Fixtures for testing elasticity of drug delivery members and related methods

A fixture assembly for testing the elasticity of a cannula of a drug delivery device, the fixture assembly comprising:

• a fixture block defining a barrel receptacle and having a distal end surface,
• wherein the barrel receptacle is adapted to receive the drug delivery device, the drug delivery device having a barrel and the cannula extending from a distal end of the barrel such that when the drug delivery device is received in the barrel receptacle, the cannula extends out of the fixture block and beyond the distal end surface, thereby defining the cannula as having a fulcrum point located at the distal end surface and spaced from the distal end of the barrel;
• and
• a movable strike member arranged to selectively apply a load to a distal end of the cannula spaced from the fulcrum point,
• wherein the strike member is disposed a predetermined distance from the distal end surface and the fulcrum point of the cannula, and
• further comprising a plurality of gauge blocks for setting the predetermined distance between the strike member and the distal end surface, each gauge block having a distinct length dimension corresponding to one of a plurality of predetermined cannula gauges.

A method of testing the elasticity of a cannula of a drug delivery device comprising:

• securing a barrel of the drug delivery device within a fixture such that the cannula fixed to a distal end of the barrel extends out from the fixture;
• applying a lateral force to a distal end of the cannula using a strike member to move the distal end of the cannula a threshold distance;
• removing the force from the cannula;
• and
• determining a final position of the distal end of the cannula after the force has been removed,
• and defining a fulcrum point of the cannula a spaced distance from the distal end of the barrel, wherein defining the fulcrum point comprises providing the fixture with a pair of fixture blocks and a support block that extends from the fixture blocks, the support block defining a top support surface supporting the cannula and a distal end surface spaced away from the distal end of the barrel of the drug delivery device and beyond which the distal end of the cannula extends, the fulcrum point of the cannula thereby being disposed at the distal end surface of the support block.