Augmented blood pressure measurement through the noninvasive estimation of physiological arterial pressure variability

Abstract

Current noninvasive blood pressure (BP) measurement methods, such as the oscillometric method, estimate the systolic and diastolic blood pressure (SBP and DBP) at two random instants in time and do not take into account the natural variability in BP. The standard for automated BP devices sets a maximum allowable system error of ±5 mmHg, even though natural BP variability often exceeds these limits. This paper proposes a new approach using simultaneous recordings of the oscillometric and continuous arterial pulse waveforms to augment the conventional noninvasive measurement by providing (1) the mean SBP and DBP over the measurement interval and the associated confidence intervals of the mean, (2) the standard deviation of SBP and DBP over the measurement interval, which indicates the degree of fluctuation in BP and (3) an indicator as to whether or not the oscillometric reading is an outlier. Recordings with healthy subjects demonstrate the potential utility of this approach to characterize BP, to detect outlier measurements, and that it does not suffer from bias relative to the conventional oscillometric method.

Oscillometric measurement of systolic and diastolic blood pressures validated in a physiologic mathematical model

“…In the auscultatory method the appearance of the Korotkoff sounds similarly denotes systolic pressure, and disappearance or muffling of the sounds denotes diastolic pressure. In the oscillometric method the cuff pressure is high pass filtered to extract the small oscillations at the cardiac frequency and the envelope of these oscillations is computed, for example as the area obtained by integrating each pulse [3]. These oscillations in cuff pressure increase in amplitude as cuff pressure falls between systolic and mean arterial pressure.…”

Uncertainty in Blood Pressure Measurement Estimated Using Ensemble-Based Recursive Methodology

“…Soueidan et al also proposed a new method to augment the noninvasive measurement by providing the mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) with CIs [15]. However, these methods did not satisfy the allowable bias specified by the standard protocol [16].…”

Support Vector Regression-Based Recursive Ensemble Methodology for Confidence Interval Estimation in Blood Pressure Measurements

“…Hence, a bootstrap technique was proposed to obtain a CI estimate from BP measurements using a small sample size [9]. Soueidan et al also developed a new technology for noninvasive measurement by providing CI to SBP and DBP [10]. Nevertheless, these techniques did not meet the tolerable bias specified by the standard protocol [11].…”