Abstract: A self-limiting electrosurgical return electrode for use with electrosurgery. Through the selection of impedance characteristics for the electrode materials of the principal body of the electrode, and through tailoring of electrode geometries, the return electrode of the present invention is self-regulating and self-limiting as to current density and temperature rise so as to prevent patient trauma. The electrosurgical return electrode includes a sheet of material having an effective bulk impedance equal to or greater than about 4,000 &OHgr;·cm and one or more connectors for making electrical connection to the sheet. The effective bulk impedance of the sheet may arise from resistive components, capacitive components, inductive components, or combinations thereof. The configuration of the presently described return electrode allows the electrode to self-limit the electrode's current densities, thereby preventing burning of a patient during surgery.

Abstract: A self-limiting electrosurgical electrode for use with electrosurgery and various other surgical procedures. The electrode can include a pad and a conductive element that collectively has an effective bulk impedance equal to or greater than about 4,000 &OHgr;·cm. The effective bulk impedance of the electrode arises from resistive components, capacitive components, inductive components, or combinations thereof of both the pad and the conductive element. Through the selection of the impedance characteristics for the electrode materials, and through tailoring of electrode geometries, the electrode of the present invention is self-regulating and self-limiting as to current density and temperature rise so as to prevent patient trauma. Additionally, the selection of materials and electrode geometries can prevent the creation of pressure sore or decubitus ulcers on a patient resting upon the electrode.

Abstract: A capacitive reusable electrosurgical return electrode pad for use with electrosurgery. Through selection of the electrode geometries and the impedance characteristics of the electrode, the electrode is self-regulating and self-limiting as to current density and temperature rise so as to prevent patient trauma. The electrosurgical return electrode can include a connector and a sheet of material having an effective bulk impedance equal to or greater than about 100,000 &OHgr;·cm. The electrode can have a working surface area from about 11 to about 1,500 square inches (or about 70 to about 10,000 square centimeters). The electrode can be disposed on the working surface of an operating table or dentist's chair immediately underlying a patient during electrosurgery. This very large working surface area eliminates the need for direct contact or contact through conducting gels and by employing washable surface areas, it is made readily cleanable and reusable.

Abstract: The present invention provides a knot tying apparatus having a notched thread cover and methods for using such a knot tying apparatus for placing knots. The present invention has particular utility in tying and placing knots during laparoscopic surgery. The thread cover includes at least one notch in the distal end which is sized so as to allow a thread such as a suture thread to pass therethrough while preventing a knot in the thread from passing therethrough. Using the notched thread cover which is attached to the distal end of a knot tying apparatus, it is possible to both pull and push on the knot when cinching the knot around the member being tied. Being able to simultaneously push and pull on the knot minimizes the forces exerted against the member being tied, thereby reducing the likelihood that fragile members such as blood vessels and the like are damaged during the tying procedure. The knot tying apparatus includes a knot carrier and a knot slider slidably connected thereto.

Abstract: A reusable electrosurgical return electrode pad for use with electrosurgery. In one embodiment it includes a presentation or working surface area lying in the range of from about 11 to about 1,500 square inches. In another the working surface is at least as large as that of a projection of about half of the profile of the trunk of a patient. In yet another, it includes a working surface area at least as large as that of a projection of the profile of both the trunk and legs of a patient. It is adapted for disposition on the working surface of an operating table or dentist's chair immediately underlying a patient during electrosurgery. By presenting a very large surface area, the need for direct contact or contact through conducting jells is eliminated; through employment of washable surface areas, it is made readily cleanable and reusable; and through the inclusion of capacitive.

Abstract: A reusable electrosurgical return electrode pad for use with electrosurgery. In one embodiment it includes a presentation or working surface area at lying in a range of from about 100 to about 20,000 square centimeters. In another the working surface is at least as large as that of a projection of about half of the profile of the trunk of a patient. In yet another, it includes a working surface area at least as large as that of a projection of the profile of both the trunk and legs of a patient. It is adapted for disposition on the working surface of an operating table or dentist's chair immediately underlying a patient during electrosurgery.

