Institute of Bioengineering and Bioimaging, A*STAR, Singapore 138667, Singapore.
Anal Chem. 2023 Mar 28;95(12):5240-5247. doi: 10.1021/acs.analchem.2c05065. Epub 2023 Mar 17.
Confocal Raman spectroscopy (CRS) is a powerful tool that has been widely used for biological tissue analysis because of its noninvasive nature, high specificity, and rich biochemical information. However, current commercial CRS systems suffer from limited detection regions (450-1750 cm), bulky sizes, nonflexibilities, slow acquisitions by consecutive excitations, and high costs if using a Fourier transform (FT) Raman spectroscopy with an InGaAs detector, which impede their adoption in clinics. In this study, we developed a portable CRS system with a simultaneous dual-wavelength source and a miniaturized handheld probe (120 mm × 60 mm × 50 mm) that can acquire spectra in both fingerprint (FP, 450-1750 cm) and high wavenumber (HW, 2800-3800 cm) regions simultaneously. An innovative design combining 671 and 785 nm lasers for simultaneous excitation through a compact and high-efficiency (>90%) wavelength combiner was implemented. Moreover, to decouple the fused FP and HW spectra, a first-of-its-kind precise Raman spectra separation algorithm (PRSSA) was developed based on the maximum probability (MAP) estimate. The accuracy of spectra separation was greater than 99%, demonstrated in both phantom experiments and human skin measurements. The total data acquisition time was reduced by greater than 50% compared to other CRS systems. The results proved our proposed CRS system and PRSSA's superior capability in fast and ultrawideband spectra acquisition will significantly improve the integration of CRS in the clinical workflow.
共聚焦拉曼光谱（CRS）是一种强大的工具，由于其非侵入性、高特异性和丰富的生化信息，已被广泛用于生物组织分析。然而，目前的商业 CRS 系统受到检测区域有限（450-1750cm）、体积庞大、不灵活、通过连续激发进行缓慢采集以及如果使用具有 InGaAs 探测器的傅里叶变换（FT）拉曼光谱则成本高的限制，这阻碍了它们在临床上的采用。在这项研究中，我们开发了一种便携式 CRS 系统，该系统具有同时的双波长源和小型化的手持式探头（120mm×60mm×50mm），可以同时在指纹（FP，450-1750cm）和高波数（HW，2800-3800cm）区域采集光谱。实施了一种创新设计，将 671nm 和 785nm 激光器结合在一起，通过紧凑且高效（>90%）的波长组合器进行同时激发。此外，为了分离融合的 FP 和 HW 光谱，我们开发了一种基于最大概率（MAP）估计的首创精确拉曼光谱分离算法（PRSSA）。在体模实验和人体皮肤测量中，光谱分离的准确性大于 99%，证明了该算法的准确性。与其他 CRS 系统相比，总数据采集时间减少了 50%以上。结果证明，我们提出的 CRS 系统和 PRSSA 在快速和超宽带光谱采集方面的卓越性能将显著提高 CRS 在临床工作流程中的集成度。
