The development of PC-based fetal monitoring and analysis system

Digital fetal monitoring system based on the personal computer combined with the low cost, minimum system digital signal processing (DSP) board is implemented. The DSP board acquires the ultrasound fetal Doppler signal and processes digital rectification, FIR filtering, autocorrelation function calculation, its peak detection and median filtering for fetal heart rate estimation. It also processes the toco signal and fetal movement. The authors used a recursive technique for autocorrelation calculation and median filtering which greatly reduces the amount of calculation and increases the accuracy. The authors also implemented various kinds of analysis algorithm of fetal heart rate change based on the more than 5000 normal sample data for computer assisted diagnosis.