Dual Fluorescence Emission by Irradiation of Single Optical Source for Fluorescein Sodium and 5-ALA Applications

Abstract

Most brain surgeries aim to completely resection a tumor. However, the arrangement of blood vessels around brain tumors is often complex. Moreover, the tumors and blood vessels have similar colors, making it difficult to identify the boundaries between them with the naked eye. Fluorescent staining is a method used to distinguish the borders between brain tumors and blood vessels. The fluorescent contrast agents commonly used to observe tumors are 5-aminolevulinic acid and fluorescein sodium, which have different surgical sensitivities, depending on the type of tumor. In this article, a dual band bandpass filter with dual-wavelength emission for 5-aminolevulinic acid and fluorescein sodium is designed, and the dual-band bandpass filter capable of inducing simultaneous fluorescence emission of fluorescein sodium and 5-aminolevulinic acid was investigated experimentally to improve accuracy, speed, and energy efficiency in clinical settings. The possibility of dual fluorescence emission with a single irradiation is proposed. The efficiency of transmission and reflection (optical density) is 98% and 0.01%, respectively, and the bandwidth is 50% in the proposed filter. The proposed fluorescent dual-band filter has the advantage of saving energy, reducing auxiliary manpower and unit costs, and reducing operating room space requirements by producing two fluorescence diagnostic effects using a single equipment.