This application is related to the following copending applications: application Ser. No. 08/856,534 filed May 14, 1997 which was issued as U.S. Pat. No. 5,984,921 Nov. 16, 1999; application Ser. No. 08/877,715, filed Jun. 18, 1997 which was issued as U.S. Pat. No. 5,961,514 on Oct. 5, 2001; application Ser. No. 08/878,421, filed Jun. 18, 1997 which has issued as U.S. Pat. No. 5,925,041 on Jul. 20, 1999; application Ser. No. 08/885,458, filed Jun. 30, 1997 which has issued as U.S. Pat. No. 6,106,519 on Aug. 22, 2000; application Ser. No. 08/884,949, filed Jun. 30, 1997 which has issued as U.S. Pat. No. 5,951,552 on Sep. 14, 1999; and application Ser. No. 08/885,166, filed Jun. 30, 1997, which as issued as U.S. Pat. No. 5,916,215 on Jun. 29, 1999.
The present invention relates, in general, to an improved electrosurgical instrument and method of use and, more particularly, to an inductively coupled cordless electrosurgical instrument adapted to receive electrosurgical energy from a specially adapted electrosurgical trocar.
The surgical trocar has become the mainstay in the development and acceptance of endoscopic surgical procedures. Endoscopic surgery involves the performance of surgery through a number of openings having a relatively small diameter. These openings are made with the trocar, which typically includes a trocar obturator and a trocar cannula. The obturator is the piercing implement which punctures the body wall to make the opening. Once the puncture is made, the obturator is withdrawn from the cannula. The cannula then provides a small diameter passageway into and through the body wall to provide access for additional surgical instrumentation to the surgical site. The function, structure and operation of a typical trocar is described in detail in U.S. Pat. No. 5,387,197, which is hereby incorporated herein by reference.
Such additional surgical instruments may include, for example, bipolar or monopolar electrosurgical instruments which utilize radio frequency electrosurgical energy. Known electrosurgical instruments include, for example, bipolar forceps, bipolar scissors, monopolar-hooks, monopolar-scissors and bipolar endocutters. Each of those instruments has an electrosurgical end effector which is adapted to treat tissue through the application of electrosurgical (e.g. radio frequency or RF) energy to tissue which is brought in contact with the electrosurgical end effector. Most known electrosurgical instruments are connected by electrical cords to electrosurgical generators. The structure and operation of a typical mechanical cutter/stapler is described in U.S. Pat. No. 5,597,107 which is hereby incorporated herein by reference. The structure and operation of a typical bipolar cutter/stapler (xe2x80x9cbipolar endocutterxe2x80x9d) is described in U.S. Pat. No. 5,403,312 which is hereby incorporated herein by reference.
Electrosurgical generators, such as the Force II generator (which is available from Valleylab of Bolder Colo.), supply electrical energy to known electrosurgical instruments through electrical cords. The electrical cords, being attached directly to the electrosurgical instrument, may make the electrosurgical instrument inconvenient to use. Alternatively, electrical cords may cause undesirable delays as one electrosurgical instrument is unplugged from the generator and another is plugged in. Thus, it would be advantageous to design a cordless electrosurgical instrument such as a cordless instrument wherein electrosurgical energy is inductively coupled to the instrument. However, such a cordless electrosurgical instrument would have to be connected to the electrosurgical generator through some alternate arrangement. Therefore, it would also be advantageous to design a trocar or a trocar adapter which is adapted to inductively couple electrosurgical energy to specially designed cordless electrosurgical instruments. It would further be advantageous to design a cordless electrosurgical instrument and electrosurgical trocar or trocar adapter wherein the electrosurgical energy is inductively coupled from the electrosurgical trocar to the cordless electrosurgical instrument when electrosurgical energy is applied to the electrosurgical trocar or trocar adapter.
In the present invention, a cordless inductively coupled electrosurgical instrument is adapted to receive electrosurgical energy from a specially designed trocar or trocar adapter. In one embodiment of the present invention, an electrosurgical instrument includes a handle, an elongated tube and an electrosurgical end effector. The handle may include an actuator, such as a trigger, which is operatively connected to the end effector through the elongated tube. The elongated tube may be, for example, a closure tube which is adapted to close the end effector when the handle actuator is moved. Alternatively, the closure tube may include a mechanism connecting the handle actuator to the end effector, which mechanism acts to close the end effector when the handle actuator is moved. The electrosurgical end effector is adapted to apply electrosurgical energy to biological tissue in order to effect treatment of the tissue. The elongated closure tube includes one or more inductor coils adapted to couple electrosurgical energy to the end effector. The one or more inductor coils are electrically connected to the end effector through, for example, one or more electrical conductors.
In one embodiment of the present invention, the elongated closure tube is electrically conductive and is electrically connected to one end of the inductor coils and to one of the electrodes on the end effector. The opposite end of the inductor coil is connected to the opposing electrode on the end effector such that, when the end effector is used to grasp electrically conductive material (e.g. biological tissue), the electric circuit within the instrument is complete and electrical current can flow through the inductor coil and the biological tissue. In a further embodiment of the invention, the closure tube may be covered by an electrically insulating material.
In a further embodiment of the present invention, the electrosurgical instrument according to the present invention is adapted to fit through a trocar which includes an electrosurgical adapter. The electrosurgical adapter includes an elongated aperture with one or more inductor coils positioned around the aperture of the adapter and extending axially along the elongated aperture, at least a first electrical conductor, an outer housing and an electrical cord connected to the first conductor.
In a further embodiment of the present invention, the closure tube of the inductively coupled electrosurgical instrument is constructed, at least in part, of a ferromagnetic material, which may be, for example, iron. The adapter wall may alternatively be constructed of any material having a high relative magnetic permeability, that is, a permeability of greater than 100.