Introduction
With an estimated 141,210 cases of colorectal cancer (CRC) resulting in approximately 49,380 deaths in 2011, CRC is recognized as the third most common cancer in both men and women in United States. While colonoscopy is the gold standard for CRC screening, compliance is low due to the invasive and sometimes painful nature of the endoscopic procedure. Wireless Capsule Endoscopy (WCE) provides an alternative to conventional endoscopy that enjoys greater patient acceptance. A successful implementation for colon evaluation has been challenging due to numerous factors including related issues and patient related conditions that make the sensitivity and specificity for detection of colon lesions low. One of the major problems of the commercially available capsules conceived to investigate the colon (PillCam Colon, Given Imaging) is the inability to distend the colon lumen. This limitation leads to a low diagnostic yield, due to the elastic and loose nature of a deflated colon. To provide a means of insufflation from a wireless capsule platform, in this work is considered the use biocompatible effervescent reaction to create volume. In the proposed solution, the patient swallows the insufflation capsule, which embodies a triggering mechanism and uses a localization system. When the capsule is in the colon, the insufflation capsule mechanism is triggered to inflate the colon and endoscopist can perform capsule colonoscopy. In this thesis different possibilities are considered, regarding not only the chemicals to be used but also the chemical form
Introduction of the reactants. To evaluate the efficacy of the different combinations, as regarding the behaviour of the reaction and the yield of gas obteined, first benchtop tests were performed. Then, in order to assess the ability of these reactions to generate gas in a condition that simulates the temperature, pressure and volume found in the human colon a secondary bench top test was designed. The study of various possibilities entails the design of different capsules. Prototypes of said capsule were constructed and feasibility of wireless insufflation capsule is demonstrated in an ex-vivo model.
