New Techniques in Gastrointestinal Endoscopy

As result of progress, endoscopy has became more complex, using more sophisticated devices and has claimed a special form. In this moment, the gastroenterologist performing endoscopy has to be an expert in macroscopic view of the lesions in the gut, with good skills for using standard endoscopes, with good experience in ultrasound (for performing endoscopic ultrasound), with pathology experience for confocal examination. It is compulsory to get experience and to have patience and attention for the follow-up of thousands of images transmitted during capsule endoscopy or to have knowledge in physics necessary for autofluorescence imaging endoscopy. Therefore, the idea of an endoscopist has changed. Examinations mentioned need a special formation, a superior level of instruction, accessible to those who have already gained enough experience in basic diagnostic endoscopy. This is the reason for what these new issues of endoscopy are presented in this book of New techniques in Gastrointestinal Endoscopy

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

Magnetically Assisted Capsule Endoscopy: A Viable Alternative to Conventional Flexible Endoscopy of the Stomach?

INTRODUCTION: Oesophagogastroduodenoscopy is the investigation of choice to identify mucosal lesions of the upper gastrointestinal tract, but it is poorly tolerated by patients. A simple non-invasive technique to image the upper gastrointestinal tract, which could be made widely available, would be beneficial to patients. Capsule endoscopy is well tolerated by patients but the stomach has proved difficult to visualise accurately with capsule technology due to its’ capacious nature and mucosal folds, which can obscure pathology. MiroCam Navi (Intromedic Ltd, Seoul, Korea) is a capsule endoscope containing a small amount of magnetic material which has been made available with a handheld magnet which might allow a degree of control. This body of work aims to address whether this new technology could be a feasible alternative to conventional flexible endoscopy of the stomach. METHODS: Four studies were conducted to test this research question. The first explores the feasibility of magnetically assisted capsule endoscopy of the stomach and operator learning curve in an ex vivo porcine model. This was followed by a randomised, blinded trial comparing magnetically assisted capsule endoscopy to conventional flexible endoscopy in ex vivo porcine stomach models. Subsequently a prospective, single centre randomised controlled trial in humans examined whether magnetically assisted capsule endoscopy could enhance conventional small bowel capsule endoscopy by reducing gastric transit time. Finally a blinded comparison of diagnostic yield of magnetically assisted capsule endoscopy compared to oesophagogastroduodenoscopy was performed in patients with recurrent or refractory iron deficiency anaemia. RESULTS: In the first study all stomach tags were identified in 87.2% of examinations and a learning curve was demonstrated (mean examination times for the first 23 and second 23 procedures 10.28 and 6.26 minutes respectively (p<0.001). In the second study the difference in sensitivities between oesophagogastroduodenoscopy and conventional flexible endoscopy for detecting beads within an ex vivo porcine stomach model was 1.11 (95% CI 0.06, 28.26) proving magnetically assisted capsule endoscopy to be non-inferior to flexible endoscopy. In the first human study, although there was no significant difference in gastric transit time or capsule endoscopy completion rate between the two groups (p=0.12 and p=0.39 respectively), the time to first pyloric image was significantly shorter in the intervention group (p=0.03) suggesting that magnetic control hastens capsular transit to the gastric antrum but cannot impact upon duodenal passage. In the last study, a total of 38 pathological findings were identified in this comparative study of magnetically assisted capsule endoscopy and conventional endoscopy. Of these, 16 were detected at both procedures, while flexible endoscopy identified 14 additional lesions not seen at magnetically assisted capsule endoscopy and magnetically assisted capsule endoscopy detected 8 abnormalities not seen by oesophagogastroduodenoscopy. No adverse events occurred in either of the human trials. Finally magnetically steerable capsule endoscopy induced less procedural pain, discomfort and distress than oesophagogastroduodenoscopy (p=0.0009, p=0.001 and p=0.006 respectively). CONCLUSION: Magnetically assisted capsule endoscopy is safe, well tolerated and a viable alternative to conventional endoscopy. Further research to develop and improve this new procedure is recommended

