WO2005035039A2

WO2005035039A2 - Vascular catheter

Info

Publication number: WO2005035039A2
Application number: PCT/EP2004/011318
Authority: WO
Inventors: Abdolhamid Huschmand Nia
Original assignee: Georg-August-Universität Göttingen
Priority date: 2003-10-10
Filing date: 2004-10-09
Publication date: 2005-04-21
Also published as: EP1677865A2; DE10347198A1; WO2005035039A3; DE10347198B4

Abstract

A vascular catheter (1), especially a vein indwelling catheter, comprising a bas body (2), a catheter which extends from the base body (2), a cannula (5) extending from a handle area (7) through a sealing area (8) in the base body (2) through the entire catheter (3), the tip (6) thereof protruding above the catheter (3), and a connection channel laterally adjoining to the catheter in front of the sealing area (8). At least the handle area (7) on the cannula (5) extends into a dimensionally stable cannula cage (10) which can only be removed from the base body (2) when the cannula (5) and the tip thereof (6) is drawn out of the base body (2) and drawn into the cannula cage (10).

Description

GEFAßKATHETER

The invention relates to a vascular catheter, in particular an indwelling vein catheter, with the features of the preamble of claim 1.

STATE OF THE ART

In the case of a vascular catheter, the cannula serves to stabilize the catheter when it is inserted into the vessel through the skin, the vessel wall and the tissue located between them. The sharp tip of the cannula, which is usually made of steel, facilitates the penetration of the catheter into the vessel. The inflow of blood from the vessel into the cannula or the re-emergence of the blood at the proximal end of the cannula is an indication that the cannula, and with it the catheter, has entered the vessel. The cannula can then be withdrawn from the catheter in order to release the catheter, for example, for drawing blood from the vessel. If the catheter is to remain in the vessel for a longer period of time, the base body of the vascular catheter must be attached to the patient's arm, for example.

The present invention is concerned with the safety problem associated with the cannula drawn out of the catheter and the base body after the catheter has been inserted. There is a considerable risk of injury from the sharp tip of the cannula. In addition to the purely mechanical risk of injury, there is also the risk of infection, since the cannula has come into contact with the patient's blood inside and outside. Vascular catheters are known in which the cannula is pulled out of the catheter and the base body with a tube that was previously collapsed in the base body. This hose can be held in a warning color.

In addition, it is known in the case of vascular catheters that when the cannula is pulled out of the catheter and the base body, a cover clip is placed on the tip, which is pulled out of the base body with the cannula. In order to achieve this, the cannula of these known vascular catheters is kept somewhat thicker at the tip in order to form a shoulder that takes the cover clip with it.

In the combination of both known measures, protection against the withdrawn cannula and in particular the tip thereof can be provided. If a high level of functional reliability is to be achieved, however, the effort for this is very high. The cannula must be specially made. Both the collapsed hose and the cover clip must be accommodated in the base body.

As a countermeasure to the problem that still arises, which blood can drip out of the base body after the cannula has been pulled out of the catheter and the base body, a known vascular catheter with the features of the preamble of patent claim 1 has a sealing area through which the cannula projects into the catheter from the grip area and automatically seals the base body behind the pulled-out tip of the cannula. In a known vascular catheter with the features of the preamble of claim 1, the sealing area is designed such that it releases the catheter again, for example, a syringe when it is subsequently attached. However, this requires a rather complex construction of the sealing area.

In another vascular catheter with the features of the preamble of claim 1, the sealing area consists essentially of an elastic sealing body through which the cannula is pierced into the catheter and which closes automatically behind the tip of the cannula when the cannula is pulled out, but which except does not provide access to the catheter for the cannula. Here, the connection to the catheter is effected by an inclusion channel of the base body, which is laterally connected to the catheter in front of the sealing area and opens into a connecting piece. On the connecting piece can be connected, for example, to a hose leading to a syringe when the catheter is placed. The free connection of the connection channel with the catheter is established as soon as the cannula has been pulled out of the region of the junction of the connection channel into the catheter. OBJECT OF THE INVENTION

The invention has for its object to show a vascular catheter with the features of the preamble of claim 1, in which the cannula pulled out of the catheter and the base body is no longer a source of danger without thereby complicating the structure of the base body.

SOLUTION

The object of the invention is achieved according to the invention by a vascular catheter with the features of claim 1. Preferred embodiments of the new vascular catheter are described in subclaims 2 to 11.

