Patent ID: 8608697

Claim:
An apparatus comprising: a handle having proximal end and distal end connected at the distal end to a hollow needle having a sharp distal end for penetrating tissue, wherein the handle and needle form a conduit for passing fluid or instruments or both through the distal end of the needle; a hollow stylet having a proximal end and a blunt distal end, which extends through the hollow needle, wherein the proximal end of the stylet is disposed on a proximal side of the distal end of the handle and the blunt distal end includes an opening for passing fluid through the blunt distal end; a spring housed within the handle for biasing the stylet to extend past the sharp distal end of the needle absent resistance by tissue against the stylet; and an at least partially translucent indicator chamber configured to hold visibly a quantity of indicator fluid under elevated pressure, wherein the indicator chamber has a distal end connected to the proximal end of the stylet, wherein the indicator chamber and stylet form a conduit for passing indicator fluid through the opening in the blunt distal end of the stylet when the stylet extends past the sharp distal end of the hollow needle.