| 摘要 |
The invention is directed to a pin and slot design where the driving slots are moved from the tips to the actuation rod in one aspect of the invention. As a result, the back end of each blade or tip can be dramatically reduced in area so that during full deflection, very little or no part of the blade or tip extends beyond the outside diameter of the shaft. This ensures that nothing catches on the blades or tips during grasper use and the shrink tubing found on the scissors would not be deformed. This can be done because the area for the slots is not needed. Moreover, the usable area for the drive slots on the blade or tip of the actuation rod is maximized to the overall diameter of the outer tube or shaft which provides additional leverage to the blades or tips. In addition, the depth of each slot can be varied such that during actuation, increased tension can be put on the blades or tips throughout the cut. More specifically, the surgical instrument of the invention comprises an elongate tube extending along an axis including an actuation rod coaxially slidable within the elongate tube, a first tip including a first pin formed on a proximal end surface of the first tip, and a second tip including a second pin formed on a proximal end surface of the second tip, the second tip pivotally connected to the first tip at a common pivot pin operably connected to the elongate tube to open and close the tips in response to movement of the actuation rod. The actuation rod has a slot to accept the pins of the first and second tips, the slot has camming surfaces for the pins to slide within the slot, and the proximal ends of the tips extend minimally outside the diameter of the elongate tube during actuation of the tips.
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