Ibrahimy, Muhammad Ibn

The International Islamic University Malaysia Repository

ISSN 0276−6574 785 Computing in Cardiology 2010;37:785−788.786               Figure 5. Receiving file at server (RPMS).  The chat session module is intended to provide a mean of communication between the physician at RPMS and patient at LPMS are shown in Figure 6 and Figure 7 respectively so that it can be possible to provide important medical advice.    Figure 6. Chatting from server side (RPMS).       Figure 7. Chatting from client side (LPMS). 2.3. FECG extraction algorithm The system is required to record the FHR by processing the AECG signal acquired from the abdomen of pregnant women. The algorithm is a crucial part of the recorder for processing the AECG to detect the fetal and maternal R peaks for measuring the FHR and maternal heart rate (MHR).  The algorithm has been developed based on digital filtering, adaptive thresholding, and statistical properties in the time domain. The AECG signal is obtained from the maternal abdomen and first passed through a finite impulse response band pass filter (cut-off frequencies of 10 and 40 Hz) to remove baseline drift. The algorithm then detects the maternal QRS complexes by thresholding the maximum value of the match filter output. A maternal ECG (MECG) template is formed from successfully detected maternal QRS complexes using the R peak as the fiducial point.  The digital filter’s coefficients have been chosen to effectively pass the highest power density of the maternal and fetal R waves. The filtered signal has then been cross-correlated with an 80 ms averaged maternal QRS template, based on the normal width of the maternal QRS complex. An initial template resembling the QRS complex has been first used, and then continuously updated based on a running average of detected QRS complexes. The algorithm mainly contains various routines, the initialization, search for maternal R peak, update maternal template, search for maternal R peaks using updated template, validate and save the maternal RR interval, MECG template formation, subtract MECG template. Each sample data within these routines, notch filter, cross-correlation and local maximum search routines are performed.  The MECG template for subtraction is formed. The duration of this template is fixed, 160 ms before and 320 ms after the R peak instant, that the average MHR is less than 125 BPM and it can be easily include the maternal P and T waves, if any. First subtraction and MECG template formation are done simultaneously. The signal buffer are replaced by the MECG template which are initially set to zeros for the first subtraction of MECG complex by itself and the data samples associated the R peak. At the end of this routine, the samples of maternal QRS template are copied to the data memory of the maternal template section. To check the coincidences of the maternal with the fetal R waves, four latest maternal RR intervals are maintained in the data memory. The subroutine also identifies the position based on the R peak position in the signal buffer for the start of the subtraction window. The update subroutine adapts the thresholds according to the signal and noise levels and compares the latest RR interval with the RR interval limits. The local maximum values are then set to zero for further R wave search. The 787788

Emergency medical care information system for fetal monitoring

http://irep.iium.edu.my/25194/1/05738090.pdf

Emergency medical care information system for fetal monitoring

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