Improving the quality and accuracy of non-invasive blood pressure measurement by visual inspection and automated signal processing of the Korotkoff sounds

Abstract

We conclude that large intra-personal variability in Korotkoff signal morphology and amplitudes, as well as variations in the hearing acuity of the operator, make accurate NIBP measurements using sphygmomanometry difficult and should not be used as the gold standard against which automated NIBP devices are calibrated. We propose an alternative method of visualizing the energy of the Korotkoff sounds and applying simple algorithms to determine systolic and diastolic pressure points, which whilst mimicking classical sphygmomanometry eliminates the problems associated with operator hearing acuity and complex and variable Korotkoff signal morphology.

Novel methods of testing and calibration of oscillometric blood pressure monitors

“…In Phase 1 of this study we use an industry standard NIBP simulator to determine the characteristic ratios used in a number of NIBP monitors available in the market and to explore differences between them. In Phase 2, we then make the assumption that classical auscultatory sphygmomanometry provides the best approximation to intra-arterial pressure [ 1 , 2 , 4 , 5 , 8 , 9 ], and directly compare the results obtained from oscillometric measurements for a range of characteristic ratios, against a modified auscultatory method [ 3 , 7 ]. This method accurately determines systolic pressure from simultaneous recordings of the blood pressure trace, the oscillometric waveforms and the Korotkoff sounds.…”

“…Numerous studies [ 3 – 8 ] point out that there are considerable inter-operator differences in estimating blood pressure using classical sphygmomanometry, particularly with the determination of diastolic pressure [ 5 , 6 ]. In previous studies [ 3 , 7 ], we presented data to suggest that the accuracy of sphgmomanometry is dependent on (i) the hearing acuity of the operator, (ii) the amplitude and particular waveform morphometry of the Korotkoff sounds, and (iii) the sensitivity of the stethoscope.…”

Towards wearable blood pressure measurement systems from biosignals: a review

“…Vierordt's instrument had measurement errors. Basch [26] took more accurate measurements using a device that was attached to a wrist cuff and could be filled with water, for the first time in 1881. In 1896, Riva-Rocci measured the blood pressure with a manometer with an air fillable cuff that he connected to the arm.…”

Response to exercise‐induced blood pressure elevation is blunted in wrist‐cuff automated oscillometric measurement in healthy young college students

“…However, mercury-containing products have recently been restricted from the viewpoint of environmental protection, and the use of mercury sphygmomanometers is expected to decrease (Asayama et al, 2016). In addition, the auscultatory method requires training for stable BP measurement and lacks objectivity, leading to inter-operator differences (Celler, Le, Basilakis, & Ambikairajah, 2017). Furthermore, the auscultatory method is not suitable for self-monitoring of BP, which is considered to be more important than office BP monitoring to prevent cardiovascular events (Noguchi et al, 2013).…”