Comparison of the actograms obtained using the actogramCOG and the actogramQRS: (a) Heart rate, (b) actogram, and (c) fetal movement quantified using ultrasound. The arrows indicate the time points noted as fetal movements by a clinical expert blinded to the results of the study. The “*” (at 424 s) indicates the fetal movement caused by maternal movement. In (a), the significant acceleration in fHR is shown by vertical dashed line. In (b), the significant movement detected using actogramCOG, is indicated by solid vertical lines. In (b), the y-axis range for the actogramQRS is adapted from the original work.11 The correlation coefficient and p value between the actogramCOG and actogramQRS in the instances of the fetal movements measured using ultrasound (shown in arrows) and also obtained objectively using actogramCOG are given in the inset.