Abstract: Surgical cutting instrument includes an electrically heated cutting edge and an automatic control system for maintaining the cutting edge at a constant high temperature for sterilizing the blade, cutting tissue, and cauterizing the incised tissue to reduce hemorrhage from the cut surfaces of the tissues (hemostasis).

Abstract: Stable emulsions of highly fluorinated organic compounds for use as oxygen transport agents, "artificial bloods" or red blood cell substitutes and as contrast agents for biological imaging. The emulsions comprise a highly fluorinated organic compound, an oil that is not substantially surface active and not significantly soluble in water, a surfactant and water.

Abstract: Stable emulsions of highly fluorinated organic compounds for use as oxygen transport agents, "artificial bloods" or red blood cell substitutes and as contrast agents for biological imaging. The emulsions comprise a highly fluorinated organic compound, an oil that is not substantially surface active and not significantly soluble in water, a surfactant and water.

Abstract: Methods and apparatus are provided for use in performing electrosurgery, wherein a power supply supplies an electrosurgical instrument with a low voltage power signal having a substantially constant peak-to-peak voltage that is independent of the load impedance and which has a crest factor near unity. A power supply is provided to supply a voltage waveform in accordance with the methods of the invention. A clipping circuit is also provided to permit practice of the methods using conventional electrosurgcial generators and previously known electrosurgical instruments, wherein the voltage amplitude and waveform is modified to the desired regime.

Abstract: A system and method that controls node congestion in a packet switching network by allowing the congested node to seize control of transmission on the packet switching network and not relinquishing control until it has drained its buffer of the backlog of packets. In response to the node's buffer reaching a predetermined occupancy level, the node requests from the network's arbiter for exclusive transmission rights on the network. When the node receives transmission rights, the node continues to process packets in the buffer. When the occupancy of the buffer reaches a second predetermined threshold, the node releases the transmission right, and thus permits other nodes to transmit packets to it (and to other nodes) again.

Abstract: A non-volatile memory disposed within electrically powered medical equipment is described. The non-volatile memory may be preprogrammed to store utilization limits and parametric data for the equipment. An external control module may be programmed to store the utilization history for the equipment in the non-volatile memory on an on-going basis. The control module compares the utilization limits and utilization history during each use, and disables the equipment if a utilization limit is exceeded. The control module may also use the parametric data stored in the non-volatile memory to regulate the power supplied to the equipment.

Abstract: A hemostatic surgical blade and methods of manufacturing such blades are provided, wherein the blade comprises a laminate region having a hardenable center layer and highly thermally conductive outer layers, joined to a second region of a low thermal conductivity material. A heating element is secured to the laminate region and in thermal communication therewith to thermally reform the collagen of tissue as it is incised. The heat generated by the heating element is conducted to the cutting edge of the blade to maintain the cutting edge temperature within 20.degree. C. to 70.degree. C. of a user-selected operating temperature. The second region reduces the conduction of heat to the handle of the instrument.

Abstract: Method and means are disclosed for preventing tissue from adhering to surgical apparatus while operating at tissue temperatures at which hemostasis with minimal tissue damage occurs, and include interposing between the surgical apparatus and the tissue being heated thereby an abherent coating which exhibits electrical insulation and thermal impedance, thickness and thermal drop thereacross within specified limits.

Abstract: A thermodilution catheter has electrodes in electrical contact with the blood flowing adjacent to the catheter. A potential difference applied to the electrodes causes electrical current to flow in the volume of blood in the region of the electrodes, thereby creating a bolus of blood at elevated temperature suitable for measurement of blood flow by the thermodilution principle.

Abstract: Catheter apparatus having transmitting and receiving optical fibers for photometric analysis of a fluid eliminates the need for individually calibrating each catheter within a population of catheters by making substantially uniform the center-to-center spacing between the outlet aperture of each and every transmitting fiber and the inlet aperture of each and every receiving fiber of an individual catheter for all catheters within a population of catheters; and by making the size and shape of all the outlet apertures of all transmitting fibers generally uniform and the size and shape of the inlet apertures of all receiving fibers generally uniform in each catheter and from catheter to catheter and that the orientation of all transmitting fibers relative to all receiving fibers be similar.