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

ADVANCING CAPSULE ENDOSCOPY IN THE EXAMINATION OF THE UPPER GASTROINTESTINAL TRACT

Advancements in capsule endoscopy technology allow it to image the upper gastrointestinal tract. Oesophagogastroduodenoscopy (OGD) is the gold standard examination, but it is often poorly tolerated and requires sedative premedication. This thesis examines how capsule endoscopy can improve the quality of an upper GI endoscopic examination. The first study examines the rate of, and factors affecting missed cancer occurrence after conventional OGD. In this retrospective study, a total of 48 (7.7%) of 627 patients with oesophagogastric cancer had OGDs up to three years prior, which are considered missed opportunities to diagnose early neoplasia. Endoscopy sessions with missed cancer occurrence had at least one procedure more when compared to sessions where cancer was subsequently diagnosed or sessions where benign focal lesions were diagnosed. In the next two studies, we examine the patients experience in a comparative study of tolerance and acceptability between magnet controlled capsule endoscopy (MACE) and conventional OGD (n=44) and transnasal endoscopy (TNE; n=16). By comparison to OGD in Chapter 4 and TNE in Chapter 5, patients were more accepting of and preferred MACE. Patients experienced significantly more distress (greater distress with higher median score) due to gagging (6 vs 1), choking (5 vs 1), abdominal bloating (2 vs 1), instrumentation (4 vs 1), discomfort during (5 vs 1) and after (2 vs 1) OGD when compared to MACE (all p<0.0001). Patients undergoing TNE were more distressed by gagging (1.5 vs 1, p=0.03), choking (3 vs 1, p=0.001), instrumentation (4.5 vs 1, p=0.001), discomfort during (5 vs 1, p=0.001) and after TNE (2 vs 1, p=0.01) by comparison to MACE. A small bowel examination can be performed immediately after an upper GI MACE. It is hypothesised that laxative pre-procedure preparation may benefit small bowel mucosal visualisation, although likely to impact on tolerability and acceptance. The fourth study examines how to optimise an upper GI MACE examination to investigate iii the small bowel. In advance of a small bowel capsule endoscopy, 186 patients were randomised to three pre-procedure preparation groups: clear fluids only or a single or split dose of polyethylene glycol (PEG) the examine the need for laxative pre-procedure medication. Split dose PEG improved distal small bowel mucosal views and overall adequacy of examination compared to clear fluids alone, although patients tolerated better and were more accepting of the later. Acceptance of novel technology may be prohibited by cost. In the final study, we perform a cost minimisation analysis to examine how the cost of MACE compares to TNE and OGD, and examine in scenario analyses the potential effects of the COVID-19 pandemic and need for endoscopic biopsies on cost. We found that per procedure, MACE was most expensive, followed by OGD and TNE. As a result of the COVID-19 pandemic, the costs of OGD and TNE would rise by between 27% to 112% depending on changes in endoscopy capacity. In scenario analyses, cost parity between MACE and OGD could be reached if the price of single use capsule endoscopes fell by two thirds. If endoscopy capacity fell to 40%, cost parity could be reached if the price of capsule endoscopes fell by a third. This thesis supports the use of MACE in the upper GI tract from the perspective of a superior patient experience compared to conventional OGD. Further improvements in imaging technology and reduction in cost of MACE will advance capsule endoscopy in the examination of the upper GI tract

Miniaturisation and testing of an optical interference block for fluorescence imaging in capsule endoscopy

Early detection of gastrointestinal cancer is crucial to increase the life span of patients. The implementation of new imaging modalities, such as fluorescence imaging, in traditional endoscopy is the key in the detection of early signs of cancer. Fluorescence imaging techniques for clinical applications can be divided in two groups defined as autofluorescence imaging and fluorescence-labelling imaging. The former exploits the natural green fluorescence emitted by human tissues when excited by blue or ultra-violet light. Detection of cancer through autofluorescence imaging relies on the fact that cancer tissues have a much lower autofluorescence signal than healthy tissues. On the other hand, fluorescence-labelling imaging is used when the difference in autofluorescence between cancer and healthy surroundings is too weak to detect. Therefore, external fluorescence agents are used to target and label cancer lesions. Although traditional endoscopy has been successfully equipped with fluorescence imaging capabilities, the discomfort caused in patients and the incapability to reach the small intestine represent two main limitations. Fluorescence capsule endoscopy can enhance diagnostic accuracy with less inconvenience for patients. The optical components in traditional endoscopes are bulky and implemented outside the body of the patients. Therefore, there is a demand to develop highly miniaturised optical components for integration in capsule endoscopy. This thesis describes the design, fabrication, characterisation, and testing of a 5 mm x 6 mm x 6 mm optical interference block with the capability of fluorescence imaging in capsule endoscopy. The block accommodates ultrathin filters for optical isolation and was successfully integrated with a sensitive 64 x 64 pixels complementary metal oxide semiconductor single photon avalanche diode array to detect green fluorescence from Flavin Adenine Dinucleotide. This coenzyme is among the fluorophores responsible for autofluorescence in human tissues. The fluorescence-labelling capabilities of the imaging system were also tested to detect fluorescence from the cancer selective molecular probe ProteoGREEN-gGluTM which was used to label colorectal cancer cells. In vitro studies were also validated using a commercial ModulusTM Microplate reader. The potential use of the miniaturised block in capsule endoscopy was further demonstrated by imaging healthy and malignant resected human tissues from the colon to detect changes in autofluorescence signal that are crucial for cancer diagnosis. The results obtained demonstrated that the system successfully imaged the differences in the autofluorescence signal from resected healthy and malignant human tissues from the colon. Moreover, results from the in vitro tests showed that the system detected changes in the fluorescence signal induced in colorectal cancer cells after labelling with ProteoGREEN-gGluTM

