Abstract
Capsule endoscopy is a noninvasive method for examining the gastrointestinal (GI) tract and has been very successful in small intestine studies. Recent attempts have been made to utilize this procedure in effective colon screening. However, in the wider colonic lumen the small capsule tumbles, resulting in missed regions and the transmission of images with little clinical utility. In addition, the capsule does not have the capability to insufflate the lumen to provide a more complete visualization of collapsed colonic segments. These limitations in the current application of capsule endoscopy outline the need for a novel method that allows for effective capsule–based imaging of the colon.
A self–stabilizing capsule endoscope (SCE) is a unique method that eliminates capsule tumbling in the colon, hence allowing systematic visualization. In this research, a prototype of an SCE enclosed in a colon targeting shell was proposed and tested. The SCE design consists of an inner capsule endoscope (CE) that has an expandable component attached to its trailing end. Upon arrival at the colon, the outer shell dissolves, activating the inner capsule and the expandable component which then grows to stabilize the implement. The SCE travels through the colon by peristalsis, capturing intraluminal images and transmitting them in real time to an external receiver, and is then excreted from the body. As a safety measure, the expandable component can be remotely separated from the capsule. Feasibility of the SCE has been demonstrated in laboratory and acute canine experiments. The self–stabilization technology vastly improves the image quality over commercial, non–stabilized CEs in the colon. In addition, SCE delivers a significant improvement in detection rates of simulated colonic lesions when compared to standard CEs. The SCE is an important contribution to the development of a reliable colon CE.
Additionally, a novel biopsy module for the CE was proposed and tested. This module collects samples of tissue and luminal juices anywhere along the GI tract. It is a remotely operated device capable of taking a sample from any point around the 360˚ circumference of the capsule. The functionality and feasibility of the biopsy module for CE was verified in a silicon stomach model.
