Key Technical Research And Development Of Signal Source System In Endocardial Catheter 3D Positioning Device

Atrial fibrillation (AF) is a familiar complex arrhythmia disease in clinic. AF and its complications are serious harm to people's health. At present, radio-frequency (RF) ablation operation is widely used to cure AF due to its three dimension (3D) positioning system. Through this system, the ablation catheter can detect endocardial target easily. In recent years, detect technology in catheter positioning is developed from two-dimensions (2D) to 3D, therefore, catheter can located the pathologic focus in human heart effectively, and operative success rate is raised greatly.Based on positioning technology in bioelectric field, a signal source system is researched in this dissertation according to endocardial catheter 3D positioning. At the same time, considering RF ablation operation, various performance indexes of the system are introduced. Subsequently, a special signal source system is developed with high integration and stability; experiments are performed to test its various indexes.The main researches are described as follows:1) Principle of positioning technology based on the bioelectric field is analyzed. Functional requirements in the whole positioning device are discussed. Moreover, indexes range of current and frequency in the output signal are specified. Based on these results, schematic design of the whole signal source is completed.2) Signal generating module, signal conditioning module, voltage controlled current source (VCCS) module and regulated power supply module are designed, furthermore, software control program are compiled for debugging.3) Constant current effect in VCCS module is verified through simulation methods; hardware circuit of the whole system is built up for proving feasibility and reliability; printed circuit boards (PCB) are produced in each step in order to test the system performance.4) A kind of positioning device is designed to simulate the process of endocardial catheter inserting human thorax. Because signal source system is connected to the positioning device, within breath and heartbeat effects, the sensibility of biological electric field must be considered. Through animal experiments, system performances are analyzed for further research. By linking the signal source system with data acquisition and signal process device, current and frequency characteristics in the output signal are explored for clinical medicine research.