Blind source separation in characterizing ECG pre-shock waveforms during Ventricular Fibrillation.

Ventricular Fibrillation (VF) is a cardiac arrhythmia for which the only available treatment option is defibrillation by electrical shock. Existing literature indicates that VF could be the manifestation of different sources controlling the heart with different degrees of organization. In this work we test the hypothesis that the pre-shock waveforms of successful and unsuccessful shock outcomes could be related to the number of independent sources present in these waveforms. The proposed method uses Blind Source Separation (BSS) to extract independent components in frequency direction from a pig database consisting of 20 pre-shock waveforms. The slope of the energy capture curve was used as an indicator to demonstrate the number of independent sources required to model the pre-shock waveforms. The results were also quantified by performing a linear discriminant analysis based classification achieving an overall classification accuracy of 75%. The results indicate that successful cases can be modeled with less number of independent sources compared to unsuccessful cases.

Prevalence of antibody to Brucella species in butchers, slaughterers and others.

Brucellosis is being reported with increasing frequency in the Islamic Republic of Iran. Serum antibodies in high-risk and general populations help to define cut-off levels and can be used as a simple and rapid diagnostic tests in infected areas. We performed the rose Bengal test (RBT), serum agglutination test (SAT) and 2-mercaptoethanol (2ME) titre determination on 415 healthy individuals including butchers, slaughterers and others. Positive results were found by RBT, SAT titre (1:80) and 2ME titre > or = 1:20 in slaughterers (10%, 20% and 6% respectively), butchers (6%, 4% and 1% respectively) and the general population (1%, 2% and < 1% respectively). A single SAT titre > or = 1:80 in the presence of 2ME titre > or = 1:20 can be diagnostic in this region.