[Comparison of the automatic sphygmo-oscillographic and auscultation methods of blood pressure measurements]

Abstract

Sphygmomanometer S is the microcomputer device measuring blood pressure for (BP) on the basis of amplitude height and morphology of pulse waves, registered by the pulse converter placed in the air system of a cuff. The letter S stands the sphygmo-oscillographic method used in BP measurement (11). Sphygmomanometer S may be used to determine BP in infants, babies, children and adults (9, 10, 11, 12). The BP measurement results obtained in this way approximate the results of a direct method (1, 3, 8, 14). In order to carry out the simultaneous BP measurement by the sphygmo-oscillographic and the ascultatory methods, sphygmomanometer S was connected trough a manufactured Y-shaped joint with the aneroid-sphygmomanometer manufactured by INCO. This type of connection enabled the measurement to be realized with one cuff and both sphygmomanometers coincidentally. The measurement results of the systolic, diastolic and mean pressures, determined by the sphygmo-oscillographic method, were read from the sphygmomanometer S digital display. At the same time, the Korotkov tones were listened to through the stethscope placed over the brachial artery. The first phase of Korotkov tones was considered to be the systolic pressure while the fourth phase was the diastolic one. The mean pressure is determined by the sphygmomanometer S on the basis of the pulse wave peak amplitudes. In other words, pressure in the cuff, corresponding to the peak pulse waves, is the mean. However, in the ausculatory method, the mean pressure was calculated from the formula; Pm = Pd + 0,4 (Ps-Pd) where 'Pm is the mean pressure, Pd--the diastolic pressure and Ps the systolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)