Augmented Reality in Minimally Invasive Surgery

In the last 15 years Minimally Invasive Surgery, with techniques such as laparoscopy or endoscopy, has become very important and research in this field is increasing since these techniques provide the surgeons with less invasive means of reaching the patient’s internal anatomy and allow for entire procedures to be performed with only minimal trauma to the patient. The advantages of the use of this surgical method are evident for patients because the possible trauma is reduced, postoperative recovery is generally faster and there is less scarring. Despite the improvement in outcomes, indirect access to the operation area causes restricted vision, difficulty in hand-eye coordination, limited mobility handling instruments, two-dimensional imagery with a lack of detailed information and a limited visual field during the whole operation. The use of the emerging Augmented Reality technology shows the way forward by bringing the advantages of direct visualization (which you have in open surgery) back to minimally invasive surgery and increasing the physician's view of his surroundings with information gathered from patient medical images. Augmented Reality can avoid some drawbacks of Minimally Invasive Surgery and can provide opportunities for new medical treatments. After two decades of research into medical Augmented Reality, this technology is now advanced enough to meet the basic requirements for a large number of medical applications and it is feasible that medical AR applications will be accepted by physicians in order to evaluate their use and integration into the clinical workflow. Before seeing the systematic use of these technologies as support for minimally invasive surgery some improvements are still necessary in order to fully satisfy the requirements of operating physicians

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

A comprehensive evaluation of work and simulation based assessment in otolaryngology training

Introduction: The otolaryngology curriculum requires trainees to show evidence of operative competence before completion of training. The General Medical Council recommended that structured assessment be used throughout training to monitor and guide trainee progression. Despite the reduction in operative exposure and the variation in trainee performance, a ‘one size fits all’ approach continues to be applied. The number of procedures performed remains the main indicator of competence. Objectives: To analyse the utilisation, reliability and validity of workplace-based assessments in otolaryngology training. To identify, develop and validate a series of simulation platforms suitable for incorporation into the otolaryngology curriculum. To develop a model of interchangeable workplace- and simulation-based assessment that reflects trainee’s trajectory, audit the delivery of training and set milestones for modular learning. Methods: A detailed review of the literature identified a list of procedure-specific assessment tools as well as simulators suitable to be used as assessment platforms. A simulation-integrated training programme was piloted and models were tested for feasibility, face, content and construct validity before being incorporated into the North London training programme. The outcomes of workplace- and simulation-based assessments of all core and specialty otolaryngology trainees were collated and analysed. Results: The outcomes of 6535 workplace-based assessments were analysed. The strengths and weaknesses of 4 different assessment tools are highlighted. Validated platforms utilising cadavers, animal tissue, synthetic material and virtual reality simulators were incorporated into the curriculum. 60 trainees and 40 consultants participated in the process and found it of great educational value. Conclusion: Assessment with structured feedback is integral to surgical training. Assessment using validated simulation modules can complement that undertaken in the workplace. The outcomes of structures assessments can be used to monitor and guide trainee trajectory at individual and regional level. The derived learning curves can shape and audit future otolaryngological training.Open Acces

Patterns of injury and violence in Yaoundé Cameroon: an analysis of hospital data.

BackgroundInjuries are quickly becoming a leading cause of death globally, disproportionately affecting sub-Saharan Africa, where reports on the epidemiology of injuries are extremely limited. Reports on the patterns and frequency of injuries are available from Cameroon are also scarce. This study explores the patterns of trauma seen at the emergency ward of the busiest trauma center in Cameroon's capital city.Materials and methodsAdministrative records from January 1, 2007, through December 31, 2007, were retrospectively reviewed; information on age, gender, mechanism of injury, and outcome was abstracted for all trauma patients presenting to the emergency ward. Univariate analysis was performed to assess patterns of injuries in terms of mechanism, date, age, and gender. Bivariate analysis was used to explore potential relationships between demographic variables and mechanism of injury.ResultsA total of 6,234 injured people were seen at the Central Hospital of Yaoundé's emergency ward during the year 2007. Males comprised 71% of those injured, and the mean age of injured patients was 29 years (SD = 14.9). Nearly 60% of the injuries were due to road traffic accidents, 46% of which involved a pedestrian. Intentional injuries were the second most common mechanism of injury (22.5%), 55% of which involved unarmed assault. Patients injured in falls were more likely to be admitted to the hospital (p < 0.001), whereas patients suffering intentional injuries and bites were less likely to be hospitalized (p < 0.001). Males were significantly more likely to be admitted than females (p < 0.001)DiscussionPatterns in terms of age, gender, and mechanism of injury are similar to reports from other countries from the same geographic region, but the magnitude of cases reported is high for a single institution in an African city the size of Yaoundé. As the burden of disease is predicted to increase dramatically in sub-Saharan Africa, immediate efforts in prevention and treatment in Cameroon are strongly warranted

