Studies in health technology and informatics
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Measurement of arterial compliance is of interest in evaluating patients with atherosclerosis and other diseases which affect the vessels. Arterial compliance is the relation between changes in transmural pressure and volume of an arterial segment, where a high compliance signifies large changes in volume per change in transmural pressure. The relation between changes in transmural pressure and volume is far from linear as compliance increases progressively with decreases in blood pressure. ⋯ Using this method on normal subjects has shown that the arterial compliance decreases with increasing age and that females have lower compliance than males primarily due to a smaller diameter of their arteries. It has also been shown that patients with essential (diastolic) hypertension have compliances which are higher or equal to those of normal subjects, and that patients with systolic hypertension have lower arterial compliances than normal subjects. The former finding is in contrast with pulse wave velocity measurements, where diastolic hypertension was associated with low arterial compliance.
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The arterial system can be modelled by means of distributed analogs and by lumped parameter representations, such as the Windkessel. The distributed models, together with biological data, lead to the explanation of arterial function in terms of pressure and flow. The lumped parameter models form the basis of arterial compliance and characteristic impedance estimation. They also make comparison between mammals possible and it could be shown that input impedance, when scaled, is similar in mammals.