Patent ID: 8002751

Claim:
A method for using a disposable injection device, wherein a cylindrical needle has an integral shaft with an outer surface, a proximal end with an inlet, a distal end with an outlet and a passageway along a longitudinal axis to a dispensing device, the passageway for communicating fluids therethrough between the inlet and the outlet, the proximal end adapted to be mounted to the outlet of the dispensing device, the distal end with a first piercing point; a frangible deformation in the outer surface of the needle; a filter in the passageway downstream of the frangible deformation and near the distal end, comprising the steps of: aspirating a liquid through the outlet at the distal end into said passageway through the said filter and through the inlet end at the proximal end to the dispensing device; filtering the liquid as it passes through the filter; breaking the needle along the said frangible deformation to thereby separate the distal end of the needle with the filter and to form a fresh piercing point along the deformation; and wherein the breaking step further comprises installing a resilient cover over the needle enclosing the frangible deformation therewithin, applying the shear forces to the cover, transferring the shear forces to the needle through the cover and removing the cover and separated part after the breaking step.