WO2009006960A1

WO2009006960A1 - Cannula device for collecting spinal fluids (liquor)

Info

Publication number: WO2009006960A1
Application number: PCT/EP2008/003657
Authority: WO
Inventors: Hans Haindl
Original assignee: Hans Haindl
Priority date: 2007-07-07
Filing date: 2008-05-07
Publication date: 2009-01-15
Also published as: DE102007031799B3

Abstract

Cannula device for collecting spinal fluid (liquor), with a thin spinal cannula (2) which is ground to a sharp finish at a free end (4) and which, at its other end, is connected to a connection part, wherein the spinal cannula (2) has a lateral opening directly behind its sharp free end (4), and the connection part is at least partially transparent, and wherein the connection part has a cannula with a pointed end which is directed away from the spinal cannula (2) and on which a retractable protective cap (28) is arranged which is punctured and pushed back when an attachment piece is fitted, but which moves forwards again and closes the cannula when the attachment piece is removed.

Description

Needle device for the removal of spinal fluid (cerebrospinal fluid)

The invention relates to a cannula device for the removal of cerebrospinal fluid (CSF), which has a thin spinal cannula sharpened at one free end and is connected at its other end fixed to a connecting part, wherein the spinal cannula (2) immediately behind her sharpened free end (4) has a lateral opening, and the connecting part is at least partially transparent.

Cannula devices of the type in question are well known and serve in neurology to remove cerebrospinal fluid (CSF) from the patient for diagnostic purposes. For diagnostic differentiation, this spinal fluid is taken in three fractions, which are then examined separately. The known cannula devices have a thin spinal cannula, with which the spinal space containing the spinal fluid is punctured. When the spinal space is reached, the cerebrospinal fluid drips off the spinal cannula. Then the first drops are collected in a small cuvette. Then the cuvette is changed and the next drops are collected, after which the cuvette is changed again to catch the last fraction of the cerebrospinal fluid.

This handling is cumbersome and often leads for the investigator to come into contact with the patient's CSF. For hygienic reasons, it is customary to wear gloves during the procedure, but nevertheless it would be desirable to avoid contamination of the gloves or even the hands of the examining physician.

This contamination is so dangerous because in the new variant of the Kreutzfeld-Jacob disease the cerebrospinal fluid is extremely infectious. There have been described infections caused solely by skin contact with the cerebrospinal fluid. Already by small, imperceptible skin injuries, eg. B. in the nail folds, it can come to such infections. Since this disease is not curable until today and inevitably leads to death, protective measures are urgently indicated.

Similar risks of infection also exist in the removal of venous or arterial blood. In the meantime, systems have become established for these applications, which reliably prevent the contamination of the treating physician with the blood. In a known system, the cannula has at its end remote from the tip of a connecting part, often called safety connector, in which there is a receiving opening for coupling a cuvette. The cannula protrudes with its tip facing away from the end in this interior, by this end is covered by a retractable protective cap. When coupling a special cuvette, which is closed at its entrance by a pierceable membrane, this membrane is pierced through the rear end of the cannula, while the protective cap pushed back over the cannula, so that blood can enter the cuvette. If the cuvette is then removed, the protective cap expands again beyond the cuvette. tere end of the cannula and thus closes it. In the same way then another or more cuvettes can be connected, so that several samples can be removed in succession.

For various reasons, such contamination-safe systems (safety cuvettes) for the removal of spinal fluid can not be used. This has the following reasons:

1. All spinal cannulas common today have a stylet inside their lumen that closes off the lumen of the spinal cannula. This has the meaning that this prevents tissue, z. As fat cells, penetrate the puncture into the cannula and thus the return of the spinal fluid, which is only under very low pressure, does not take place.

2. The safety connectors for the safety cuvettes are in hibernation, ie without a connected cuvette, tight. Thus, if, with the removal of the stylet, such a safety connector were placed on the spinal cannula, it would not be possible to withdraw any spinal fluid, since the pressure under which it is located is not able to compress the air cushion in the cannula so far. that the liquid column is visible in the neck of the cannula.

EP 0 682 954 B1 describes a spinal cannula which has a thin cannula with a piercing point sharpened at its free end, which is provided with an opening and the rear end portion of which is fastened in a one-piece, clear-plastic grip part. Inside the transparent handle part is located between two flange a CSF control chamber, by means of which in the spinal puncture the liquor reflux can be controlled. At the piercing point opposite Overlying side of the handle portion is provided a cylindrical projection with a Luer-bore for positive reception of the Luer plug cone of a drug tip. In addition, this spinal cannula is provided with a stylet, which is insertable through the hollow handle portion into the cannula, to the extent that there the front end of the stylet, the opening of a piercing tip can be closed.

