Abstract
Medical treatments for hypertension have made to avoid myocardial infarction and cerebral hemorrhage. Over-dosage is dangerous. It causes the reduction of blood pressure during sleep. It is important to presume the variation of blood pressure after drug administration from the fluctuation of blood pressure before drug administration to prevent a secondary reaction and to improve the quality of life. In this paper, a 24-hour mean blood pressure in 12 essential hypertensive subjects was measured. Power spectrum and phase spectrum in mean blood pressure time series are obtained by a FFT. Power spectrum and phase spectrum were discussed before and after drug administration. According to the relationships of power spectrum and phase spectrum before and after drug administration, mean blood pressure time series after drug administration would be presumed.
