Cobe Laboratories, Inc.

Gambro, Inc.

Rollei of America, Inc.

Honeywell G.m.b.h.

Emerson Electric Company

Statitrol Corporation

Statitrol Division Emerson Electric Co.

Francis T Ogawa

James M Brugger

George W Buffaloe, Iv

Dennis J Wilwerding

Donn D Lobdell

George J Eilers

Michael R Manes

James R Adams, Jr

Terry D Boucher

Richard A Langlais

Methods and apparatuses for determining a fluid parameter in a vessel by altering a property of the fluid, sensing the difference in the property after the fluid is altered, particularly as related to the property in an unaltered portion of the fluid.

Differential fluid parameter determination

Method and apparatus for quantitatively determining a degree of recirculalion flow in a vessel of a fluid by altering the electrical conductivity of the fluid, sensing the difference in electromagnetic field after the fluid is altered, and integrating the sensed difference over a period of time including any time of potential recirculation of any altered conductivity fluid.

Differential conductivity hemodynamic monitor

A flow rate of a fluid flowing in a tube is quantitatively determined by altering the electrical conductivity of the fluid by injection of a bolus of saline. The electrical conductivity of the altered conductivity is measured over the time it takes the altered conductivity fluid to pass a conductivity measuring location. The measured conductivity is integrated over the time it takes to pass the conductivity measuring location. The integral is interpreted to determine the flow rate.

The presence of air bubbles entrained in a liquid flowing through a tube is detected flowing the liquid through a conduit which comprises a conductivity cell with a continuous path configuration. An electrical current is induced in the liquid in the conductivity cell. The electrical current in the liquid in the conductivity cell is sensed and interpreted, a decrease in the electrical current being indicative of the presence of an air bubble in the liquid. The conductivity cell comprises an upstream connection, a downstream connection, and two branches connecting the upstream connection to the downstream connection with a continuous path configuration from the upstream connection to the downstream connection through one of the two branches and returning to the upstream connection through the other one of the two branches.

Hemodynamic monitor for detecting air bubbles

A differential conductivity recirculation monitor quantitatively determines the degree of recirculation in a fistula by comparing the conductivity of blood entering the fistula to the conductivity of blood being withdrawn from the fistula. A discrete quantity of a high conductivity marker fluid is injected into the blood entering the fistula, altering the conductivity of the blood entering the fistula. The altered conductivity blood enters the fistula and, if recirculation is present, co-mingles with blood in the fistula, altering the conductivity of the blood in the fistula in proportion to the degree of recirculation. Blood withdrawn from the fistula has an altered conductivity related to the degree of recirculation. Quantitative values of the conductivity of the altered conductivity blood entering the fistula and the conductivity of the blood being withdrawn from the fistula are measured and a difference determined. The determined difference between the conductivities is used to determine a quantitative measurement of the degree of recirculation in the fistula.

Altered fluid conductivity monitor

A differential conductivity recirculation monitor quantitatively determines the degree of recirculation in a fistula by comparing the conductivity of blood entering the fistula to the conductivity of blood being withdrawn from the fistula. A discrete quantity of a high conductivity marker fluid is injected into the blood entering the fistula, altering the conductivity of the blood entering the fistula. The altered conductivity blood enters the fistula and, if recirculation is present, co-mingles with blood in the fistula, altering the conductivity of the blood ion the fistula in proportion to the degree of recirculation. Blood withdrawn from the fistula has an altered conductivity related to the degree of recirculation. Quantitative values of the conductivity of the altered conductivity blood entering the fistula and the conductivity of the blood being withdrawn from the fistula are measured and a difference determined. The determined difference between the conductivities is used to determine a quantitative measurement of the degree of recirculation in the fistula.

Differential conductivity recirculation monitor

A liquid conductivity sensor which features simply and inexpensively driving the excitation transformer of a two-transformer/fluid-loop remote conductivity sensor with a square wave excitation signal provided by a digital timer and a flip-flop. Also disclosed is using an electrodeless conductivity sensor to sense conductivity of dialysate.

Remote conductivity sensor using square wave excitation

A cell for remotely sensing conductivity of a fluid passing through it, the cell having an inlet and an outlet and two fluid paths between the two, thereby defining a fluid loop, an excitation transformer comprising a first toroidal core having a hole through it and wire turns around it, the core encompassing a portion of the fluid loop therein, and a sensing transformer comprising a second toroidal core having a hole through it and wire turns around it, the core encompassing a portion of the fluid loop, the cores being coplanar to thereby reduce leakage between the transformers.

Remote conductivity sensor having transformer coupling in fluid flow path

An external light integrating circuitry connectable over two-wires to a flash control circuitry, for causing automatic disabling of an internal light integrating circuitry connected within the control circuitry. The external integrating circuitry receives power over the two wires and transmits light integrating information back to flash termination circuitry within the control circuitry. Camera shutter contacts are connectable with the external integrating circuitry for transmitting a flash initiating signal via the two wires for initiating the photographic flash.

