Portable Ecg Monitor With High-capacity Flash Memory

Heart disease is one of the most prevalent diseases to endanger human's lives. ECG (Electrocardiograph) is an important reference for preventing and diagnosing heart disease. It has been proved that the most effective means for treating heart disease is to prevent and to protect from the clinical medicine practice. Heart disease is paroxysmal,so the patients repose impossibly in hospital for a long time. But they need to ward real-time,so it is very important to develop a portable ECG monitor.The portable Holter finished in this research is composed of two parts,the analog signal collection unit and the related data storage unit based on doulble C8051F processors. Considering the features of ECG signal,the former amplify circuit used a high performance instrument amplifier INA118. The signal buffer circuit,the right-leg drive circuit and the outside drive circuit were added in order to improve CMRR. The high accuracy 2nd order switched-capacitor filter LT1068-200 was adopted in the hardware filter to build 8nd Buterworth 50Hz trap filter. Then the signal was amplified for the second time and modified before sending to the master processor on-chip 12-bit ADC0.C8051F040 finished the signal's AD convertion and digital filter and wrote the result data into the dual-port RAM IDTIDT70V08S.The slave processor C8051F340 read the result data from the IDTIDT70V08S and stored them into the mass-storage NAND flash K9F2G08UXA. C8051F340 has the on-chip USB controller. With the assistance of the USB development kit,the device's API and the host's API have been used to simplified the USB port design between the slave processorand the PC's softwaredesigned by Labview8.5.The paper has discussed all the items mentioned above in detail and all the related unit has been realized to validate the feasibility of the design practically. The PC's software has been made by Labview8.5 to reproduce the ECG waveform. It also has established a firm foundation for the computer-aided analysis in the future.