| abstract |
The invention is a pressure sensitive valve that in different forms can be used to provide: an adjustable resistance to flow, adjustable positive or negative pressure relief, negative pressure isolation, isolation of pressure sensitive devices (e.g. pressure monitors) from blood and controlled recirculation between the inlet and outlet of pumps, particularly extracorporeal circulation. The construction of the valve is especially advantageous for extracorporeal circuits because the valve is made from one continuous length of tubing, thereby providing a valve that is more reliable, safer, and has fewer parts. A simple, compact and disposable system to adjust, regulate, and indicate negative or positive pressure applied to the valve is also described. |