Comparisons of blood pressure measurements by auscultation and Physiometrics Infrasonde recording techniques.

The levels of blood pressures measured by a Physiometrics Infrasonde recorder (model SR-2) were compared with the levels simultaneously measured byt auscultation utilizing a standard mercury sphygmomanometer (Baumanometer). The measurements were made on 1530 adult women and their 1760 adolescent children 15-17 years old. Two sets of blood pressures were taken about 3 minutes apart, each with an occluding cuff connected to the Physiometrics recorder as well as to the mercury sphygmomanometer. The reproducibility of the Physiometrics method was similar to that of the auscultation method. The means of the systolic pressures measured by the Physiometrics method were virtually equal to those of the auscultation method for women and girls; for boys, the means of the former method surpassed those of the latter by about 3 mm. The mean diastolic pressures by the Physiometric method were very close to the Korotkoff sound 5 (K5) pressure by the auscultation method for all three groups. The correlation coefficients between both methods were 0.98 for the systolic and 0.93 for the diastolic pressure of the adult women, and 0.94 for the systolic pressure of the adolescents. The correlations between the two diastolic pressures of adolescents were much less (0.69). The Physiometrics measurements were consistent with the measurements by auscultation for systolic and diastolic pressures of women and systolic pressure of adolescents, but the consistency was low for diastolic pressure of adolescents. An effort has been made to relate differences between the two methods with other anthropometric variables, but the correlations with these variables were of low level.