Uncertainty quantification of the pressure waveform using a Windkessel model.

The Windkessel (WK) model is a simplified mathematical model used to represent the systemic arterial circulation. While the WK model is useful for studying blood flow dynamics, it suffers from inaccuracies or uncertainties that should be considered when using it to make physiological predictions. This paper aims to develop an efficient and easy-to-implement uncertainty quantification method based on a local gradient-based formulation to quantify the uncertainty of the pressure waveform resulting from aleatory uncertainties of the WK parameters and flow waveform.

Water exchange capability induced by seasonal and regional variability: Assessment of Hong Kong waters.

Assessing water exchange capability is an essential step to understand the vulnerability of waterbody to potential pollution. To characterize the spatiotemporal variations of water exchange rate in Hong Kong waters, a three-dimensional hydrodynamic and transport model was implemented. In this study, water residence time (T) representing the water exchange rate was <10 days in open waters but exceeded 60 days in weakly-flushed Tolo Harbour.

Signatures of obstructions and expansions in the arterial frequency response.

Background And Objective: The blood pressure and flow waveforms carry valuable information about the condition of the cardiovascular system and a patient's health. Waveform analysis in health and pathological conditions can be performed in the time or frequency domains; the information to be emphasised defines the use of either domain. However, physicians are more familiar with the time domain, and the changes in the waveforms due to cardiovascular diseases and ageing are better characterised in such domain.

Computational modelling and application of mechanical waves to detect arterial network anomalies: Diagnosis of common carotid stenosis.

Background And Objective: This paper proposes a novel strategy to localize anomalies in the arterial network based on its response to controlled transient waves. The idea is borrowed from system identification theories in which wave reflections can render significant information about a target system. Cardiovascular system studies often focus on the waves originating from the heart pulsations, which are of low bandwidth and, hence, can hardly carry information about the arteries with the desired resolution.