Patent ID: 7147607

Claim:
A medical device, comprising: a flexible outer tubular member having proximal and distal ends; a flexible inner stylet having proximal and distal ends slidably and coaxially received within the outer tubular member; a spring member having proximal and distal ends oriented adjacent the distal end of the outer tubular member, the spring member being coaxially received within the outer tubular member and surrounding a portion of the inner stylet, wherein the proximal end of the spring member is coupled to the stylet; a retractable outer hollow needle member having a proximal end coupled to the distal end of the spring member; and a retractable inner hollow needle member slidably and coaxially received within the outer hollow needle member and having a proximal end coupled to the distal end of the stylet; wherein the device has a retracted position wherein the inner and outer hollow needle members are completely housed within the outer tubular member, a first extended position wherein the outer hollow needle member and a first length of the inner hollow needle member extend beyond the distal end of the outer tubular member, and a second extended position wherein the outer hollow needle member and a second length of the inner hollow needle member extend beyond the distal end of the outer tubular member, the second length being longer than the first length.