Cannula, in Particular for Lumbar Puncture and Lumbar Injection, as Well as Method of Production of Same

Abstract

A cannula, in particular for lumbar puncture and lumbar injection, with a proximal end and a distal end, can include a cannula tube with an inner side, and outer side, a cannula canal having a first end region and a second end region. The cannula tube can include at the second end region a tip which forms the distal end of the cannula, and the cannula tube can include an opening of the cannula canal, and a coating is provided about the opening of the cannula canal on the inner side.

Claims

1. A cannula comprising: a cannula tube with an inner side an outer side, and a cannula canal formed of a first end region and a second end region, a tip of the cannula tube located at the second end region and which forms a distal end of the cannula, an opening of the cannula canal of the cannula tube, and wherein a coating is provided in the cannula canal on the inner side about the opening.

2. The cannula as in claim 1, wherein the coating covers an internal edge of the opening.

3. The cannula as in claim 1, wherein the coating is disposed on the outer side about the opening.

4. The cannula as in claim 3, wherein the coating on the inner side of the cannula tube and on the outer side of the cannula tube is connected through the opening.

5. The cannula and in claim 1, wherein the coating completely covers the inner side of the cannula tube, the outer side of the cannula tube, or both the inner side of the cannula tube and the outer side of the cannula tube.

6. The cannula as in claim 1, wherein the tip is closed and approximately conically and the opening is disposed adjacently to the tip of the cannula tube.

7. The cannula as in claim 6, wherein the opening is elongated in a longitudinal direction of the cannula tube.

8. The cannula as in claim 1, wherein the cannula tube comprises an oblique beveling by which the tip is formed and the opening is disposed at a front end in the second end region of the cannula tube.

9. The cannula as in claim 1, wherein an extension is provided at the proximal end.

10. The cannula as in claim 9, wherein the coating sheathes the extension.

11. The cannula as in claim 1, wherein the coating is unitary or monolithic.

12. The cannula as in claim 1, further comprising a mandrin which comprises a second coating.

13. The cannula as in claim 1, wherein the cannula tube has an outer diameter (DA) in the range of 0.2 to 1.5 mm, an inner diameter (DI) in the range of 0.15 to 1.4 mm and a length (l) in the range of 90 to 500 mm, or a combination thereof.

14. The cannula as in claim 1, wherein the coating has a thickness (d) in the range of 0.1 to 50 μm.

15. A method of producing a cannula, comprising: providing a cannula tube with an inner side, an outer side, and a cannula canal formed of a open first end region and a second end region, machining an opening of the cannula canal of the cannula tube, and coating an inner side of the cannula tube at least about the opening.

16. The method as in claim 15, wherein the second end region comprises a tip which is closed and developed approximately conically and the opening is worked in adjacently to the tip.

17. The method as in claim 15, wherein the cannula tube is worked at the second end region with an oblique beveling through which a tip is formed and the opening is disposed at the front end in the second end region of the cannula tube.

18. The method as in claim 15, further comprising coating the entire inner side or the entire inner side and outer side of the cannula tube.

19. The method as in claim 15, wherein before the coating an extension is formed onto the cannula tube at the first end region by an injection molding process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] With reference to the accompanying drawing, an embodiment example of a cannula, in particular for lumbar puncture and lumbar injection, will be described in detail. Therein depict:

[0037] FIG. 1a a schematic, partially sectioned and highly simplified representation of a first embodiment example of a cannula for lumbar puncture and lumbar injection,

[0038] FIG. 1b an enlarged representation of a distal end of the cannula with a conical and closed tip,

[0039] FIG. 2 a schematic, partially sectioned and highly simplified representation of a mandrin of a cannula for lumbar puncture and lumbar injection according to FIG. 1,

[0040] FIG. 3a a schematic, partially sectioned and highly simplified representation of a second embodiment example of a cannula for lumbar puncture and lumbar injection,

[0041] FIG. 3b an enlarged representation of a distal end of the cannular with a tip formed by an oblique beveling,

[0042] FIG. 4 a schematic, partially sectioned and highly simplified representation of a mandrin of a cannula for lumbar puncture and lumbar injection according to FIG. 3.

DETAILED DESCRIPTION

[0043] FIG. 1a shows a cannula 1 for lumbar puncture and lumbar injection which can be utilized to inject an anesthetic substance into the spinal canal of the vertebral column of a patient. The cannula 1 depicted in FIG. 1a can furthermore be utilized for diagnostic purposes or for early detection examinations to withdraw cerebrospinal fluid from the spinal canal of a patient or to inject a radiopaque substance into the spinal canal.

[0044] The cannula 1 has a proximal end 4 and a distal end 5 and comprises a cannula tube 10 and a (necked) extension 30.

[0045] The cannula tube 10 can be produced of a metal material or a synthetic material, for example of a carbon fiber-reinforced synthetic material. The cannula tube 10 can have an outer diameter DA in the range of 0.2 to 1.5 mm, preferably in the range of 0.4 to 1.2 mm. The cannula tube 10 can furthermore have an inner diameter DI in the range of 0.15 to 1.4 mm. Lastly, the cannula tube 10 can have a length l in the range of 90 to 500 mm, preferably of 90 to 300 mm, especially preferred of 90 to 120 mm.

[0046] The cannula tube 10 comprises an open first end region and, according to the first embodiment example depicted in FIGS. 1a and 1b, a closed second end region. The cannula tube 10 comprises an inner side 11 and an outer side 12, wherein the inner side 11 forms the wall of a lumen or of the cannula canal 15. The second end region of the cannula tube 10 comprises a conical or cone-shaped tip 14 that forms the distal end 5 of the cannula 1.