Abstract: A reusable electrosurgical return electrode pad for use with electrosurgery. In one embodiment it includes a presentation or working surface area lying in the range of from about 11 to about 1,500 square inches. In another the working surface is at least as large as that of a projection of about half of the profile of the trunk of a patient. In yet another, it includes a working surface area at least as large as that of a projection of the profile of both the trunk and legs of a patient. It is adapted for disposition on the working surface of an operating table or dentist's chair immediately underlying a patient during electrosurgery.

Abstract: An improved bipolar electrosurgical instrument with multi-coated electrodes for use in performing medical procedures. The electrodes of the instrument include opposed electrically conductive working surfaces at the distal ends thereof which are coated with a thin layer of a nickel-free high chromium material. At least non-working exposed surfaces of the distal ends are coated with a coating of an insulating material so as to be electrically insulated.

Abstract: A method and apparatus for relieving insufflation pressure in a body cavity (18) in excess of a predetermined value are provided. A conduit assembly (24) extends from the body cavity (18) through the surface (61) of a fluid reservoir and has a port (63) positioned beneath the fluid surface (61). The relief pressure is selected by setting the relative positioning of the open end (63) and fluid surface (61). The apparatus avoids insufflation gas leakage problems associated with known insufflation pressure relief devices.

Abstract: A method and apparatus for placing a knot such as a laparoscopy knot. Knot material containing a knot is wound around a ferrule surrounding a cylinder. A second ferrule surrounds the first ferrule so that the edge of the second ferrule abuts and attaches to the end windings of the knot material. Sliding the second ferrule pushes the windings of knot material including the knot off of the first ferrule and free of the cylinder. The cylinder, ferrules, and knot material containing the knot may be assembled as one disposable unit.

Abstract: A suturing device includes a rod partially covered by an elongate tube. A guide containing a one way slot is mounted to an end of the rod; a similar guide is mounted to the same end of the tube. The rod and tube may be rotated with respect to each other by manipulating an attached handle. A suturing needle with suture material attached may be fitted into a slot in one of the guides. Rotating the guides allows the needle to be passed between the needle guides, and the one way slot action allows the needle to be separated from one of the guides, so that the needle may passed around the device in an approximate circle. The device may be moved longitudinally as the needle is passed between the needle guides to form a series of stitches.

Abstract: A method and apparatus for placing and tying a knot such as laparoscopy knot. A knot pusher assembly including an outer tube and an inner tube are positioned, and a plunger assembly is plunger through the knot pusher assembly. The plunger assembly includes a knot carrier having an at least partially formed knot with a free end. The free end is placed around the object to be tied and grasped with a clamp. The knot is released from the knot carrier and the free end is pulled back through the partial knot to complete and tighten the knot. The knot is tightened and placed using the knot pusher assembly, and the free end is cut by placing it into aligned slots on the outer tube and inner tube, and rotating the inner tube in relation to the outer tube to unalign the slots.

Abstract: A bipolar electrosurgical instrument for use in laparoscopic surgery or other minimally invasive internal surgical procedures is disclosed. In one embodiment, a bipolar electrosurgical apparatus (10) is provided which is suitable for laparoscopic applications. The apparatus (10) comprises an active electrode (18) and a current return electrode shoe (34). A spring (44) or other resilient member urges the shoe (34) into tissue contact when the active electrode (18) is positioned for surgery. In another embodiment, an axially retractable active electrode (90) is used to grip tissue and draw the tissue back to a passive electrode (92) The apparatus of the present invention is capable of functioning in cutting, coagulation and desiccation modes.

Abstract: An apparatus for supporting an electrosurgical generator (14) and interfacing the generator (14) with an electrosurgical pencil (40, 234, or 254) and a supply of inert gas to allow gas-enhanced electrosurgery. One embodiment generally includes an accessible platform (134) for supporting the generator (14), a receiving area (146) for containing a supply of inert gas, an adaptor (142) for receiving an electrosurgical pencil interconnected with the supply of inert gas, and an interface structure (210) which allows an operator, through use of a control device, to control the flow of gas and electrical output to the pencil. Consequently, existing generators may be used with the present invention to conduct gas-enhanced electrosurgery.

