Ncpap (nasal continuous positive airway pressure) jetpiece flow simulations
The project is a collaboration between KTH, Karoliska sjukhuset (Solna) and Östersunds sjukhus and is divided in four different parts, in which CFD simulations is used in one of the projects. Nasal Continuous Positive Airway Pressure (NCPAP) has been used in infants for more than thirty years. The treatment has advantages over more invasive ventilator support and has been evaluated in several studies. NCPAP would be the first choice of treatment for a preterm infant with respiratory distress today. There are several different systems available to deliver NCPAP. In the mid-eighties in a new system was designed in Östersund, Sweden by Kjell Nilsson and Gunnar Moa. The aim was to reduce the imposed work of breathing compared to traditional systems. The final design achieved this with a small jet of gas entering an angulated tube. It has been hypothesized that this design uses the Coanda effect in combination with an unstable pneumatic fluidic flip to provide a pressure stable CPAP system. CFD simulations fully resolving the flow field in the jetpiece is therefore applied in this project to elucidate the flow phenomenon of this device as its function is not fully understood. A pulsating inflow profile corresponding to the breathing cycle of an infant is applied to match the conditions at which it is clinically used. Within the project, the aim is also to develop the device in order to use it for neonatal resuscitation having low imposed work of breathing as well as introducing drug delivery through nebulisation.