Parameter quantification for oxygen transport in the human brain DOI Creative Commons
Yun Bing, Tamás Józsa, Stephen J. Payne

et al.

Computer Methods and Programs in Biomedicine, Journal Year: 2024, Volume and Issue: 257, P. 108433 - 108433

Published: Sept. 24, 2024

Oxygen is carried to the brain by blood flow through generations of vessels across a wide range length scales. This multi-scale nature and oxygen transport poses challenges on investigating mechanisms underlying both healthy pathological states imaging techniques alone. Recently, models describing whole perfusion have been developed. Such rely effective parameters that represent microscopic properties. While characterised, those for are still lacking. In this study, we set quantify associated with their uncertainties.

Language: Английский

Dynamic cerebral autoregulation is governed by two time constants: Arterial transit time and feedback time constant DOI
Stephen J. Payne

The Journal of Physiology, Journal Year: 2024, Volume and Issue: 602(9), P. 1953 - 1966

Published: April 17, 2024

Abstract Dynamic cerebral autoregulation (dCA) is the mechanism that describes how brain maintains blood flow approximately constant in response to short‐term changes arterial pressure. This known be impaired many different pathological conditions, including ischaemic and haemorrhagic stroke, dementia traumatic injury. Many approaches have thus been used both analyse quantify this a range of healthy diseased subjects, data‐driven models (in time frequency domain) biophysical models. However, despite substantial body work on dCA, there remains little links two together. One reasons for proposed discrepancies between constants govern dCA experimental data. In study, processes are examined it application limited due lack understanding about physical being modelled, partly specific model formulation has most widely (the equivalent electrical circuit). Based analysis presented here, important transit feedback constant. It therefore revisit circuit develop more physiologically realistic alternative, one can easily related image Key points governed by constants. The first time, rather than traditional ‘RC’ previous 1 s brain. second constant, which less accurately known, although somewhat larger time. dynamic should replaced with representative model.

Language: Английский

Citations

4
Oxygen transport in pulsatile non-Newtonian fluid through a stenosed artery DOI

P. Nagarani,

Victor M. Job, Alana Sankar

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

This paper explores non-Newtonian fluid flow and the transport of oxygen through a stenosed artery. The Casson model was used to describe pulsatile blood within artery, whereas modeled using convection-diffusion equation with suitable initial boundary conditions. An analytical solution for axial velocity obtained based on regular perturbation technique, then finite element method solve nonlinear compute local concentration. impact yield stress, Schmidt number, Womersley frequency parameter, maximum stenosis height, pressure fluctuating parameter investigated velocity, wall shear concentration, average Sherwood number.

Language: Английский

Citations

0
Adopting whole-brain computational modelling to investigate neurophysiological features associated with cognition DOI

Ching Hei Kuang,

Niall W. Duncan

˜The œPsychology of learning and motivation/˜The œpsychology of learning and motivation, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

Citations

0
Interstitial fluid transport in a multi-compartment model of cerebral blood flow DOI Creative Commons
Stephen J. Payne

Journal of Mechanics, Journal Year: 2023, Volume and Issue: 39, P. 508 - 517

Published: Jan. 1, 2023

Abstract Whole brain models are a valuable tool to gain better understanding of cerebral blood flow and metabolism. Recent work has developed multi-compartment oxygen transport that can be used in finite element framework simulate whole behaviour with low computational expense, helping move such tools towards clinical application. However, the fluid between vascular space interstitial not yet been considered detail this context, despite playing an important role several cerebrovascular diseases. In study, extended is proposed include transport, coupled linear elastic model tissue displacement movement resulting tissue. This compared previous models. The equations found exhibit multiple time scales, separation scales performed analyse at different scales. Finally, simplified easily implemented within existing frameworks, providing extension pathological conditions simulated.

Language: Английский

Citations

2
Parameter quantification for oxygen transport in the human brain DOI Creative Commons
Yun Bing, Tamás Józsa, Stephen J. Payne

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 15, 2024

Abstract Oxygen is carried to the brain by blood flow through generations of vessels across a wide range length scales. This multi-scale nature and oxygen transport poses challenges on investigating mechanisms underlying both healthy pathological states imaging techniques alone. Recently, models describing whole perfusion have been developed. Such rely effective parameters that represent microscopic properties. While characterised, those for are still lacking. In this study, we set quantify associated with their uncertainties. We first present multi-scale, multi-compartment model based porous continuum approach. then determine values parameters. By using statistically accurate capillary networks, geometric (vessel volume fraction surface area ratio) capture microvascular topologies found be 1.42% 627 [mm 2 /mm 3 ], respectively. These compare well obtained from human monkey vascular samples. addition, maximum consumption rates optimised uniquely define distribution over depth. Simulation results one-dimensional tissue column show qualitative agreement experimental measurements partial pressure in rats. highlight importance anatomical accuracy simulation performed within patient-specific mesh. Finally, one-at-a-time sensitivity analysis reveals not sensitive most its parameters; however, perturbations solubilities plasma concentration ratio considerable impact oxygenation. findings demonstrate validity approach organ-scale draw attention significance anatomy certain parameter values.

Language: Английский

Citations

0
Parameter quantification for oxygen transport in the human brain DOI Creative Commons
Yun Bing, Tamás Józsa, Stephen J. Payne

et al.

Computer Methods and Programs in Biomedicine, Journal Year: 2024, Volume and Issue: 257, P. 108433 - 108433

Published: Sept. 24, 2024

Oxygen is carried to the brain by blood flow through generations of vessels across a wide range length scales. This multi-scale nature and oxygen transport poses challenges on investigating mechanisms underlying both healthy pathological states imaging techniques alone. Recently, models describing whole perfusion have been developed. Such rely effective parameters that represent microscopic properties. While characterised, those for are still lacking. In this study, we set quantify associated with their uncertainties.

Language: Английский

Citations

0