Padre Conceicao College of Engineering, Goa, India.
Goa University, Goa, India.
J Healthc Eng. 2018 Mar 29;2018:5485728. doi: 10.1155/2018/5485728. eCollection 2018.
Fetal heart rate (FHR) detection can be monitored using either direct fetal scalp electrode recording (invasive) or by indirect noninvasive technique. Weeks before delivery, the invasive method poses a risk factor to the fetus, while the latter provides accurate fetal ECG (FECG) information which can help diagnose fetal's well-being. Our technique employs variable order linear phase sharp transition (LPST) FIR band-pass filter which shows improved stopband attenuation at higher filter orders. The fetal frequency fiduciary edges form the band edges of the filter characterized by varying amounts of overlap of maternal ECG (MECG) spectrum. The one with the minimum maternal spectrum overlap was found to be optimum with no power line interference and maximum fetal heart beats being detected. The improved filtering is reflected in the enhancement of the performance of the fetal QRS detector (FQRS). The improvement has also occurred in fetal heart rate obtained using our algorithm which is in close agreement with the true reference (i.e., invasive fetal scalp ECG). The performance parameters of the FQRS detector such as sensitivity (Se), positive predictive value (PPV), and accuracy (F) were found to improve even for lower filter order. The same technique was extended to evaluate maternal QRS detector (MQRS) and found to yield satisfactory maternal heart rate (MHR) results.
胎儿心率 (FHR) 检测可以通过直接胎儿头皮电极记录（侵入性）或间接非侵入性技术进行监测。在分娩前几周，侵入性方法对胎儿构成风险因素，而后者提供准确的胎儿心电图 (FECG) 信息，有助于诊断胎儿的健康状况。我们的技术采用变阶线性相位急剧过渡 (LPST) FIR 带通滤波器，在较高的滤波器阶数下显示出改进的阻带衰减。胎儿频率基准边缘形成滤波器的带边缘，其特征是母体心电图 (MECG) 频谱的重叠量不同。发现具有最小母体频谱重叠的滤波器是最佳的，没有电源线干扰，并且可以检测到最大数量的胎儿心跳。改进的滤波反映在胎儿 QRS 检测器 (FQRS) 的性能增强上。使用我们的算法获得的胎儿心率也得到了改善，与真实参考（即侵入性胎儿头皮 ECG）非常吻合。FQRS 检测器的性能参数，如灵敏度 (Se)、阳性预测值 (PPV) 和准确性 (F)，即使在较低的滤波器阶数下也有所提高。该技术还扩展到评估母体 QRS 检测器 (MQRS)，并发现可获得令人满意的母体心率 (MHR) 结果。