DESCRIPTION OF THE INVENTION

With the new vascular catheter, at least the grip area on the cannula or even a part of the cannula itself extends into a dimensionally stable cannula cage, this cannula cage, which is able to hold the cannula over its entire length, can only be removed from the main body if the Cannula including its tip is drawn out of the main body into the cannula cage. That is, the cannula is transferred directly from the base body into the cannula cage and is housed entirely in the latter before the cannula cage can be removed from the base body. The cannula cage is comparatively large due to its dimensional stability, but this is not a problem because the cannula cage is not accommodated in the molded body but is attached to it. The attached cannula cage does not affect the structure of the molded body itself. However, the shape stability of the cannula cage ensures that it is sufficient if the cannula is completely drawn into the cannula cage in order to also remove the danger from its tip. There are no additional measures at the top of the list Cannula are provided. This means that the cannula can be a standard cannula, so it does not require any special manufacturing effort.

The selective removability of the cannula cage from the base body only when the cannula including its tip is drawn out of the base body into the cannula cage can be provided by a connection between the base body and the cannula cage which is locked as long as the tip of the cannula is not is drawn into the cannula cage. This means that the cannula itself serves as a locking element for the connection.

The term cannula cage is to be understood such that contact with the cannula enclosed in the cannula cage is prevented on all sides by the cannula cage. This does not necessarily mean that the cannula cage does not allow access to the cannula. However, the access openings are so small and the cannula is so far behind them that, for example, contact of a hand enclosing the cannula cage with the cannula is excluded.

The cannula can be guided in a guide groove in the cannula cage via a guide head of the grip area. In the preferred, because particularly simple embodiment of the present invention, the cannula is received by an open groove, wherein the grip area protrudes through the opening of the groove and can be actuated. So that the cannula cannot get out through the opening of the groove, although it typically does not have a larger diameter than the width of the opening, it is anchored in a guide head of the grip area, which is guided in the guide groove in the cannula cage in such a way that the application of Forces between the grip area and the cannula cage do not cause the cannula and in particular its tip to come out of the groove. In addition, cross bolts can be provided, which close the guide groove upwards and which can be temporarily pushed sideways away from the grip area displaced along the groove.

To further increase the safety of the new vascular catheter, provision can be made for the grip area to latch with the cannula cage when the tip of the cannula has entered the cannula cage. The latch prevents the tip of the cannula from coming back is pushed over the cannula cage. Therefore, it is useful to make this latching inseparable.

Another safety advantage results from the fact that a latching arrangement between the grip area and the cannula cage is designed such that it pulls the cannula a little further into the cannula cage under the action of a latching force. If the cannula is pulled so far into the cannula cage that the connection of the cannula cage to the base body of the vascular catheter is released, the tip of the cannula is automatically pulled a little further into the cannula cage by the locking arrangement in order to make it completely disappear into it ,

A latching arrangement can also be provided, in which the tip of the cannula jumps behind a projection, through which it cannot come out again. For example, if the guide groove for the guide head of the handle part is slightly curved and there is a side pocket in the guide groove on the side facing away from the curvature, into which the tip of the cannula can snap due to the restoring force of the cannula, the cannula can no longer be pushed forward Grip area out of the pocket.

In any case, the guide groove is preferably closed at its end facing away from the base body in order to prevent the grip area with the cannula from being pulled out there.

The grip area can also be locked on the base body in order to hold the cannula in its advanced position desired for the placement of the catheter. However, this is in any case a releasable latching.

So that it can quickly be seen that the cannula has penetrated into the vessel to be reached, the cannula can open into a cavity of the handle area that is visible from the outside and vented to the outside. The cavity can be vented in the usual way through an air-permeable but blood-impermeable filter. Visibility of the cavity is particularly given when all parts of the vascular catheter except the cannula, which usually consists of steel, are transparent or at least translucent. With the new vascular catheter, the cannula cage can be connected to the base body so stably before it is unlocked by pulling in the cannula that it forms a guide handle for the placement of the vascular catheter.

The connection between the cannula cage and the base body can be brought about by plug-in and / or swivel connection elements running perpendicular to the cannula.

The cannula cage of the new vascular catheter is particularly advantageously combined with a connection channel which is connected laterally to the catheter in the base body in front of the sealing region through which the cannula passes.

BRIEF DESCRIPTION OF THE FIGURES

In the following, the invention is further explained and described with reference to a preferred exemplary embodiment shown in the figures.

1 shows a perspective view of the entire vascular catheter in the configuration for the placement of the vascular catheter.

FIG. 2 shows the vascular catheter in the configuration according to FIG. 1, with a cannula cage shown in FIG. 1 being omitted to make further details visible.

