Research On Some Key Technologies In Interstitial Fluid Transdermal Extraction

Blood glucose monitoring plays an important role in the treatment of diabetes, which provides data basis for its diagnosis and treatment. Currently, blood glucose monitoring consists of invasive blood glucose monitoring, minimally invasive blood glucose monitoring and non-invasive blood glucose monitoring, in which minimally invasive glucose monitoring technology is simple, reliable and easily implemented. In the minimally invasive blood glucose monitoring, interstitial fluid is extracted out by the minimally invasive method, and then concentration of glucose in blood is forecasted through the concentration of glucose in interstitial fluid. In this paper, several key technologies in interstitial fluid transdermal extraction are researched. Measurement methods of skin normal impedance in a single point are investigated and summarized at home and abroad. Animal experiments are carried out and the optimal measurement method of skin normal impedance is found out. The low-frequency ultrasound circuit and impedance measurement circuit is designed and made. The experiment platform is set up for micro-device and its properties is evaluated.Several key technologies in interstitial fluid transdermal extraction have been studied in this paper. The main works include:⑴Before the research of skin normal impedance measurement in a single point, measurement methods of skin normal impedance in a single point are investigated and summarized at home and abroad.⑵Based on the theory of equal potential between ptysma and interstitial fluid, the electrode is put in the oral cavity to measure the skin normal impedance in a single point. Through comparing with subcutaneous electrode method, the effectiveness of its performance is verified. Further, a large area electrode method is brought forward to measure the skin normal impedance in a single point, and experiments are carried out to compare with subcutaneous electrode method. In the end, the impact of skin humidity and pressure on measure results is researched in the method of electrode in oral cavity.⑶Because commercial instruments are bulky and operation cannot be automated, dual-channel signal source circuit based on DDS technologies, high voltage ultrasonic drive circuit and skin impedance measurement circuit are designed. Then the printed circuit boards are made, and the circuit modules are debugged.⑷Because the volume of interstitial fluid extracted out is small, it is difficult to extract and collect it. Miniaturized and integrated interstitial fluid extraction, collection and measurement system is designed. Experiment platform is set up for the micro-flowmeter and performance evaluation experiments are carried out. Then the viability and rationality of system is verified and data is provided for system optimization.