For decades, the Intra-Aortic Balloon Pump (IABP) has been used in clinical applications as support to patients recovering from heart failure or as a bridge therapy for permanent implantable devices like LVAD or for cardiac transplantation. The main benefits obtained through IABP therapy during Diastolic phase are the increase of blood flow to the coronary circulation (which leads to an increase of oxygen supply to the myocardium) and the reduction of the After-Load charging the left ventricle (which leads to a decrease of the ventricular contraction required to pump blood during Systole). The topic that has been investigated in this project is the influence of the patient’s position on IABP efficacy. In fact, when patient is nursed in ICU for a longer period of time, it is recommended to keep his position at an angle of 30/45° in order to avoid complication charging the lungs. Nevertheless, this clinical procedure causes the reduction of both the main benefits of IABP therapy. Aims and Objectives: The aim of the project was to better understand the behaviour of blood upstream and downstream IAB during inflation and deflation at both horizontal and angled positions, by quantifying the reduction in benefit during angulation. The objectives of this study were: • To build a CDF model, using the software Ansys, to evaluate and quantify how much flow is displaced by the Intra-Aortic Balloon (IAB) during its working phases. IAB has been tested considering both Aorta as aligned with the horizontal plane and as tilted at an angle of 45° on the horizontal. • To investigate the influence of geometry on the IAB performances by evaluating how blood is displaced using different designs: the standard design, which is characterized by a cylindrical geometry, and two alternative designs, in which cylindrical and conical shapes were combined using different ratios as an attempt to counterbalance the negative effects caused by angulation.
Background: Per decenni il contropulsatore aortico (IABP) è stato utilizzato in ambito clinico come supporto al paziente in seguito ad insufficienza cardiaca o come terapia momentanea in attesa di impianto di device di supporto permanente come LVAD o di trapianto cardiaco. I principali benefici ottenuti attraverso questa terapia vengono ottenuti durante la fase di Diastole e sono l’aumento del flusso in ingresso alla circolazione coronarica (con conseguente aumento dell’apporto di ossigeno al miocardio) e la riduzione del post carico a cui è soggetto il ventricolo sinistro (con conseguente riduzione della contrazione ventricolare necessaria a pompare il sangue in Sistole). La problematica che è stata studiata in questo progetto è l’influenza della posizione in cui il paziente viene trattato durante la terapia sull’efficacia di IABP. Il paziente infatti, quando è ricoverato in terapia intensiva per tempi prolungati è mantenuto ad una certa inclinazione rispetto al piano orizzontale (30/45°) per prevenire complicanze a livello polmonare. L’effetto che questa posizione provoca è la riduzione di entrambi i principali benefici del trattamento. Obiettivo: L’obiettivo del progetto è stato quello di comprendere meglio il comportamento del sangue a monte e a valle di IAB durante gonfiamento e sgonfiamento in posizione orizzontale e inclinata, attraverso la quantificazione della riduzione dei benefici in posizione inclinata. Gli obiettivi realizzati in questo studio sono stati: • Costruzione di un modello CFD, utilizzando il software Ansys, per valutare e quantificare il flusso spinto dal palloncino (IAB) durante le fasi di funzionamento del device. IAB è stato testato sia in caso di Aorta posta lungo il piano orizzontale, sia che sia posta ad un angolazione di 45° rispetto al piano orizzontale. • Studio dell’influenza della geometria sulle performance di IAB per valutare come viene spostato il sangue usando tre diverse tipologie di IAB: il design standard, di geometria cilindrica, e due design alternativi, in cui geometrie cilindriche e coniche sono state utilizzate in combinazione come tentativo di contrastare gli effetti negativi causati dall’inclinazione.
Computational fluid dynamic study for the inflation and deflation of intra-aortic balloon pump
BRESSAN, GIULIA
2016/2017
Abstract
For decades, the Intra-Aortic Balloon Pump (IABP) has been used in clinical applications as support to patients recovering from heart failure or as a bridge therapy for permanent implantable devices like LVAD or for cardiac transplantation. The main benefits obtained through IABP therapy during Diastolic phase are the increase of blood flow to the coronary circulation (which leads to an increase of oxygen supply to the myocardium) and the reduction of the After-Load charging the left ventricle (which leads to a decrease of the ventricular contraction required to pump blood during Systole). The topic that has been investigated in this project is the influence of the patient’s position on IABP efficacy. In fact, when patient is nursed in ICU for a longer period of time, it is recommended to keep his position at an angle of 30/45° in order to avoid complication charging the lungs. Nevertheless, this clinical procedure causes the reduction of both the main benefits of IABP therapy. Aims and Objectives: The aim of the project was to better understand the behaviour of blood upstream and downstream IAB during inflation and deflation at both horizontal and angled positions, by quantifying the reduction in benefit during angulation. The objectives of this study were: • To build a CDF model, using the software Ansys, to evaluate and quantify how much flow is displaced by the Intra-Aortic Balloon (IAB) during its working phases. IAB has been tested considering both Aorta as aligned with the horizontal plane and as tilted at an angle of 45° on the horizontal. • To investigate the influence of geometry on the IAB performances by evaluating how blood is displaced using different designs: the standard design, which is characterized by a cylindrical geometry, and two alternative designs, in which cylindrical and conical shapes were combined using different ratios as an attempt to counterbalance the negative effects caused by angulation.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/136120