Optical Coherence Tomography and Elastography- Translating Technology to Applications

The mechanical properties of biological tissues play a crucial role in determining tissue or organ functionalities and understanding their failure mechanisms. A comprehensive understanding of these properties is essential for advancements in healthcare research and services. Elastography, particularly Optical Coherence Tomography-based Elastography (OCT/OCE), has emerged as a promising technique for identifying variations in the mechanical properties of soft tissues. It provides a quantitative elasticity map along with a micro-structure image, offering highresolution insights that are valuable for clinical practices. This research thesis explores the feasibility of applying OCT/OCE in clinical settings and evaluates device performance through clinical case studies. A range of materials were employed, which include tissue-mimicking phantoms, animal tissues, and human Thiel cadaver tissues. A Phase-sensitive OCT (PhS-OCT) device was used to detect tissue deformation and calculate the Young’s modulus by analysing these deformations. The PhS-OCT-based elastography system not only offers high-resolution depth-resolved cross-sectional structural imaging but also maps the elasticity of soft tissue. This device, integrated into the clinical environment, complies with regulatory standards and clinical requirements. Results from experiments on tissue-mimicking phantoms and animal tissues demonstrate the PhS-OCT-based elastography device's capability to assess changes in both optical and elastic properties of soft tissues with high sensitivity and accuracy. Furthermore, the application of this technology to human Thiel-embalmed cadaver oesophageal tissues has revealed significant insights into the performance and feasibility of this device for clinical applications. This study has successfully outlined the process of translating OCT/OCE technology into a clinically approved device in accordance with current UK legislation. Additionally, our investigation into the optical and mechanical properties of oesophageal tissue layers enhances our understanding of these tissues, potentially contributing to the clinical diagnosis of oesophageal diseases. Overall, this research marks a significant step towards integrating OCT/OCE as a diagnostic imaging modality in clinical applications.