Research On The Detedtion Technology Of Blood Coagulation Time Based On Microfluidic Chip

The detection of clotting time is of great significance in clinical testing.With the development of medical technology and the gradual maturity of microfluidic technology,the detection of blood coagulation time in the medical community is increasingly moving toward the miniaturization of instruments and reagents.At present,there are some common problems in blood coagulation time detecting instruments for using large amounts of reagents,which bears big influence of the cylindrical surface effect of the test tube and the sample itself.Therefore,the use of microfluidic chips as detecting instrument for the detection of clotting time has theoretical and practical significance.Based on the research and analysis of traditional methods and principles of clotting time detection,this paper proposes the use of microfluidic technology to detect clotting time.Firstly,this paper provides the three stages of blood coagulation,including prothrombin activator formation,thrombin formation,and fibrin formation.Following the three-component model and the principle that fibrinogen is not conductive and fibrin is conductive,the overall scheme of microfluidic electrical impedance detection system is developed with theoretically analyzing the principle of bioimpedance technology and the principle of human blood impedance measurement.Secondly,the microchannel structure and electrode structure of the microfluidic electrical impedance detection chip are designed and the electrode parameters are determined.Then,the electrode potential distribution was simulated using COMSOL Multiphysics software.At the same time,the experimental platform of microhybrid system and microfluidic electrical impedance detection system is built and the functions of data graphic display,clotting time calculation,inspection report preservation and data recording are realized by the software system,LabVIEW.In order to verify the overall scheme,the microchannel PDMS substrate and the electrode glass substrate of the microfluidic electrical impedance detection chip are fabricated respectively,and the microfluidic chip strength was ensured by plasma bonding.Debuging the experimental platform from time to time ensures the stability of the detection system.Experiments are carried out with human blood and reagent which are mixed by he principle of alternating current electroosmosis.Through data processing,the thromboplastin active time is 27.4seconds,the prothrombin active time is 14.6 seconds,and the thrombin active time is 15.7seconds.Based on the principle of human blood impedance measurement and the application of the microfluidic electrical impedance detection technology,the amount of detection reagent used in the experiment becomes one-fiftieth of that of the conventional detection and the experiment is not affected by the cylindrical effect of the test tube.Small amount of reagent and no label detection is thus realized,which provides a new idea for the miniaturization and portability of the subsequent blood detection system.