System for actuating a laparoscopic surgical instrument
View Patent ↗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.
1. A surgical instrument, comprising:
an elongate tube having a central lumen extending along an axis;
an actuation rod being a two-piece fork actuation rod having a first actuation rod and a second actuation rod side by side to each other with portions of each actuation rod in contact with each other and coaxially slidable within the central lumen of 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,
wherein the first and second actuation rods each have a slot to accept the respective pins of the first and second tips, each slot having camming surfaces for the respective pins to slide within the slot, wherein the first actuation rod and the second actuation rod are independently movable to provide independent motion to the first tip and the second tip, wherein the proximal ends of the tips extend minimally outside the diameter of the elongate tube during actuation of the tips, and
wherein the slot of the first actuation rod has a depth within the slot defined from an outer surface of the first actuation rod towards an inner surface of the first actuation rod that varies along the length of the slot.
2. The surgical instrument of claim 1 , wherein the camming surface of and within the slot of the first actuation rod has a decreasing surface width from a distal end of the first actuation rod towards a proximal end of the first actuation rod to provide greater tension along the first tip.
3. A surgical instrument, comprising:
an elongate tube extending along an axis including an actuation rod having a first actuation rod and a second actuation rod, the rods being independently 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 and connected to the actuation rod,
the first actuation rod having a slot to accept the first pin, the slot having camming surfaces for the first pin to slide within the slot, the slot extending along an angle that is non-perpendicular to an axis of the first actuation rod from a distal end of the first actuation rod towards a proximal end of the first actuation rod and the camming surface of and within the slot having a decreasing surface width from the distal end of the first actuation rod towards the proximal end of the first actuation rod,
wherein a distal end of the slot is enlarged.
4. A surgical instrument, comprising:
an elongate tube extending along an axis including an actuation rod having a first actuation rod and a second actuation rod, the rods being independently 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 and connected to the actuation rod,
the first actuation rod having a slot to accept the first pin, the slot having camming surfaces for the first pin to slide within the slot, the slot extending along an angle that is non-perpendicular to an axis of the first actuation rod from a distal end of the first actuation rod towards a proximal end of the first actuation rod and the camming surface of and within the slot having a decreasing surface width from the distal end of the first actuation rod towards the proximal end of the first actuation rod,
wherein a width of the slot at an outer surface of the first actuation rod is smaller than a width of the slot at an inner surface of the first actuation rod.
5. A surgical instrument, comprising:
an elongate tube having a central lumen extending along an axis;
an actuation rod being a two-piece fork actuation rod having a first actuation rod and a second actuation rod side by side to each other with portions of each actuation rod in contact with each other and coaxially slidable within the central lumen of 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,
wherein, the first and second actuation rods each having a slot to accept the respective pins of the first and second tips, each slot having camming surfaces for the respective 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, and
the slot of the first actuation rod has a depth within the slot defined from an outer surface of the first actuation rod towards an inner surface of the first actuation rod that varies along the length of the slot.
6. The surgical instrument of claim 5 , wherein the camming surface of and within the slot of the first actuation rod has a decreasing surface width from a distal end of the first actuation rod towards a proximal end of the first actuation rod to provide greater tension along the first tip.
7. A surgical instrument, comprising:
an elongate tube extending along an axis including an actuation rod having a first actuation rod and a second actuation rod, both rods 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 and connected to the actuation rod,
wherein, the first actuation rod having a slot to accept the first pin, the slot having camming surfaces for the first pin to slide within the slot, the slot extending along an angle that is non-perpendicular to an axis of the first actuation rod from a distal end of the first actuation rod towards a proximal end of the first actuation rod and the camming surface of and within the slot having a decreasing surface width from the distal end of the first actuation rod towards the proximal end of the first actuation rod, and
a distal end of the slot is enlarged.
8. The surgical instrument of claim 7 , wherein a width of the slot at an outer surface of the first actuation rod is smaller than a width of the slot at an inner surface of the first actuation rod.