Abstract: An electrosurgical apparatus (10) is disclosed wherein the electrode (12) and nozzle (14) can be maintained in a nested arrangement when the apparatus (10) is in inactive operation, such as when the electrode (12) is being positioned for surgery or when the apparatus (10) is not in use. The apparatus (10) may be employed for gas-enhanced electrosurgery with the electrode (12) and nozzle (14) in the nested arrangement, the apparatus (10) thereby functioning as a dual mode, conventional electrosurgery and gas-enhanced electrosurgery, instrument. Embodiments are disclosed which are adapted for laparoscopic applications.

Abstract: A novel dual mode electrosurgical pencil is provided for conventional tissue cutting/coagulation use in a first mode of operation, and gas-enhanced coagulation by fulguration in a second mode of operation. The electrode and nozzle of the pencil are provided in a manner that permits relative positioning thereof, wherein the electrode extends sufficiently beyond the nozzle in the first mode for direct tissue contact, and is sufficiently nested within the nozzle in the second mode to accommodate laminar gas stream flow for effective gas-enhanced fulguration. In a preferred embodiment, a spring is utilized to maintain the nozzle in a retracted positiion during first mode use, and the pressure of an inert gas supply is utilized to move the nozzle from a retracted first mode position to a protracted second mode position. First and second mode control switches are provided on the gripping portion of the novel pencil in the preferred embodiment.

Abstract: An improved electrosurgical pencil system (10) is formed with an in-line filter (32). The system (10) comprises a disposable electrosurgical pencil (12) and a disposable gas tube (14). The filter (32), which is preferably disposable, may be installed anywhere along the system (10) and is preferably positioned at the first end (30) of the tube (14). A filter material (44) comprises a length of tubular fibrous material repeatedly folded back upon itself. The material (44) is then sealed in a cylinder (46) and provided with openings (52) therein for receiving gas. The material (44) allows the gas to pass freely therethrough while preventing the passage of any particles larger than a preselected size. Thus, any bacteria larger than the preselected size are prevented from reaching the patient through the pencil system (12).

Abstract: A cart (10) is provided for conveniently carrying an electrosurgical generator (14) and for providing electricity from the generator (14) and inert gas from gas tanks (66-68) to an electrosurgical pencil (40). The cart (10) comprises a platform (12) constructed and arranged to receive any electrosurgical generator (14). A wheeled support structure (16) allows storage and transport of the necessary components for operating the generator (14) and the pencil (40). The cart (10) contains space for receiving gas tanks (66-68) and the connections for transferring the gas from the tanks (66-68) to the pencil (40) at a desired flow rate. The cart (10) also provides the electrical connections to provide electricity to the generator (14) and to the pencil (40) simultaneously with the inert gas.

Abstract: A multi-volume displacement pipette assembly has a tubular body with a first end for receiving a plunger assembly and a second mounting end for mounting a removable dispensing tip to the tubular body. A first cylindrical chamber extends through the tubular body for holding a first volume of fluid. The first cylindrical chamber opens through the second end of the tubular body. At least one second cylindrical chamber extends through the tubular body for holding a second volume of fluid. The such at least one cylindrical chamber is coaxially aligned with the first chamber and is open through the second end of the tubular body through a fluid pathway extending through the tubular body to the second end. A plunger assembly is coaxially positioned within the tubular body and operatively mounted therein for reciprocal, longitudinal movement.

Abstract: An apparatus for automatically measuring a fluid level beneath a manhole or the like, including a depth gauge supported by a support bracket, having a seat, which clamps to the inner rim of a manhole. The depth gauge is of the reflected microwave type, including transmitting and receiving antennas which fit into the seat of the support bracket.