Prenatal identification of CHD murmur using four segment phonocardiographic signal analysis.

Congenital heart defects (CHD) are one of the utmost birth defects present in the neonatal after birth and a big challenge for the researchers to identify the structural abnormality during the antepartum period. An algorithm is presented here to identify the presence of CHD through foetal phonocardiographic (fPCG) signals. The recorded fPCG is decomposed using Daubechies4 wavelet with sub-level threshold to remove the noise in the signal. The Shannon energy is used to identify the different peaks of signals and then S1 and S2 according to the intervals between adjacent peaks. The signal is segmented into four important parts: S1, S1S2, S2 and S2S1. The FFT is used to identify the frequency component present in four segments which in turn indicates the presence of pathological murmur that may turn into CHD. The algorithm is tested on 25 samples with accuracy rate 88% in identifying the presence of a murmur.

Selection of mother wavelet and denoising algorithm for analysis of foetal phonocardiographic signals.

This paper is aimed at the selection of suitable mother wavelet and denoising algorithm for the analysis of foetal phonocardiographic (fPCG) signals. Fourier based analysing tools have some limitations concerning frequency and time resolutions. Although wavelet transform (WT) overcomes these limitations, it requires proper selection of a mother wavelet and denoising algorithm. In this study a suitable mother wavelet is selected on the basis of properties of different wavelet families and characteristics of the fPCG signals. The universal threshold, minimax threshold and rigorous SURE threshold algorithms along with soft or hard thresholding rule have been compared to denoise these signals. The mean squared error (MSE) is used to evaluate the performance of these algorithms. The results show that the fourth order Coiflets wavelet has a better performance for the analysis of fPCG signals when using the rigorous SURE threshold denoising algorithm with soft thresholding rule. The proposed approach is simple and proves to be effective when applied to the selection of suitable mother wavelet and denoising algorithm for the fPCG signals. These denoised signals can be used for the accurate determination of foetal heart rate (FHR) and further diagnostic applications of the foetus.

Time-frequency analysis of foetal heart sound signal for the prediction of prenatal anomalies.

Motion of the foetal heart gives rise to vibrations and sounds that can be acquired through the surface of the maternal abdominal wall. The process is called foetal phonocardiography (fPCG) and its study has shown to be a very useful mechanism to evaluate the wellbeing of the unborn. These signals exhibit innate rhythms and periodicity that are more readily expressed and appreciated in terms of frequency than time units. Time-frequency distribution shows the spectral composition of signal at a particular time instant, which is also known as a spectrogram. This work investigates the analysis of foetal heart sound using time frequency distribution generated by short-time Fourier transform (STFT). An innovative method is presented for foetal heart sound acquisition, processing and coloured spectral representation, which can be used in a portable foetal home monitoring system. The outcome of the work is a numerous spectral display produced by the system for varied real and simulated foetal heart sound signals. A comparative study of normal and abnormal heart sound is presented. The spectrograms exhibit noticeable morphological differences in terms of duration and spectral composition of the sounds. The study suggests that STFT based coloured spectrograms can become an important diagnostic tool, and it is expected that the presented work will facilitate the potential use of the method in prediction of the prenatal anomalies.

Effect of whole body gamma radiation on hepatic LDH activity, lactate, pyruvate concentration and rate of oxygen consumption in Bufo melanostictus.

Whole body Co60 gamma radiation induced changes in lactic dehydrogenase (LDH) activity, pyruvate, lactate content and rate of oxygen (O2) consumption in a tropical hibernating anuran (Bufo melanostictus). In 3.5 and 7 Gy treated groups, a significant increase in LDH activity and lactate/pyruvate ratio was observed, whereas a significant decrease in O2 consumption rate was observed in treated animals on post-irradiation day (PID) 1, 5 and 10. Increase in LDH activity was observed on PID-1 in both the treated groups, reached to a peak on PID-5 in 7 Gy treated group and then declined on PID-10.

An appraisal of post-irradiation metabolic changes in toad liver (Bufo melanostictus).

Whole body 60Co gamma irradiation of B . melanostictus with two sublethal doses of 3.5 and 7 Gy resulted in a significant increase (P < 0.001) in total lipid (hyperlipidemia), cholesterol content (hypercholesterolemia) and total free amino acid content, and significant decrease (P < 0.001) in total protein content in the liver tissues on post-irradiation day (PID) 1, 5 and 10 as compared to controls. The ratio of total lipid to cholesterol showed a gradual declining trend by PID-10 in the treated groups as compared to controls. However, it was more pronounced in the 7 Gy treated group. An observation on the ratio of total protein to total free amino acid content also showed a similar declining trend by PID-10 in both the treated groups as compared to controls.