Reservoir-Wave  Analysis  Applied  to  the  Pulmonary  Circulation

Bouwmeester, James Christopher

Reservoir-Wave Analysis Applied to the Pulmonary Circulation

atmire.migration.oldid	300
dc.contributor.advisor	Tyberg, John Victor
dc.contributor.author	Bouwmeester, James Christopher
dc.date.accessioned	2012-09-13T23:16:04Z
dc.date.available	2012-11-13T08:01:38Z
dc.date.issued	2012-09-13
dc.date.submitted	2012	en
dc.description.abstract	The purpose of applying the reservoir-wave model to the pulmonary circulation is to validate the resulting reservoir and wave parameters against known physiologic responses. The reservoir model represents a modified windkessel and describes the lumped resistance to flow, compliance of vessels and the downstream pressure at which modeled outflow ceases. Applied to arteries and veins in tandem, a complete description of the pulmonary circulation is possible. The reservoir model determines the reservoir pressure, which is subtracted from measured pressure. The difference is called excess pressure and it is used with wave intensity analysis to quantify the effects of incident waves and their reflections. The changes to reservoir function and wave patterns may be helpful in providing extra diagnostic information regarding pulmonary hypertension and providing targets for treatment of this disease. Measurements of pressure and flow were made in the main pulmonary artery and pulmonary vein in 15 anesthetised, open-chest dogs. Six different conditions were created by the addition of blood volume and the application of positive end-expiratory pressure (PEEP). At each condition, hypoxic ventilation was used to create vasoconstriction and then, inhaled nitric oxide was used to create vasodilation. Ventilation changes are the focus of experimentation because hypoxia represents a pulmonary hypertension disease state and nitric oxide represents a common treatment. Both arterial and venous reservoir resistance increased with hypoxia and decreased with nitric oxide but only arterial reservoir resistance was fully reversed with nitric oxide. With excess pressure, arterial wave patterns revealed the presence of a prominent negative reflection occurring from the junction of arteries branching from the left or right pulmonary artery. Venous wave patterns showed that the left atrium and ventricle are responsible for the majority of measured pressure fluctuations but a wave transmitted from the pulmonary arteries is measurable during the filling of the left atrium. Overall, results are in general agreement with hypothesized physiological changes, which serves to validate the application of the reservoir-wave model and allows both the vascular characteristics and wave propagation to be quantified in ways that other models can not.	en_US
dc.identifier.citation	Bouwmeester, J. C. (2012). Reservoir-Wave Analysis Applied to the Pulmonary Circulation (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27640	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/27640
dc.identifier.uri	http://hdl.handle.net/11023/208
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Engineering--Biomedical
dc.subject.classification	Cardiovascular Physiology	en_US
dc.subject.classification	Windkessel	en_US
dc.title	Reservoir-Wave Analysis Applied to the Pulmonary Circulation
dc.type	doctoral thesis
thesis.degree.discipline	Biomedical Engineering
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.item.requestcopy	true