top of which a continuum robot is mounted in series. The continuum robot is locally actuated with McKibben muscles. A control scheme is adopted based on quadratic programming framework. It is shown that this framework allows enforcing a set of constraints on the pose of the tip, as well as of the instrument shaft, which is commanded to slide in and out through the entry point. Results Through simulation and experiments it is shown how the robot tool-tip is able to follow sinus-oidal trajectories of 0.37 Hz and 2 Hz, corresponding to motion due to breathing and heartbeat respectively, while maintaining the instrument shaft pivoting nicely about the entry point. The positioning and tracking accuracy of such system is shown to lie below 3mm in position and 5 • in angle. Herbert De Praetere is with UZ Leuven, Cardiac surgery, Conclusion The results suggest a good potential for applying the proposed technology to assist the surgeon during complex robot-assisted interventions. It is also illustrated that even when using flexible hence relatively safe end-effectors, it is possible to reach acceptable tracking behaviour at relatively high frequencies

Development of a cognitive robotic system for simple surgical tasks

The introduction of robotic surgery within the operating rooms has significantly improved the quality of many surgical procedures. Recently, the research on medical robotic systems focused on increasing the level of autonomy in order to give them the possibility to carry out simple surgical actions autonomously. This paper reports on the development of technologies for introducing automation within the surgical workflow. The results have been obtained during the ongoing FP7 European funded project Intelligent Surgical Robotics (I-SUR). The main goal of the project is to demonstrate that autonomous robotic surgical systems can carry out simple surgical tasks effectively and without major intervention by surgeons. To fulfil this goal, we have developed innovative solutions (both in terms of technologies and algorithms) for the following aspects: fabrication of soft organ models starting from CT images, surgical planning and execution of movement of robot arms in contact with a deformable environment, designing a surgical interface minimizing the cognitive load of the surgeon supervising the actions, intra-operative sensing and reasoning to detect normal transitions and unexpected events. All these technologies have been integrated using a component-based software architecture to control a novel robot designed to perform the surgical actions under study. In this work we provide an overview of our system and report on preliminary results of the automatic execution of needle insertion for the cryoablation of kidney tumours

Force Estimation Based Compliance Control of a Two Link Harmonically Driven Robotic Manipulator

The estimation of external forces exerted on a robotic manipulator with harmonic drive gearing without a force/torque sensor is considered. Manipulator dynamics, together with motor current feedback are used to estimate external joint torques, which are transformed into estimated external end effector forces using knowledge of the manipulator's kinematics. Adaptive control is used to tune the parameters of the robot's modeled dynamics, while adaptive radial basis function (RBF) neural networks are used to learn the friction dynamics. Admittance control without force sensing is attempted on a two degree of freedom manipulator. Readings from a six-axis force/torque sensor mounted on the manipulator are used to validate the force estimates during the estimation phase