tube 32 for instance via a screw 66 joining holes 63 68 formed in the respective spring element and inner tube however it will be apparent to the skilled artisan that other manners of a fixation such as welding adhesive techniques or the like may also be employed spring element 60 further includes a free end 64 disposed through slot 36 provided in inner tube 32 a plastic or rubberized tab portion 65 may be affixed to free end 64 to assist the practitioner in manipulating free end 64 when actuation of regulating device 10 is desired the fixed end 62 of spring element 60 leads into a bend 80 which progresses towards an angle 72 formed in the spring element spring element 60 features one or more passages or openings intermediate the fixed and distal ends 63 64 respectively through which spinal needle 12 is threaded the purpose of the passages or openings is to provide means allowing spring element 60 to securely grip or lock spinal needle 12 relative to epidural needle 14 in a manner that provides a variably continuous locking ability through the range of potential extension lengths 34 x 34 of spinal needle 12 relative to epidural needle 14 in the configuration illustrated in fig4 a 5 and 5a the one or more openings comprise a distal most opening 70 and a proximal most opening 71 disposed on either side of angle 72 spinal needle 12 is disposed through both the proximal most and distal most openings 70 71 respectively.