INDWELLING VENOUS CANNULA

Abstract

The invention relates to an indwelling venous cannula (1) for application to a living being, having a venous catheter (2), wherein a puncture needle (3) can be guided in a longitudinally movable manner in the venous catheter (2). The puncture needle (3) is designed as a hollow needle over a portion of its length, wherein at least part of an additional portion of the length of the puncture needle (3) is solid.

Claims

1. An indwelling venous cannula for application to a living being, comprising: a venous catheter; and a puncture needle which is longitudinally slidably guidable in the venous catheter, wherein the puncture needle is in a form of a hollow needle over part of its length, wherein another part of the length of the puncture needle is at least partly solid.

2. The indwelling venous cannula as claimed in claim 1, wherein the venous catheter is made of a puncture-resistant material or is coated with the puncture-resistant material.

3. The indwelling venous cannula as claimed in claim 1, wherein the venous catheter is made of a self-closing material or material layers.

4. The indwelling venous cannula as claimed in claim 1, further comprising at least one holding element for facilitated application to the living being, wherein the holding element has a complementary shape or a negative contour of a human thumb or a human fingertip.

5. The indwelling venous cannula as claimed in claim 1, further comprising a fastening element, wherein the fastening element is configured to fix the indwelling venous cannula to the living being, wherein the fastening element has an adherent or adhesive surface or an adherent or adhesive coating for fixation of the indwelling venous cannula to the living being.

6. The indwelling venous cannula as claimed claim 1 wherein the venous catheter and/or the puncture needle has an undulating surface.

7. The indwelling venous cannula as claimed in claim 6, wherein the venous catheter and/or the puncture needle has a helical structure and/or is provided with a helical structure, wherein the helical structure has windings, wherein the density of the windings varies over the length of the venous catheter and/or the puncture needle.

8. The indwelling venous cannula as claimed in claim 1 wherein the venous catheter has, at a near-patient end, a dilation body for uniform expansion of a punctured body part.

9. The indwelling venous cannula as claimed in claim 8, wherein a diameter of the dilation body increases from the near-patient end along the dilation body.

10. The indwelling venous cannula as claimed in claim 9, wherein the diameter of the dilation body increases stepwise.

11. The indwelling venous cannula as claimed in claim 1 wherein the venous catheter has a connection element for connection of an aspiration element, wherein the venous catheter has a structure configured for locking with the aspiration element.

12. The indwelling venous cannula as claimed in claim 1 wherein a near-vein end of the puncture needle or a vein-remote end of the puncture needle is hollow.

13. The indwelling venous cannula as claimed in claim 12, wherein the vein-remote end of the puncture needle is hollow and is connected to at least one hole, wherein the at least one hole is arranged laterally on the puncture needle.

14. The indwelling venous cannula as claimed in claim 1 wherein the puncture needle and the venous catheter are curved and/or angled and/or helical.

15. The indwelling venous cannula as claimed in claim 1 wherein in the venous catheter is layered, wherein individual layers are detachably arranged in a lumen of the venous catheter.

16. The indwelling venous cannula as claimed in claim 1 wherein at least part of the venous catheter comprises an aramid and/or aramid fibers.

17. The indwelling venous cannula as claimed in claim 1 wherein at least part of the venous catheter and/or the puncture needle comprises a resorbable material or at least part thereof is coated with the resorbable material.

18. The indwelling venous cannula as claimed in claim 17, wherein at least part of a tip of the puncture needle consists of a resorbable material and/or is coated with a resorbable material.

19. The indwelling venous cannula as claimed in claim 1 wherein the venous catheter is stretchable in relation to its diameter.

20. The indwelling venous cannula as claimed in claim 1 further comprising a clamping element arranged on the venous catheter, wherein the clamping element is configured to interrupt a fluid flow through the venous catheter.

21. The indwelling venous cannula as claimed in claim 1 further comprising a sensor at a near-vein end.

22. The indwelling venous cannula as claimed in claim 1 wherein the venous catheter and/or the puncture needle has a helical structure and, wherein the puncture needle is detachably connected to the venous catheter.

23. The indwelling venous cannula as claimed in claim 1 wherein the venous catheter is multiluminal.

24. The indwelling venous cannula as claimed in claim 23, wherein at least one lumen is configured for rinsing of the venous catheter of the living being.

25. The indwelling venous cannula as claimed in claim 1 wherein the puncture needle and/or the venous catheter is rotatably mounted about its own longitudinal axis.

Description

[0293] The invention will be explained in more detail below on the basis of an exemplary embodiment using a drawing. What is shown is:

[0294] FIG. 1—a schematic depiction of an indwelling venous cannula in a side view.

[0295] FIG. 1 shows a schematic depiction of an indwelling venous cannula 1 in a side view. The indwelling venous cannula 1 has a venous catheter 2, and a puncture needle 3 can be longitudinally slidably guided in the venous catheter 2.

[0296] The indwelling venous cannula 1 is in the form of a peripheral-vein indwelling cannula 1. It is clear that the venous catheter 2 was formed like a tightly wound helical spring from a puncture-resistant material to give rise to an undulating surface. The venous catheter 2 consists of a puncture-resistant material over its entire length. The helical structure ensures the flexibility of the venous catheter 2. Such a design of the venous catheter 2 provides an antipiercing and anticutting guard which protects the venous catheter 2 from, for example, puncturing by a near-patient tip 6 of the puncture needle 3 during application of the indwelling venous cannula 1. The risk of a damaged venous catheter 2 is thus minimized. It can no longer be sheared off by the near-patient tip 6 of the puncture needle 3, even with repeated sliding of the puncture needle 3 relative to the venous catheter 2. Scrap due to damaged venous catheters can thus be distinctly reduced. Moreover, repeated use of the indwelling venous cannula 1 as part of a puncture process under constant sterile conditions on a living being is possible. This is especially important if mispuncture initially occurs, i.e., the blood vessel was accidentally missed during the first puncture or the venous catheter 2 could not initially be advanced far enough into the blood vessel.

[0297] For improved aspiration, the venous catheter 2 is provided with a sealing coating 4. The undulating surface can give rise to minimal openings which make aspiration difficult, since it is through said openings that, for example, air can be undesirably drawn. A sealing coating 4 can minimize or prevent the undesired aspiration of air. Advantageously, the sealing coating 4 is a PTFE coating which, at the same time, facilitates the insertion of the venous catheter 2 into the punctured body part. An additional dilation element 10 at the near-patient end of the venous catheter 2 achieves uniform expansion when the venous catheter 2 is advanced in the punctured body part.

[0298] The application of the indwelling venous cannula 1 to a living being can, for example, proceed in the following steps: [0299] 1. Puncturing a vein using the puncture needle 3 [0300] 2. Advancing the helical venous catheter 2 having the sealing coating 4 over the near-patient tip 6 of the puncture needle 3 into the vein to the desired position [0301] 3. Removing/sliding back the puncture needle 3 [0302] 4. Closing the helical venous catheter 2 at a patient-remote end.

[0303] The indwelling venous cannula 1 has two holding elements 5. Said holding elements 5 enable the user to operate the indwelling venous cannula 1 with one hand, the second hand being able to be used, for example, to stabilize the body part to be punctured. The puncture needle 3 is in the form of a hollow needle. After puncturing by the near-patient tip 6 of the puncture needle 3, the user can directly identify whether the vein has been punctured correctly, in that the hollow puncture needle 3 fills with venous blood and enters the chamber 7, whereby the blood can be directly perceived by the user.

[0304] After puncturing, the venous catheter 2 can be slid into the punctured body part and the puncture needle 3 together with the chamber 7 can immediately be pulled out of the components of the indwelling venous cannula 1 that remain in the body part. A safety mechanism can be designed so that the near-patient tip 6 of the puncture needle 3 is shielded after it has been pulled out of the indwelling venous cannula 1 and thus protects the user and the living being from possible stab injuries.

