164 research outputs found
Evaluation of robotic catheter technology in complex endovascular intervention
The past four decades have witnessed tremendous strides in the evolution of
endovascular devices and techniques. Catheter-based intervention has revolutionized
the management of arterial disease allowing treatment of aortic and peripheral
pathologies via a minimally invasive approach. Despite the exponential advances in
endovascular equipment, devices and techniques, catheter-based endovascular
intervention has certain morphological and technological constraints. Complex patient
anatomy, technological impediments and suboptimal fluoroscopic imaging, can make
endovascular intervention challenging using traditional endovascular means.
Conventional endovascular catheters lack active manoeuvrability of the tip. Manual
control can hinder overall stability and control at key target areas, leading to
significantly prolonged overall procedure and fluoroscopic times. Repeated
instrumentation increases the risk of vessel trauma and distal embolization. More
importantly, guidewire-catheter skills are not necessarily intuitive but must be
developed and are highly dependent on operator skill with long training pathways as a
result.
Recognizing the pressing need to address some of the limitations of standard catheter
technology this thesis aims to evaluate the role of advanced robotic endovascular
catheters in the aortic arch and the visceral segment. Clinical use of this technology is
currently limited to transvenous cardiac mapping and ablation procedures. A
comprehensive pre-clinical comparison and analysis of robotic versus manual catheter
techniques is presented to reveal both their advantages and limitations, with particular emphasis on the potential of robotic catheter technology to reduce the manual skill
required for complex tasks, improve stability at key target areas, reduce the risk of
vessel trauma, embolization and radiation exposure, whilst improving overall operator
performance. The worlds first clinical report of robot-assisted aortic aneurysm repair,
a “proof - of - concept” resulting from this research, is also presented, and the
potential for future advanced applications in order to increase the applicability of
endovascular therapy to a larger cohort of patients discussed
Surgical Subtask Automation for Intraluminal Procedures using Deep Reinforcement Learning
Intraluminal procedures have opened up a new sub-field of minimally invasive surgery that use flexible instruments to navigate through complex luminal structures of the body, resulting in reduced invasiveness and improved patient benefits. One of the major challenges in this field is the accurate and precise control of the instrument inside the human body. Robotics has emerged as a promising solution to this problem. However, to achieve successful robotic intraluminal interventions, the control of the instrument needs to be automated to a large extent. The thesis first examines the state-of-the-art in intraluminal surgical robotics and identifies the key challenges in this field, which include the need for safe and effective tool manipulation, and the ability to adapt to unexpected changes in the luminal environment. To address these challenges, the thesis proposes several levels of autonomy that enable the robotic system to perform individual subtasks autonomously, while still allowing the surgeon to retain overall control of the procedure. The approach facilitates the development of specialized algorithms such as Deep Reinforcement Learning (DRL) for subtasks like navigation and tissue manipulation to produce robust surgical gestures. Additionally, the thesis proposes a safety framework that provides formal guarantees to prevent risky actions. The presented approaches are evaluated through a series of experiments using simulation and robotic platforms. The experiments demonstrate that subtask automation can improve the accuracy and efficiency of tool positioning and tissue manipulation, while also reducing the cognitive load on the surgeon. The results of this research have the potential to improve the reliability and safety of intraluminal surgical interventions, ultimately leading to better outcomes for patients and surgeons
Challenges of continuum robots in clinical context: a review
With the maturity of surgical robotic systems based on traditional rigid-link principles, the rate of progress slowed as limits of size and controllable degrees of freedom were reached. Continuum robots came with the potential to deliver a step change in the next generation of medical devices, by providing better access, safer interactions and making new procedures possible. Over the last few years, several continuum robotic systems have been launched commercially and have been increasingly adopted in hospitals. Despite the clear progress achieved, continuum robots still suffer from design complexity hindering their dexterity and scalability. Recent advances in actuation methods have looked to address this issue, offering alternatives to commonly employed approaches. Additionally, continuum structures introduce significant complexity in modelling, sensing, control and fabrication; topics which are of particular focus in the robotics community. It is, therefore, the aim of the presented work to highlight the pertinent areas of active research and to discuss the challenges to be addressed before the potential of continuum robots as medical devices may be fully realised
Methods and application areas of endoscopic optical coherence tomography
We review the current state of research in endoscopic optical coherence tomography (OCT). We first survey the range of available endoscopic optical imaging techniques. We then discuss the various OCT-based endoscopic methods that have thus far been developed. We compare the different endoscopic OCT methods in terms of their scan performance. Next, we examine the application range of endoscopic OCT methods. In particular, we look at the reported utility of the methods in digestive, intravascular, respiratory, urinary and reproductive systems. We highlight two additional applications—biopsy procedures and neurosurgery—where sufficiently compact OCT-based endoscopes can have significant clinical impacts
Intravascular Ultrasound
Intravascular ultrasound (IVUS) is a cardiovascular imaging technology using a specially designed catheter with a miniaturized ultrasound probe for the assessment of vascular anatomy with detailed visualization of arterial layers. Over the past two decades, this technology has developed into an indispensable tool for research and clinical practice in cardiovascular medicine, offering the opportunity to gather diagnostic information about the process of atherosclerosis in vivo, and to directly observe the effects of various interventions on the plaque and arterial wall. This book aims to give a comprehensive overview of this rapidly evolving technique from basic principles and instrumentation to research and clinical applications with future perspectives
Magnetic navigation in percutaneous coronary and non-coronary interventions
There is no question that Percutaneous Coronary Intervention has revolutionized the way we
manage coronary artery disease. Over the past two decades we have witnessed maturity in
several techniques and equipment enabling the interventional cardiologist to manage lesions
that have previously been entirely in the domain of the cardiac surgeon. Despite these remarkable
achievements there still remain lesions that are complex enough to create a challenge
in the most experienced hands.The inherent tortuosity in complex vascular anatomies,
branching segments and chronically occluded vessel have been all associated with lower
procedural success and higher complication rates when compared to the “straight forward vessels”. The Magnetic Navigation System (MNS) is a novel and versatile technology that allows
the re-orientation of a wire within the patient’s body. This unique ability means that the “trial
and error” method of externally re-shaping the tip of the wire and re-engaging the vessel can
be effectively eliminated. As such previously “unreachable areas” in the heart or within the
vascul
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