CANNULA SYSTEM WITH RIGID CANNULA

Abstract

Disclosed is a cannula system having a rigid cannula, a cannula assembly and an insertion assembly. The rigid cannula is connected to the cannula assembly. The cannula assembly has a septum mounted to a mounting structure of the cannula assembly, a connecting structure for reversibly or irreversibly connecting the cannula assembly to a cannula assembly holder, a cavity being at least partially formed by the septum. The rigid cannula is in fluidic communication with the cavity. Furthermore, the insertion assembly has a rigid needle at least partially penetrating the septum and an attachment structure for reversibly attaching the insertion assembly to the cannula assembly.

Claims

1. A cannula system, comprising: a cannula assembly comprising a septum mounted to a mounting structure of the cannula assembly, a connector configured for reversibly or irreversibly connecting the cannula assembly to a cannula assembly holder, and a cavity at least partially formed by the septum; a rigid cannula connected to the cannula assembly and in fluidic communication with the cavity; an insertion assembly having a rigid needle at least partially penetrating the septum; and an attachment structure configured for reversibly attaching the insertion assembly to the cannula assembly.

2. The cannula system according to claim 1, wherein the rigid needle penetrates the septum in an essentially central position of the septum, when the insertion assembly is attached to the cannula assembly.

3. The cannula system according to claim 1, wherein the cavity is formed by inner walls of the cannula assembly and the septum.

4. The cannula system according to claim 1, wherein the rigid cannula comprises a lock configured for fixedly connecting the rigid cannula to the cannula assembly.

5. The cannula system according to claim 4, wherein the lock provides a positive lock and/or an adhesive bond between the rigid cannula and the cannula assembly.

6. The cannula system according to claim 5, wherein the lock includes at least one protrusion, arranged at the most distal part of the rigid cannula, protruding from the rigid cannula and/or at least one hole.

7. The cannula system according to claim 6, wherein the lock includes the at least one hole and the at least one hole comprises a through bore or a blind hole.

8. The cannula system according to claim 6, wherein the lock comprises the protrusion and the protrusion comprises a collar.

9. The cannula system according to claim 1, wherein the insertion assembly comprises a connector configured for connecting the insertion assembly to an inserter.

10. The cannula system according to claim 1, wherein the insertion assembly comprises a slit extending towards the rigid needle, wherein the slit comprises an adhesive.

11. The cannula system according to claim 1, wherein the rigid needle is unmovably connected to the rest of the insertion assembly.

12. The cannula system according to claim 1, wherein the attachment structure comprises a releasable adhesive or a releasable form-locking structure.

13. The cannula system according to claim 1, wherein a force required for release of the cannula assembly from the insertion assembly is smaller than a force exerted by the connecting structure for reversibly or irreversibly connecting the cannula assembly to the cannula assembly holder and/or smaller than a force required to separate the rigid cannula from the cannula assembly.

14. The cannula system according to claim 1, wherein the rigid needle does not extend into the rigid cannula.

15. The cannula system according to claim 14, wherein the tip of the rigid needle does not extend into the lumen of the rigid cannula.

16. An infusion system for the infusion of liquid drugs comprising a cannula system according to claim 1.

17. A method of using a cannula system according to claim 1 to administer a drug to a patient.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above-mentioned aspects of exemplary embodiments will become more apparent and will be better understood by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0026] FIG. 1 shows a schematic cross-sectional view of a cannula system according to an embodiment of this disclosure.

DESCRIPTION

[0027] The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of this disclosure.

[0028] FIG. 1 depicts a cannula system 1 with rigid steel cannula 2, cannula unit 3 (also referred to herein as a “cannula assembly”) and insertion unit 4. Rigid cannula 2 is connected to cannula unit 3 via locking structure 21 (also referred to herein as a “lock”), which in the particular embodiment shown, comprises an enlarged cross-section at the most distal end area of cannula 2, such as a collar. Cannula unit 3 comprises septum 31, which is mounted to mounting structure 32 of cannula unit 3. As can be seen, mounting structure 32 is formed by inner wall 35 of the cannula unit 3, which crimp the septum into cannula unit 3. Cannula unit 3 further comprises cavity 34, which is partially formed by septum 31 and partially by inner wall 35 of cannula unit 3. As can be readily seen from FIG. 1, rigid cannula 2 is in fluidic communication with cavity 34, such that a liquid medicament can be delivered to cavity 34 and infused into the patient via cannula 2 in an operative state, i.e., in a state in which inserter 4 is removed and an infusion pump is in fluidic communication with cavity 34 via septum 31. Cannula unit 3 further comprises connecting structure 33 for connecting cannula unit 3 to an infusion pump cradle. As shown, connecting structure 33 comprises protrusions and recesses which may be part of a snap fit connection.

[0029] Insertion unit 4 comprises rigid needle 41, which maintains insertion unit 4 and cannula unit 3 axially aligned to each other. Rigid needle 41 penetrates septum 31 in an essentially central position and preferably extends up to the cavity 34. Rigid needle 41 preferably does not extend into rigid cannula 2, in particular, the tip of the rigid needle 41 does not extend into the lumen of the rigid cannula 2. Due to its rigidness, the rigid cannula 2 is able to penetrate and insert into the skin without help of a rigid insertion needle that envelopes or is enveloped by the rigid cannula 2. This is in contrast to hitherto known soft cannulas which require a rigid insertion needle that either envelops the soft cannula or is enveloped by the soft cannula for stabilization of the soft cannula at least during insertion of the soft cannula into the skin. Insertion needle 41 may be fixedly connected to the insertion unit by an adhesive, which is provided within slit 44. As can be seen, slit 44 extends transversally towards needle 41, such that the adhesive can fixedly connect insertion needle 41 and insertion unit 4. It should be noted that in contrast to rigid cannula 2, needle 41 aims to provide a fixed connection, thus needle 41 is typically a compact body, i.e., is not a hollow needle. Insertion unit 4 further comprises attachment structure 42 for releasably connecting insertion unit 4 and cannula unit 3. Via connecting means 43a and 43b, the insertion unit 4, respectively the cannula system 1 may be connected to an inserter as known in the prior art. In use, cannula system 1 is connected to an inserter, inserted into the patient, upon which cannula unit 1 is preferably connected to an infusion pump cradle via connecting structure 33 and then the insertion unit is released. Importantly, attachment structure 42 is in general configured such that a force required for releasing the cannula unit 3 from the insertion unit 4 is smaller than a force exerted by the connecting structure 33 for reversibly or irreversibly connecting the cannula unit 3 to the cannula unit holder (5) (cannula holder not shown) and/or smaller than a force required to separate rigid cannula 2 from cannula unit 3.

[0030] While exemplary embodiments have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.