Cannula for use with a medical syringe
AssigneeInviro Medical Devices Ltd.
InventorsFraser R. Sharp, Neil Sheehan
Life of this patent
Estimating the term…
Abstract
A blunt needle plastic cannula for a syringe has a central axial passage terminating in a tip opening axially through one end thereof. Different axial sections along the cannula have respective differential resistances to movement relative to a membrane upon insertion of the cannula into the membrane. The opposite end of the cannula may have a Luer fit or Luer lock or may have integrally formed therewith an adapter for releasably connecting the adapter and cannula to the distal end of the barrel of the syringe. A syringe plunger and the adapter have connective structure whereby the adapter and cannula can be withdrawn into the interior of the barrel. The opposite ends of the barrel are sealed by portions of the plunger.
Claims22
A cannula for use with a syringe and for insertion through a membrane, comprising:
- a cannula body including an elongated sleeve and having a central axial passage therethrough for transmitting a fluid between opposite ends thereof;
- said sleeve terminating in a tip at one end with said passage opening axially through said tip;
- an opposite end of said sleeve adapted for connection with the syringe;
- mechanical formations formed on an outer surface of said cannula body along one of first and second axially spaced sections along said sleeve affording respective differential resistances to movement relative to the membrane as a function of the depth of penetration of the cannula body relative to the membrane, said first section being located axially intermediate said tip and said second section;
- and
- a transition section between said first and second sections having a diameter larger than the diameters of said first and second section.
A cannula for use with a syringe and for displacement through a membrane, comprising:
- a cannula body including an elongated sleeve formed of a plastic material and having a central axial passage therethrough for transmitting a fluid between opposite ends thereof;
- said sleeve terminating in a tip at one end with said passage opening axially through said tip;
- an opposite end of said sleeve adapted for connection with the syringe;
- first and second axially spaced sections along said sleeve, said first section being located axially intermediate said tip and said second section;
- a transition section between said first and second sections having a diameter larger than the diameters of said first and second sections;
- said transition section having a first surface facing said tip and a second surface on a side thereof opposite said first surface, said first and second surfaces affording respective differential resistance to movement in opposite directions relative to the membrane.
A cannula for use with a syringe and for displacement through a membrane, comprising:
- a cannula body including an elongated sleeve and having a central axial passage therethrough for transmitting a fluid between opposite ends thereof;
- said sleeve terminating in a tip at one end with said passage opening axially through said tip;
- an opposite end of said sleeve adapted for connection with the syringe;
- first and second axially spaced ribs along said sleeve axially intermediate said tip and said opposite end of the sleeve;
- said ribs having diameters larger than the diameter of said sleeve;
- said ribs having first surfaces axially facing one another and second surfaces on sides thereof opposite said first surfaces, respectively, said first and second surfaces affording respective differential resistances to movement in opposite directions relative to the membrane;
- said first surfaces being shaped to releasably capture an opening through the membrane therebetween and affording greater resistance to movement of the cannula.
Dependencies are inferred from the claim text.