[0047] Adjacent to the tip 14 of the cannula tube 10, which is depicted in detail in FIG. 1b, the opening 20 is disposed with an internal edge 25 surrounding the opening 20, through which the cannula canal 15 is accessible from a radial direction.

[0048] The spacing between the opening 20 and the distal end 4 or the tip 14 is selected such that the opening 20 is developed completely on a lateral surface of the cannula tube 10.

[0049] Onto the proximal end 4 the extension 30 is formed onto the cannula tube 10, wherein, preferably the extension 30 forms a connection on which a tube or a syringe can be secured. The connection can be developed as a Luer lock connector or as an NRFit® connector.

[0050] As is evident in FIGS. 1a and 1b, the cannula 1 comprises a coating 18 depicted in dashed lines. The coating 18 is applied onto the inner side 11 and/or the outer side 12 of the cannula tube 10 around the opening 20 and closes the cannula canal 15 between the opening 20 and the distal end 5. The coating 10—as depicted—can furthermore extend completely over the internal edge 25 of the opening 20 whereby a unitary or monolithic coating 18 can be formed. The coating [18] preferably covers completely and non-intermittently all surface areas of the cannula tube 10 or of the cannula 1 and preferably imbeds possible contaminants on the surfaces, whereby these are rendered harmless. The coating 18 is preferably diffusion-tight and/or abrasion resistant.

[0051] For the production of the cannula according to FIG. 1, first, the cannula tube 10 is preferably provided as a discrete part and subsequently the extension 30 can be formed onto the open first end region of the cannula tube 10, using, for example injection molding. In a subsequent step, the opening 20 can be worked into the cannula tube 10 in the second end region adjacent to the tip 14, wherein the opening 20 preferably can be worked into the cannula tube 10 as an elongated opening by a machining fabrication method, in particular by grinding.

[0052] After the opening [20] has been worked into the cannula tube 10, the already functionable cannula 1 can be cleaned by a cleaning method in order to remove contaminants due to the working-in of the opening 20 and the other production steps. To ensure that even after the cleaning, in particular at sites difficult of access, such as, for example, within the closed and conical tip 14 at the distal end 5 of the cannula 1 or in a “dead” end between the opening 20 and the closed second end region of the cannula tube 10, no contaminants remain, a coating 18, which is depicted in the accompanying Figures in dashed lines, can be applied over the entire surface on all inner surfaces as well as outer surfaces.

[0053] The coating 18 can embed or agglutinate all contaminants which may be located in the cannula tube 10 and on the extension [30].

[0054] The coating 18 can preferably be applied using a thin-layer method and can be formed of a synthetic material as well as also of a metal material. A thickness d of the coating can be in the range of 0.1 to 50 μm, preferably in the range of 0.1 to 30 μm especially preferred in the range of 0.1 to 15 μm.

[0055] FIG. 2 shows a mandrin 40, comprising a rod section 42 and an extension section 44, wherein the rod section 32 [sic: 42] is introducible into the lumen or the cannula canal 15 and, in the inserted state, stabilizes the cannula tube 10. The mandrin 40 can close the opening during the penetration and prevent tissue from entering which could plug up the cannula tube 15 [sic: 10]. The mandrin 40, in particular the rod section 42, can comprise a metal core or a core of a synthetic material, for example a carbon fiber-reinforced synthetic material, while the extension* section 44, analogous to the (necked) extension 30 of the cannula 1, can be formed onto the core. The mandrin 40 can furthermore comprise a coating 48 which fully covers the mandrin 40. The material and the coating method of the coatings 18, 48 of cannula 1 and of mandrin 40 can be identical.

[0056] The second embodiment example of a cannula 1′, depicted in FIGS. 3a and 3b, as well as the second embodiment example of a mandrin 40′, depicted in FIGS. 4, differ from the cannula 1, depicted in FIGS. 1a and 1b, or the mandrin 40, depicted in FIG. 2, only in the embodiment of the distal end. The additional explanations regarding cannula 1 and mandrin 40 are transferable to cannula 1′ and to mandrin 40′.

[0057] The cannula tube 10 comprises an open first end region and an open second end region. The second end region of the cannula tube 10 comprises herein an oblique beveling through which the tip 14 is formed which forms the distal end 5 of the cannula 1. The opening 20 in this embodiment example is not developed on the lateral surface of the cannula tube 10 but rather at the front end in the second end region of the cannula tube 10.

[0058] Cannula 1′ also comprises a coating 18 shown in dashed lines. The coating 18 is applied on the inner side 11 and/or on the outer side 12 of cannula tube 10 about the opening 20. The coating 18—as depicted—can moreover extend completely over the internal edge 25 of opening 20, whereby a unitary or monolithic coating 18 can be formed. The coating [18] preferably covers completely and non-intermittently all surface areas of the cannula tube 10 or of cannula 1.

[0059] Cannula 1′ can also comprise a mandrin 40′ which is depicted in FIG. 4 and differs from the mandrin 40 depicted in FIG. 2 only therein that a distal end of the mandrin 40′ is developed to be slanted.

LIST OF REFERENCE SYMBOLS

[0060] 1, 1′ Cannula

[0061] 4 Proximal end

[0062] 5 Distal end

[0063] 10 Cannula tube

[0064] 11 Inner side

[0065] 12 Outer side

[0066] [13 on FIG. 1a, unused]

[0067] 14 Tip

[0068] 15 Cannula canal

[0069] [18 Coating]

[0070] 20 Opening

[0071] 25 Internal edge

[0072] 30 Extension

[0073] 40, 40′ Mandrin

[0074] 42 Rod section

[0075] 44 Extension section

[0076] 48 Coating

[0077] d Thickness

[0078] DA Outer diameter

[0079] DI Inner diameter

[0080] l Length