Patent ID: 7565907
Filing Date: 2009-07-28
Classification: A61M

Abstract:
1. A method of forming a cannula comprising the steps of: assembling a cannula mandrel assembly, which comprises separable engageable parts including a facepiece mandrel and a pair of mouthpiece/nasal mandrels with an intermediate section of the facepiece mandrel being provided with a pair of spaced apart through holes for each receiving a remote free end of one of the mouthpiece/nasal mandrels, by passing the remote free ends of each one of the pair of mouthpiece/nasal mandrels completely through a respective through hole in the facepiece mandrel such that the facepiece mandrel slides along the pair of mouthpiece/nasal mandrels until the through bores of the facepiece mandrel each have an interference fit with a respective larger transverse cross section of the mouthpiece/nasal mandrels which prevents further sliding movement while also avoiding flow of a polymeric material, between the facepiece mandrel and the mouthpiece/nasal mandrels, when applying at least one coating of uncured polymeric material to the cannula mandrel assembly; heating the cannula mandrel assembly to a desired temperature; providing an uncured polymeric material in flowable state; applying at least one coating of the uncured polymeric material to the cannula mandrel assembly to provide a desired material thickness coating on the cannula mandrel assembly; at least partially curing the coating of the polymeric material on the cannula mandrel assembly to form the cannula; disassembling the cannula mandrel assembly by first sliding both the facepiece mandrel and the formed cannula along the mouthpiece/nasal mandrels toward the remote free ends of the mouthpiece/nasal mandrels until the facepiece mandrel and the partially cured cannula are completely removed from the pair of mouthpiece/nasal mandrels; and then withdrawing the facepiece mandrel from the formed cannula.