Today´s standard procedure for the examination of the colon uses a digital endoscope located at the tip of a tube encasing wires for camera read out, fibers for illumination, and mechanical structures for steering and navigation. On the other hand, there are swallowable capsules incorporating a miniaturized camera which are more cost effective, disposable, and less unpleasant for the patient during examination but cannot be navigated along the path through the colon. We report on the development of a miniaturized endoscopic camera as part of a completely wireless capsule which can be safely and accurately navigated and controlled from the outside using an electromagnet. The endoscope is based on a global shutter CMOS-imager with 640x640 pixels and a pixel size of 3.6μm featuring through silicon vias. Hence, the required electronic connectivity is done at its back side using a ball grid array enabling smallest lateral dimensions. The layout of the f/5-objective with 100° diagonal field of view aims for low production cost and employs polymeric lenses produced by injection molding. Due to the need of at least one-time autoclaving, high temperature resistant polymers were selected. Optical and mechanical design considerations are given along with experimental data obtained from realized demonstrators.

Date Published: 25 September 2014
PDF: 6 pages
Proc. SPIE 9192, Current Developments in Lens Design and Optical Engineering XV, 91920Z (25 September 2014); doi: 10.1117/12.2061221

Published in SPIE Proceedings Vol. 9192:
Current Developments in Lens Design and Optical Engineering XV
R. Barry Johnson; Virendra N. Mahajan; Simon Thibault, Editor(s)