The Pedagogy Of The Operating Theatre

This thesis outlines the findings of a large body of research work undertaken during 3 years of full-time study. The findings have already provided the author with helpful anchors for structuring formative feedback to surgical trainees within a simulation program, as well as helpful insights into her own learning. This thesis explores the operating theatre as a teaching and learning environment for postgraduate surgical trainees. The work crosses paradigms and uses contrasting methodologies to provide rich insights into surgical pedagogic practice. The first chapter is an introduction to the subject material, outlining the thesis aims and research questions, making clear why the research is important. The perspectives of the researcher are explained, in the first person, to make explicit her background and epistemological stance. The next chapter presents a narrative review of the literature, providing a background to the subject and a theoretical framework. Chapters three to six constitute empirical work. The third and fourth chapters use a grounded theory method to explore surgeons’ perceptions of the content and process of learning in the operating theatre. Chapter five uses case study methodology to illustrate teaching and learning in the operating theatre with concrete examples of pedagogic practice. The sixth chapter is a quasi-experimental study of learning which makes comparison between different pedagogic styles. The final chapter of the thesis draws together the findings from the empirical investigations. The personal development of the researcher is discussed in the first person and the body of research work is critically examined in view of its contribution to the field and its implications for future educational innovation.Open Acces

OPTICAL NAVIGATION TECHNIQUES FOR MINIMALLY INVASIVE ROBOTIC SURGERIES

Minimally invasive surgery (MIS) involves small incisions in a patient's body, leading to reduced medical risk and shorter hospital stays compared to open surgeries. For these reasons, MIS has experienced increased demand across different types of surgery. MIS sometimes utilizes robotic instruments to complement human surgical manipulation to achieve higher precision than can be obtained with traditional surgeries. Modern surgical robots perform within a master-slave paradigm, in which a robotic slave replicates the control gestures emanating from a master tool manipulated by a human surgeon. Presently, certain human errors due to hand tremors or unintended acts are moderately compensated at the tool manipulation console. However, errors due to robotic vision and display to the surgeon are not equivalently addressed. Current vision capabilities within the master-slave robotic paradigm are supported by perceptual vision through a limited binocular view, which considerably impacts the hand-eye coordination of the surgeon and provides no quantitative geometric localization for robot targeting. These limitations lead to unexpected surgical outcomes, and longer operating times compared to open surgery. To improve vision capabilities within an endoscopic setting, we designed and built several image guided robotic systems, which obtained sub-millimeter accuracy. With this improved accuracy, we developed a corresponding surgical planning method for robotic automation. As a demonstration, we prototyped an autonomous electro-surgical robot that employed quantitative 3D structural reconstruction with near infrared registering and tissue classification methods to localize optimal targeting and suturing points for minimally invasive surgery. Results from validation of the cooperative control and registration between the vision system in a series of in vivo and in vitro experiments are presented and the potential enhancement to autonomous robotic minimally invasive surgery by utilizing our technique will be discussed

Next generation of atraumatic laparoscopic instruments through analysis of the instrument-tissue interface

