Portable blood pressure recorder Accuracy and preliminary use in evaluating intradaily variations in pressure

The portable blood pressure recorder described in this report offers a practical technique for determining intradaily variations in the level of pressure. The instrument is worn by the subject, enabling him to record his blood pressure at frequent intervals during the day while in his usual environment and performing his usual tasks. The readings are taken semiautomatically, and the aid of a physician or technician is not required. The subject does not know the levels recorded by the instrument. Preliminary observations on normotensive subjects showed that the portable recorder is sufficiently accurate for clinical purposes. In additional experiments, 3 subjects recorded their levels of pressure at intervals while carrying out their daily routines. The results indicated that the portable recorder provides valid data on variations in blood pressure throughout the day. Expanded studies on hypertensive patients should yield useful information for evaluating the highly variable natural history of hypertension.