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EP-4740989-A2 - CANNULA & INFUSION DEVICES

EP4740989A2EP 4740989 A2EP4740989 A2EP 4740989A2EP-4740989-A2

Abstract

Infusion devices including a cannula (2) have a tubular body member (14) comprising a tubular wall enclosing a longitudinal extending internal bore (13). The cannula (2) is adapted to flex in response to a compression force and/or an increased internal pressure in the cannula (2).

Inventors

  • SCHØNDORFF, Pernelle, Kruse
  • THEANDER, Julie
  • JULIUSSEN, Rasmus, Boje Vendelbo

Assignees

  • Unomedical A/S

Dates

Publication Date
20260513
Application Date
20170119

Claims (9)

  1. A cannula for subcutaneous infusion of a therapeutic agent, the cannula comprising a tubular body member comprising a tubular wall at least partly enclosing a longitudinal extending internal bore, a distal portion of the tubular body member being tapered and having a distal tip end having at least one tip opening, wherein the tubular wall has six slits about a circumference of the tubular body, each of the slits extending across a boundary between a cylindrical shaped portion of the tubular body and a tapered distal portion, each of the slits having a width in a range of 20-45 µm the cannula being operable to flex in weakened areas comprising the slits when the cannula is exposed to at least one of a compression force or an increased internal pressure so as to allow therapeutic agent to flow out of the cannula through one or more of the slits.
  2. The cannula of claim 1 wherein three of the slits have a width in a range of 20-25 µm, and three of the slits have a width in a range of 40-45 µm.
  3. The cannula of any one of the preceding claims wherein each slit is equidistant from adjacent ones of the slits in a direction around the circumference of the tubular body.
  4. The cannula of any one of the preceding claims wherein a width of each of three particular ones of the slits is about twice as large as a width of a corresponding slit located about 180° from the particular slit.
  5. The cannula of any one of the preceding claims, wherein each of the weakened portions are at least 0.25-2.5 mm, or 0.5-1.5 mm, or 0.75-1.25 mm from the tip opening and extends towards the proximal portion of the cannula.
  6. The cannula of any one of the preceding claims, wherein the weakened portions are formed at the same circumferential location of the tubular body member.
  7. The cannula of any one of the preceding claims, wherein the weakened portions all are formed as slits and formed at the same circumferential location of the tubular body member wherein the slits extend in the longitudinal direction parallel with the longitudinal axis of the internal bore, the length of the slits being 0.2-1.5 mm, or 0.4-0.8 mm, or 0.4-0.6 mm.
  8. The cannula of any one of the preceding claims, wherein the weakened portions all are formed as slits and formed at the same circumferential location of the tubular body member, the slits providing slats between said slits, the slats adapted to flex outwards away from the internal bore, when the cannula is exposed for compression forces or/and an increased internal pressure.
  9. The cannula of claim 8, wherein the slats are delimited by sidewalls parallel to the longitudinal axes of the tubular body member and said sidewalls delimiting each slat are parallel to each other in radial direction.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Application No. 62/280,345 (attorney docket no. 43247-693.101) filed on January 19, 2016, the content of which is incorporated herein in its entirety. FIELD OF THE DISCLOSURE This disclosure describes infusion and cannula devices and methods for use of the infusion and cannula devices. The medical devices disclosed herein are configured for introduction of a therapeutic agent (e.g., a drug), including a therapeutic liquid or suspension or other suitable material, into a subject. In certain embodiments, the medical device is an infusion device comprising a cannula configured for this purpose. BACKGROUND Infusion devices comprising a flexible cannula, are designed to be inserted into the skin by means of an introducer needle and the needle is then removed. A therapeutic agent, such as insulin, is then delivered through the cannula. However, there is a risk that the cannula may become occluded (e.g., obstructed) upon delivery of the therapeutic agent. This can happen when the tip of the cannula is blocked for instance by inflammation in the tissue, or due to kinking of the cannula. It is therefore desirable to minimize the risk of blocking of the cannula outlet, and/or the risk that kinking obstructs the discharge of the therapeutic agent (e.g., a drug). Previous attempts to circumvent these obstructions, including the use of cannulas with several openings (see, e.g., US Patent Pre-Grant Publication No. 2013/0245555) have been reported, but the risk of kinking and occlusion (e.g., obstruction) still remains. SUMMARY This disclosure describes methods and devices, that in some cases, can reduce or minimize the drawbacks and issues of cannula and infusion devices, including partial and/or complete occlusion and/or insufficient delivery of therapeutic agents to a subject in a simple, reliable and safe infusion device without substantially increasing the cost of the device. In certain embodiments, disclosed herein are infusion devices comprising a cannula, the cannula having a tubular body member comprising a tubular wall. In some embodiments, the tubular wall of the cannula encloses a longitudinal extending internal bore. In other embodiments, the distal portion of the tubular wall comprises a distal end comprising at least one tip opening. In some embodiments, provided herein is a cannula, wherein the cannula comprises at least two weakened portions in the tubular wall, a first weakened portion and a second weakened portion in the distal end of the tubular wall of the cannula and having a compression strength being (a/k/a compressive strength) smaller than the compression strength of the remaining part of the distal portion of the cannula, wherein the cannula is adapted to flex in an area comprising the weakened portions when for example the cannula is exposed to a compression force and/or an increased internal pressure taking place inside the longitudinal extending bore, wherein the fluid pressure at the weakened portion exceeds the fluid pressure at the tip opening, whereby at least one of the weakened portions provides a fluid communication between the internal bore and the outside of the cannula. In some embodiments, the increased internal pressure is caused by the flow of a therapeutic agent or other liquid, solution or suspension flowing through the distal portion of the cannula. In yet other embodiments, the cannula disclosed herein comprises at least two weakened portions in the tubular wall: a first weakened portion and a second portion, the second weakened portion in the distal end of the cannula and having a compression strength smaller than the compression strength of the remaining part of the distal portion. In some embodiments, the cannula is adapted to flex in an area comprising the weakened portions when the cannula is exposed to a compression force and/or an increased fluid (e.g., flow of a therapeutic agent) pressure which may take place inside the longitudinal extending bore of the distal end of the cannula tip. In yet other embodiments, at least one of the weakened portions of the tubular wall provides a fluid communication between the internal bore and the outside of the cannula. In some embodiments, provided herein are cannulas for subcutaneous infusion of a therapeutic agent, the cannula comprising a tubular body member comprising a tubular wall at least partly enclosing a longitudinal extending internal bore, the distal portion of the tubular body member having a distal tip end comprising at least one tip opening, wherein the tubular wall comprises at least two weakened portions in the wall, the weakened portions being capable of allowing the cannula to flex in an area comprising the weakened portions when the cannula is exposed to a compression force and/or an increased internal pressure. In some embodiments, at least one of the weakened portions of the cannulas described herein is in the distal po