Mechanically induced (or iatrogenic) bowel injury from the use of laparoscopic instruments can result in devastating effects on patient outcomes both during and after surgery. The aim of this work was to investigate exactly how colonic tissue behaves both mechanically and structurally when it is subjected to a mechanical load. Analysis of force application in laparoscopic surgery is critical to understanding the nature of the instrument-tissue interaction. The development of a novel method of both histological analysis and mechanical analysis (by which the tool-tissue interaction can be characterised) has evolved through this thesis. Mechanical and histological analysis was undertaken to quantify the instrument-tissue interaction in laparoscopic surgery. This was done in both ex vivo and in vivo experiments, using an indentation method and laparoscopic instrument respectively, in porcine tissue. Mechanical stress was applied to the colon by indentation applied using the Modular Universal Surface Tester (MUST) (FalexTM Tribology USA) in ex vivo experiments to mechanically characterise the response of tissue to mechanical loading. Histological analysis was performed to examine the architecture of the tissue after loading. In vivo analysis of colon grasping was then performed to characterise grasper damage both mechanically and histologically. A mechanical measure of energy input into the tissue has been linked to consistent histological damage, above a 50 N grasping force and a loading input of 300 N.s This work has successfully identified specific loading conditions that result in tissue injury and is the first to make a link between the mechanical analyses of tissue manipulation with change to the architecture of the tissue

Application of intraoperative quality assurance to laparoscopic total mesorectal excision surgery

Introduction: The role of laparoscopy in the surgical management of rectal cancer is debated. Randomised trials have reported contrasting results with inadequate specimens obtained in a minority of patients. The reasons behind these findings are unclear. Complex surgical interventions and human performance are prone to variation, which may account for outcome differences, but neither are robustly measured. Application of quality assurance (QA) to the intraoperative period could explore surgical performance and any relationship with subsequent outcomes. The overarching aim of this thesis is the promotion of oncological and patient safety through application of QA to laparoscopic TME surgery. Methods: Evidence synthesis of QA tools was obtained through a systematic review to identify reported objective laparoscopic total mesorectal excision (TME) assessment tools. Development of novel QA tools for laparoscopic TME was performed and applied and validated using case video from two multicentre randomised trials with reliability and validity of the laparoscopic TME performance tool (L-TMEpt) assessed. A multicentre randomised trial comparing 3D vs. 2D laparoscopic TME was performed incorporating objective performance analyses. Scores divided surgeons into quartiles and compared with histopathological and clinical endpoints. A novel intraoperative adverse event classification was developed and piloted. Results: 176 cases from 48 credentialed surgeons were analysed. L-TMEpt inter-rater, test-retest and internal consistency reliabilities were established. Substantial variation in surgical performance were seen. Scores were strongly associated with the number of intraoperative errors, plane of mesorectal dissection and short-term patient morbidity. Upper quartile surgeons obtained excellent results compared with the lower quartile (mesorectal fascia 93% vs. 59%, NNT 2.9, p=0.002; 30-day morbidity 23% vs. 48%, NNT 4, p=0.043). Conclusions: Intraoperative QA using assessment tools can objectively and reliably measure complex cancer interventions. Laparoscopic TME surgical performance assessment showed substantial variation which is strongly associated with clinical outcomes holding implications for surgical trial design and interpretation.Open Acces

Doppler SD-OCT Blood Flow Analysis and Extraneous Operator Influences

Purpose: The RTVue-100 is a new instrument for measuring retinal blood flow (RBF), but image quality needs to be optimized in order for valid blood flow results. The primary aim of this thesis was to assess the presence of learning effects with novice and experienced operators. Methods: Twelve upper-year optometric students from the University of Waterloo, School of Optometry and Vision Science, were trained in operating RTVue-100. Nine healthy participants, with a mean age (± SD) of 25.7 ± 3.8 years, underwent OCT imaging. Using the Doppler OCT of Retinal Circulation (DOCTORC) software, images were assessed by computer for various image quality parameters. Results: Paired samples t-tests showed significant statistical differences between the novice and experienced operators for the following image acquisition parameters: total acquisition time (TAT), number of attempts to complete total scan protocol, and number of valid images. Mean values for TAT and the number of attempts decreased, whereas the mean number of valid images increased from novice to experienced level. Conclusions: The results confirm that there are learning effects observed within the image acquisition process using the RTVue-100 SD-OCT