Medical Scientific, Inc.

Kevin P Lemire

Thomas A Wrublewski

Kevin M Allaire

Paul C Nardella, Sr

William L Frey

An adapter unit for a mechanical tissue cutting implement such as a shaver, morcellator or the like includes a mounting block from which an electrically insulating sheath extends. The sheath fits over the cannula or shaft of the cutting implement, and is secured in alignment and attached so that the cutting tip, for example, the tool and its window in the cannula tip, are exposed through the sheath. A conductor, which may be a conductive layer, extends along the length of the sheath and is exposed to form a distal electrode at the tip in close proximity to the opening, constituting one electrode of a bipolar electrode arrangement at the exposed tool. The other electrode is provided by electrical connection to the implement itself, so that a high current density path is formed through tissue in the cutting region. Preferably both output connections of an electrosurgical generator are coupled through a matching transformer to the mounting block by a plug, socket, cable or fixed cord arrangement, and the mounting block may, for example, be formed of plastic, preferably having an alignment feature such as a notch to fasten to the implement so that the sheath opening aligns with the cutter. Electrical connection to the implement may be effected via a conductive bushing, fastening bolt or the like which contacts one of the supply leads through a wire, spring or other conductive path. The adapter may also provide a sheath opening and distal electrode about a non-apertured region of the cannula, for example on the rear surface of the cannula opposed to the cutting tool aperture, to form a hemostasis element that may be rotated into position to coagulate bleeding. In this case the bipolar electrode geometry may be configured for high energy density delivery that does not vary with tool rotation. The adapter may also convert a monopolar device to bipolar operation, providing a single additional electrode positioned by the sheath at the cutting aperture.

Device for converting a mechanical cutting device to an electrosurgical cutting device

An electrosurgical instrument has a handle and a body which position and close a jaw about a tissue site for simultaneously cutting and sealing relatively large tissue structures. The jaw includes an electrosurgical cutting member, which may be a blade or wire, against which tissue is biased along a cut line, and a clamping assembly that clamps a region adjacent to or surrounding the cut line. The clamping assembly includes sealing electrodes for heating the region and welding tissue along the side of the cut as the cutter parts the tissue. The clamping assembly preferably has first and second clamping jaws extending in parallel to grip the tissue as tension is released by the cut, allowing dependable and complete sealing of the cut ends over an extended time while the tissue is immobilized. Sealing electrodes formed of thermally conductive material may be covered by a thinner coating or thermally non-impeding or heat transfer cover, which preferably includes a material to assure biocompatibility and prevent sticking. The handle, body and jaw may be configured in the shape of a hemostat to allow simple positioning, or may be configured with an elongated body and a mechanism that operates the jaw through a stationary or telescoping handle for endosurgical use through a small incision. The blade may extend entirely to the tip, or the clamp assembly may extend forward of the blade. An energy ratio input element may attach to an energy source to apportion electrosurgical energy between the cutting member and the sealing electrodes. The element may include a pair of transformers, or a transformer with a split secondary or a tapped secondary winding, with the primary configured for connection to the output of an RF scalpel drive console. The windings of the transformer match impedances and power requirements of the different cutting and sealing electrodes to coordinate effective tissue sealing and welding with the cutting operation.

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E. Douglas, MA, United States of America

Kevin P Lemire