DE 42 26 476 C1 describes a cannula with a through-channel and a cylindrical, rigid cannula tube whose ground tip is curved on a central axis. The tip has a facet cut at the very front and immediately thereafter a ground cut, where the through-channel also opens.

DE 101 42 450 C1 describes a device for combining a liquid component accommodated in a first container and a solid or liquid component received in a second container under sterile conditions. For this purpose, the device has a first cylindrical hollow body for receiving the first container in the region of its closure and a second cylindrical hollow body for receiving the second container in the region of its closure. The first hollow body serves for the displaceable reception of a cup-shaped cannula carrier and can be inserted into the second hollow body. The cup-shaped cannula carrier takes in the region of its bottom portion fixed to a central, axially directed transfer cannula, which is provided with spit ends. After the first container in the hollow body and the second container are inserted into the hollow body, the two containers are pushed towards each other, until initially the cannula of the remaining in its position cannula carrier the closure of the container pierces and thereafter - upon further compression - pierces the other end of the cannula the closure of the container, so that the two containers are connected via the cannula.

DE 203 11 868 Ul describes a closed passive bloodletting, ascites, pleural, lumbar puncture system (with backflow safety device) for the contamination-free removal and disposal of body fluids (blood, cerebrospinal fluid, ascites fluid, pleural exudate / transudate).

A steel cannula for spinal and epidural anesthesia known from EP 0 359 987 A2 consists essentially of a straight cylindrical tube made of steel, at the front end of which a piercing point is formed and whose rear end is fastened to a grip sleeve of transparent material. The grip sleeve is concentrically penetrated by a conically widened to the rear cavity, which is composed of two coaxial successive conical sections of different opening width. The rear conical portion terminates open and at its edge the grip sleeve is provided with radially outwardly directed lugs which serve as locking elements for the coupling part of a syringe. In the tube, a cylindrical tube channel is present, which opens at the front at a sideways opening and at the rear at a central passage. The piercing tip can have a convexly curved wall side which, with the opposite straight wall side, delimits the lateral opening, which is provided with a rear cutting edge and a lancet-shaped front piercing part ending in a point-faceted cut. However, it is also possible for a cylindrical straight tube to be made thinner at its front end section and to be designed as a closed pointed cone. finished piercing point. Immediately behind the cone may be in the pipe wall an opening with a circular or square cross-section. In both cases, however, there is a concentric mandrel made of steel in the tube and the grip sleeve. The manifold has a circular cross-section and its thickness is such that it approximately circumferentially fills the narrowed tube channel end portion. The tip of the stylet is ground so that it fills the bevel eye of the opening without heels.

The invention has for its object to provide a cannula device, in short a puncture set, for the removal of spinal fluid, which is completely safe from contamination and at the same time allows a simple puncture and easy detection of Liquorrückflusses.

The problem underlying the invention is achieved by the teaching specified in the characterizing part of claim 1.

The basic idea of the teaching according to the invention is to combine a spinal cannula without stylet with a suitable safety connector. According to the invention, the spinal cannula has a lateral hole and is preferably sharpened pencil-shaped at the tip. This combination creates a system for the contamination-free removal of spinal fluid.

As long as the cannula is sealed at its rear end by the protective cap, no spinal fluid can escape or even only flow into the connecting part, since it is prevented from doing so by the enclosed air column.

In order for the surge to be visible to the physician, an opening of the cannula must be made at its end, and Although so that it is safe against contamination. For this purpose, the protective cap must be pierced, either by placing a cuvette or a corresponding venting part.

According to claim 4, the connecting part of a first and a second part, which are interconnected via a conical pin / receiving opening, wherein the second part forms a safety adapter for connecting a cuvette. The safety adapter has at its one end the conical pin and at the other end a female bayonet receptacle into which the corresponding counterbay of a safety cuvette can be snapped. Inside this bayonet mount is a sharpened cannula suitable for penetrating the protective cap and stopper of the safety cuvette. This cannula is protected by a condom-like silicone or rubber cap, so that they are at rest, d. H. is tight without coupled cuvette.

In detail, according to claim 4, a first part 8 having at one end the conical pin for insertion into the conical receiving opening and at its other end an opening for receiving the connecting part of a cuvette. In addition, a second part is provided which has an end which, instead of a cuvette, can be inserted into the receiving opening for a cuvette in the first part and has a cavity which is closed by a membrane which is permeable only to air and not to spinal fluid and is punctured upon insertion of the second part by a short cannula which projects from the conical pin in the region of the receiving opening and at its end facing away from the conical pin end has a sharp point, the membrane when placed of the second part pierces the first auxiliary part. The cavity avoids the build up of an air back pressure in the spinal cannula and the cavity in the region of the connecting part is at least partially transparent, so that as a result, the outflow of liquor and entry into the cavity is not obstructed and so by observing the cavity for the attending physician it can be determined that he has hit the CSF area. The cavity can also be located in the first part of the connecting part.

