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Cuffless Blood Pressure Estimation Using Cardiovascular Dynamics

Noninvasive estimation of blood pressure is important in preventing and managing cardiovascular disease. The cuffless technique has captured a lot of attention in recent years to unobtrusively provide continuous monitoring of blood pressure. This paper proposes a calibration-free approach, which makes use of dynamic changes of the pulse waveform over brief time intervals. Experimental results from two studies, the first using normalized intra-arterial blood pressure waveforms from 390 patients and the second using photoplethysmogram (PPG) waveforms from 200 patients, show that the accuracy of the proposed method for estimating the diastolic blood pressure (DBP) falls within the accuracy criteria of the Association for Advancement of Medical Instrumentation/European Society of Hypertension/International organization for Standardization (AAMI/ESH/ISO) standard and achieves grade B based on the British Hypertension Society (BHS) standard. In addition, a correlation of 99.4% was found between the inter-beat intervals (IBIs) obtained from the PPG and the intra-arterial waveforms in 390 patients. This paper demonstrates the possibility of using the PPG signal for estimation of blood pressure based on analysis of dynamic changes in the IBI.