Research On Integrating Technology Of Minimally Invasive Blood Glucose Continuous Detection Prototype

Continuous blood glucose testing is of great significance for the diagnosis and treatment of diabetes.This paper designs an integrated and automated minimally invasive blood glucose continuous detection prototype.The prototype uses a microfluidic chip to percutaneously extract interstitial fluid(ISF)and adopt enzyme colorimetry to measure its glucose concentration.The method detects the glucose concentration of the ISF,uses the correlation between the ISF and the blood glucose concentration to achieve continuous blood glucose detection,and saves the measured blood glucose data in the database system for subsequent review and study.The work of this paper mainly includes the following two aspects:(1)Development of a minimally invasive blood glucose continuous detection prototype.In order to complete the continuous detection of blood glucose,the prototype is mainly divided into three parts: fluid system,optical detection system and software control system.The fluid system mainly accomplishes two tasks.1)Transdermal extraction,delivery and volumetric quantification of the ISF.The process detects the change of the voltage on the electrode pair in the microfluidic chip by the single chip microcomputer,determines the position of the fluid,and controls the opening of the pneumatic microvalve in the chip.The volume of the extracted ISF is calculated according to the time of the fluid flowing through the electrode pair and the tube size of the chip.2)During the detection process of glucose concentration,the peristaltic pump and the quantitative pump are controlled by the upper computer to realize the quantitative injection of the sample solution and the reagent,as well as mixing and cleaning of the sample cell,removal of waste liquid and other functions.The optical inspection system consists of an enzyme colorimetric optical detection module composed of a light source,a lens,a slit,a sample cell,a spectrometer for high-precision detection of low glucose concentrations,and a motor lifting platform specifically designed for fluid pumping and extraction in the sample cell.The software control system can be divided into three modules: 1)The real-time control module of the microfluidic chip for ISF transdermal extraction,2)The upper computer for controlling the peripheral devices,receiving signals and processing data,3)A database system for statistically and comparatively analyzing the information from continuous blood glucose monitoring of multiple objects.(2)Testing and evaluation of minimally invasive blood glucose continuous testing prototype.In order to evaluate the performance of the prototype,three confirmatory experiments were designed.1)For the experiments on the microfluidic chip for ISF transdermal extraction,the results show that the ISF extraction module can complete the ISF transdermal extraction,collection,delivery and volumetric function.2)Glucose measurement experiments are performed using the enzyme colorimetric detection module.In the experiment,10 concentrations of glucose solution in the range of 1-50mg/dL are selected for absorbance measurement.The absorbance model is established based on the spectral data and glucose concentration.The results show that the enzyme colorimetric detection method has good linearity in the glucose concentration range of 1-50mg/dL.Relative standard deviation is less than 0.65%.3)In the patient information,blood glucose data preservation and query function verification experiments,the database realizes the functions of adding patient information,saving blood glucose data and querying the patients' blood glucose levels in a period of time through the interface of the upper computer.