Generally forceps may be utilized for laparoscopic surgery. The forceps may be used to control delicate movements inside a patient. These forceps may be used to grip an anatomical feature. The forceps may include a gripping assembly or a cutting assembly. The forceps may include electrical energy for use in the gripping assembly. The forceps have a pair of opposed resilient jaws that are closed against each other by pulling the jaws into a distal end of a shaft that captures a portion of the jaws that is wider than the distal end opening of the shaft so that the jaws are moved together. Similarly the shaft may be pushed over the jaws so that the jaws are moved together to create a gripping force. In both of these the shaft captures the jaws and acts as a cam that forces the jaws together to create the gripping force. Examples of some forceps with resilient jaws closed by a camming action may be found in U.S. Pat. Nos. 5,458,598; 5,735,849; 5,445,638; 6,190,386; 6,113,596; and 6,679.882 and HALO cutting forceps, available at http://www.olympus-osta.com/halo.htm last accessed on Apr. 3, 2014 all of which are incorporated by reference herein in their entirety for all purposes.
Some laparoscopic forceps include jaws that have two legs that are connected at a distal end forming a gap between the two legs so that a blade can travel down the gap in center of the two opposing jaws. During the camming of the jaws, the jaws may be moved into contact with the blade creating a drag force which may prevent the blade from moving and/or may cause misalignment of the blade. Further, the camming force on the opposing jaws may not be equal and the uneven application of forces on the opposing jaws may cause the distal ends of the jaws to be misaligned during gripping.
The laparoscopic forceps after the jaws are released and the jaws are no longer constrained by the shaft typically move apart. This opening force may be used to push apart tissue by extending the closed jaws proximate to tissue and then allowing the jaws to open so that tissue is moved. However, some of the laparoscopic forceps when released from a closed position do not have a sufficient amount of force to move tissue for dissection. Other active dissection tools allow the user to open and close the jaws through mechanical linkages. These mechanical linkages generally allow the user some control over the amount of force applied to the tissue. However, the mechanical linkages include multiple delicate parts that are difficult to assemble, are expensive, and results in a complex device to move tissue.
It would be attractive for the forceps to include a device that controls the movement between the two opposing jaws. What is needed is a device that assists in biasing the jaws and maintains alignment of the blade. What is needed is a device that opens the jaws. It would be attractive to have a device that spreads the jaws with sufficient force so that the jaws can be used for dissection. What is needed is a device that spreads the jaws and does not interfere with a reciprocating blade.