用于OCT成像与pH测量的双模态内窥探头

Dual-Modality Endoscopic Probe for Optical Coherence Tomography Imaging and pH Sensing

为了实现生物组织化学特性与物理结构的同时测量,提出了结合光学相干层析扫描(OCT)成像与荧光比率成像的双模态内窥探头。根据OCT成像原理,确定OCT系统的中心波长为1300 nm;根据所选用pH指示剂(SNARF-1)的吸收光谱与反射光谱,确定荧光的激发波长为520 nm。根据ABCD矩阵计算并确定探头的基本结构,基于理论计算结果进行光学元件的加工与探头的组装。此外,搭建了双模态系统,采用该系统测量了探头的横向分辨率与工作距离。通过猪大肠验证了探头同时进行成像和pH检测的能力,实验结果表明:探头能同时进行OCT成像与pH测量,并且具有较高的精度。OCT成像在空气中的横向分辨率约为52μm,工作距离约为14.6 mm,在生物组织中可以实现精度为0.01的pH测量。

To achieve simultaneous measurements of biochemical properties and physical structures, we proposed an endoscopic probe that combines optical coherence tomography(OCT) imaging and fluorescence ratio imaging. Based on the OCT imaging principle, the center wavelength of the OCT system was determined to be 1300 nm. Based on the absorption and reflection spectra of the selected pH indicator, the excitation wavelength of the fluorescence was determined to be 520 nm. Moreover, the basic structure of the probe was calculated and determined according to the ABCD matrix. The processing of the optical element and actual assembly of the probe were performed based on the theoretical calculation results. Furthermore, the dual-modality system was built to measure the transverse resolution and working distance of the probe. The ability of simultaneous imaging and pH detection was demonstrated on pork intestine. The probe can simultaneously perform OCT imaging and pH measurement with high accuracy. The resolution of OCT imaging in air is approximately 52 μm, and the working distance is approximately 14.6 mm. Moreover, the proposed system can measure the pH value of 0.01 units.