Development of a Low Pressure Pouch Sensor for Force Measurement in Colonoscopy Procedures

This paper presents a novel pneumatic pouch sensor, designed to mount on a colonoscope, that can effectively estimate the contact forces with the environment. The pouch sensor was designed to maximize the sensing range, and it was fabricated using a 2D laser welding technique from our track record. A flow compensation (FC) algorithm was introduced to improve the accuracy of the sensor in the presence of static load. The proposed system can reliably measure external forces up to 9.5 N with high repeatability. The system allows discriminating between different levels of force which are typically associated with increasing patient discomfort in colonoscopy: low (0-4 N), medium (4-6 N), and high (>6 N). This system achieves over 80% accuracy in comparison to the ground truth under steady state conditions (P ≤0.05) and maintains over 68% accuracy in dynamic scenarios.