TE Enriched Sample (E)

Non-ionizing Medical Imaging 2 86 Endoscopy • Working principle: guiding light through an optical fibre with multiple total internal reflection cladding core • Optical fibre: a glass core of higher n surrounded by a cladding of lower n • Tools and mechanism (see p. 78) control to remove body fluids movable section tip grasping forceps water/air control locking control to fix tip position tool channel magnifying eyepiece light for illumination • How images are formed 1. The surface under examination is illuminated by the light coming from the incoherent fibre bundle. 2. Light from objects enters the objective end of the coherent fibre bundle. 3. An image is reproduced on the viewer end of the fibre bundle. • Resolution - with higher fibre density • Advantages and limitations: see p. 81 resolution: bending: low less high more Sample © United Prime Educational Publishing (HK) Limited, Pearson Education Asia Limited 2023 All rights reserved; no part of this publication may be reproduced, photocopied, recorded or otherwise, without the prior written permission of the Publishers.