Photographic flash control circuitry having selectively operable

A system for determining the range to an object utilizing a plurality of radiation responsive detectors arranged in groupings wherein a first grouping of detectors receives radiation from the object in a first pattern and the second grouping of detectors receives radiation from the object in a second pattern. The patterns move with respect to one another as the distance between the object and the system changes. The range is determined from a determination of the relative position of the patterns by computing where the patterns will coincide if the focusing lens of the system is moved. The output is a signal having a characteristic indicative of the desired direction of motion of the lens and a characteristic indicative of the amount of such motion necessary to produce a proper focus condition.

Method and apparatus for determining focus direction and amount

Circuitry for digitizing received light into a digital pulsating signal, including a photodiode operable in response to light intensity for passing current to a capacitor for developing a voltage level thereacross. A voltage comparator with a hysteresis responds to the magnitude of the capacitor voltage level for tripping the comparator's output between a HIGH and LOW state which directs capacitor discharge to cycle the comparator output in a pulsating manner. In a preferred embodiment, the circuitry is powered by a flash storage capacitor along a pair of conductors which serve both to power the circuitry and to receive pulsating current levels indicating voltage comparator switching. The current levels are sensed and counted for producing a binary count output of received light energy. In another embodiment, the conductors also serve to carry a trigger signal for directing flash initiation.

Light digitizing circuit for an electronic flash device

A self-monitoring ion chamber type combustion products detection apparatus operable to generate perceptibly different output signals indicative of, respectively: the apparatus is being tested; the condition of the apparatus is normal; an alarm condition is detected; an apparatus malfunction is detected; and, a low power supply voltage is detected. The impedance of the ion chamber of the apparatus varies as a function of the degree of combustion products in the atmosphere being monitored and this change in impedance produces a variation in the output voltage of the ion chamber which is used by the apparatus to produce an alarm signal. In generating different output signals, the apparatus employs test, alarm, fault and low power supply reference voltages. An oscillator circuit is selectively driven by one or more substantially constant current sources to produce output pulses having predetermined frequencies which are utilized in producing at least some of the perceptibly different output signals. A battery may be used to provide power for the apparatus, and the perceptibly different output signals are preferably produced as visible light or audible sound signals.

Combustion products detection apparatus

Alarm condition detecting apparatus in the form of a combustion products detection system for monitoring a zone to detect the occurrence of fire therein. The apparatus has a plurality of detecting units adapted to be interconnected as parallel loads with a control unit. Each detecting unit receives operating power which may be from the control unit and functions to monitor a selected portion of the zone, generating, as appropriate, condition signals indicative of condition normal, impending alarm, alarm or unit malfunction. The impending alarm and unit malfunction signals are preferably pulsed signals of distinctly different frequencies and a light emitting diode (LED) arrangement is included in the detecting units to generate visual ouputs corresponding to the impending alarm, alarm and unit malfunction signals. The condition signals generated by the detecting units may be transmitted to and monitored by the control unit by the method of correspondingly changing the parallel load impedance thereacross to cause changes in a loop current flowing in the control unit. In response to such loop current changes, the control unit is adapted to appropriately indicate that the zone is in a normal state, an impending alarm condition, an alarm state, detecting unit malfunction or system trouble. To indicate alarm condition, the control unit latches in an alarm output state. The control unit has time delay circuitry to prevent latching into the alarm output state until an alarm condition signal of predetermined duration has been received.

Alarm condition detecting apparatus and method

An alarm condition detection apparatus and method is embodied in the form of a combustion products detector for detecting fire. The detector generates a difference voltage signal proportional to the degree of combustion products in the atmosphere being monitored. The difference signal is employed to generate an alarm signal to indicate when the condition reaches an alarm state. The detector is adjustable to control the level of a reference voltage which in turn controls the difference signal voltage change needed to cause generation of an alarm signal. Thereby, detector sensitivity is set. The detector includes circuitry operable to generate in response to the difference signal a series of perceptible pulses having a pulse rate proportional to the magnitude of the difference signal. Thereby, with the condition normal, the pulse rate provides a perceptible indication of detector sensitivity. Further, the pulse rate change occurring as the condition approaches alarm state provides a perceptible indication of the approach. Additionally, the detector may be arranged so that a change in the difference signal to a predetermined trouble level causes a trouble signal to be generated to indicate low operating voltage, component failure, or improper sensitivity setting. Alarms may be included or associated with the detector for indicating occurrence of the alarm condition and/or to indicate trouble.

Growing community of inventors

Lakewood, CO, United States of America

Francis T Ogawa