The Analysis And Improvement Of Hardware Circuit Based On Three-Dimensional Electric Field Positioning Device

Atrial fibrillation is a manifestation of arrhythmia, treating it mainly through drug, medical instruments and surgical operation. Atrial fibrillation is treated by the surgical operation, which make ablation therapy by intracardiac catheter on the international, however, it is the key to fix the intracardiac catheter. The paper improve the circuit of hardware in positioning device causing by three-dimensional electric field, based on researched positioning device. The improved three-dimensional electric field positioning device could output signal continuously in signal source system, and the electrocardiosignal is transmitted to filter module by PCI data acquisition card; finally, the voltage values of the signal is obtained by AD digital to analog conversion, which locate the catheter of surgery in real time. The paper designs the multi-channel high-speed automatic collect measure test system, based on the PXI bus technology. The system has high integration, and it could work on the condition of damp and vibration, which greatly improve the interoperability and safety of ablation surgery.This paper mainly study on the following points:(1)In term of the hardware circuit in three dimensional electric field, from constant current source signal generating device to Signal filter module and Digital to analog conversion module, the whole set of equipment adopts the advanced operational and filter chip, guaranteeing the continuity of signal transmission and the high signal-to-noise ratio when collecting the electrocardiosignal signal. Meanwhile, through introducing the corresponding filter module and modulation demodulation circuit, the system isolating power line interference and electromagnetic clutter and improve the Clarity of electrocardiosignal signal.(2)Redesigning the Source Code of triggering signal in single-chip microcontroller, to ensure the sine wave signal which causing by constant current source module do not appeared the case of communications interruptions at the same time, the whole circuit system uses the circuit design of linear power supply and multipoint earthing, avoiding the possible noise jamming in the system.(3)The paper verify the operability of the three-dimensional electric field hardware circuit, comparing the animals electrocardiosignal obtained by the improved hardware circuit and the analog signals obtained by noise-reduction in the simulation analysis software, guaranteeing the reliability of the hardware circuit.(4)The paper set up a corresponding virtual instrument based on PXI bus technology, designing the industrial chassis, through multi-channel signals gathering and filtering at the same time. Finally, the signals is transformed between Analogue and Digital and analysed, what is more, the system establish the signal database, providing efficiently data references and practice foundation for scientific research institutions.