A Finger Volume-Oscillometric Device for Monitoring Ambulatory Blood Pressure: Laboratory and Clinical Evaluations

Abstract

A new portable device for the indirect measurement of ambulatory blood pressure in the finger was successfully applied to normotensive and hypertensive subjects in and outside a ward setting. The device uses the volume-oscillometric technique and, equipped with a microprocessor, permits long-term ambulatory monitoring of indirect systolic and mean blood pressure at desired intervals (once every 1-10 min). Systolic and mean blood pressures obtained by this method were well correlated with those measured by the direct (Oxford) and arm-cuff methods. Systolic and diastolic blood pressure obtained by the volume-oscillometric device were almost identical with those recorded by an arm-cuff. Systolic blood pressure obtained by the volume oscillometric method was, however, significantly lower than that measured by the direct method. The new device has also been used to measure blood pressure during treadmill exercise and ice-water immersion. Mean values of blood pressure and the SD of these averaged for 24 hours, or for every hour, were reproducible when the measurements were repeated under the same condition. The present device is portable, causes minimal noise, can detect rapid change in blood pressure and causes less discomfort when compared to the conventional arm-cuff method. Regular measurements can be made with minimal sleep disturbance. This fully automatic volume-oscillometric device allows reliable 24-hour monitoring of ambulatory blood pressure not only in but also outside a ward setting, and as such is useful for studies of hypertension.

Differential effects of antihypertensive drugs with differing pharmacological properties on the basal ambulatory blood pressure

“…However, BP was measured at least every 30 min for 24 h. Artifactual readings were edited out according to previously described criteria. 5 'Nighttime' was defined as 23.00 to 05.00 h and 'daytime' as 08.00 to 21.00 h. Drug compliance was examined by each physician in each institution using pill count. When the subjects were defined as non-compliant, these were not registered in the present database.…”

How many measurements are needed to provide reliable information in terms of the ambulatory arterial stiffness index? the Ohasama study

“…In agreement with current guidelines, 13 we defined ambulatory hypertension as an awake blood pressure of at least 135 mm Hg systolic or 85 mm Hg diastolic, or use of antihypertensive drugs. From 24-h recordings edited according to previously published criteria, 14 we computed for each participant the regression slope of diastolic on systolic blood pressure. 1,2 We did not force the regression line through the origin (intercept¼0) because during diastole when flow drops to zero, such phenomenon does not occur for blood pressure 15 We defined AASI as one minus the regression slope.…”

Potential for Health Screening Using Long-Term Cardiovascular Parameters Measured by Finger Volume-Oscillometry: Pilot Comparative Evaluation in Regular and Sleep-Deprived Activities

“…Pulse pressure (PP) is calculated by subtracting DBP from SBP. This finger volume-oscillometric method has previously been clinically validated against direct (Oxford) and conventional upper arm-cuff methods using normotensive and hypertensive subjects [26], [27]. In addition, we have already compared BP values obtained with the present instrument to those obtained with the conventional upper arm-cuff method in a previous report (in Japanese) [12].…”