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

Monolithic self-supportive bi-directional bending pneumatic bellows catheter

The minimally invasive surgery has proven to be advantageous over conventional open surgery in terms of reduction in recovery time, patient trauma, and overall cost of treatment. To perform a minimally invasive procedure, preliminary insertion of a flexible tube or catheter is crucial without sacrificing its ability to manoeuvre. Nevertheless, despite the vast amount of research reported on catheters, the ability to implement active catheters in the minimally invasive application is still limited. To date, active catheters are made of rigid structures constricted to the use of wires or on-board power supplies for actuation, which increases the risk of damaging the internal organs and tissues. To address this issue, an active catheter made of soft, flexible and biocompatible structure, driven via nonelectric stimulus is of utmost importance. This thesis presents the development of a novel monolithic self-supportive bi-directional bending pneumatic bellows catheter using a sacrificial molding technique. As a proof of concept, in order to understand the effects of structural parameters on the bending performance of a bellows-structured actuator, a single channel circular bellows pneumatic actuator was designed. The finite element analysis was performed in order to analyze the unidirectional bending performance, while the most optimal model was fabricated for experimental validation. Moreover, to attain biocompatibility and bidirectional bending, the novel monolithic polydimethylsiloxane (PDMS)-based dual-channel square bellows pneumatic actuator was proposed. The actuator was designed with an overall cross-sectional area of 5 x 5 mm2, while the input sequence and the number of bellows were characterized to identify their effects on the bending performance. A novel sacrificial molding technique was adopted for developing the monolithic-structured actuator, which enabled simple fabrication for complex designs. The experimental validation revealed that the actuator model with a size of5 x 5 x 68.4 mm3 i.e. having the highest number of bellows, attained optimal bi-directional bending with maximum angles of -65° and 75°, and force of 0.166 and 0.221 N under left and right channel actuation, respectively, at 100 kPa pressure. The bending performance characterization and thermal insusceptibility achieved by the developed pneumatic catheter presents a promising implementation of flexibility and thermal stability for various biomedical applications, such as dialysis and cardiac catheterization

Medical Robotics

The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

Endoscopy

Endoscopy is a fast moving field, and new techniques are continuously emerging. In recent decades, endoscopy has evolved and branched out from a diagnostic modality to enhanced video and computer assisting imaging with impressive interventional capabilities. The modern endoscopy has seen advances not only in types of endoscopes available, but also in types of interventions amenable to the endoscopic approach. To date, there are a lot more developments that are being trialed. Modern endoscopic equipment provides physicians with the benefit of many technical advances. Endoscopy is an effective and safe procedure even in special populations including pediatric patients and renal transplant patients. It serves as the tool for diagnosis and therapeutic interventions of many organs including gastrointestinal tract, head and neck, urinary tract and others

Integration of shape memory alloy for microactuation

Shape memory alloy (SMA) actuators in microelectromechanical system (MEMS) have a broad range of applications. The alloy material has unique properties underlying its high working density, simple structures, large displacement and excellent biocompatibility. These features have led to its commercialization in several applications such as micro-robotics and biomedical areas. However, full utilization of SMA is yet to be exploited as it faces various practical issues. In the area of microactuators in particular, fabricated devices suffer from low degrees of freedom (DoF), complex fabrication processes, larger sizes and limited displacement range. This thesis presents novel techniques of developing bulk-micromachined SMA microdevices by applying integration of multiple SMA microactuators, and monolithic methods using standard and unconventional MEMS fabrication processes. The thermomechanical behavior of the developed bimorph SMA microactuator is analyzed by studying the parameters such as thickness of SMA sheet, type and thickness of stress layer and the deposition temperature that affect the displacement. The microactuators are then integrated to form a novel SMA micromanipulator that consists of two links and a gripper at its end to provide three-DoF manipulation of small objects with overall actuation x- and y- axes displacement of 7.1 mm and 5.2 mm, respectively. To simplify the fabrication and improve the structure robustness, a monolithic approach was utilized in the development of a micro-positioning stage using bulk-micromachined SMA sheet that was fabricated in a single machining step. The design consisted of six spring actuators that provided large stage displacement range of 1.2 mm and 1.6 mm in x- and y-axes, respectively, and a rotation of 20° around the z-axis. To embed a self-sensing functionality in SMA microactuators, a novel wireless displacement sensing method based on integration of an SMA spiral-coil actuator in a resonant circuit is developed. These devices have the potential to promote the application of bulk-micromachined SMA actuator in MEMS area

