Cable-driven parallel mechanisms for minimally invasive robotic surgery

Minimally invasive surgery (MIS) has revolutionised surgery by providing faster recovery times, less post-operative complications, improved cosmesis and reduced pain for the patient. Surgical robotics are used to further decrease the invasiveness of procedures, by using yet smaller and fewer incisions or using natural orifices as entry point. However, many robotic systems still suffer from technical challenges such as sufficient instrument dexterity and payloads, leading to limited adoption in clinical practice. Cable-driven parallel mechanisms (CDPMs) have unique properties, which can be used to overcome existing challenges in surgical robotics. These beneficial properties include high end-effector payloads, efficient force transmission and a large configurable instrument workspace. However, the use of CDPMs in MIS is largely unexplored. This research presents the first structured exploration of CDPMs for MIS and demonstrates the potential of this type of mechanism through the development of multiple prototypes: the ESD CYCLOPS, CDAQS, SIMPLE, neuroCYCLOPS and microCYCLOPS. One key challenge for MIS is the access method used to introduce CDPMs into the body. Three different access methods are presented by the prototypes. By focusing on the minimally invasive access method in which CDPMs are introduced into the body, the thesis provides a framework, which can be used by researchers, engineers and clinicians to identify future opportunities of CDPMs in MIS. Additionally, through user studies and pre-clinical studies, these prototypes demonstrate that this type of mechanism has several key advantages for surgical applications in which haptic feedback, safe automation or a high payload are required. These advantages, combined with the different access methods, demonstrate that CDPMs can have a key role in the advancement of MIS technology.Open Acces

The KiHM-9: A Novel Self-Deploying PicoSat Antenna Design for Reflectarray Antennas

Reflectarray antennas are popular on satellites for their ability to achieve similar performance to parabolic antennas in a more compact volume. This project shows how integrating novel technologies achieves the benefits of larger antennas while maintaining the advantages of small satellites. The objective of this research is to create a reflectarray antenna for a holographic metasurface that utilizes the volume surrounding a CubeSat when stowed, incorporates a novel pin-less hinge, includes a self-deploying and stabilizing joint, and is manufactured out of space-grade materials. By using hinges embedded with membranes and magnets, issues with lubrication and outgassing may be avoided, and the same motion and stability of pin-joints may be maintained with no external structure required. These technologies also result in a self-deploying and self-stabilizing design. The Radii Controlled Embedded Lamina (RadiCEL) hinge design was incorporated into the final model and allows the geometry of the hinge joint to be specifically tuned to control the stress in the hinge membrane while minimizing required hinge volume. Metal meshes were used as membrane joints, increasing the durability and robustness of the hinge. Feasibility of the RadiCEL joint is shown through fatigue testing of various materials at a range of hinge radii. The testing shows the viability of metal meshes, as well as other common membranes. Magnets were used in a MaLO configuration, which allowed for a smaller footprint in the antenna and required no external actuation or power source to deploy and stabilize the antenna. Various prototypes of the system were manufactured and are presented. Modeling and testing efforts presented create various opportunities to build on current research to improve mission capability by increasing antenna gain while eliminating peripherals required for antenna deployment

Intrinsic Force Sensing for Motion Estimation in a Parallel, Fluidic Soft Robot for Endoluminal Interventions

Determining the externally-induced motion of a soft robot in minimally-invasive procedures is highly challenging and commonly demands specific tools and dedicated sensors. Intrinsic force sensing paired with a model describing the robot's compliance offers an alternative pathway which relies heavily on knowledge of the characteristic mechanical behaviour of the investigated system. In this work, we apply quasi-static intrinsic force sensing to a miniature, parallel soft robot designed for endoluminal ear interventions. We characterize the soft robot's nonlinear mechanical behaviour and devise methods for inferring forces applied to the actuators of the robot from fluid pressure and volume information of the working fluid. We demonstrate that it is possible to detect the presence of an external contact acting on the soft robot's actuators, infer the applied reaction force with an accuracy of 28.1 mN and extrapolate from individual actuator force sensing to determining forces acting on the combined parallel soft robot when it is deployed in a lumen, which can be achieved with an accuracy of 75.45 mN for external forces and 0.47 Nmm for external torques. The intrinsically-sensed external forces can be employed to estimate the induced motion of the soft robot in response to these forces with an accuracy of 0.11 mm in translation and 2.47 in rotational deflection. The derived methodologies could enable designs for more perceptive endoscopic systems and pave the way for developing sensing and control strategies in endoluminal and transluminal soft robots

