Flexible cylindrical diffusing fiber for cervical canal photodynamic therapy

Cervical cancer is one of the most common cancers among women worldwide. It originates from the cervix, and may expand to the cervical canal, which may lead to the removal of the cervix or endanger life in severe cases . Photodynamic therapy (PDT) is an important non-invasive treatment for cervical precancerous lesions. Cylindrical light diffusers, bare fiber and the flat-topped optical fiber are often used for such treatment. However, poor accessibility and nonuniformity irradiance distribution in the cervical canal cause unsatisfactory therapeutic effect. To optimize the light utilization and uniformity of light distribution in the cervical canal, and reduce the cost for treatment, a flexible diffusi ng fiber was developed by silica gel with specific concentrations of light scattering particles. The diffusing fiber is comprised of four distinct segments, each segment measuring 6 millimeter in length and 5 millimeter in diameter. Within these segments, an optimal concentration of light scattering particles is strategically embedded, facilitating the efficient diffusion of light as it traverses through the fiber. The longitudinal light intensity distribution of the diffusing fiber is systematically characterized through power meter measurements and photographic. The result reveals that the variance in this configuration does not exceed 20% of the mean value, indicating a high degree of uniformity and consistency for PDT treatment.