Abstract: A device is provided for use with a medical instrument including a tip which is designed to penetrate the wall of an internal cavity (e.g., the abdomen) of a patient, for detecting when that tip penetrates through the wall. The device includes a source of a medium frequency detection signal and circuitry for coupling the signal to the tip of the medical instrument. The circuitry includes a transformer forming a high Q resonant circuit having an initial value of Q when the medical instrument is not in use. A return path for the signal provides that, in use of the instrument, a circuit is completed through the resonant circuit such that when the tip contacts patient tissue the initial Q of the resonant circuit changes and when the tip penetrates through the patient tissue of the Q of the circuit is restored to the initial value thereon.

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: A manual control device for laparoscopic patient treatment by use of electrical curetage or coagulation, with means for clearing the surgical sight by irrigation or suction, finger operated buttons controlling the various functions, and an interlock mechanism disabling the electrical functions when a push button is depressed to enable irrigation or suction.

Abstract: A current sensing device enables sensing the current being delivered from a source to a load at a medical implement connected to the distal end of a primary conductor connected between the source and the load in situations wherein distributed capacitance between the primary conductor and a return path to the source prevents a measurement of current at the source end of the primary conductor from being an accurate measurement of the delivered current. The current sensing device includes a reference conductor which is located beside and is preferably twisted together with the primary conductor along the length thereof and which is connected to the medical implement load through a resistor at the load of a value such as to effectively electrically isolate the reference conductor from the load.

Abstract: A current sensing device enables sensing the current being delivered from a source to a load at a medical implement connected to the distal end of a primary conductor connected between the source and the load in situations wherein distributed capacitance between the primary conductor and a return path to the source prevents a measurement of current at the source end of the primary conductor from being an accurate measurement of the delivered current. The current sensing device comprises a reference conductor which is located beside and twisted together with the primary conductor along the length thereof but which terminates short of, and is not connected to, the medical implement load, and a subtractor for subtracting the current flowing through the reference conductor from the total load current flowing to the medical implement so as to offset the effect of the distributed capacitance and to thereby produce a current measurement corresponding to the delivered current.

Abstract: A simple and reliable electrosurgical instrument includes a cable having a main contact wire and first and second insulated switch wires. The cable is received into a main member having three electrical terminals to secure the three wires to three electrically isolated conducting strips which are mounted longitudinally in a fluid-sealed switch assembly. The main contact wire is connected to the main conducting strip, and the first and second switch wires are connected to the first and second switch conducting strips. The main conducting strip permanently connects the main contact wire to a socket which receives a electrode blade. A switch device selectively connects the main conducting strip to one of the two switch conducting strips. When a user pushes one of two buttons mounted on the outside of the electrosurgical instrument, the instrument provides a cutting current or a coagulation current.

Abstract: An electrode for establishing electrical connection between a leadwire and a surface includes a contact portion and a conductive bridge portion. The contact portion includes a conductive layer, an insulator layer on one side thereof, and an anchor or adhesive layer on the other side thereof for anchoring the contact portion to the surface. The bridge portion extends from the contact portion and is electrically connected with the conductive layer. The bridge portion includes a receptor to which the leadwire is attachable and a series of perforations which form a breakaway or yieldable connection mechanism for allowing the bridge portion to be partially pulled apart when applied to the surface. The series of perforations thus allow the receptor to move yieldably with six degrees of freedom of movement relative to the contact portion while still maintaining electrical connection with the conductive layer.

Abstract: A trocar assembly includes an elongate trocar device and a surrounding cannula. The trocar device incorporates an electrosurgical cutting element which is used to make a guide hole for the cannula and thus enables the remainder of the trocar assembly to enlarge the puncture. The cutting element comprises a bi-polar electrode assembly. An electronic control circuit senses the current flow to the cutting element and, when the trocar device breaks through the wall of the body cavity being cut into, this circuit cuts off the connection to the associated electrosurgical generator. Further control circuitry prevents a surgeon from resuming electrosurgery until a predetermined time period has elapsed. Multiple trocars of different diameters are provided for the same assembly.

Abstract: An apparatus for inserting a thoracotomy tube in a patient without damaging adjacent lung tissues is provided. The thoracotomy tube is adapted to receive a trocar having screw threads on the distal end thereof. The proximal end of the trocar has a handle thereon to rotate the trocar so that the screw threaded distal end forms an incision within the skin of the patient and the tip end of the screw thread passes into the pleural cavity. The distal end of the thoracotomy tube is provided with screw threads on the outer surface thereof to form a continuation of the screw threads of the trocar. The distal tip or end of the trocar terminates in a short flexible tube. A hollow needle extends through a central passageway in the trocar and through the flexible tip on the trocar. The opposite end of the hollow needle is provided with a pressure chamber which is in fluid communication with the passageway in the needle.

Abstract: An electrosurgical probe is provided which reduces the likelihood of arcing from the probe. In addition, the probe provides the ability to place a fiber-optic cable through the probe for providing for laser surgery or for laproscopic examination of the patient. The electrosurgical probe comprises an electrosurgical tip, a cylindrical body attached to the tip, and a base attached to the cylindrical body. The tip may have many different shapes but a spatula shape is generally preferred. The tip has at least one notch in the periphery of the spatula shape for retaining a fiber-optic cable. The cylindrical body is substantially hollow so that suction, irrigation, and laparoscopy may be carried out through the probe. To aid the surgeon in determining dimensions of organs within a patient, the cylindrical body has a plurality of striped regions having a predetermined thickness spaced apart at predetermined intervals on an outer surface of the cylindrical body.

