Patent ID: 8298208

Claim:
A method for installing a flexible spinal needle assembly, the method comprising: inserting a distal end of a flexible spinal needle assembly through dura mater and into an intrathecal space of a subject, the flexible spinal needle assembly comprising: a support needle with a non-cutting piercing point at a distal end and a hollow bore; and a flexible spinal needle with a tip at a distal end and slidably mounted on and supported by the support needle to expose the piercing point slightly extending beyond the tip in the distal end thereof, the flexible spinal needle having an outside diameter sufficiently small so that, upon insertion of the flexible spinal needle assembly and withdrawal of the support needle from the flexible spinal needle, the dura mater is permitted to substantially seal against the outside diameter of the flexible spinal needle; removing the support needle from within the flexible spinal needle while maintaining the tip of the flexible spinal needle within the intrathecal space to expose an inner flow path; and thereafter, connecting a flow element to the flexible spinal needle and disposing an anti-restriction member of the flow element having an elongated body comprising a freely extending twisted set of wires formed by at least two wires into the inner flow path of the flexible spinal needle to substantially prevent fluid occlusion in the inner flow path of the flexible spinal needle caused by bending or kinking of the flexible spinal needle.