Components for medical circuits

摘要

A method of manufacturing a medical circuit component comprises the steps of: mixing a foaming agent into a polymeric base material and forming a liquefied mixture; allowing the foaming agent portion to release gas bubbles into the base material portion of the liquefied mixture; and arresting the release of gas bubbles and processing the mixture to form a water-vapor permeable component, wherein the foaming agent and polymeric base material are selected and the mixture is processed to form a water-vapor permeable component comprising a solid polymer and voids distributed throughout the solid polymer, wherein the permeability P of the component in g-mm/m2/day is at least 60 g-mm/m2/day measured according to Procedure A of AST 'I E96 (using the desiccant method at a temperature of 23°C and a relative humidity of 90%) and satisfies the formula: P > expf0.019[1n(14)]2 - 0.71n(M)+6.5), in which Al represents the elastic modulus of the foamed polymer in Iv1Pa and M is between 30 and 1000 MPa.