[Comparative clinical study on the accuracy of conventional and electronic blood pressure self-measuring devices...

19 conventional and 19 electronic blood pressure measuring devices were tested on a average of 23 patients each. The patients were classified according to age, sex, and experience in blood pressure measurement. Altogether, the accuracy of the electronic devices was inferior to that of the conventional apparatus. Especially the diastolic blood pressures were estimated considerably too low by the electronic devices. Furthermore, these instruments were more sensitive to a false position of the microphone membrane than the conventional devices and they showed, in the average, greater differences between two exemplars of the same instrument. Blood pressure readings with conventional devices were significantly influenced by the patients' experience (systolic blood pressure) and age (diastolic blood pressure), whereas the readings with electronic machines were significantly affected by the patients' sex (systolic and diastolic blood pressure) and age (diastolic blood pressure). The result of the technical development of blood pressure devices for self-measurement is rather disappointing, especially with respect to costs and benefits.