Product design and its relation to the generation of gaseous microemboli in the extracorporeal circuit

In the design of extracorporeal devices, consideration is given to the materials of construction, which affect wetting, blood compatibility, and the production and separation of gaseous microemboli (GME). The wetting characteristics of the materials can affect both the generation and separation of GME. Consideration must also be given to the fluid mechanics of extracorporeal devices, since turbulence, cavitation, and zones of stagnation all affect the production and release of GME. The effects of pressure gradients within the extracorporeal circuit cannot be neglected, since significant pressure differences generated within the system can easily de-gas the blood. The hemodynamics of cannulae, oxygenators, connectors, cardiotomy reservoirs, arterial blood filters, and the perfusion circuit must be considered as potential contributors to GME production.