Validazione Sperimentale di Sensori Impiantabili per il Monitoraggio dell'Attività Biomeccanica del Cuore

This thesis presents the development, fabrication, and validation of a fiber optic sensor based on Fiber Bragg Gratings (FBG) for real-time myocardial strain monitoring. The research is part of the NeuHeart Project, which aims to develop innovative technologies for cardiac function assessment. The sensor leverages five FBGs embedded in a Dragon Skin 20 silicone matrix, ensuring high mechanical stability, flexibility, and sensitivity to strain variations. The fabrication process included CAD modeling, 3D-printed molds, and a two-stage silicone casting technique to guarantee precise fiber positioning while preventing structural defects. A degassing step was implemented to remove air bubbles and optimize optical signal integrity. The five-FBG configuration, arranged in a double-triangle pattern, was introduced to overcome mathematical ambiguities in strain tensor calculation, ensuring a unique and reliable strain matrix solution. The sensor underwent extensive bench-top testing using a cardiac phantom and a linear stage, confirming its mechanical and optical performance. Finally, in vivo experiments on a porcine heart demonstrated the sensor’s ability to capture strain variations during the cardiac cycle, yielding promising results for real-time myocardial deformation analysis. Data analysis involved applying a calibration matrix to in vivo measurements, enabling the extraction of primary and secondary strain components. These results provide a physiological interpretation of myocardial mechanics, highlighting the sensor’s potential for clinical applications in cardiac monitoring and assistive devices. This study lays the groundwork for future miniaturization and implantable solutions, paving the way for advanced biomedical sensing technologies in cardiac diagnostics and therapy.