Patient-Specific Oscillometric Blood Pressure Measurement: Validation for Accuracy and Repeatability

Abstract

Oscillometric devices are widely used for automatic cuff blood pressure (BP) measurement. These devices estimate BP from the oscillometric cuff pressure waveform using population average methods. Hence, the devices may only be accurate over a limited BP range. The objective was to evaluate a new patient-specific method, which estimates BP by fitting a physiologic model to the same waveform. One-hundred and forty-five cardiac catheterization patients and normal adults were included for study. The oscillometric cuff pressure waveform was obtained with an office device, while reference BP was measured via brachial artery catheterization or auscultation, during baseline and/or nitroglycerin administration. Fifty-seven of the subject records were utilized for refining the patient-specific method, while the remaining 88 subject records were employed for evaluation. The precision errors for all BP levels of the patient-specific method ranged from 6.3 to 7.6 mmHg. These errors were significantly lower than those of the office device (by 29% on average) in subjects with high pulse pressure (>50 mmHg) while being comparable to those of the device in subjects with normal pulse pressure (<50 mmHg). The bias and precision of the differences in repeated estimates for all BP levels of the patient-specific method ranged from 0.1 to 1.1 and 2.1 to 5.9 mmHg, respectively. These precision differences were significantly lower than those of the office device (by 64% on average). The patient-specific method may afford more accurate automatic cuff BP measurement in patients with large artery stiffening while limiting the number of required cuff inflations/deflations per measurement.

Noninvasive Cardiac Output and Central Systolic Pressure From Cuff-Pressure and Pulse Wave Velocity

“…This can limit the accuracy of the device in a certain pressure range. A noteworthy approach has been proposed by Liu et al [57]. They used a physiologic model in conjunction with model fitting [58].…”

Smartphone-based blood pressure monitoring via the oscillometric finger-pressing method

“…However, by also studying experienced users during a hydrostatic challenge, we were able to extend the tested range of each BP measurement to 40 to 50 mmHg. The device may be improved by leveraging additional sensing to confirm correct device usage, by mitigating the adverse effect of finger vascular tone changes via inclusion of a temperature sensor to assess cold-induced finger vasoconstriction, or by applying a physics-based algorithm to compute both BP and the arterial compliance curve (rather than an empirical algorithm, which may implicitly assume invariant arterial compliance curves despite finger vascular tone changes) ( 29 ). The smartphone could also warn users of high BP, securely transmit the measured BP to caregivers, and send text reminders to patients with uncontrolled BP to take their medications.…”

“…In this equation, x and y are the abscissa and ordinate, respectively, of the oscillogram, and A i and B i are the parameters that define the oscillogram. This equation models the oscillogram as an asymmetric function, as justified elsewhere ( 29 ), via two half Gaussian functions. As illustrated to the right of Eq.…”

Central blood pressure for the management of hypertension: Is it a practical clinical tool in current practice?

“…In a recently published systematic review, cuff BP has variable accuracy for measuring either brachial or aortic intra‐arterial BP, which adversely influences correct BP classification and inevitably makes waveform calibration inadequate. Therefore, the measurement accuracy of both noninvasive brachial and central BP still has room for improvement . Recently, World Hypertension League, International Society of Hypertension, and other supporting hypertension organizations have together issued a position statement to call for regulating manufacture and marketing of BP devices and cuffs .…”