Cardiovascular disease is the number 1 cause of death globally, with elevated blood pressure (BP) being the single largest risk factor. Hence, BP is an important physiological parameter used as an indicator of cardiovascular health. Noninvasive cuff-based automated monitoring is now the dominant method for BP measurement and irrespective of whether the oscillometric or the auscultatory method is used, all are calibrated according to the Universal Standard (ISO 81060-2:2019), which requires two trained operators to listen to Korotkoff K1 sounds for SBP and K4/K5 sounds for DBP. Hence, Korotkoff sounds are fundamental to the calibration of all NIBP devices. In this study of 40 lightly sedated patients, aged 64.1 ± 9.6 years, we compare SBP and DBP recorded directly by intra-arterial fluid filled catheters to values recorded from the onset (SBP-K) and cessation (DBP-K) of Korotkoff sounds. We demonstrate that whilst DBP-K measurements are in good agreement, with a mean difference of -0.3 ± 5.2 mmHg, SBP-K underestimates true intra-arterial SBP (IA-SBP) by an average of 14 ± 9.6 mmHg. The underestimation arises from delays in the re-opening of the brachial artery following deflation of the brachial cuff to below SBP. The reasons for this delay are not known but appear related to the difference between SBP and the pressure under the cuff as blood first begins to flow, as the cuff deflates. Linear models are presented that can correct the underestimation in SBP resulting in estimates with a mean difference of 0.2 ± 7.1 mmHg with respect to intra-arterial SBP.

中文翻译：

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柯氏音的准确检测揭示了动脉内收缩压与臂带血压计同步无创测量血压之间的巨大差异。

心血管疾病是全球第一大死因，其中高血压 (BP) 是最大的单一危险因素。因此，血压是用作心血管健康指标的重要生理参数。基于无创袖带的自动监测现在是血压测量的主要方法，无论使用示波法还是听诊法，都根据通用标准（ISO 81060-2:2019）进行校准，需要两名经过培训的操作员对于 SBP 听 Korotkoff K1 声音，对于 DBP 听 K4/K5 声音。因此，柯氏音是所有 NIBP 设备校准的基础。在这项对 40 名年龄为 64.1 ± 9.6 岁的轻度镇静患者的研究中，我们将通过动脉内液体填充导管直接记录的 SBP 和 DBP 与柯氏音开始 (SBP-K) 和停止 (DBP-K) 记录的值进行比较。我们证明，虽然 DBP-K 测量值非常一致，平均差为 -0.3 ± 5.2 mmHg，但 SBP-K 低估了真实动脉内 SBP (IA-SBP)，平均为 14 ± 9.6 mmHg。低估是由于肱动脉收缩压低于收缩压后肱动脉重新开放的延迟造成的。这种延迟的原因尚不清楚，但似乎与收缩压和袖带放气时血液首先开始流动时袖带下压力之间的差异有关。提出的线性模型可以纠正 SBP 的低估，从而导致估计值与动脉内 SBP 的平均差异为 0.2 ± 7.1 mmHg。