| 摘要 |
A Veress needle assembly comprises an outer steel tube with a sharpened tip at the distal end surrounding an inner rod having a blunt distal end. The proximal end of the inner rod is spring biased towards a position in which its distal end extends beyond the distal end of the outer stainless steel tube so that while piercing the wall of a body cavity the inner rod is forced upwardly against the spring bias to allow the sharpened end of the outer tube to extend into a cutting position. An indicator light supported on the proximal end of the assembly is controlled by a switch which is in a first position when the outer tube is passing through the wall of the body cavity and a second position when the outer tube enters the body cavity behind the wall, allowing the rod to move beyond the distal end of the outer tube, thereby changing the illumination of the light source so that the operator is signaled that the Veress needle has passed into the body cavity. |
