Non-invasive fetal electrocardiogram measurements Adviser ：蔡亮宙 Student ；蔡政宏

 Non-invasive fetal electrocardiogram measurements have the potential to monitor and reduce newborn clinical complications. Fetal electrocardiogram signals, however, are relatively weak and difficult to extract from the maternal electrocardiogram signal and other sources of interference. Abstract

 Electrocardiography is the recording of the electrical activity of the heart. Traditionally this is in the form of a transthoracic (across the thorax or chest) interpretation of the electrical activity of the heart over a period of time,  as detected by electrodes attached to the surface of the skin and recorded or displayed by a device external to the body.  The recording produced by this noninvasive procedure is termed an electrocardiogram (also ECG or EKG). Principle of ECG

 This study outlines the design of a precise and highly parallel monitor for detecting and quantifying low-level fetal electrical ECG signals.  An ECG hardware simulator capable of simulating fetal and maternal ECG pulses is constructed to test the apparatus. A precision instrumentation amplifier is designed and implemented.  A microprocessor and field  programmable gate array (FPGA) are interfaced to the analog front end via a precision multi-channel analog to digital converter (A/D). Using the hardware simulator,  preliminary data is presented to illustrate the feasibility of the overall architecture for extracting low level ECG signals from interference. This study outlines

System Block Diagram

Hardware Electrocardiogram Simulator

Analog Pre-Amplification, Filtering, and Gain Stages

A fourth-order low-pass Bessel filter stage

shows the analog unfiltered ECG signal

ECG

 A high performance ECG monitoring system has been  designed to allow up to 32 channels of simultaneous leads to be sampled. The system is interfaced to a cortex M4 microprocessor and Virtex-7 field programmable gate array to allow real time processing. Preliminary testing indicates that this precision, highly parallel architecture has the capacity to extract low-level fetal ECG signals surrounded by a background of interfering maternal and noise signals. CONCLUSION

 [1] Chris D. Samuel and Anthony E. English, “A Fetal Electrocardiogram Data Acquisition and Analysis System ” IEEE Trans th Annual Northeast Bioengineering Conference  [2]Siamak Ebadi 2, and Saeid Sanei, “ Fetal Electrocardiogram Signal Modelling Using Genetic Algorithm ” IEEE Trans International Workshop on Medical Measurements and Applications - MeMeA 2007Warsaw, Poland, May 4-5, 2007 REFERENCES 表 1 、導電布比較