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Sensors 2014, 14(9), 16148-16158;

Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing

Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan
Firstep Bioresearch, Incorporation, Tainan 701, Taiwan
Author to whom correspondence should be addressed.
Received: 17 July 2014 / Revised: 18 August 2014 / Accepted: 25 August 2014 / Published: 1 September 2014
(This article belongs to the Special Issue Opto-Microfluidics for Bio Applications)
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This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP). View Full-Text
Keywords: optical inspection system; Taguchi method; detection limit; linearity optical inspection system; Taguchi method; detection limit; linearity
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

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Yeh, C.-H.; Zhao, Z.-Q.; Shen, P.-L.; Lin, Y.-C. Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing. Sensors 2014, 14, 16148-16158.

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