US Patent 7833217 Floating spinal cannula and method of use

A spinal cannula for delivering a therapeutic agent to a spinal cord target includes proximal and distal end portions, a middle portion, and a deployable cannula member having distal and proximal end portions and a first lumen extending between the end portions. The spinal cannula includes a fluid delivery line operably connected to the proximal end portion of the deployable cannula member, and a fluid delivery line including a second lumen in fluid communication with the first lumen. The spinal cannula includes a support cannula proximally located from the deployable cannula member and securely connected to a portion of the fluid delivery line. Additionally, the spinal cannula includes a delivery cannula having distal and proximal end portions and a third lumen extending between the end portions for receiving the support cannula. The proximal end portion includes a locking mechanism for releasably engaging the proximal end portion of the support cannula.