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Noninvasive Accelerometric Approach for Cuffless Continuous Blood Pressure Measurement

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Abstract

Pulse transit time (PTT) has been widely used for cuffless blood pressure (BP) measurement. But, it requires more than one cardiovascular signals involving more than one sensing device. In this paper, we propose a method for cuffless continuous blood pressure measurement with the help of left ventricular ejection time (LVET). A MEMS-based accelerometric sensor acquires a seismocardiogram (SCG) signal at the chest surface, and then, the LVET information is extracted. Both systolic and diastolic blood pressures are estimated by calibrating the system with the original arterial blood pressures of the subjects. The performance evaluation is done using different statistical quantitative measures for the proposed method. The performance is also compared with two earlier approaches, where PTT intervals are measured from electrocardiogram (ECG)-photoplethysmogram (PPG) and SCG-PPG pairs, respectively. The performance results clearly show that the proposed method is comparable with the state-of-the-art methods. Also, the estimated blood pressure is compared with the original one, measured through a reference system. It gives the mean errors of the systolic and diastolic BPs within the range of -0.197±3.332 mmHg and -1.299±2.578 mmHg, respectively. The BPs estimation errors satisfy the requirements of the IEEE standard 5±8 mmHg deviation, and thus, our method may be used for ubiquitous continuous blood pressure monitoring.

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Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies
Prospective Studies Collaboration, "Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies," The Lancet, vol. 360, no. 9349, pp. 1903-1913, Dec. 2002.