Assisted Endoscopy – A Tactile Pressure-Sensing Array for Use During Colonoscopy

Abstract

Gastrointestinal perforations are a potentially deadly risk associated with colonoscopy procedures and occur in about 0.1% of the 14.2 million colonoscopies performed each year in the United States. The majority of these perforations occur from excessive pressure on the bowel wall from the insertion tube of the colonoscope. A distributed pressure-sensing array can provide the physician with extremely useful data to aid in safe navigation of the intestines for the duration of the procedure. The scope of this project is to develop a pressure-sensing array that is suitable in a medical environment, specifically for use during upper and lower endoscopy procedures. The project utilizes a unique approach to pressure sensing using optical fibers. Optical fiber pressure sensors are advantageous for medical settings because they are immune to electromagnetic interference as well as axial forces induced by bends along the intestinal tract. They are also extremely small and suitable for harsh environments. Extensive research and design work was performed to develop the sensor geometry, node density, range and sensitivity. The resulting prototype measures pressure around the critical range for perforation, with a sensing node density that is suitable for the intestinal tract. Currently research is being performed to improve sensing accuracy, and decrease thickness of the sensor. Ultimately, the sensor will be built in a manner that is suitable for human use and it will be connected to a microcontroller and audio/visual display to alert the physician when perforation is imminent.