Towards in vivo laser coagulation and concurrent optical coherence tomography through double-clad fiber devices

There is a strong clinical need for an optical coherence tomography (OCT) system capable of delivering concurrent coagulation light enabling image-guided dynamic laser marking for targeted collection of biopsies, as opposed to a random sampling, to reduce false-negative findings. Here, we present a system based on double-clad fiber (DCF) capable of delivering pulsed laser light through the inner cladding while performing OCT through the core. A previously clinically validated commercial OCT system (NVisionVLE, Ninepoint Medical) was adapted to enable in vivo esophageal image-guided dynamic laser marking An optimized DCF coupler was implemented into the system to couple both modalities into the DCF. A DCF-based rotary joint was used to couple light to the spinning DCF-based catheter for helical scanning DCF-based OCT catheters, providing a beam waist diameter of 62 mu m at a working distance of 9.3mm, for use with a 17-mm diameter balloon sheath, were used for ex vivo imaging of a swine esophagus. Imaging results using the DCF-based clinical system show an image quality comparable with a conventional system with minimal crosstalk-induced artifacts. To further optimize DCF catheter optical design in order to achieve single-pulse marking, a Zemax model of the DCF output and its validation are presented.

临床上非常需要一种光学相干断层扫描（OCT）系统，该系统能够同时提供凝固光，从而实现图像引导的动态激光标记，以便有针对性地采集活检样本，而不是随机取样，以减少假阴性结果。在此，我们介绍一种基于双包层光纤（DCF）的系统，它能够通过内包层传输脉冲激光，同时通过纤芯进行OCT。一个先前经过临床验证的商用OCT系统（NVisionVLE，Ninepoint Medical）经过改造，能够在体内进行食管图像引导的动态激光标记。系统中采用了一种优化的DCF耦合器，将两种模态耦合到DCF中。一个基于DCF的旋转接头用于将光耦合到基于DCF旋转的导管上，以进行螺旋扫描。基于DCF的OCT导管在9.3毫米的工作距离处具有62微米的束腰直径，可与直径为17毫米的球囊鞘一起使用，用于猪食管的体外成像。使用基于DCF的临床系统的成像结果显示，其图像质量与传统系统相当，且由串扰引起的伪影极少。为了进一步优化DCF导管的光学设计以实现单脉冲标记，本文还介绍了DCF输出的Zemax模型及其验证。