[0305] In its end position in the punctured body part, the venous catheter 2 can be held fixed to the living being via fastening elements 8. The fixation can be done by means of a self-adhesive wound dressing, which fixes the indwelling venous cannula 1 to the living being via the fastening elements 8. The fastening elements 8 described, which can be in the form of wings for example, are optional elements of the indwelling venous cannula 1.

[0306] Here, the puncture needle can run essentially in the middle between the holding elements 5 and/or the fastening elements 8.

[0307] It is clear that the function of the holding element 5 and the fastening element 8 can be combined in one element. This allows simple production of the indwelling venous cannula 1, while at the same time the structure of the indwelling venous cannula 1 is kept simple for the user.

[0308] An aspiration element such as a syringe can be connected via a connection element 9. The connection element 9 can be in the form of a valve which allows simple drug administration or aspiration of blood. Here, when the valve is untouched, it prevents liquids, such as blood, from running retrogradely out of the connection element 9. Moreover, when the valve is untouched, it prevents air from penetrating into the connection element 9 from the outside. The connection element 9 can moreover contain a filter which prevents coarse particles, bacteria and air from penetrating into the interior of the connection element 9 and thus into the interior of the indwelling venous cannula.

[0309] An aspiration element such as a syringe can be connected to the chamber 7. As a result, the indwelling venous cannula can be inserted into a vein under continuous aspiration using the syringe. The success of puncture can therefore be established directly and very precisely. Here, chamber 7 can also be in the form of a further valve which allows the flow of fluids in only one defined direction. Moreover, chamber 7 can alternatively or additionally also be designed in such a way that it prevents air from penetrating or only allows passage of air and other gases and vapors in one defined direction. The chamber 7 can, for example, be designed in the same way as the connection element 9.

[0310] The chamber 7 and the connection element 9 can be covered by a protective cap, so that undesirable contamination does not occur when the chamber 7 and the connection element 9 are not in use. The protective cap can be connected to the chamber 7 via a tab and/or to the connection element 9 via a tab.

[0311] It is also conceivable that when a protective cap, which can be connected to the connection element 9 or to the chamber 7 via a tab, is pressed down, the fluid flow in the indwelling venous cannula is interrupted or slowed down.

[0312] At the near-patient end, the venous catheter 2 has holes 11 distributed over the circumference. It is through the holes 11 that a homogeneous delivery of, for example, a drug into the living being can be achieved. An undesired, locally highly concentrated delivery of the drug into the living being is thus avoided. By arrangement of a plurality of holes 11, it is moreover possible to increase the flow rates of the administered infusion solutions and drugs. Moreover, this can facilitate aspiration of liquids, such as blood collection, from the living being via the situated venous catheter or via the situated indwelling venous cannula. With appropriate construction of other components of the indwelling venous cannula, what may also be possible as a result is fluids, vapors and/or gases spontaneously escaping from the indwelling venous cannula in a desired and retrograde manner, if it is to be used, for example, for drainage of fluids, vapors and/or gases, for example as part of a puncture of the pleural space, other cavities or the above-described body spaces.

[0313] What is presently depicted is merely a schematic depiction giving a good overview of the components of the indwelling venous cannula according to the invention. However, the lengths and proportions can differ in reality.

[0314] FIG. 1 is one possible exemplary embodiment. Other forms of the teaching according to the invention are also conceivable. Furthermore, the embodiments of the exemplary embodiment are not inseparably linked to one another, and so, for example, the implementation of the invention is not dependent on the embodiments of the exemplary embodiment that have been specifically described. Thus, variability of, for example, the number, length or size of the individual elements is always conceivable.

LIST OF REFERENCE SIGNS

[0315] 1—Indwelling venous cannula [0316] 2—Venous catheter [0317] 3—Puncture needle [0318] 4—Sealing coating [0319] 5—Holding element [0320] 6—Tip [0321] 7—Chamber [0322] 8—Fastening element [0323] 9—Connection element [0324] 10—Dilation body [0325] 11—Holes