Reference to the drawing, the invention of an exemplary embodiment will be explained in more detail.

1 shows the embodiment of the invention in an overall view in section,

FIG. 2 shows an enlarged section within a circle A in FIG. 1, FIG.

Fig. 3 corresponds substantially to Fig. 2 and illustrates the function of the second part of the connecting part,

4 shows a modification of FIG. 3.

The cannula device shown in section in FIG. 1 has a spinal cannula 2 whose free end 4 is ground sharply, which is protected in its entirety by a tube 6 which is attached to a part 8 of which the rear end of the spinal cannula 2 is held , The part 8 has a conical receiving opening 10, in which a conical pin 12 of a second part 14 is inserted, which has a receiving opening 16, in which a venting part 19 is inserted, which is closed at the rear by a membrane 21, for air, but not permeable to cerebrospinal fluid. The parts lying in a circle marked A The cannula device are shown enlarged in Fig. 2, wherein the venting part 19 is replaced by a conventional cuvette 20.

From Fig. 2 it can be seen that the usual cuvette 20 has a cavity 22 which is closed by a membrane 24.

In the conical pin 12 is a short cannula 26 which projects into the receiving opening 16 and is covered there by a protective cap 28. The membrane 24 facing the end of the short cannula 26 has a sharp tip 30.

The part 8 is made of transparent material, but may also have a transparent window, so that a provided in the connecting part 8 cavity 32 and therein entering Liquor can be observed.

In the position shown in Fig. 2, the cannula device is not yet suitable for the removal of cerebrospinal fluid. To bring this cannula device in the position of use, the cuvette 20 is pushed with its end 18 into the receiving opening 16, whereby the sharp tip 30 of the short cannula 26 first pierces the front end of the protective cap 28 and then the membrane 24 with the result that the interior of the spinal cannula 2 communicates with the cavity 22 of the cuvette 20 via the cavity 32 in the part 8, the receiving opening 10 and the interior of the short cannula 26, as shown in FIG. The protective cap 28, which consists of elastic material, has thereby pushed onto the short cannula 26, as shown in FIG. 3 can be seen.

In the position shown in Fig. 3, the cannula device is prepared for spinal cord puncture. At a puncture the attending physician observes the Cavity 32 and recognizes by the entry of liquor in this cavity 32 that its puncture is successful. If this is the case, he pulls back the piston of the cuvette 20, then enters the liquor. When removing the cuvette 20, the free end of the short cannula 26 is closed again by the protective cap 28, after which again a second or a third cuvette can be placed in order to remove several parts of liquor.

Fig. 4 corresponds substantially to Fig. 3, but only the lower parts in the illustration are shown in section. The difference from Fig. 3 is that the part 8 has a lateral opening 34 which is closed by a filter 36 which allows air to escape, but when liquid wetting is allowed to enter air.

Claims

claims

1. Needle device for the removal of cerebrospinal fluid (CSF), with a thin spinal cannula

(2) which is sharpened at a free end (4) and connected at its other end to a connecting part, the spinal cannula (2) immediately behind its sharply ground free end

(4) has a lateral opening, and the connecting part is at least partially transparent, characterized in that the connecting part has a cannula with a tip facing away from the spinal cannula (2), on which a retractable protective cap (28) arranged is that pierced and pushed back when placing a connector, but when removing the connector moves forward again and closes the cannula.

2. cannula device according to claim 1, characterized in that the cap (28) provided with the cannula through the rear end of the spinal cannula (2) is formed.

3. cannula device according to claim 1, characterized in that there is a cavity in the connecting part.

4. cannula device according to claim 1, characterized

that the connecting part of a first part (8), with which the free end (4) of the spinal cannula (2) facing away from the end of the spinal cannula (2) is firmly connected and a conical receiving opening (10) for sealingly receiving a complementary to the receiving opening (10) shaped conical pin (12) of a second part (14) of the connecting part, in which there is a receiving opening (16) for a cuvette (20) which is closed on the protective cap (28) side facing by a membrane (24), which causes puncture of the retractable protective cap (28) upon insertion of the cuvette (20).

5. A cannula device according to claim 4, characterized in that a cavity (32) in the first part (8) or the second part (14) of the connecting part is located.

6. cannula device according to claim 4, characterized in that the first part (8) of the connecting part is transparent or at least has a viewing window.

7. cannula device according to claim 4, characterized in that in the first part (8) of the connecting part is a lateral opening (34) which is closed by a filter (36) which allows air to escape, but in liquid wetting no air entering leaves.

8. A cannula device according to claim 4, characterized in that the second part (14) of the connection partly at least partially transparent.

9. cannula device according to claim 4, characterized in that a venting part (10) is provided, which instead of a cuvette (20) in the receiving opening (16) can be inserted, which is closed at its end by a membrane (21) for Air, but not permeable to CSF.