Study On The Non-invasive Blood Glucose Detection System Based On Near Infrared Transmission Method

In recent years,the percentage of population diagnosed with diabetes has become higher and higher.Blood glucose control is an important daily task for the treatment and health care of people with diabetes and high-risk pre-diabetics.Blood glucose monitoring helps patients to grasp the status of blood glucose control and evaluate the effects of diet,exercise,and medication,and further help patients adjust their lifestyles.At present,blood glucose concentration testing is mainly performed through invasive methods such as venous blood sampling or fingertip blood sampling,which can cause great pressure on the patient’s heart and physiology,and may even cause wound infections.This topic uses the principle of non-invasive detection combined with PPG and near-infrared spectroscopy to design a non-invasive blood glucose detection system,It mainly includes the design of weak current detecting circuit and the removal of pulse wave baseline drift.The specific research contents and work conclusions are as follows:1)In the further research of the theory analysis of near infrared spectral and the infrared absorption peak of human body’s main substances A non-invasive blood glucose detection system based on near-infrared transmission method was designed,and the detection method,location and wavelength of detection were determined,and the overall block diagram of the system was designed.The optical path system and corresponding mechanical support structure are built according to the requirements of the system diagram.2)According to the requirements of the system diagram,the optical path system and corresponding mechanical support structure are designed.3)According to the signal characteristics of the photoelectric pulse wave transmitted by the finger,the selection of the photoelectric detector and the processing circuit of the output weak current signal are designed.Choosing ADA4530-1,ADA4891 and ADA4522-1 to design the primary amplifying circuit,secondary amplifying circuit and the low-pass filter circuit.The output current of the photodiode is converted to a voltage signal above 0.5mV.4)Using Labview to design the photoelectric volume pulse wave signal acquisition system,and the filter and cycle recognition,finally using cubic spline interpolation method fitting completed baseline drift to remove baseline drift curve,and acquisition peak-peak value.5)Using the principle of least square method,fitting the signals of using the noninvasive blood glucose detection system and traditional blood glucose detection method,obtaining the correlation between the predicted blood glucose and the real value was 0.8267.Then analysis the peak-peak and the stability of light source,the body’s slight change,minor activity or detecting position,get the body slightly activities or slight change detection position has obvious influence on the peak-peak,in the next work to overcome this difficulty,can further improve the detection effect.In this paper,the hardware and software system of non-invasive blood glucose detection based on the near-infrared spectrum transmission method can also be used in other applications of the optical method to detect the concentration of human blood components.