Study On Necessary Conditions Of Non-invasive Blood Glucose Sensing With Near-infrared Spectroscopy And Their In Vivo Validation

In the field of non-invasive blood glucose concentration measurement with nearinfrared spectroscopy,the successful cases reported are all achieved by multiwavelength spectroscopy combined with multivariate regression.This cannot directly prove the feasibility of non-invasive blood glucose concentration measurement with near-infrared spectroscopy.This thesis systematically studies how to directly obtain real and effective blood glucose signals,giving six necessary conditions for achieving noninvasive blood glucose concentration measurement with near-infrared spectroscopy,and proposing corresponding solutions to meet the six necessary conditions by discussing and analyzing them.Finally,the spectral signal synchronized with the change of blood glucose concentration is successfully obtained,thus directly proving the feasibility of non-invasive blood glucose concentration measurement with nearinfrared spectroscopy.Firstly,this thesis proposes a reasonable measurement system design scheme,which meets the three necessary conditions related to instruments and measurement principles.The three necessary conditions are the reasonable and as few measurement wavelength position and number as possible,the ability to sense the minimum change of blood glucose concentration,and the appropriate light propagation path within the tissue,respectively.According to this design scheme,a designed measurement system that meets the above three necessary conditions,has high instrument precision,and is able to meet the clinical precision requirements of blood glucose.Secondly,this thesis proposes a reasonable method for optimizing differential positions to make sure that the differential measurement method can not only reduce the influence of background changes effectively,but also achieve satisfactory blood glucose measurement precision,which meets the necessary condition related to the measurement methods.Following this method,this thesis puts out the reference position optimization result of five parts of human body(forearm flexion,forearm flexion,cheek,forehead and back of the hand)in the band of 1000-1700 nm.Thirdly,this thesis proposes a reasonable human-machine interface design scheme and a high-precision optical positioning method to ensure the reproducibility of the external and internal measurement conditions,respectively,which meet the two necessary conditions related to the measurement conditions.In addition,it has been verified through in-vivo experiments that stable human body spectral data with highly repeatable signal-to-noise ratio can be obtained when using these two methods.At last,this thesis carries out clinical experimental research.The experiment results show that,on the premise that the above six necessary conditions are well guaranteed,the blood glucose signal synchronized with the change of blood glucose can be extracted directly by the signal-wavelength measurement.This is realized for the first time in the field of non-invasive blood glucose measurement with near-infrared spectroscopy.And this directly proves the feasibility of non-invasive blood glucose concentration measurement with near-infrared spectroscopy.In conclusion,this thesis summarizes six necessary conditions for achieving noninvasive blood glucose measurement with near-infrared spectroscopy,through systematic research on the instruments,methods,and measurement conditions of noninvasive blood glucose concentration measurement by near-infrared spectroscopy.And finally,reliable and real blood glucose signal detection is achieved,laying the foundation for the subsequent development of blood glucose instruments.The work in this thesis has good application value,and can provide a good reference for the development of the non-invasive blood glucose concentration measurement technique with spectroscopy and the development of instruments.