Novel methods of testing and calibration of oscillometric blood pressure monitors

• Published in: PloS one Vol. 13; no. 8; p. e0201123
• Main Authors: Celler, Branko G., Argha, Ahmadreza, Le, Phu Ngoc, Ambikairajah, Eliathamby
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.08.2018; Public Library of Science (PLoS)
• Subjects: Acoustics; Adult; Aged; Aged, 80 and over; Algorithms; Artificial intelligence; Bioengineering; Biomedical engineering; Blood; Blood Pressure; Blood Pressure Determination - instrumentation; Blood Pressure Determination - standards; Blood Pressure Determination - statistics & numerical data; Blood pressure measurement; Blood Pressure Monitors - standards; Blood Pressure Monitors - statistics & numerical data; Calibration; Catheters; Communications networks; Computer simulation; Databases, Factual; Devices; Electrical engineering; Engineering and Technology; Female; Fuzzy logic; Health aspects; Humans; Industry standards; Laboratories; Male; Medicine and Health Sciences; Middle Aged; Monitors; Optimization; Oscillometry - instrumentation; Oscillometry - standards; Oscillometry - statistics & numerical data; Physical Sciences; Physiology; Pressure measurement; Rangefinding; Ratios; Research and Analysis Methods; Standard deviation; Systolic pressure; Test procedures; Veins & arteries; Waveforms; Young Adult; Japan; Germany; Australia; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0201123

We present a robust method for testing and calibrating the performance of oscillometric non-invasive blood pressure (NIBP) monitors, using an industry standard NIBP simulator to determine the characteristic ratios used, and to explore differences between different devices. Assuming that classical auscultatory sphygmomanometry provides the best approximation to intra-arterial pressure, the results obtained from oscillometric measurements for a range of characteristic ratios are compared against a modified auscultatory method to determine an optimum characteristic ratio, Rs for systolic blood pressure (SBP), which was found to be 0.565. We demonstrate that whilst three Chinese manufactured NIBP monitors we tested used the conventional maximum amplitude algorithm (MAA) with characteristic ratios Rs = 0.4624±0.0303 (Mean±SD) and Rd = 0.6275±0.0222, another three devices manufactured in Germany and Japan either do not implement this standard protocol or used different characteristic ratios. Using a reference database of 304 records from 102 patients, containing both the Korotkoff sounds and the oscillometric waveforms, we showed that none of the devices tested used the optimal value of 0.565 for the characteristic ratio Rs, and as a result, three of the devices tested would underestimate systolic pressure by an average of 4.8mmHg, and three would overestimate the systolic pressure by an average of 6.2 mmHg.