Název: Hemodynamic modelling in the calf — A pilot study
Autoři: Matějková, M. ; Jurák, Pavel ; Soukup, L. ; Halámek, Josef ; Viščor, Ivo ; Langer, P. ; Vondra, Vlastimil
Typ dokumentu: Příspěvky z konference
Konference/Akce: Computing in Cardiology (CinC) 2016, Vencouver (CA), 20160911
Rok: 2016
Jazyk: eng
Abstrakt: With increasing age, the cardiovascular system loses its efficiency. The goal of this work was to investigate the hemodynamic system response to a head-up tilt test in two groups of different aged people. We used a model for describing this response in the right calf based on a non-invasive, non-occlusive, bioimpedance signal measurement technique. A decrease in the bioimpedance value in the calf during the head-up tilt test is associated with the accumulation of blood in the calf, which can be expressed by a model parameter. Subjects were examined in both a head-up tilt test and a supine position. 50 healthy non-smoking volunteers were divided into two groups according to age. The impedance signal during the tilt test for each subject was fitted by a model exponential function: Z0 model EF(t) =A exp(-t/B)+C, where Z0 model EF(t) is the calculated model of electrical impedance in the calf by an exponential function, A is the amplitude of impedance change, B is the time constant of the impedance decrease, C is the value of the steady state after the tilt test and t denotes time. A lower time constant B shows a faster filling of the vascular system in the investigated part. The Mann-Whitney test (p-value<;0.005) revealed that the time constant B for the older group was significantly lower than for the young group (145.24+/- 80.28 vs. 239.23+/-136.59 sec.). A lower time constant value means a faster response to blood filling in the lower limbs and directly reflects decreased vessel elasticity. This time constant was lower in the older group. The results show increased vessel stiffness in old age and could lead to a non-invasive evaluating the cardiovascular system state.
Klíčová slova: bioimpedance; biomedical monitoring; blood; impedance
Zdrojový dokument: Computing in Cardiology (CinC) 2016, ISBN 978-1-5090-0896-4, ISSN 2325-8861

Instituce: Ústav přístrojové techniky AV ČR (web)
Informace o dostupnosti dokumentu: Dokument je dostupný v příslušném ústavu Akademie věd ČR.
Původní záznam: http://hdl.handle.net/11104/0271753

Trvalý odkaz NUŠL: http://www.nusl.cz/ntk/nusl-373371


Záznam je zařazen do těchto sbírek:
Věda a výzkum > AV ČR > Ústav přístrojové techniky
Konferenční materiály > Příspěvky z konference