Laser manufacturing distal-end-optical-systems for endoscopic optical-biopsy diagnostics

用于内窥镜光学活检诊断的激光制造远端光学系统

• 批准号: ST/M007839/1
• 负责人: Robert Thomson
• 金额: $ 36.52万
• 依托单位: Heriot-Watt University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FM007839%2F1
• 关键词: Laser; manufacturing; distal; end; optical

Oesophageal cancer has the fastest rate of increase of any cancer in the developed world and a poor prognosis with low survival after five years. Early identification of changes in oesophageal tissue leads to improved prognosis, but current techniques rely on traditional endoscopy and biopsy, which are invasive and exhibit poor sampling, and are only capable of identify issues that have already manifested through changes in the cellular structure. Recent developments in photonic-based technologies mean that it is now feasible to develop a medical diagnostic that is capable of identifying pre-cancerous (Barrett's syndrome), cancerous and non-cancerous tissues, by analysing the spectral properties of laser light inelastically scattered from tissue (Raman spectroscopy). By performing Raman spectroscopy at the end of a thin and flexible fibre-optic, that is used to precisely guide light into and out from the region of interest, it will be possible to test in-vivo whether oesophageal tissue is malignant or normal. This technique may also be able to pick up abnormalities that would not be picked up during histopathology, crucial information that could enable early diagnosis and mean that unnecessary invasive surgical procedures could be avoided. Such a technology would also find applications in the endoscopic treatment of Barrett's oesophagus and oesophageal cancer, enabling the clinician to assess the margins of the relevant tissue regions before and during resection.There is, however, a significant manufacturing issue that stands in the way of fully developing these new and exciting photonic-based clinical tools; in order to control the properties of the light leaving and entering the distal (in-vivo) end of the fibre-optic, it is necessary to use a distal-end-optical-system (DOS) of some form. This DOS can be as simple as a single lens, or a more complicated construction, requiring mirrors, spectral filters and lenses, as is the case in the optical-biopsy Raman-based instrument. Currently, manufacturing such DOS devices requires discrete micro-optic components to be aligned and bonded together. These techniques are labour intensive, time-consuming and expensive. In short, current DOS fabrication techniques are non-optimal and are not suitable to commercial manufacturing; a new and more flexible manufacturing technique is required.During this STFC-CLASP project, we will develop new DOS manufacturing processes using ultrafast laser based techniques. These processes use focused ultrashort laser pulses, each only a few hundred femtoseconds long, to locally and precisely modify the structure of a substrate material in three-dimensions. The laser-induced modification manifests itself in a variety of ways, examples of which include changes to the chemical etch-rate and/or refractive index of the modified material. Using these manifestations, it is possible to directly write optical components, such as diffraction gratings, into the substrate material, and by using a post-irradiation chemical-etch step we can sculpt precision micro-optics. The fact that "ultrafast laser inscription" enables micro-optic components, such as lenses, mirrors and optical waveguides to be combined onto a single substrate, using a single manufacturing process, makes it the ideal route to commercially manufacture precision DOS technologies.

食管癌在发达国家的任何癌症中增长速度最快，预后不良，五年后生存率低。早期识别食管组织的变化可以改善预后，但目前的技术依赖于传统的内窥镜检查和活检，这些技术是侵入性的，采样效果差，并且只能识别已经通过细胞结构变化表现出来的问题。基于光子的技术的最新发展意味着现在可以通过分析从组织非弹性散射的激光的光谱特性（拉曼光谱）来开发能够识别癌前（巴雷特综合征）、癌组织和非癌组织的医学诊断。通过在用于精确地引导光进出感兴趣区域的薄且柔性的光纤的端部处执行拉曼光谱，将有可能在体内测试食管组织是恶性的还是正常的。这种技术还可以发现组织病理学中无法发现的异常，这是能够进行早期诊断的关键信息，并意味着可以避免不必要的侵入性外科手术。这种技术也可以应用于巴雷特食管和食管癌的内窥镜治疗，使临床医生能够在切除之前和切除过程中评估相关组织区域的边缘。为了控制离开和进入光纤远端（体内）的光的特性，必须使用某种形式的远端光学系统（DOS）。这种DOS可以是简单的单个透镜，或者是更复杂的结构，需要反射镜、光谱滤波器和透镜，如基于拉曼的光学活检仪器中的情况。目前，制造这种DOS器件需要将分立的微光学部件对准并接合在一起。这些技术是劳动密集型的，耗时且昂贵。简而言之，目前的DOS制造技术是非最佳的，不适合商业制造;一个新的和更灵活的制造技术是必需的。在这个STFC-CLASP项目中，我们将开发新的DOS制造工艺使用超快激光为基础的技术。这些工艺使用聚焦的超短激光脉冲，每个脉冲只有几百飞秒长，以局部和精确地修改三维衬底材料的结构。激光诱导的改性以各种方式表现出来，其示例包括改变改性材料的化学蚀刻速率和/或折射率。使用这些表现形式，可以直接将光学元件（例如衍射光栅）写入衬底材料中，并且通过使用照射后化学蚀刻步骤，我们可以雕刻精密的微光学器件。事实上，“超快激光雕刻”使微光学元件，如透镜，镜子和光波导被组合到一个单一的基板上，使用一个单一的制造工艺，使其成为商业化制造精密DOS技术的理想途径。

项目成果

A Miniature Fibre-optic Raman Probe Fabricated by Ultrafast Laser Assisted Etching

超快激光辅助蚀刻制造的微型光纤拉曼探针

• DOI: 10.20944/preprints202001.0351.v1
• 发表时间: 2020
• 作者: Ross C