Cannula, infusion devices and methods

The cannula of any of the preceding claims, wherein the number of holes in the second plurality of holes is between 4 to 16.

The cannula of any of the preceding claims, wherein the first plurality of holes have a diameter in the range of 61 to 75 pm.

The cannula of any of the preceding claims, wherein the second plurality of holes have a diameter in the range of 50 to 60 pm.

The cannula of any of the preceding claims, wherein the distal tip end is shaped to a point.

The cannula of any of the preceding claims, wherein the cannula is arranged so that at least a portion of the therapeutic agent is released from the distal tip end.

The cannula of any of the preceding claims, wherein the weakened section has a compression strength smaller than a compression strength of remaining portions of the tubular body member.

The cannula of any of the preceding claims, wherein when the cannula is exposed to a compression force and/or an increased internal pressure and an internal pressure

• in the longitudinal extending bore exceeds an internal pressure in a tip opening of the distal tip end, the weakened section provides a fluid communication between the internal bore and outside of the cannula.

The cannula of any of the preceding claims, wherein each of the first plurality of holes are at the same distance from a tip opening of the distal tip end.

An infusion device for subcutaneous delivery of a therapeutic agent to a patient comprising:

• a 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 having a distal tip end, wherein the distal portion comprises a weakened section comprising a first plurality of holes and a second plurality of holes, the weakened section being capable of allowing the cannula to flex in an area comprising the weakened section when the cannula is exposed to a compression force and/or an increased internal pressure, wherein the first plurality of holes comprise holes of larger diameter than the second plurality of holes;
• and
• a hub part configured to be fastened onto a patient's skin via a mounting pad.

A method of administering a therapeutic agent via an infusion device, the method comprising:

• providing a 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 having a distal tip end comprising at least one tip opening, wherein the tubular wall comprises a weakened section comprising a first plurality of holes and a second plurality of holes, and wherein the first plurality of holes comprise holes of larger diameter than the second plurality of holes;
• and
• causing the cannula to flex in an area comprising the weakened section when 1) the cannula is exposed to a compression force whereby the tip opening is substantially closed and/or 2) the cannula is exposed to an increased internal pressure exceeding the pressure at the tip opening, wherein the compression force or increased internal pressure opens the weakened section allowing fluid communication between the internal bore and the external environment, thereby discharging the therapeutic agent.