FIG. 3 shows the basic body of the vascular catheter according to FIGS. 1 and 2 with the catheter attached, from which, compared with FIG. 2, a cannula with the grip area attached is also pulled out.

FIG. 4 shows the lower part of the base body according to FIG. 3 with the catheter attached to illustrate the internal structure of the base body.

FIG. 5 shows the cannula cage according to FIG. 1, into which the cannula with the grip area according to FIG. 3 is drawn. Fig. 6 shows in a separate representation, which does not correspond to any functional position of the venous catheter, the cannula with the handle area attached to it.

DESCRIPTION OF THE FIGURES

The vascular catheter 1 shown in FIG. 1 is provided, for example, as an intravenous catheter. It has a catheter attached to a base body 2, which is connected to a connection piece 4 in the interior of the base body 2. 1, however, a cannula 5 is also arranged in the catheter 3, which stabilizes the catheter for placement, the tip 6 of the cannula 5 projecting distally over the catheter in order to facilitate advancement into the respective vessel. As long as the cannula 5 is in the catheter 3, the connection between the catheter 3 and the connecting piece 4 is not yet free. However, a syringe, a hose or the like can then already be connected to the connecting piece 4. After the catheter 3 has been placed, the cannula 5 can be pulled out of the catheter 3 to the rear by engaging a grip region 7 in which the cannula 5 is mounted and which projects laterally from the cannula 5. The base body 2 is sealed behind the tip 6 of the cannula 5 by a sealing area 8, in which the cannula 5 passes through a body made of elastic material. A grip area 9 is also formed on the base body 2 in order to make it easier to pull out the cannula 5. Already in its foremost position, which is shown in FIG. 1, the grip area 7 projects into a guide groove 13 of a cannula cage 10, which is connected to the base body 2 via connecting elements 11 and 12. The connecting elements 11 and 12 are rigidly locked by the grip area 7 in its position according to FIG. 1, so that the cannula cage 10 can serve as a fixed guide handle when the catheter 3 is placed. After placement, the cannula cage 10 picks up the cannula 5 mounted thereon when the grip area 7 is withdrawn. When the grip area 7 snaps onto locking lugs 14 on the cannula cage 10, the cannula 5 is completely in the guide groove 13 and it does not come out of the guide groove 13 due to the defined guidance of the grip area 7 in the guide groove 13, even if the diameter of the Cannula 5 is smaller than the free opening of the guide groove 13. When the cannula 5 is completely drawn into the cannula cage 13, the connecting elements, which extend transversely to the main direction of extension of the cannula 5, are unlocked. Depending on the design of the connecting elements 11 and 12 in detail, the cannula cage 10 can then be used with the captured cannula are pushed laterally from the base body 2 or folded up.

The part of the grip area 7 which projects into the cannula cage 10 according to FIG. 1 and thereby locks the connecting elements 11 and 12 can be seen particularly well in FIG. 2. This figure does not correspond to any functional position of the vascular catheter 1 according to FIG. 1, because in the position of the cannula 5 shown in the catheter 3, the cannula cage 10 is firmly connected to the base body 2. FIG. 2 is therefore used only to illustrate, in particular, the extension 15 of the grip area 7, which projects into the cannula cage 10 in FIG. 1. In addition, a filter 16 can be seen here, with which a cavity is vented somewhere inside the handle area 7, which can be seen from the outside and into which the cannula 5 opens. When blood flows into the cannula 5 at the tip 6, this blood reaches the cavity 26, and the displaced air exits through the filter 16. The filter 16, which is a common component for vascular catheters, however, does not allow blood to leak or even to emerge.

3 shows the base body 2 with the catheter 3 after the removal of the cannula 5 with the cannula cage 10 according to FIG. 1. Now the catheter 3 communicates with the connecting piece 4, which will be explained in more detail below. In Fig. 3 also locking lugs 17 can be seen, which hold the grip area 7 in the front position, in which the cannula 5 mounted on it protrudes with its tip 6 over the catheter 3.

