Influence of ageing on human body blood flow and heat transfer: A detailed computational modelling study

Abstract

Ageing plays a fundamental role in arterial blood transport and heat transfer within a human body. The aim of this work is to provide a comprehensive methodology, based on biomechanical considerations, for modelling arterial flow and energy exchange mechanisms in the body accounting for age‐induced changes. The study outlines a framework for age‐related modifications within several interlinked subsystems, which include arterial stiffening, heart contractility variations, tissue volume and property changes, and thermoregulatory system deterioration. Some of the proposed age‐dependent governing equations are directly extrapolated from experimental data sets. The computational framework is demonstrated through numerical experiments, which show the impact of such age‐related changes on arterial blood pressure, local temperature distribution, and global body thermal response. The proposed numerical experiments show that the age‐related changes in arterial convection do not significantly affect the tissue temperature distribution. Results also highlight age‐related effects on the sweating mechanism, which lead to a significant reduction in heat dissipation and a subsequent rise in skin and core temperatures.

Modeling arterial pulse waves in healthy aging: a database for in silico evaluation of hemodynamics and pulse wave indexes

“…Parameters were changed with age, allowing the effects of aging to be investigated, and were also varied within normal ranges at each age, allowing the influences of individual parameters to be elucidated. This builds on previous work modeling changes with age (34, 39, 59, 60, 94, 114, 119).…”

Modeling radio-frequency energy-induced heating due to the presence of transcranial electric stimulation setup at 3T

“…Realistic modeling of the human head in the presence of a tES setup is challenging because variation in the skin material properties, in close proximity to the electrodes, interference from hair, etc., can impact the quality of electrical contact with the skin. As one example, the electrical [ 48 ] and thermal [ 49 ] properties of human tissues are known to be age dependent. However, limited information is available for frequencies around 125 MHz because most previous studies focused on telecommunication frequency bands (500 MHz–2.5 GHz).…”

Fractional-order model representations of apparent vascular compliance as an alternative in the analysis of arterial stiffness: an in-silico study

“…In order to generate the investigated data in the present work (samples of healthy adults' pulse waves, aged 25-75 years old, in ten-year increments), the input parameters of the Nektar1D were set and varied based on real value and range of cardiovascular properties with respect to age recognized on previous scientific reviews [45], [46], [47], [48], [49], [50], [51], [52], [53], [54]. The input parameters have been varied with age allowing the effects of aging to be examined, and were also varied within normal ranges at each age, permitting the influences of individual parameters to be illustrated [55], [56], [57], [58], [59], [60], [61]. It is worth noting that the adopted approach to generate the insilico database consolidates the connections between some cardiovascular input parameters, including the dependencies of left ventricular ejection time on stroke volume as well as the heart rate (HR) and the arterial stiffness on mean blood pressure and vascular geometry.…”