Frontiers of robotic endoscopic capsules: a review

Digestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd., is an example of disruptive technology and represents an attractive alternative to traditional diagnostic techniques. WCE overcomes conventional endoscopy enabling inspection of the digestive system without discomfort or the need for sedation. Thus, it has the advantage of encouraging patients to undergo gastrointestinal (GI) tract examinations and of facilitating mass screening programmes. With the integration of further capabilities based on microrobotics, e.g. active locomotion and embedded therapeutic modules, WCE could become the key-technology for GI diagnosis and treatment. This review presents a research update on WCE and describes the state-of-the-art of current endoscopic devices with a focus on research-oriented robotic capsule endoscopes enabled by microsystem technologies. The article also presents a visionary perspective on WCE potential for screening, diagnostic and therapeutic endoscopic procedures

Snake-Like Robots for Minimally Invasive, Single Port, and Intraluminal Surgeries

The surgical paradigm of Minimally Invasive Surgery (MIS) has been a key driver to the adoption of robotic surgical assistance. Progress in the last three decades has led to a gradual transition from manual laparoscopic surgery with rigid instruments to robot-assisted surgery. In the last decade, the increasing demand for new surgical paradigms to enable access into the anatomy without skin incision (intraluminal surgery) or with a single skin incision (Single Port Access surgery - SPA) has led researchers to investigate snake-like flexible surgical devices. In this chapter, we first present an overview of the background, motivation, and taxonomy of MIS and its newer derivatives. Challenges of MIS and its newer derivatives (SPA and intraluminal surgery) are outlined along with the architectures of new snake-like robots meeting these challenges. We also examine the commercial and research surgical platforms developed over the years, to address the specific functional requirements and constraints imposed by operations in confined spaces. The chapter concludes with an evaluation of open problems in surgical robotics for intraluminal and SPA, and a look at future trends in surgical robot design that could potentially address these unmet needs.Comment: 41 pages, 18 figures. Preprint of article published in the Encyclopedia of Medical Robotics 2018, World Scientific Publishing Company www.worldscientific.com/doi/abs/10.1142/9789813232266_000

From Concept to Market: Surgical Robot Development

Surgical robotics and supporting technologies have really become a prime example of modern applied information technology infiltrating our everyday lives. The development of these systems spans across four decades, and only the last few years brought the market value and saw the rising customer base imagined already by the early developers. This chapter guides through the historical development of the most important systems, and provide references and lessons learnt for current engineers facing similar challenges. A special emphasis is put on system validation, assessment and clearance, as the most commonly cited barrier hindering the wider deployment of a system

Actuation Fatigue Characterization Methods and Lifetime Predictions of Shape Memory Alloy Actuators

Shape Memory Alloys (SMAs) are a class of intermetallic alloys that possess the ability to repeatedly sustain large amounts of deformation and recover a designed geometry through a thermal-induced, diffusionless, solid-to-solid phase transformation. Due to their high actuation energy density and ability to recover large strains, SMAs have many promising engineering applications in the aerospace, automotive, biomedical, and energy industries. In recent years, the interest in high temperature SMAs (HTSMAs) has increased dramatically due to their potential applications in harsh environments, such as those commonly seen in the aerospace industry. However, the lack of standard testing methods which accurately characterize and model thermomechanical fatigue in SMA actuators frequently limits their use to non-structural/non-critical components or results in actuators being severely overdesigned. While many actuation fatigue studies have been completed over the last three decades, the vast majority have only considered isobaric loading paths with full or partial degrees of transformation. However, many potential applications, such as morphing aerostructures or deployable space structures, require more complex thermomechanical loading paths. In order for SMAs to be used in such applications, existing testing standards and actuation fatigue lifetime prediction methods must be improved. The four objectives of this study are: First, the fatigue behavior of equiatomic NiTi is investigated in order to develop methods for studying actuation fatigue and provide a baseline actuation fatigue response for constant force biasing loads. Second, the actuation fatigue behavior of equiatomic Nickel-Titanium and the HTSMA Ni50.3Ti29.7Hf20 is studied to create a fatigue database for the purpose of actuator design. Third, improved testing and data collection methods and processes are developed for characterizing the actuation fatigue response of SMAs for complex thermomechanical loading paths. Fourth, the axial actuation fatigue data collected and the provided torsional fatigue data are utilized to analyze and evaluate the capabilities of the previously proposed actuation fatigue lifetime predictions. These actuation fatigue lifetime prediction methods are modified, as needed, to account for minor loops and variable loading conditions. This research will enhance future testing methods and understanding of actuation fatigue and improve the design of SMA-based solid state actuator systems