4 outlines the internal structure of the base body 2. The catheter 3 is mounted in a connecting piece 27. At the proximal end of the connecting piece there is a lateral opening 23 of a connecting channel 20 into the catheter 3. The connecting channel 20 leads to the connecting piece 4. Aligned with the catheter 3, a guide channel 22 for the cannula runs in the lower part 19 of the base body 2 shown. The guide trough 22 is interrupted by a recess 21 into which a sealing body is inserted to form the sealing area 8 in the assembled molded body 2. As long as the cannula extends through the guide channel 2 into the catheter 3, the connection between the connection channel 20 and the catheter 3 at the mouth 23 is blocked. As soon as the cannula clears this mouth, the connecting piece 4 communicates with the catheter 3. FIG. 5 shows the cannula cage 10 with the cannula 5 completely retracted therein, the tip 6 of the cannula lying securely in the guide groove 13 and being unable to emerge from the guide groove 13 because of a precisely fitting guidance of the grip area 7 in the guide groove 13. A displacement of the grip area 7 along the guide groove 13 is prevented by the grip area 7 being snapped onto the locking lugs 14 according to FIG. 1. FIG. 5 shows that, contrary to the representation of the exemplary embodiment in the figures, it would be more favorable if the connecting elements 11 and 12, which were designed according to the tongue and groove principle, were split up in exactly the opposite manner between the base body 2 and the cannula cage 10. The connecting elements should only be unlocked when the tip 6 of the cannula 5 has already been drawn into the guide groove 13 of the cannula cage 10. This would be ensured even better if the groove-like connecting element 11 were provided on the cannula cage 10, because then the tip 6 of the cannula 5 would already be inside the cannula cage 10 when the connecting elements were released and not in the area of the projecting spring-like connecting element 12. In addition, for the safety of the locking between the base body 3 and the cannula cage 10, it would also be advantageous if a sealing body in the base body 2, which guides the cannula 5 without play, extends to the connecting line to the cannula cage 10.

6 shows the cannula 5 with the grip area 7 in a separate illustration. The grip area 7 comprises a guide head 25 which is guided in the guide groove 13 of the cannula cage 10 and which ends proximally in the extension 15 with the filter 16. The cannula 5 is mounted in the guide head 25. Furthermore, the grip area 7 has locking recesses 24 for locking the grip area 7 on the locking projections 14 and 17. Between its two main surfaces, on which the grip area is gripped, the grip area 7 has the cavity 26, in which blood can flow through the cannula 5 in order to indicate that the cannula 5 has entered the respective vessel. LIST OF REFERENCE NUMBERS

Vein indwelling catheter 11 connecting element

Base body 12 connecting element

Catheter 13 guide groove

Connection piece 14 locking lug

Cannula 15 extension

Tip 16 filter

Handle part 17 latch

Sealing area 18 groove

Handle part 19 lower part

Cannula cage 20 connecting channel

recess

guide trough

junction

latching depression

guide head

cavity

spigot

Claims

PATENT CLAIMS

1. Vascular catheter, in particular intravenous vein catheter, with a base body, with a catheter that extends away from the base body, and with a cannula that extends from a grip area through a sealing area in the base body and through the entire catheter, their Tip protrudes over the catheter, characterized in that at least the grip area (7) on the cannula (5) extends into a dimensionally stable cannula cage (10) which can only be removed from the base body (2) when the cannula ( 5) including its tip (6) is drawn out of the base body (2) into the cannula cage (10).

2. Vascular catheter according to claim 1, characterized in that a connection (11, 12) between the base body (2) and the cannula cage (10) is locked as long as the tip (6) of the cannula (5) is not in the cannula cage (10 ) has moved in.

3. Vascular catheter according to claim 1 or 2, characterized in that the cannula cage (10) prevents contact on all sides with the inserted cannula (5).

4. Vascular catheter according to one of claims 1 to 3, characterized in that the cannula (5) is guided via a guide head (25) of the grip area (7) in a guide groove (13) in the cannula cage (10).

5. Vascular catheter according to one of claims 1 to 4, characterized in that the grip area (7) with the cannula cage (10) latches when the tip (6) of the cannula (5) has entered the cannula cage (10).

6. Vascular catheter according to claim 5, characterized in that a latching arrangement (14, 24) between the handle region (7) and the cannula cage (10) is designed such that it extends the cannula (5) a little further under the action of a latching force pulls in the cannula cage (10).

7. Vascular catheter according to one of claims 1 to 6, characterized in that the grip area (7) is releasably locked to the base body (2).

8. Vascular catheter according to one of claims 1 to 7, characterized in that the cannula (5) opens into an externally visible and externally vented cavity (26) of the handle part (7).

9. Vascular catheter according to one of claims 1 to 8, characterized in that the cannula cage (10) forms a guide handle for the placement of the vascular catheter (1).

10. Vascular catheter according to at least one of claims 1 to 9, characterized in that the cannula cage (10) is connected to the base body by means of plug-in and / or pivoting connection elements (11, 12) running perpendicular to the cannula (5).

11. Vascular catheter according to at least one of claims 1 to 10, characterized in that the base body (2) has a connection channel (20) laterally connected to the catheter (5) in front of the sealing region (8).