Patent ID: 7458142

Claim:
A method of fabricating a spinal anesthesia cannula, the method comprising: a) providing a rigid cannula tube including a 5 cylinder over its entire length; b) forming a tapering conical region from the cylindrical cannula tube by tapering the cylindrical cannula tube at a distal end; c) chamfering the distal end of the cannula tube on only one side right to its distal end to produce a chamfered region; d) producing edges in the chamfered region during the chamfering of the distal end; and e) bending the edges together to form and define a substantially conical envelope configured so that the edges touch each other at an outermost distal edge of the chamfered region and thus form an insertion point, but in a region there behind the edges are spaced from each other and thus form an outlet aperture of the cannula adjacent the insertion point.