Wireless capsule endoscope for targeted drug delivery

The diagnosis and treatment of pathologies of the gastrointestinal (GI) tract are performed routinely by gastroenterologists using endoscopes and colonoscopes, however the small intestinal tract is beyond the reach of these conventional systems. Attempts have been made to access the small intestines with wireless capsule endoscopes (WCE). These pill-sized cameras take pictures of the intestinal wall and then relay them back for evaluation. This practice enables the detection and diagnosis of pathologies of the GI tract such as Crohn's disease, small intestinal tumours such as lymphoma and small intestinal cancer. The problems with these systems are that they have limited diagnostic capabilities and they do not offer the ability to perform therapy to the affected areas leaving only the options of administering large quantities of drugs or surgical intervention. To address the issue of administering therapy in the small intestinal tract this thesis presents an active swallowable microrobotic platform which has novel functionality enabling the microrobot to treat pathologies through a targeted drug delivery system. This thesis first reviews the state-of-the-art in WCE through the evaluation of current and past literature. A review of current practises such as flexible sigmoidoscopy, virtual colonoscopy and wireless capsule endoscopy are presented. The following sections review the state-of-the-art in methods of resisting peristalsis, drug targeting systems and drug delivery. A review of actuators is presented, in the context of WCE, with a view to evaluate their acceptability in adding functionality to current WCEs. The thesis presents a novel biologically-inspired holding mechanism which overcomes the issue of resisting natural peristalsis in the GI tract. An analysis of the two components of peristaltic force, circumferential and longitudinal peristaltic contractions, are presented to ensure correct functionality of the holding mechanism. A detailed analysis of the motorised method employed to deploy the expanding mechanism is described and a 5:1 scale prototype is presented which characterises the gearbox and validates the holding mechanism. The functionality of WCE is further extended by the inclusion of a novel targeting mechanism capable of delivering a metered dose of medication to a target site of interest in the GI tract. A solution to the problem of positioning a needle within a 360 degree envelope, operating the needle and safely retracting the needle in the GI tract is discussed. A comprehensive analysis of the mechanism to manoeuvre the needle is presented and validation of the mechanism is demonstrated through the evaluation of scale prototypes. Finally a drug delivery system is presented which can expel a 1 ml dose of medication, stored onboard the capsule, into the subcutaneous tissue of the GI tract wall. An analysis of the force required to expel the medication in a set period of time is presented and the design and analysis of a variable pitch conical compression spring which will be used to deliver the medication is discussed. A thermo mechanical trigger mechanism is presented which will be employed to release the compressed conical spring. Experimental results using 1:1 scale prototype parts validate the performance of the mechanisms.Open Acces

Modern Telemetry

Telemetry is based on knowledge of various disciplines like Electronics, Measurement, Control and Communication along with their combination. This fact leads to a need of studying and understanding of these principles before the usage of Telemetry on selected problem solving. Spending time is however many times returned in form of obtained data or knowledge which telemetry system can provide. Usage of telemetry can be found in many areas from military through biomedical to real medical applications. Modern way to create a wireless sensors remotely connected to central system with artificial intelligence provide many new, sometimes unusual ways to get a knowledge about remote objects behaviour. This book is intended to present some new up to date accesses to telemetry problems solving by use of new sensors conceptions, new wireless transfer or communication techniques, data collection or processing techniques as well as several real use case scenarios describing model examples. Most of book chapters deals with many real cases of telemetry issues which can be used as a cookbooks for your own telemetry related problems