Scientific Abstract

Proposal No. IBD-0196R
Principal Investigator:  Caroline Cao, Ph.D.
Applicant Organization:  Tufts University (Medford, Massachusetts, U.S.A.)
Project Title:  Image-guided research in colonoscopy to improve diagnosis of inflammatory bowel disease
Period of Award:  February 1, 2007 – January 31, 2009

Currently, colonoscopy is the most sensitive test for diagnosing IBD and screening for colon cancer.  In colonoscopy, a flexible endoscope is used to examine the inner wall of the entire length of the large intestine.  Even though colon cancer is 90% successfully treated if detected at an early stage, the compliance rate for screening is only 30% in the United States. This resistance to regular colonoscopies is due, in large part, to the fact that the procedure is uncomfortable.  The uncomfortable nature of the procedure is due, in part, to the trial-and-error manipulations of the scope in order to navigate the flexible and elastic colon.  In particular, loops can form in the flexible endoscope anywhere along the length of the scope.  Loops can inflict discomfort on the patient.  Loops can also lead to physician disorientation in the colon, resulting in misdetection of lesions and incorrect localization that can lead to unnecessary patient pain.  In addition, the procedure may be abandoned before its completion due to difficulty in ‘near-blind’ navigation.  The lack of full visual guidance in these procedures is often the bottleneck in the completion of colonoscopy procedures.  Therefore, a robust tracking and guidance system that can provide position and shape information for the colonoscope is needed.

The objective of this proposed research is to study the laboratory feasibility of a new nano-based fiber optic sensor design for tracking the colonoscope.  We aim to develop an affordable and easy to implement flexible sensor that can track its own position and shape.  The tracker can then provide 3D data for the purpose of spatial visualization in real-time.  The rationale for the proposed research is that, once the shape and position of the colonoscope can be tracked, coupled with effective display design, visualization and navigation in colonoscopy can be more effective.  These colonoscopy navigation improvements will lead to improved detection and diagnosis of IBD and potential increase in screening of the at risk population.

Our novel shape tracker would be constructed from a single optical fiber and use fluorescence dye (i.e., quantum dots) emission techniques to determine the radius and direction of bends along the length of the optical fiber. Our design is unique in that a single optical fiber provides all of the information necessary to fully represent its shape. Its small size will enable easy implementation with the current design of colonoscopes. For example, it can be inserted into the biopsy channel of the colonoscope, or embedded in the body of the colonoscope to track the position and shape of the scope in real-time. The position data would then be used to drive a 3D graphical model of the scope in real-time, which would then serve as a navigational aid for the physician during the colonoscopy procedure. For the physician, such a shape sensor device can be coupled with a visual guidance system to reduce disorientation during colonoscopy and improve decision-making and accurate diagnosis.