Improved multiple cannula systems

摘要

A multiple cannula assembly for insertion into a patient, comprising:
- a flexible outer cannula (30) having a proximal head;
- a flexible inner cannula (55) having a proximal hub;
- said inner cannula being longitudinally insertable into said outer cannula to an insertion position with said hub proximate said head;
- said outer cannula including a substantially rigid tip portion (70) and a substantially flexible portion, said substantially rigid tip portion being made with a rigid PVC material having a shore D hardness of between about 55 to 65 and said substantially flexible portion being made with a flexible PVC material having a shore A hardness of between about 80 to 90.