Standard Deviation Of Mean Arterial Pressure Research Articles

A Deep Learning-Based Continuous Blood Pressure Measurement by Dual Photoplethysmography Signals

This study proposed a measurement platform for continuous blood pressure estimation based on dual photoplethysmography (PPG) sensors and a deep learning (DL) that can be used for continuous and rapid measurement of blood pressure and analysis of cardiovascular-related indicators. The proposed platform measured the signal changes in PPG and converted them into physiological indicators, such as pulse transit time (PTT), pulse wave velocity (PWV), perfusion index (PI) and heart rate (HR); these indicators were then fed into the DL to calculate blood pressure. The hardware of the experiment comprised 2 PPG components (i.e., Raspberry Pi 3 Model B and analog-to-digital converter [MCP3008]), which were connected using a serial peripheral interface. The DL algorithm converted the stable dual PPG signals acquired from the strictly standardized experimental process into various physiological indicators as input parameters and finally obtained the systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP). To increase the robustness of the DL model, this study input data of 100 Asian participants into the training database, including those with and without cardiovascular disease, each with a proportion of approximately 50%. The experimental results revealed that the mean absolute error and standard deviation of SBP was 0.17 ± 0.46 mmHg. The mean absolute error and standard deviation of DBP was 0.27 ± 0.52 mmHg. The mean absolute error and standard deviation of MAP was 0.16 ± 0.40 mmHg.

Role of vasopressin in salt-induced hypertension in baroreceptor-denervated uninephrectomized rabbits.

To elucidate the contributions of renal, humoral, and arterial baroreceptor reflex components to salt-induced hypertension, we administered 10% NaCl intravenously for 10 days to sinoaortic-denervated rabbits with unilateral nephrectomy (n = 7), sinoaortic-denervated rabbits with intact kidneys (n = 7), and sham-operated sinoaortic-denervated rabbits with unilateral nephrectomy (n = 7). Serial changes in mean arterial pressure (MAP), heart rate, and blood pressure variability were recorded. In sinoaortic-denervated rabbits with unilateral nephrectomy, MAP increased significantly from 109 +/- 2 to 124 +/- 3 mm Hg (day 4) and remained elevated for the rest of the experiment. This elevation of MAP was accompanied by a reduction in the standard deviation of MAP, with significant elevations in plasma vasopressin, norepinephrine, and atrial natriuretic peptide concentrations and in sodium retention. In the other groups, there were no significant changes in these vasoactive hormones. In the sham-operated sinoaortic-denervated rabbits with unilateral nephrectomy, sodium retention was similar to that of sinoaortic-denervated rabbits with unilateral nephrectomy. Continuous infusion (1 microgram/kg/hr) of a V1 antagonist prevented the elevation of blood pressure and plasma norepinephrine, the accumulation of sodium, and the reduction of blood pressure lability, whereas a bolus injection (10 micrograms/kg) on day 4 reduced blood pressure from 128 +/- 3 to 115 +/- 2 mm Hg (p less than 0.005). These results imply that vasopressin plays a crucial role in the expression of salt-induced hypertension in rabbits with compromised baroreceptor and renal function.