應用於口腔疾病診斷之新型光學同調斷層掃瞄探頭

Abstract

在本論文中，我們架設了一套光纖式光學同調斷層掃瞄系統，採用中心波長為1327 奈米，具有頻寬 117 奈米的掃頻式光源。我們針對口腔內掃瞄的需求設計並製作了一個可進行三維掃瞄的探頭。在空氣中，系統本身的縱向解析度為7微米，橫向解析度為10微米，靈敏度為 100 dB。利用這個特殊設計的三維探頭，我們先針對皮膚及指甲做活體的掃瞄。根據掃瞄的結果，我們可清楚分辨皮膚中角質層、表皮及真皮，三層主要結構。除此之外，我們在手指的掃瞄上也可以觀察到汗腺、指甲板及指甲根。在皮膚的影像掃瞄深度可達1.4到1.8毫米。對於準三維掃瞄影像的掃瞄面積為15平方毫米。準三維影像是由10張的二維影像所組成，擷取速度約1.5秒。 為了測試臨床掃瞄的可靠性，我們掃瞄了活體口腔黏膜。在我們的掃瞄過程中，我們針對口腔黏膜中，頰面黏膜、嘴唇黏膜及特化黏膜(舌頭背面)從事掃瞄。由這些口腔黏膜的掃瞄結果，我們可以分辨上皮層和固有層兩層結構，部分能看到次黏膜及某些腺體。在特化黏膜的掃瞄影像上，我們觀察到乳突及骨骼肌。口腔黏膜的掃瞄深度可達1.8到2毫米。這套系統將在台灣大學醫學院附設醫院進行口腔癌的臨床掃瞄。

In this research, a fiber-based OCT system with a newly 3-D probe was built, which utilized the broadband swept-frequency light source with the central wavelength at 1327 nm and the spectral width at 117 nm. The axial resolution of the OCT system was 7 microns in free space. Its sensitivity was 100 dB. A compact two-axis probe specially designed for the oral cavity scanning was fabricated. The lateral resolution of the system is 10 microns. With this hand-held probe, the in vivo scanning results of human skin and fingernail were obtained. In such scanning, three major layers, including stratum corneum, epidermis, and dermis, could be clearly identified. Beside, the sweat gland in finger tip skin and the structures in fingernail, including nail plate, nail body, and nail root, were observed. The penetration of depth of human skin scanning images was 1.4~1.8 mm. The quasi-3-D image size of human skin scanning of 10 mm × 1.5 mm, composed of ten 2-D images of 6000 A-scan, could be completed in less than 1.8 second. To test the clinical application, in vivo scanning of oral mucosa was performed. In such scanning, two types of oral mucosa, including lining mucosa (lip), including labial mucosa and buccal mucosa, and specialized mucosa (the dorsal surface of tongue) were scanned. In the lining scanning images, three major layers, including epithelium, lamina propria, and submucosa, could be identified. The scanning depth of oral mucosa was 1.8~2 mm. In scanning the images of specialized mucosa, tongue papillae, skeletal muscle and some glands could be observed. This OCT system will be used for clinical diagnosis of oral cancer at the National Taiwan University Hospital.