Abstract: An improved electrosurgical safety circuit where the currents in the active and patient leads are monitored, the monitored currents being respectively rectified and then subtracted from one another. Whenever the active current exceeds the patient or return current by an amount corresponding to a dynamically variable threshold, an appropriate measure is taken such as the sounding of an alarm and/or the de-energization of the electrosurgical generator. The dynamic threshold varies in accordance with the level of the signal applied to the patient and compensates for leakage current through stray capacitance from the active lead to ground.The patient lead is substantially grounded at radio frequencies through a frequency sensitive network. The frequency sensitive network may include a capacitor, the value of which is such as to provide the foregoing frequency response.

Abstract: Method for intravenous feeding of a patient by a pump and a pump actuator which is provided with readily insertable and removable cams which control the number of pump strokes per unit of time and also the amount of intravenous fluid injected by each stroke in accordance with a prescription of intravenous fluid placed in a container. A predetermined prescription of intravenous fluid is prepared and placed in a container. The container and a cam which is tailored to the requirements of the prescription in the container is delivered to the patient. The cam is placed on the pump actuator. The container is connected to the pump and the pump is connected to a vein of the patient. The pump actuator is operated by the use of the cam to operate the pump to supply the prescribed intravenous liquid in the container to the patient in accordance with the prescription.

Abstract: The combination drug administration device and alarm system is adapted to be connected to a source of intravenous liquid and to a patient. A container is provided having a inlet and an outlet. A piston is slidably mounted in the container for movement between extended and retracted positions. A stem is secured to the piston and has a portion thereof remaining out of the container during movement between the extended and retracted positions. A switch is provided and is mounted on the stem exterior of the container so that the switch means can be slidably positioned on the stem and will be retained on the stem in an adjusted predetermined position thereon but which will not impede movement of the piston and the stem in the container.

Abstract: An electrosurgical instrument comprising a support member; at least one electrode mounted on the support, the electrode consisting essentially of a material having a figure of merit of at least 0.15 at room temperature where the figure of merit is the product of the thermal conductivity, the heat capacity and the density of the material in the metric system; and a heat sink in thermal contact with the electrode for removal of heat therefrom. A carbon coating for the electrode is also disclosed where the coating may be formed by different techniques including thermal decomposition of certain carbohydrate containing materials, the latter method providing a porous carbon coating particularly suited for expediting the starting of the instrument. Also disclosed are a number of heat sinks for effecting removal of heat from the electrode. Further disclosed is a monolithic blade made from carbon.

Abstract: An electrosurgical method and apparatus for coagulating by fulguration where the electrical discharge is established through a formation of flowing inert gas where the formation may either be a diffuse blanket of the flowing gas or a well defined column thereof.

Abstract: A method and apparatus for initiating an electrical discharge in a formation of flowing inert gas disposed adjacent the end of an electrode by generating charged particles in the vicinity of said inert gas formation. The charged particles may be generated by various means such as an electron emissive filament, a radioactive material or an auxiliary electrical discharge located adjacent to the electrode but removed from the end thereof. The auxiliary electrical discharge may be in electrical series with the electrode and it may be located inside or outside the flow of inert gas needed to establish the gas formation at the end of the electrode.RELATED APPLICATIONSThis application is related to a first U.S. patent application Ser. No. 649,725 filed on Jan. 16, 1976 by Charles F. Morrison, Jr., Frank W. Harris, and Michael C. Patzer, entitled "Electrosurgical Method and Apparatus for Establishing an Electrical Discharge in an Inert Gas Flow" and a second U.S. patent application Ser. No. 649,682 filed on Jan.

Abstract: The present invention relates to a failure alarm system for an intravenous feeding pump in which the pumping force is secured by the projection of a plunger into a chamber filled with the liquid to be pumped, which plunger is encased in a tightly fitting sheath of elastic material. In such a pump, actuation is secured by the application of a force from an actuator to the end of the plunger extending without the wall of a pumping chamber and the return force is secured by the elasticity of the sheath. The actuator of such a pump provides an actuator which can be selectively set to provide an extended range of operations per unit of time and can be modified to control the amount of projection into the pumping chamber by the plunger. In such a combination means is provided by the present invention for sensing the fact that there is a negative pressure, or suction, in the system that is not balanced by the in-flow of liquid, i.e.

Abstract: Universal drip chamber and spike assembly for use with a source of intravenous liquid contained in a bottle having a neck with a permeable stopper disposed in the neck and for use with a tube adapted to be connected to a patient. The Universal drip chamber comprises a body defining the upper portion of a drip chamber. The drip chamber body has a relatively rigid substantially transparent wall surrounding the upper portion of the chamber and being open at its lower end. A drip chamber booth formed of a flexible rubber-like material is secured to the lower end of the said drip chamber body and defines the lower portion of the drip chamber. The booth has an outlet flow passage extending through the lower extremity of the same and is in communication with the drip chamber. The booth has means forming a valve seat in the lower portion of the drip chamber surrounding the outlet flow passage.

Abstract: An electrosurgical device adapted for connection to an electrical generator having active and return output terminals, the device being used to cut, coagulate, or otherwise treat organic tissue or the like, the device comprising: an insulative support connectors; an active electrode responsive to the active output terminal and a return electrode responsive to the return output terminal, the electrodes being supported by the electrode support connectors, the return electrode being symmetrically disposed completely about the active electrode, the active electrode extending as far as or beyond the distal end of the return electrode, both the electrodes being adapted for electrical connection to the tissue, the ratio of the return electrode area adapted to electrically connect to the tissue to the active electrode area adapted to electrically connect to the tissue being in the range of approximately 2 to 200; and connectors for connecting the active electrode to the active output terminal and the return electrode

Abstract: An electrosurgical forceps including a switching member disposed on only one tine thereof where the switching member may be disposed on the outside of the tine to permit operation thereof independent of the closing of the forceps or where the switching member is disposed on the inside of the tine such that the electrical contacts thereof are provided with an electrically insulative covering. There are also provided unique circuit paths on the tines whereby the forceps may be operated in either a monopolar mode with or without switching or a bipolar mode with or without switching. Also disclosed is a spacer for separating the tines and a removable sleeve which snaps over the spacer to hold the tines in place. Further, there is disclosed a double molding method for constructing an electrosurgical forceps or the like.

