Experimental Research On Noninvasive Blood Glucose Monitoring Based On Human Body Communication

The World Health Organization(WHO)claimed that diabetes has been classified as the third global chronic non-infectious diseases after tumor,cardio-cerebrovascular diseases,and there is no radical cure for diabetes at present.Measuring blood glucose level frequently has become one of most important work of diabetes management.Nowadays,almost glucose meters are invasive.These glucose meters are painful for diabetics and cannot be used for continuous blood glucose measurement.Therefore,non-invasive blood glucose monitoring has become main developing tendency of blood glucose testing.A method based on dielectric properties of human body communication channel has become investigation focus out of various types of noninvasive blood monitoring.Although many progress has been achieved,some problems still exist as following: firstly,there were few reports about experiment in vivo,because the researchers mainly focused on studying the dielectric properties of sodium chloride solution or simulated blood solutions with different glucose concentrations,which was different from the real human blood environment;Secondly,bio-impedance,not bio-impedance spectroscopy,was used for noninvasive blood glucose testing,which leaded to the results influenced by many factors.Thirdly,the dielectric spectrum of human body were obtained by large measuring equipment,which was not convenient for developing portable blood glucose meters.In this paper,according to the problems mentioned above,we mainly discusses the feasibility of using the fingertips’ impedance spectroscopy parameters at 10 KHz~100 KHz by experiments in vivo for non-invasive blood glucose monitoring.The following works are completed:(1)The development status about non-invasive blood glucose monitoring and the current status of diabetes are simply introduced.We main focus on the principle of non-invasive blood glucose monitoring based on dielectric properties of human body communication channel.(2)The impacts of electrodes types(rectangular electrode,rectangular four electrode and ring electrode)on glucose monitoring is studied by electromagnetic simulation and experiments about glucose solution.The fourth-order Cole-Cole electromagnetic simulation model of human fingertips is established.Simulation and experimental results show that the rectangular four electrodes have been sensitive to blood glucose concentration.(3)A wearable prototype system of bio-impedance spectroscopy based on AD5933 was developed,which can achieve the measurement of impedance at 10 KHz ~ 100 KHz.(4)A normal procedure of oral glucose tolerance test(OGTT)has been used for assessing the relationship between the bio-impedance spectroscopy in vivo and blood glucose level.In result,the characteristic parameter fc of bio-impedance spectroscopy has been shown to exhibit significant changes in its response corresponding to changes in blood glucose level,which provides the basic for non-invasive blood glucose monitoring.