Objective: The aim of this study is to evaluate the relationship between carotid intima-media thickness (IMT) and arterial wall inertial behaviour.
Methods: The simultaneous and noninvasive assessment of the intima-media complex and arterial diameter waveform was performed using high-resolution ultrasonography. The common carotid artery of eleven normotensive subjects (NTA) and eleven mild-to-moderate essential hypertensive patients (HTA) were measured noninvasively using tonometry and an automatic densitometric analysis of B-mode images to obtain IMT and instantaneous pressure (P) and diameter (D) loops. A linear discrete time model was used to estimate the inertial index (K(M)) using a system modelling-identification approach.
Results: In NTA K(M) was 0.333+/-0.256 (mmHg x s2/mm) and IMT 0.643+/-0.061 (mm), whereas in HTA K(M) was 0.798+/-0.590 (P < 0.05) and IMT 0.760+/-0.034 (P < 0.025). When all data of K(M) versus IMT of NTA and HTA were pooled in a linear regression analysis, a correlation coefficient of r = 0.61 (P < 0.05) was obtained.
Conclusion: Wall inertia increase was associated with a higher IMT, suggesting that the intima-media thickening might be partially related to vascular hypertrophy manifested as increase of inertial behaviour.
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http://dx.doi.org/10.1097/00004872-199917121-00007 | DOI Listing |
Micromachines (Basel)
September 2024
Department of Mechanical Engineering, York University, BRG 433B, 4700 Keele St., Toronto, ON M3J 1P3, Canada.
The rising global need for clean water highlights the importance of efficient sample preparation methods to separate and wash various contaminants such as microparticles. Microfluidic methods for these purposes have emerged but they mostly deliver either separation or washing, with very low throughputs. Here, we investigate parallelization of a curved-channel particle separation and washing device in order to increase its throughput for sample preparation.
View Article and Find Full Text PDFUltrason Sonochem
December 2024
International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560089, India.
Mikrochim Acta
September 2024
Department of Mechanical Engineering, York University, Toronto, ON, M3J1P3, Canada.
Inertial microfluidic technologies have proven effective for particle focusing and separation in many microchannels, typically the channels with the rectangular and trapezoidal shapes. To advance particle focusing in complex channels, we propose a spiral channel combining rectangular and concave cross-sections for high-resolution particle and cell focusing and separation. Numerical simulations were conducted to illustrate the effects of channel geometry on secondary flow distribution and particle focusing positions.
View Article and Find Full Text PDFLab Chip
October 2024
School of Microelectronics, Hefei University of Technology, Hefei, 230601, China.
Phys Rev E
July 2024
Gulliver UMR CNRS 7083, ESPCI Paris, PSL Research University, 10 Rue Vauquelin, 75005 Paris, France.
We extend the study of the inertial effects on the two-dimensional dynamics of active agents to the case where self-alignment is present. In contrast with the most common models of active particles, we find that self-alignment, which couples the rotational dynamics to the translational one, produces unexpected and nontrivial dynamics, already at the deterministic level. Examining first the motion of a free particle, we contrast the role of inertia depending on the sign of the self-aligning torque.
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