Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
  • A61M5/158—Needles for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/31—Details
  • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
  • A61M5/3286—Needle tip design, e.g. for improved penetration

Definitions

• the invention relates to a cannula of the type known in the preamble of claim 1.
• a cannula of the type in question is known from US Pat. No. 2,746,454 and from EP 0 301 246 B.1. It has a rigid cannula tube, which is ground at an angle at the tip and carries two further facet cuts, which are arranged at an angle to one another, on the front half of this connection.
• the tip of the cannula is bent over the central axis of the cannula into the area between two imaginary parallel lines, which extend the inner surface and the outer surface of the cannula tube to the front.
• the rear edge of the basic grinding is rounded inwards.
• cannulas have been proposed from the point of view that such a bent cannula tip is less likely to puncture the opposite vessel wall when puncturing a blood vessel. Because of the reduced punching effect, such cannulas are also used for puncturing so-called implantable port catheters. With these port catheters, a membrane is pierced under the patient's skin and a drug is then injected through the cannula. Since these cannulas gouge out parts of the membrane when piercing these membranes, the portals quickly leak and the patient is burdened with the I Leu parts that are lifted out. These parts can also cause the system to fail.
• the property of punching freedom is interesting not only for the above-described applications for puncturing port catheters, but also for puncturing body cavities, e.g. B. joints, for the purpose of injection of medication or the suction of liquids located therein.
• Klinge and Müller were able to show that normal cannulas when puncturing human skin regularly lead to the formation of skin punch particles, which are mostly bacterially populated. This punching out of skin particles can be avoided by a low-punch or punch-free cannula, and this can reduce the risk of infection of the punctured body cavity, e.g. B. the joint.
• the cannula known from EP 0 301 246 B1 very largely fulfills the requirements to be placed on such a ranule. Their suitability has been proven many times in practice, but it creates considerable manufacturing problems. On the one hand, these are due to the fact that, due to the relatively strong bend in the area of the cut, the cut typically bends outwards. This makes the cannula wider in the reed area. This can be partially compensated for by suitable bending devices. However, some of the cannulas are caused by the tensile forces that occur in the reed area Tearing in the rear edge of the scuff, especially where the weld of the welded cannula is located.
• the invention is therefore based on the object of improving a cannula of the type in question so that it is simple to manufacture and has a low reject rate.
• the puncture part which has a lancet-shaped tip with a facet cut, is less bent inwards than in the known cannulas. It is bent so far inwards that it lies within the inner cross section of the cannula tube, which is intended to be extended towards the front. This smaller bend primarily means that the
• Fig. 2 is a plan view rotated by 90 degrees to
• FIG. 3 shows a longitudinal section A-A through the puncture part of the cannula according to FIG. 2 on an enlarged scale
• FIG. 4 shows an enlargement of the rear and side grinding edge of the rear grinding eye in accordance with the circular cutout B in FIG. 3.
• the first and 2 consists of a cylindrical, rigid cannula tube 2, at the rear end of which a connection or a hose can be connected.
• the cannula tube 2 is essentially straight. Its outside diameter d is preferably between 0.5 and 1.2 mm.
• a through channel 3 can preferably have a diameter of 0.3-1.0 mm.
• a ground tip 4 of the cannula tube 2 is curved in the direction of a central axis 6. This curvature is such that a tip 10 of the puncture part lies between lines 7, which are imaginary extensions of the inner cross section of the cannula.
• a cut 5 of the cannula is composed of a basic cut 8 and two facet cuts 9 arranged at an angle to one another, which lead to the formation of a sharp tip 10.
• the basic grinding 8 forms after
• a relatively sharp edge 11 which has its greatest sharpness at the rear end of a grinding eye 12.
• This entire edge which is shown in bold on one side in FIG. 2 and has the length L, is produced by bead blasting or a similar process blunted.
• the basic grinding 8 is defused from the end of the facet to the rear end of the grinding eye 12, so that this part of the grinding no longer has a cutting effect.

Landscapes

• Health & Medical Sciences (AREA)
• Vascular Medicine (AREA)
• Engineering & Computer Science (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6465253

Family Applications (1)

Country Status (4)

Cited By (3)

Families Citing this family (30)

Citations (3)

Family Cites Families (2)

• 1992
  • 1992-08-10 DE DE19924226476 patent/DE4226476C1/de not_active Expired - Lifetime
• 1993
  • 1993-07-23 EP EP93917630A patent/EP0655006A1/de not_active Ceased
  • 1993-07-23 JP JP6504954A patent/JPH07509634A/ja active Pending
  • 1993-07-23 WO PCT/EP1993/001961 patent/WO1994003223A1/de not_active Application Discontinuation

Patent Citations (3)

Also Published As

Similar Documents

Legal Events