A dual-modality endoscopic imaging and localized thermal therapy system integrating photoacoustic amplitude-based thermometry

Minimally invasive diagnosis and treatment within narrow luminal structures such as the gastrointestinal tract and blood vessels remain clinically challenging due to limited imaging feedback and the lack of controllable therapeutic mechanisms. These limitations hinder the realization of integrated functions for diagnosis, therapy, and monitoring. To address these issues, we propose a dual-modality endoscopic imaging and localized heating system that incorporates photoacoustic amplitude-based temperature measurement. The system utilizes a 1064nm pulsed laser to achieve deep tissue photoacoustic imaging and an 808nm continuous-wave laser for localized heating. A fiber-based optical combiner ensures precise spatial alignment of imaging and therapeutic beams. A high-frequency ultrasound transducer with a center frequency of 40MHz is employed for the synchronized acquisition of photoacoustic and ultrasound signals. Phantom experiments using agar–carbon composites demonstrated that the system is capable of dual-modality fused imaging at a speed of 10frames per second and can achieve a local temperature elevation close to 50°C. A linear correlation was established between the photoacoustic signal amplitude and temperature, enabling single-point thermal monitoring with an accuracy of ±0.91°C. By integrating multi-modal imaging and temperature monitoring local heating into a single endoscopic platform, this system provides a comprehensive solution for diagnosis, treatment, and real-time monitoring in the luminal environment, demonstrating enormous clinical translational potential.