Harmonic variations of arterial pulse during dying process of rats

"Death" is often the largest issue people must face, but it is even more so in the medical field. Accurate forecasting of death not only has positive significance in treatment but also great helps the doctor-patient relationship and the economics of medical treatment. However, accurate forecasting is not easy, so many studies to generate forecasting systems have been conducted. In this experiment, a fatal dose of anesthetics, urethane, was injected into the abdomen of rats. Blood pressure waves in the rats' caudate arteries were then recorded during the dying process, and an analysis was conducted on the harmonics of the Fourier transform obtained. Of the 24 rats used in the experiment, 18 died and 6 survived. When a Kappa test was performed on the coefficient variation of the fourth harmonic magnitude (C.V.4) for the two groups of rats, it was found that when C.V.4 exceeded 1.7, the Kappa value was 0.75. This shows that during the death process the coefficiency variation of the fourth harmonic magnitude clearly increases.