Abstract: The cutting edge of a scalpel blade is heated to an elevated preselected constant operating temperature for cutting tissue with simultaneous hemostasis by dielectric heating of the internal structure of the blade in the region along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by contact with tissues during surgical cutting is provided for by constructing the heating elements of the blade of ferroelectric materials that have a Curie point in the operating temperature range and that provide large increases in loss factor (the product of relative dielectric constant times the ratio of loss current to charging current) for temperature decrements below the Curie point.

Abstract: An optical scattering reference medium is formed of a plurality of scattering particles substantially uniformly dispersed in a substantially compliant, non-compressable transparent solid medium which is selectively positionable against the distal end of an optical catheter for use therewith within a sterilizable disposable package for performing repeatable photometric measurements to standardize the performance of the photometric measuring instrument.

Abstract: Catheter apparatus having transmitting and receiving optical fibers for photometric analysis of a fluid eliminates the need for individually calibrating each catheter within a population of catheters by making substantially uniform the center-to-center spacing between the outlet aperture of each and every transmitting fiber and the inlet aperture of each and every receiving fiber of an individual catheter for all catheters within a population of catheters; and by making the size and shape of all the outlet apertures of all transmitting fibers generally uniform and the size and shape of the inlet apertures of all receiving fibers generally uniform in each catheter and from catheter to catheter and that the orientation of all transmitting fibers relative to all receiving fibers be similar.

Abstract: A high efficiency selenium photovoltaic solar cell comprises a transparent base; a pellucid layer of conductive oxide; a layer of polycrystalline selenium forming a heterojunction to the underlying oxide; a thin layer of tellurium interposed between the oxide and selenium layers providing a metallurgical bond therebetween; a layer of high work function metal forming an ohmic contact to the selenium layer. A process of optimizing the optical and electrical characteristic of each component of the solar cell results in increased sunlight engineering efficiencies in excess of about 3.5%.

Abstract: Particulate sources of signal which can be detected outside the body of a patient are introduced into the circulating blood and are tracked in three dimensions in the region of the heart using suitable detectors disposed about the patient's chest. This permits the sequence of positions of each particle to be recorded as a function of time as each particle flows through a coronary vessel. Data analyses of these recordings of particle positions provide information about the velocity of blood flow through the course of each coronary artery. This velocity information is used to determine the extent, severity and location of stenotic lesions of the coronary arteries.

Abstract: The cutting edge of a scalpel blade is heated to an elevated preselected constant operating temperature for cutting tissue with simultaneous hemostasis by radiant heating of the blade in the region along the cutting edge. Radiant energy is contained within the blade by a reflective coating over the transparent or translucent blade material. Heating along the cutting edge is provided by the disposition of a radiation-absorptive material beneath the reflective coating in the region along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by contact with tissues during surgical cutting is provided for by fabricating the radiation-absorptive element of the blade of a thermochromic material that exhibits a substantial increase in absorption coefficient for a temperature decrement within the operating temperature range.

Abstract: The cutting edge of a scalpel blade is heated to an elevated preselected constant operating temperature for cutting tissue with simultaneous hemostasis by dielectric heating of the internal structure of the blade in the region along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by contact with tissues during surgical cutting is provided for by constructing the heating elements of the blade of ferroelectric materials that have a Curie point in the operating temperature range and that provide large increases in loss factor (the product of relative dielectric constant times the ratio of loss current to charging current) for temperature decrements below the Curie point.

Abstract: The temperature of the cutting edge of a surgical cutting instrument is maintained within a preselected temperature range for surgical cutting and simultaneous hemostasis by conducting heat from a thermal distributing means that is disposed along the cutting edge of the instrument. The thermal distributing means selectively heats regions of the cutting edge that are locally cooled by the tissue contact of surgical cutting by condensation in the regions of the cooled edge of previously evaporated fluids, with concomitant release of the heat previously absorbed upon evaporation of the fluid.

Abstract: A surgical cutting instrument includes an electrically heated cutting edge and an automatic control system for maintaining the cutting edge at a constant high temperature for sterilizing the blade, cutting tissue, and cauterizing the incised tissue to reduce hemorrhage from the cut surfaces of the tissues (hemostasis).

Abstract: A surgical cutting instrument includes an electrically heated cutting edge and an automatic control system for maintaining the cutting edge at a constant high temperature for sterilizing the blade, cutting tissue, and cauterizing the incised tissue to reduce hemorrhage from the cut surfaces of the tissues (hemostasis).