Combinational scissor-grasper for use in laparoscopy
Disclosed is a four-jawed combinational scissor-grasper surgical tool for use in laparoscopy. Cutting and grasping functionalities are respectively enabled via movement of a pair of such specially contoured jaw members sliding against or splaying apart from the other pair. Also disclosed are means for achieving selectable interlocking of jaw members and mechanical linkage for their actuation by human user.
1. An apparatus comprising:
first, second, third, and fourth jaw elements, each of the first, second, third, and fourth jaw elements comprising a serrated surface, an extension, and a depression;
a shifter shaft coupled to the second and fourth jaw elements at a distal end of the shifter shaft, there being a longitudinal axis defined by opposite ends of the shifter shaft;
the serrated surfaces of the first and second jaw elements being configured to engage each other;
the serrated surfaces of the third and fourth jaw elements being configured to engage each other;
the shifter shaft being in a first position along the longitudinal axis causing the first and second jaw elements to be coupled to each other by the depression of the second jaw element receiving the extension of the first jaw element, and further causing the third and fourth jaw elements to be coupled to each other by the depression of the fourth jaw element receiving the extension of the third jaw element;
the shifter shaft being in a second position along the longitudinal axis causing the first and fourth jaw elements to be coupled to each other by the depression of the fourth jaw element receiving the extension of the first jaw element, and further causing the second and third jaw elements to be coupled to each other by the depression of the second jaw element receiving the extension of the third jaw element, the second position being different from the first position.
2. The apparatus of claim 1 , the first position being closer to the first, second, third, and fourth jaw elements along the longitudinal axis than the second position.
3. The apparatus of claim 1 , each serrated surface comprising teeth separated by a distance equal to or larger than a distance between the first position and the second position.
4. The apparatus of claim 1 , further comprising a controller coupled to an end of the shifter shaft, the controller being configured to translate manual movement by an operator into translation of the shifter shaft along the longitudinal axis.
5. The apparatus of claim 1 , further comprising a hinge coupled to the first, second, third, and fourth jaw elements, each of the first, second, third, and fourth jaw elements being configured to rotate about the hinge.
6. The apparatus of claim 5 , each of the second and fourth jaw elements comprising a first slot along which the hinge can move in a direction parallel to the longitudinal axis.
7. The apparatus of claim 6 , each of the second and fourth jaw elements further comprising a second slot defined by two arcs, an end of the shifter shaft being configured to engage the second slots of the second and fourth jaw elements to shift the second and fourth jaw elements relative to the hinge when the shifter shaft is moved between the first and second positions.
8. The apparatus of claim 7 , further comprising:
an inner shaft having a distal end;
a pair of connecting links each coupled to the distal end of the inner shaft, a first one of the connecting links being coupled to the first jaw element, a second one of the connecting links being coupled to the third jaw element; and
a common pin inserted through a hole in the first jaw element and through a hole in the third jaw element.
9. A method comprising:
configuring first, second, third, and fourth jaw elements into a cutting configuration by coupling serrated surfaces of the first and second jaw elements to each other and by coupling serrated surfaces of the third and fourth jaw elements to each other, the configuring into the cutting configuration comprising placing a shifter shaft defining a longitudinal axis at a first position along the longitudinal axis;
configuring the first, second, third, and fourth jaw elements into a grasping configuration by coupling the first and fourth jaw elements to each other and by coupling the second and third jaw elements to each other, the configuring into the grasping configuration comprising positioning the shifter shaft at a second position along the longitudinal axis, the second position being different from the first position; wherein:
each of the first, second, third, and fourth jaw elements further comprises an extension and a depression;
the placing of the shifter shaft in the first position along the longitudinal axis comprises causing the first and second jaw elements to be coupled to each other by the depression of the second jaw element receiving the extension of the first jaw element, and causing the third and fourth jaw elements to be coupled to each other by the depression of the fourth jaw element receiving the extension of the third jaw element; and
the placing of the shifter shaft in the second position along the longitudinal axis comprises causing the first and fourth jaw elements to be coupled to each other by the depression of the fourth jaw element receiving the extension of the first jaw element, and causing the second and third jaw elements to be coupled to each other by the depression of the second jaw element receiving the extension of the third jaw element.