Hardware Approach of R-Peak Detection for the Measurement of Fetal and Maternal Heart Rates

Fetal heart rate (FHR) monitoring is a routine for obtaining significant information about the fetal condition during pregnancy and labour. Fetal condition may change abruptly during the pregnancy period. Therefore, a continuous fetal electrocardiogram (FECG) monitoring will ease the fetal well-being. An algorithm has been developed to detect R-peak for the simultaneous measurement of the fetal and maternal hearts rates during pregnancy and labor for fetal monitoring. The algorithm is based on a cross-correlation, adaptive threshold and statistical properties in the time domain. The performance achieved for the R-peak detection for the heart rate measurements shows that the model can extract R-peak for both, mother and fetus utilizing a single-lead configuration. The algorithm has been implemented in the field of propagation gate array (FPGA). The design was synthesized and fitted into Altera's Stratix EP1S10 using the Quartus II platform because of its enhanced DSP capability. Test case results showed an error percentage of around +/- 0.3% and +/- 0.5% for the R-peak detection of maternal and fetal mortality respectively. The system is capable of running at a maximum clock frequency of 48.56MHz, and consumes 9633 logic elements, 101616 memory space and 4 units of DSP blocks.