In {TAIL ~ a further preferred aspect} of the present invention, {HEAD ~ the elongate penetrating element} is a needle, having a retractable obturator at its distal end 
In
In { TAIL ~ a further preferred aspect } of the present invention , { HEAD ~ the elongate penetrating element } is a needle , having a retractable obturator at its distal end
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH