Research Of Miniaturized Glucose Measurement System Based On Optofluidics

In recent years,minimally invasive blood glucose continuous monitoring technology based on transdermal extraction of interstitial fluid(ISF)has become a research hotspot because of the advantages of painless and harmless.This thesis investigated a miniaturized optofluidic glucose monitoring system which was highly automated and portable.Firstly,the optofluidic glucose detection system was generally designed,the communication manner between telephone and external equipment was determined,the principle and algorithm of Digital Lock-In Amplifier(DLIA)was studied,and the fixed bracket of this system was designed.Then,the following four aspects of research contents are performed:(1)The hardware design of photoelectric detection module.A power amplifier module was designed to enable the power amplification of mobile phone audio signal and convert the optical signals into electrical signals.The sinusoidal voltage signals with different frequencies and peaks emitted by the mobile phone were tested.And the frequency and peak satisfying the requirements of the system were identified as 2100Hz and 284 mV,respectively.(2)The design of DLIA based on Android mobile phone in the photoelectric detection module.An application for DLIA was designed under Android Studio environment,which realized the collection of electrical signal output from hardware module and data processing.The application for DLIA(integration time was 100 ms)had good linearity(R~2(28)0.9999),repeatability and the attenuation of noise signals,meeting the test requirements of the system.(3)The design and optimization of the microfluidic control and driving module.A microfluidic control and driving scheme,which has three working modes of cleaning the sample cell,cleaning the pipeline inlet of the measured liquid,and injecting the liquid into the sample cell,was designed.The fabrication procedure of the electrodes was optimized.A new electrode fabrication method was proposed to make the distance between the tips of electrode pair uniform with 50?m.(4)Evaluation of the miniaturized glucose detection system.The whole system was evaluated in two aspects:linearity and repeatability.The experimental result showed that the maximum relative error of the system for glucose detection was 3.83%.And the linearity(R~2(28)0.9977)of the system was good.It was proved that the miniaturized system designed in this thesis could realize high precision detection of glucose with low concentrations.