Abstract: A method and apparatus for initiating an electrical discharge in a formation of flowing inert gas disposed adjacent the end of an active electrode by generating charged particles in the vicinity of said inert gas formation. The charged particles are generated by an auxiliary electrical discharge produced between the active electrode and a surrounding tube, which is not connected to any external source of biasing potential. Electrostatic charge is generated on the tube as the inert gas flows thereby. This charge bleeds off the tube through inwardly pointed tips on the tube, which act as discharge points. The charge then passes to the active electrode via the auxiliary discharge through the gas.

Abstract: A single or multichannel electrical connector including a male connector having at least two prongs depending resiliently from a base, the prongs each having defined in the outer edge thereof a notch with at least one of the notches having at least one conductor exposed at the bottom portion of the notch, the conductor extending internally through the prong, the prongs also having end portions with outwardly facing mutually inclined surfaces, the male connector being adapted to fit a female connector having an opening defined therethrough and configured to receive the prongs with the sides of the notches engaging the front and back endwalls of the female connector adjacent the opening and the connector in the bottom of the notch engaging a contact in a sidewall of the opening in the female connector such that the male connector may be inserted by engaging the opposed inclined planes of the prongs within the opening of the female connector, deforming the prongs towards one another to pass through the female co

Abstract: A single or multichannel electrical connector including a male connector having at least two prongs depending resiliently from a base, the prongs each having defined in the outer edge thereof a narrow notch with at least one of the notches having at least one conductor exposed at the bottom portions of the notch, the conductor extending internally through the prong, the prongs also having end portions with outwardly facing mutually inclined surfaces, the male connector being adapted to fit a female connector having an opening defined therethrough the configured to receive the prongs with the sides of the notches and the connector at the bottom of the notch engaging a protruding contact in a sidewall of the opening in the female connector such that the male connector may be inserted by engaging the opposed inclined planes of the prongs within the opening of the female connector, deforming the prongs towards one another to pass through the female connector thereupon again expanding the prongs to bring the conta

Abstract: A drug injection device (or what some might prefer to call a "drug injection site") comprises a doubled wall, doughnut-shaped cylinder adapted to be inserted into an intravenous delivery tube. Preferably it is made of a pair of identically shaped elements having an outer end an inner circular wall, both of which, when the two elements are placed together in opposed relationship, form continuous walls of a doughnut or O-ring shape. The interior of the doughnut is filled with a soft surgical grade rubber which, when under compression, permits ready insertion of a hypodermic needle therethrough but which, when the needle is withdrawn, is self-sealing. A plurality of radially aligned apertures, or windows, are provided in the inner and outer walls, so that the hypodermic needle can be inserted through the outer wall, through the rubber sealing element and then through the aligned window in the inner wall.

Abstract: The present invention relates to a timing device for an intravenous feeding pump, whereby the pump can be set to operate at its regular rate for a predetermined period (preferably up to about 4 hours) and thereafter at a reduced rate just sufficient to keep the needle open. The apparatus comprises a gear train driven by the main drive shaft of the intravenous feeding pump actuator, which drives a setting dial at a considerably reduced speed back to a "0" position. The setting dial is clutched to a final gear of the gear train through a spring slip clutch, so that the setting dial can be set to a desired position without driving the gear train or the gear train continue to drive even though the setting dial is latched in its 0 position.

Abstract: An electrosurgical device connected to an electrical generator having active and return output terminals, the device being used to cut, coagulate, or otherwise treat human tissue or the like, the device comprising: an electrode support; an active electrode responsive to the active output terminal and a return electrode responsive to the return output terminal, the electrodes being supported by the electrode support, both the electrodes being adapted for electrical connection to the tissue, the ratio of the return electrode area adapted to electrically connect to the tissue to the active electrode area adapted to ohmically or arc-wise connect to the tissue being in the range of approximately 2 to 200. Arrangements are also provided for separating the active electrode from the tissue when the device is placed in contact with the tissue to insure that a current arc is established between the active electrode and the tissue. Various electrode configurations are also disclosed.

Abstract: An electrosurgical device connected to an electrical generator having active and return output terminals, the device being used to cut, coagulate, or otherwise treat human tissue or the like, the device comprising: an insulative electrode support; an active electrode responsive to the active output terminal and a return electrode responsive to the return output terminal, the electrodes being supported by the electrode support, both the electrodes being adapted for electrical connection to the tissue, the ratio of the return electrode area adapted to electrically connect to the tissue to the active electrode area adapted to ohmically or arc-wise connect to the tissue being in the range of approximately 2 to 200. Apparatus is also provided for separating the active electrode from the tissue when the device is placed in contact with the tissue to insure that a current arc is established between the active electrode and the tissue. Various electrode configurations are also disclosed.

Abstract: A signal generating device and method for producing an RF output signal regulated in power and of decaying amplitude suitable for use in an electrosurgical generator for surgical coagulation purposes. The device includes a circuit tuned to a predetermined radio frequency suitable to prevent nerve stimulation and the tuned circuit has connected therewith an unregulated power supply with current through the tuned circuit being controlled by means of a solid state switching system. The tuned circuit includes an inductor initially charged to a predetermined energy level.