Electrocardiogram-Assisted Blood Pressure Estimation

Abstract

Accurate automatic noninvasive assessment of blood pressure (BP) presents a challenge due to conditions like arrhythmias, obesity, and postural changes that tend to obfuscate arterial amplitude pulsations sensed by the cuff. Researchers tried to overcome this challenge by analyzing oscillometric pulses with the aid of a higher fidelity signal-the electrocardiogram (ECG). Moreover, pulse transit time (PTT) was employed to provide an additional method for BP estimation. However, these methods were not fully developed, suitably integrated, or tested. To address these issues, we present a novel method whereby ECG-assisted oscillometric and PTT (measured between ECG R-peaks and maximum slope of arterial pulse peaks) analyses are seamlessly integrated into the oscillometric BP measurement paradigm. The method bolsters oscillometric analysis (amplitude modulation) with more reliable ECG R-peaks provides a complementary measure with PTT analysis (temporal modulation) and fuses this information for robust BP estimation. We have integrated this technology into a prototype that comprises a BP cuff with an embedded conductive fabric ECG electrode, associated hardware, and algorithms. A pilot study has been undertaken on ten healthy subjects (150 recordings) to validate the performance of our prototype against United States Food and Drug Administration approved Omron oscillometric monitor (HEM-790IT). Our prototype achieves mean absolute difference of less than 5 mmHg and grade A as per the British Hypertension Society protocol for estimating BP, with the reference Omron monitor.

Cuffless Blood Pressure Estimation Algorithms for Continuous Health-Care Monitoring

“…On the other side, in many works, the Pulse Transit Time (PTT), the time interval that heart beat transfers to a body peripheral, is used for the PWV estimation. Ahmad et al [5] and Xuan et al [6] showed that there is a significant correlation between BP and PTT, but this correlation depends on many parameters, which are varying among individuals [7], [4]. Many other works tried to fit regression models for BP estimation using PTT [8], [9], [10], but did not satisfy the standard criteria.…”

Cuff-Less and Continuous Blood Pressure Monitoring: A Methodological Review

“…The underlying principle of these devices is based on the relation of the time it takes for a volume of blood (in the form of a pulse) to travel from the heart to a peripheral organ, which could be in the form of pulse transit time (PTT) or pulse arrival time (PAT) [22][23][24]. Algorithms and mathematical models have been proposed and developed to optimize the regression process and calibration of the traveling/delay time ("Time Delay") and BP [25][26][27].…”

A Robust Algorithm for Real-Time Peak Detection of Photoplethysmograms Using a Personal Computer Mouse

“…Lmt.) that has high accuracy [29]; and w is number of samples. Experiment results on datasets recorded from 10 subjects during relaxation and after exercise using equations (9) and (10) showed in Table V and Table VI. The results demonstrated the error of heart rate estimation in the RPD is more accurate compared to the ADT and LCM.…”