Two computation cases were introduced, one with a polyurethane graft and another with a silicon rubber graft. The computations were done under a pulsatile flow. Both cases were computed under maximum peak pressure as mentioned in the method section.
The flow volume rate is expressed by integrating on surface as followed:
Q=∬_A^ ▒v.dA (5)
By integrating flow volume rate in time the whole volume was examined on three different conditions, one on the inlet and the others two on outlet section of polyurethane and silicon rubber. Extracted from the solver, the flow rate of these three cases is displayed in Figure 4 over one heart …show more content…
It can be understood from the displacement contours that polyurethane graft is deflected more than the vessel under the same load. As a result the graft part is wider than the vessel itself. On the other hand, silicon rubber is displaced less than the vessel and axiomatically narrower than the vessel itself. The reason and main cause of this difference between two materials is that, the stiffness of polyurethane is lower than that of the vessel and on the other side silicone rubber has a higher stiffness value. This matter can affect hemodynamic parameters as narrowing the section can increase the velocity and decrease the pressure. It is worth mentioning that the difference between graft and vessel average displacements in the case with polyurethane grafted is lower than that of silicone rubber grafted case. It may be a reason to make polyurethane application more …show more content…
Although we have grafts fabricated from PTFE or Dacron ingredients, the properties of these two materials (for example module of elasticity) are much different from that of materials fabricated by silicon rubber and polyurethane. Silicon rubber and polyurethane as grafts, has approximate similar properties which bring difficulty for the surgeons to make a best decision in the process of type of graft selecting. The small difference in material properties between these grafts (Silicon rubber and polyurethane) can be investigated in view point of hemodynamic effects. The authors acknowledge that it is necessary to investigate the effects of these two grafts in clinical aspect of view and compare them with the other grafts like PTFE or Dacron to have the better understanding of grafts efficiency and consequently to provide surgeons a more comprehensive database in order to do their bests. This work started this investigation through investigation of Silicon rubber and polyurethane as grafts in view aspect of hemodynamic effects. This study also contains information for surgeons to have a better point of view on hemodynamic behavior of the blood after
The flow volume rate is expressed by integrating on surface as followed:
Q=∬_A^ ▒v.dA (5)
By integrating flow volume rate in time the whole volume was examined on three different conditions, one on the inlet and the others two on outlet section of polyurethane and silicon rubber. Extracted from the solver, the flow rate of these three cases is displayed in Figure 4 over one heart …show more content…
It can be understood from the displacement contours that polyurethane graft is deflected more than the vessel under the same load. As a result the graft part is wider than the vessel itself. On the other hand, silicon rubber is displaced less than the vessel and axiomatically narrower than the vessel itself. The reason and main cause of this difference between two materials is that, the stiffness of polyurethane is lower than that of the vessel and on the other side silicone rubber has a higher stiffness value. This matter can affect hemodynamic parameters as narrowing the section can increase the velocity and decrease the pressure. It is worth mentioning that the difference between graft and vessel average displacements in the case with polyurethane grafted is lower than that of silicone rubber grafted case. It may be a reason to make polyurethane application more …show more content…
Although we have grafts fabricated from PTFE or Dacron ingredients, the properties of these two materials (for example module of elasticity) are much different from that of materials fabricated by silicon rubber and polyurethane. Silicon rubber and polyurethane as grafts, has approximate similar properties which bring difficulty for the surgeons to make a best decision in the process of type of graft selecting. The small difference in material properties between these grafts (Silicon rubber and polyurethane) can be investigated in view point of hemodynamic effects. The authors acknowledge that it is necessary to investigate the effects of these two grafts in clinical aspect of view and compare them with the other grafts like PTFE or Dacron to have the better understanding of grafts efficiency and consequently to provide surgeons a more comprehensive database in order to do their bests. This work started this investigation through investigation of Silicon rubber and polyurethane as grafts in view aspect of hemodynamic effects. This study also contains information for surgeons to have a better point of view on hemodynamic behavior of the blood after