Salem, Ahmed; (2025) Printed Implantable Devices for Gastro-oesophageal Reflux Disease (GORD) Diagnosis. Doctoral thesis (Ph.D), UCL (University College London).

Preview

Text Salem_10214136_thesis_sigs_removed.pdf Download (11MB) | Preview

Abstract

Ambulatory pH monitoring is crucial for diagnosing gastro-oesophageal reflux disease (GORD), but current devices are often large, uncomfortable, poorly tolerated, and inaccurate. This work introduces novel pH-sensing devices that address these issues through soft, miniaturised, flexible, and biocompatible mucosa-interfacing electronics. Designed to adhere seamlessly to the oesophageal mucosa, these enable less invasive and more accurate GORD diagnostics. A comprehensive investigation into electrochemical pH sensors details the promise of polymer/carbon-based electrode materials due to their exceptional flexibility, biocompatibility, and high reactivity. Customised inks for nanosensor fabrication were developed, facilitating the creation of robust and highly sensitive sensors. Through refinement of both materials and fabrication methods, these sensors were optimised to deliver stable and reliable performance over a large pH range. Further advancements involved integrating covalent organic frameworks (COFs) as electrochemical composites, enhancing the sensitivity and stability of the sensors. COFs were also tested for their biocompatibility, ensuring the sensors would be safe for long-term use in vivo. Wireless communication was then incorporated into the device, employing near-field communication (NFC) to enable real-time data transmission. Simulations and experiments demonstrated the feasibility of transmitting data readings wirelessly and without a battery, offering an avenue for minimally invasive and efficient in vivo monitoring. Finally, to ensure secure attachment to the oesophageal lining, bioadhesives were explored and built upon a gelatine-poly(acrylic acid) hydrogel matrix. This bioadhesive was characterised for its mechanical and oesophageal mucoadhesive properties, with successful ex-vivo testing showing its ability to withstand conditions mimicking the oesophagus during fluid intake. This work demonstrates the feasibility of a novel mucosa-interfacing sensor for GORD diagnosis, combining advanced sensing materials, wireless communication, and secure bioadhesion into a fully integrated, minimally invasive device. Despite some current limitations, particularly the need for in vivo validation, this approach offers a promising path toward more comfortable, accurate, and efficient GORD monitoring.

Download activity - last month

Export as XMLCSVJSON

Download activity - last 12 months

Export as JSONCSVXML

Downloads by country - last 12 months

Export as XMLCSVJSON

Archive Staff Only

View Item