Design and development of endoluminal catheters for advanced diagnosis

Esophageal manometry is a widely used diagnostic technique for real-time measurement of pressure within the esophagus, typically employing sensor-equipped flexible catheters. These devices are crucial in assessing esophageal muscular contractions and peristaltic wave patterns, providing valuable insights into gastrointestinal health. However, despite their clinical utility, existing catheters face several significant limitations. A major issue is their fragility; the sensors are prone to damage, requiring data interpolation and reducing spatial resolution until costly repairs are made. Additionally, these catheters exhibit limited bending capability, being unidirectional while the esophagus itself has complex multi-planar curvature, which often leads to patient discomfort during insertion. The lack of endoscopic guidance can result in insertion failures, particularly in patients with esophageal diverticula, which are abnormal pouches that can trap the catheter. Furthermore, the need for frequent sterilization between uses generates high operational costs, as the devices are marketed as reusable. In response to these challenges, this thesis presents the design and development of an innovative, capacitive-based multi-sensor device for pressure detection within the esophageal lumen, with particular emphasis on diagnosing esophageal motility disorders. The thesis details the physical principles behind the capacitive sensors, the fabrication of custom-built sensing units, and the integration of these sensors into a scalable array. A key innovation is the device's enhanced anatomical compliance, which allows for improved fit and comfort during use, addressing the issue of unidirectional bending. Additionally, the design includes a novel endoscopic-guided placement feature, which mitigates insertion failures. The resulting device achieves an impressive accuracy of over 2% across the entire clinical pressure range. Overall, the work offers a significant advancement in both the functionality and usability of esophageal manometry, providing a more durable, accurate, and patient-friendly alternative to current catheter-based systems.