Simulation and dynamic monitoring of microthrombus-related impedance changes based on interdigital electrode

CHANG Liyun; ZHANG Yizhi; YANG Yamin

doi:10.19529/j.cnki.1672-6278.2025.06.01

Abstract：To alleviate the difficulties in the early identification of microthrombi and the lack of dynamic monitoring methods,we developed a high-sensitivity impedance monitoring system based on interdigital electrode(IDE)for label-free,real-time monitoring of microthrombus formation.Firstly,the finite element simulations were combined with in vitro thrombus formation experiments,thrombin was used to induce fibrinogen to form microthrombi,and the fluorescence intensity of fibrin was measured to quantify the formation process of microthrombi.Then,the influences of different red blood cell(RBC)concentrations,spatial distributions and thrombus sizes on the system impedance characteristics were comprehensively analyzed,and the real-time impedance changes and impedance frequen-cy responses during the dynamic development process of microthrombus were studied by using the IDE impedance monitoring system.Experimental results demonstrated that RBC aggregated on the IDE surface or bridging across positive and negative electrodes disrupted current conduction and increased system impedance.Low-frequency impedance was more sensitive to conductivity changes induced by microthrombi.High-frequency impedance exhibited only minor variations during thrombus formation.Real-time impedance monitoring further showed that the impedance-time curve followed the same trend as fibrin fluorescence intensity,characterized by a rapid initia-tion,gradual progression and plateau phase.The research provides an experimental approach for label-free,real-time monitoring of microthrombi,with potential applications in blood disease diagnosis and antithrombotic drug screening.