Recent Advances in Forensic Anthropological Methods and Research

Forensic anthropology, while still relatively in its infancy compared to other forensic science disciplines, adopts a wide array of methods from many disciplines for human skeletal identification in medico-legal and humanitarian contexts. The human skeleton is a dynamic tissue that can withstand the ravages of time given the right environment and may be the only remaining evidence left in a forensic case whether a week or decades old. Improved understanding of the intrinsic and extrinsic factors that modulate skeletal tissues allows researchers and practitioners to improve the accuracy and precision of identification methods ranging from establishing a biological profile such as estimating age-at-death, and population affinity, estimating time-since-death, using isotopes for geolocation of unidentified decedents, radiology for personal identification, histology to assess a live birth, to assessing traumatic injuries and so much more

William Hewson (1739-1774) and the Craven Street Anatomy School – Anatomical teaching in the 18th century

In 1998 a small excavation, covering less than a cubic meter, was carried out in the basement of Benjamin Franklin house, 36 Craven Street, London. The finds revealed over 3500 dissected human and animal skeletal remains and a number of artefacts (incl. glass, microscopic slides and tubes, ceramics and metal). The finds were linked to the Craven Street anatomy school (1772-1778), founded by anatomist William Hewson. The tight time frame predating the anatomy act of 1832 and the association with a single well documented figure, allows for an unparalleled insight into the organisation of a private anatomy school through archaeological and historical records. It is a rare opportunity to place archaeological findings within a framework wherein it is possible to distinguish individual motivation and action and how these relate to broader tendencies in society. The recent surge in archaeological excavations of anatomy school has enabled Craven Street to be placed into a wider context comparing private anatomy schools to hospital anatomy schools. Patterns of procurement, use and disposal of human and animal remains shed light on the organisation of the school and its social and economic status in society, allowing reflections on the clandestine body trade and vivisections. The archaeological findings revealed at least 28 human individuals (over half were sub-adults) and a minimum of 43 species of animals; mainly cats, dogs and mallards, but also included exotic species such as green turtle. The human bones were testament to body sharing and surgical practice. Some cut marks suggested an experimental approach to making anatomical preparations and techniques applied to Hewson’s own research. The animals exhibited limited cut marks, and therefore most likely used for vivisections. The burial environment reflected delayed burial procedures, with gnawing marks present on the bones, as well as casual disposal techniques reflecting the removal of the person and objectification of the body at the point of disposal

Childhood Health and Diet in Roman London: The Palaeodemographic, Palaeopathological and Isotopic Evidence

Roman London has been extensively excavated, particularly over the last two decades, and substantial cemetery sites have been uncovered within and around the City. This study represents the first to undertake an integrated analysis of the palaeodemographic, palaeopathological, isotopic and funerary evidence from Roman London. This thesis seeks to identify social age transitions and the impact of these on the growing body. The specific aim of the research was to examine the perceptions of childhood and childcare in Roman London, utilising skeletal and funerary indicators of diet, health and social status. A total sample of 967 individuals formed the sample for analysis. The osteological data was obtained via the WORD database and the funerary data from archives and available publications. A further 120 number of individuals were sampled for carbon and nitrogen isotope analysis of diet. The results yielded a number of interesting patterns regarding age, sex and social status, and the impact of these identities on diet and well-being. Overall, subadults at Roman London were found to have experienced higher rates of health stress than their adult counterparts, with subadults exhibiting higher prevalence rates for four of the six stress indicators examined. Causative stressors identified within the population included poor living conditions and population mobility. Within the subadult age group, differences in the level of health stress were experienced during the life course, with weaning and the introduction of occupationally related activities being pivotal points of increased health stress. An infant feeding pattern specific to Roman Britain and distinctive from Roman Italy was identified and further evidence for a special breastfeeding diet for women implicated. Distinctions in diets between males and females were identified, with females yielding greater variation, potentially linked to social stratification. Shifting dietary isotope signatures and indicators of health stress throughout the growth period were linked to social age transitions. Temporal trends within Roman London were also identified, with health in the early Roman period being worse than the preceding Iron Age period, but declining further during the later period of Roman occupation. In times of economic uncertainty the exploitation of local freshwater fish also occurred, but these supplemented the diet of children alone. No statistically significant difference between diet, health and social status were observed, which suggests that status was not simply a linear, ranked, hierarchy, but cross-cut by other aspects of the social personae such as gender and age. This integrated approach is the first of its kind to be undertaken in order to examine the Roman perceptions of childhood. It makes a number of important contributions regarding the experience of infancy and childhood in Roman Britain and the Roman life course more generally