PDMS Microlenses for Focusing Light in Narrow Band Imaging Diagnostics

Journal article (2019)

Authors

Adriana C. Costa Chongqing Technology and Business University, University of Minho
S. Pimenta University of Minho
João F. Ribeiro University of Minho
Manuel F. Silva University of Minho
R.F. Wolffenbuttel Electronic Instrumentation - EEMCS
Jun Tao Dong Chongqing Technology and Business University, University of South-Eastern Norway
Zhaochu Yang Chongqing Technology and Business University
JHG Correia Chongqing Technology and Business University, University of Minho
Research Group
Electronic Instrumentation (EEMCS) (TU Delft)
Copyright: © 2019 Adriana C. Costa, Sara Pimenta, João F. Ribeiro, Manuel F. Silva, R.F. Wolffenbuttel, Tao Dong, Zhaochu Yang, José H. Correia
DOI: https://doi.org/10.3390/s19051057
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Published Date

2019

Language

English

Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Research Group

Electronic Instrumentation

Abstract

Minimally invasive medical devices can greatly benefit from Narrow Band Imaging (NBI) diagnostic capabilities, as different wavelengths allow penetration of distinct layers of the gastrointestinal tract mucosa, improving diagnostic accuracy and targeting different pathologies. An important performance parameter is the light intensity at a given power consumption of the medical device. A method to increase the illumination intensity in the NBI diagnostic technique was developed and applied to minimally invasive medical devices (e.g., endoscopic capsules), without increasing the size and power consumption of such instruments. Endoscopic capsules are generally equipped with light-emitting diodes (LEDs) operating in the RGB (red, green, and blue) visible light spectrum. A polydimethylsiloxane (PDMS) µ-lens was designed for a maximum light intensity at the target area of interest when placed on top of the LEDs. The PDMS µ-lens was fabricated using a low-cost hanging droplet method. Experiments reveal an increased illumination intensity by a factor of 1.21 for both the blue and green LEDs and 1.18 for the red LED. These promising results can increase the resolution of NBI in endoscopic capsules, which can contribute to early gastric lesions diagnosis.