Site for access to the inside of a channel, and corresponding cannula
A site for access to the inside of a channel, the site having a receptacle communicating with the inside of the channel in order to hold a plug made of an elastic material and intended to form a leak-tight barrier between the inside of the channel and the outside of the channel. The plug has a thickness on a longitudinal axis, an interior surface oriented towards the inside of the channel, and an outer surface facing away from the inner surface. Further, the plug has an upper part having an outer surface of the plug as its upper limit and having a cross section corresponding substantially to that of the receptacle so as to cooperate exactly with the receptacle. The plug also has a lower part having the inner surface of the plug as its lower limit and having a cross section increasing in two opposite directions perpendicular to the longitudinal axis of the plug.
1. A device for access to a channel comprising:
a receptacle communicating with an inside of the channel; and
a plug inserted into the receptacle and penetrable by a tube for withdrawal/injection of liquid from/into the channel, the plug being made of an elastic material and forming a leak-tight barrier between the inside of the channel and the outside of the channel, the plug having:
a thickness on a longitudinal axis;
an inner surface oriented towards the inside of the channel;
an outer surface facing away from the inner surface;
a hole starting from the outer surface of the plug and extending over part of the thickness of the plug; and
a slit starting from the inner surface of the plug and extending over part of the thickness of the plug, the slit defining two facing surfaces substantially dividing a lower part of the plug into two halves, the two facing surfaces of the slit being applied elastically against one another.
2. The device of claim 1 , wherein before the insertion of the plug into the receptacle, the slit has a maximum opening at the inner surface of the plug.
3. The device of claim 1 , wherein before the insertion of the plug into the receptacle, the slit spreads toward the inner surface of the plug.
4. The device of claim 1 , wherein before the insertion of the plug into the receptacle, the slit has an apex intersecting the longitudinal axis of the plug.
5. The device of claim 1 , wherein before the insertion of the plug into the receptacle, the cross section of the lower part of the plug increases toward the inner surface of the plug.
6. The device of claim 1 , wherein before the insertion of the plug into the receptacle, the cross section of the lower part of the plug increases in first and second directions, said first and second directions being opposite to one another and perpendicular to the longitudinal axis of the plug.
7. The device of claim 6 , wherein the slit extends perpendicular to said first and second directions.
8. The device of claim 1 , wherein an upper part of the plug has the outer surface of the plug as its upper limit.
9. The device of claim 1 , wherein before the insertion of the plug into the receptacle, an upper part of the plug has a cross section corresponding substantially to that of the receptacle so as to cooperate with the receptacle.
10. The device of claim 1 , wherein the lower part of the plug has the inner surface of the plug as its lower limit.
11. The device of claim 1 , wherein the hole extends substantially along the longitudinal axis of the plug.
12. The device of claim 1 , wherein the slit is prismatic.
13. The device of claim 1 , wherein before the insertion of the plug into the receptacle, the two facing surfaces of the slit are distanced from one another.
14. The device of claim 1 , wherein the hole has a cylindrical upper portion and a frustoconical lower portion.
15. A cannula and access site in combination, wherein the access site comprises:
a receptacle communicating with an inside of the channel;
a plug inserted into the receptacle and penetrable by a tube for withdrawal/injection of liquid from/into the channel, the plug being made of an elastic material and forming a leak-tight barrier between the inside of the channel and the outside, the plug having:
a thickness on a longitudinal axis;
an inner surface oriented towards the inside of the channel;
an outer surface facing away from the inner surface;
a hole starting from the outer surface of the plug and extending over part of the thickness of the plug; and
a slit starting from the inner surface of the plug and extending over part of the thickness of the plug, the slit defining two facing surfaces substantially dividing a lower part of the plug into two halves, the two facing surfaces of the slit being applied elastically against one another;
and wherein the cannula comprises:
a tube for withdrawal/injection of liquid, the tube having a cross section slightly greater than that of the hole of the plug, so that an upper part of the plug cooperates with the tube when the tube is driven into the hole.
16. The combination of claim 15 , wherein the cannula comprises means for preventing the end of the tube from contacting an inner wall of the channel when the cannula is driven through the site.
17. The combination of claim 16 , wherein said preventing means comprise a flange extending substantially perpendicular to the tube, said flange abutting against the outer surface of the plug.