Performance of an automated Korotkoff sound BP monitor in cardiovascular patients

Objectives: Accurate blood pressure measurement is essential for cardiovascular risk management, but conventional oscillometric devices are unreliable for atrial fibrillation and arterial stiffness. We evaluated the accuracy of a novel automated Korotkoff sound-based monitor (Ksens-BP), integrating a semiconductor strain-gauge sensor and artificial intelligence waveform classification, compared to oscillometric (Oscillo-BP) and manual auscultatory (Auscl-BP) methods. Methods: This single-center prospective observational study enrolled adults with cardiovascular disease at National Cheng Kung University Hospital, Douliu Branch (October 2023–January 2024). Eligible conditions included hypertension, diabetes, atrial fibrillation, myocardial infarction, coronary artery disease, peripheral artery disease, stroke, or heart failure. Participants underwent three paired blood pressure (BP) measurements with Ksens-BP, Oscillo-BP, and Auscl-BP using a unified cuff system. Agreement was assessed with Auscl-BP assessed by concordance correlation coefficient (CCC). Hierarchical linear models (HLMs) examined the effects of comorbidities on measurement differences. Results: A total of 178 patients (mean age 67.4 years; 80% men) contributed 686 valid paired measurements. Ksens-BP demonstrated excellent agreement with Auscl-BP (SBP CCC = 0.952; DBP CCC = 0.945) compared with Oscillo-BP (SBP CCC = 0.903; DBP CCC = 0.851). Mean absolute differences were smaller with Ksens-BP than Oscillo-BP (SBP: 2 vs. 4.4 mmHg; DBP: 2.3 vs. 5.4 mmHg). Oscillo-BP accuracy was negatively affected by PAD and atrial fibrillation, whereas Ksens-BP performance was unaffected by comorbidities. Conclusion: The Ksens-BP system demonstrated superior accuracy and robustness, providing reliable BP measurement across complex cardiovascular populations.