Abstract: A method and apparatus for induction of pneumoperitoneum and insertion of a laparoscopic sheath is provided in which a trocar carrying a sheath or cannula has a tapered distal end with screw threads formed on the outer surface of the distal end. The distal tip or end terminates in a short flexible tube. A hollow needle extends through a central passageway in the trocar and through the flexible tip on the trocar. The opposite end of the hollow needle is provided with a pressure chamber which is in fluid communication with the passageway in the needle. In use, the trocar and cannula are screwed into the body tissues of the patient and when the distal end of the needle enters the peritoneal space within the body, liquid within the pressure chamber passes through the hollow needle and into the peritoneal space. The release of the fluid from the pressure chamber is an indicator to the surgeon that the end portion of the needle has entered the peritoneal space.

Abstract: A suction and irrigation apparatus is provided for selectively delivering suction or irrigation fluid to a patient during surgery or the like. A pair of resilient tubes are provided which is connected with a suction source and irrigation source at one end and is connected through a Y-shaped connector at the other end with a handpiece having clamping valves thereon disposed between the ends of the resilient tubes. The handpiece has a housing with openings in the ends thereof to provide passageways for the resilient tubes. Clamping valves are mounted in the housing which are spring urged to close the resilient tubes. A bracket is slidably mounted on the sides of the handpiece housing and the bracket is slidable to a position overlying the clamping valves so as to maintain the clamping valves in an open position. When the clamping valves are held in an opened position by the bracket, the handpiece can be moved along the length of the resilient tubes to position the handpiece at any desired location.

Abstract: A simple and reliable electrosurgical instrument includes a cable having a main contact wire and first second insulated switch wires all provided with a short insulated or bare portion. The cable is received in a main member having a first holding mechanism for holding the switch wires adjacent uninsulated portions thereof on one lateral side and spaced from one another as well as a second holding mechanism for holding the switch wires adjacent the uninsulated portions thereof on the other lateral side so that the uninsulated portions span between the first and second holding mechanisms and are spaced longitudinally from one another. A blade receiver receives an electrode blade and is then electrically connected to the contact wire. A switch device selectively connects one of the uninsulated portions of the switch wires to the contact wire during operation. The first and second holding mechanisms preferably include channels and a cover includes projections which hold the wires in place.

Abstract: A cannula is provided for laparoscopic surgery wherein the cannula comprises a housing and elongated tube with a passageway formed within the housing so that laparoscopic instruments may be passed through the housing and the elongated hollow tube into the abdominal cavity of a patient. A pair of rollers are mounted within the housing, the rollers being spring-urged together to close the passageway through the housing when an instrument is withdrawn. A slidable plate having apertures of different sizes are mounted in the housing with the apertures provided with slitted seals therein to close the passageway through the housing. The varying sized apertures in the slidable plate permit laparoscopic instruments of varying diameters to be used and to maintain an effective seal around the instrument. In another embodiment of the cannula a valve is provided which is closed when the rollers within the housing are in engagement with each other.

Abstract: The present invention is directed to a self-contained, totally disposable apparatus for the collection and reinfusion of blood which is suitable for use with a chest drainage unit to provide for the autotranfusion of autologous blood and the method of using the apparatus. The blood collection and reinfusion apparatus is separate in structure from the chest drainage unit and comprises a rigid outer container and an inner flexible container in conjunction with portals for blood collection, reinfusion, and attachment to a vacuum source. The apparatus and method of the invention provides a closed system, requires minimal handling of the blood, and provides for greater patient safety in that no interruption of the operation of the chest drainage unit is required.

Abstract: A cannula holder is provided to maintain a cannula in a fixed position on body tissue while also allowing the cannula to be reoriented with respect to an incision. The cannula holder comprises a pad having a large surface area with integral finger shaped projections extending from the pad. The fingers form a V shaped projection from the pad. There are concave regions formed on the outer circumference of the pad adjacent to the fingers for allowing the fingers to bend around the outer surface of a cannula. A means for securing the cannula holder to a patient's skin is provided by an adhesive layer that is attached to the pad. This adhesive layer is also on the fingers so that the fingers may be adhesively attached to the cannula. A removable paper layer is provided to cover the adhesive layer to prevent the adhesive layer from drying or accidently securing to objects.

Abstract: The present invention is directed to a self-contained, totally disposable apparatus for the collection and reinfusion of blood which is suitable for use with a chest drainage unit to provide for the autotransfusion of autologous blood and the method of suing the apparatus. The blood collection and reinfusion apparatus is separate in structure from the chest drainage unit and comprises a rigid outer container and an inner flexible container in conjunction with portals for blood collection, reinfusion, and attachment to a vacuum source. The apparatus and method of the invention provides a closed system, requires minimal handling of the blood, and provides for greater patient safety in that no interruption of the operation of the chest drainage unit is required.

Abstract: An electrode for use with electrosurgical apparatus is provided which establishes capacitive coupling with the skin of a patient. The electrode includes a conductive plate connected to the electrosurgical apparatus with an insulating layer disposed in contact with the conductive plate and on the opposite face of the insulator there is provided conductive material in the form of a plurality of discreet islands of conductive adhesive material. The islands of conductive adhesive material are in contact with the skin of the patient and provide a plurality of independent current paths providing substantially uniform current flow from each element of the skin in contact with the islands of conductive material.