aBiomedical Systems Research Laboratory, University of New South Wales

bConcord Repatriation Hospital, Cardiology, University of Sydney

cFaculty of Medicine, Health and Human Sciences, Macquarie University

dGraduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia

Correspondence to Branko G. Celler, University of New South Wales – Kensington Campus: University of New South Wales, Sydney, Australia. Mobile: +61 418 228 297; fax: +61 2 9385 5993; e-mail: [email protected]

Abbreviations: CDR, absolute value of Cuff deflation rate (mmHg/s); Age, age in years; AI, augmentation index (%) before cuff inflation; ANOVA, analysis of variance; CIR, Cuff Inflation rate (mmHg/s); CP-Peak, peak cuff pressure (mmHg); DBP-Error, difference IA-DBP-DBP-K; DBP-K, estimate of IA-DBP from K4/K5 of KS; dPdtmax, Max dPdt of IABP pulse (μm/m) before cuff inflation; ECG, Lead I Electrocardiogram signal; Est-MP, estimated MP before cuff inflation (DBP+PP/3); Gender, gender (F/M); HR, heart rate before cuff inflation; HR-AC, heart rate during artery occlusion; IA-AO, intra-arterial pressure at first artery opening; IABP-dP, IA-SBP - IA-AO; IA-DBP, intra-arterial DBP before cuff inflation; IA-MP, intra-arterial MP before cuff inflation; IA-SBP, intra-arterial SBP before cuff inflation; KS, raw sampled Korotkoff sound; KSE, Korotkoff sound energy (rms Volts); LOSOCV, Leave-One-Subject-Out Cross-validation; MP-OWE, MP from peak of OWE; PP, pulse pressure before cuff inflation; PPG, photoplethysmogram signal; PWV, pulse wave velocity (m/s) before cuff inflation; RMS, root mean square; RPC, reproducibility coefficient (1.96×SD); SBP-error, difference IA-SBP - SBP-K; SBP-K, estimate of IA-SBP from K1 of KS; SD, standard deviation; SSE, sum of squared error

Received 12 September, 2023

Revised 13 December, 2023

Accepted 13 December, 2023