Research Article Linear Phase Sharp Transition BPF to Detect Noninvasive Maternal and Fetal Heart Rate Niyan Marchon , 1 Gourish Naik , 2 and K. R. Pai 1 1 Padre Conceicao College of Engineering, Goa, India 2 Goa University, Goa, India Correspondence should be addressed to Niyan Marchon; niyanmarchon@gmail.com Received 21 July 2017; Accepted 21 January 2018; Published 29 March 2018 Academic Editor: John S. Katsanis Copyright © 2018 Niyan Marchon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 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 1 ) 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. 1. Introduction All over the world, approximately 2.65 million stillbirths occur during pregnancy or labour especially in developing countries giving rise to the need for effective monitoring techniques with regard to fetal health [1]. FHR monitoring is important to recognize pathologic conditions, typically asphyxia, with sufficient warning so as to enable interven- tion by the clinician [2]. It is a screening modulus of the fetus to detect problems in advance that could result in irreversible neurological damage, even fetal death [3]. More than 85 percent of all live births in the United States undergo electronic fetal monitoring [4]. Indeed, fetal health monitoring has a significant importance in obstetri- cal procedures and is now widely accepted as the need of the hour. With electronic fetal monitoring (EFM), the following expectations came: provision of accurate FECG information, information of value in diagnosing fetal distress, prevention of fetal death or morbidity, and superiority over many methods. The fetus can be monitored electronically by two methods: direct and indirect. In the direct invasive method, the FHR is measured by a scalp electrode which is attached to the fetal scalp by means of a coiled electrode [5]. In the indirect electronic monitoring method, such as using ultra- sound Doppler principle with uterine contractions, FHR can be monitored but not as precisely as the direct invasive FECG [2]. However, the invasive procedure has a risk of infection to the fetus. The ultrasound transducer with the coupling gel is applied to the mother’s abdomen where fetal heart response is best detected. During this measurement, the pulsations of the maternal aorta could be detected and erroneously considered as FHR [6]. The noninvasive FECG (NIFECG) by indirect method can therefore be used to over- come all these limitations by placing the surface electrodes such as the 12 lead ECG electrodes over the maternal Hindawi Journal of Healthcare Engineering Volume 2018, Article ID 5485728, 14 pages https://doi.org/10.1155/2018/5485728