Abstract: A method for recognizing infrasound events includes detecting infrasonic source using one or more microphone arrays each having three equally-spaced infrasound microphones. The method includes identifying, via a data acquisition system (DAS), a level of coherence of the detected infrasonic acoustic signals from each possible pair of microphones and recognizing the infrasound source using the coherence and a time history of the detected signals. The method may include estimating source properties via the DAS, including a magnitude, azimuth angle, and elevation angle, and executing a control action in response to the estimated properties. A system includes the array and the DAS. The array may be positioned above or below ground, and may be connected to one or more aircraft in some embodiments.

Abstract: A method for recognizing infrasound events includes detecting infrasonic source using one or more microphone arrays each having three equally-spaced infrasound microphones. The method includes identifying, via a data acquisition system (DAS), a level of coherence of the detected infrasonic acoustic signals from each possible pair of microphones and recognizing the infrasound source using the coherence and a time history of the detected signals. The method may include estimating source properties via the DAS, including a magnitude, azimuth angle, and elevation angle, and executing a control action in response to the estimated properties. A system includes the array and the DAS. The array may be positioned above or below ground, and may be connected to one or more aircraft in some embodiments.

Abstract: The instrument includes a cartridge carousel assembly which receives analytical cartridges. The cartridges are self-contained units which incorporate a sample metering/separation system which is operated by centrifugal force. The cartridge carousel is composed of a cartridge rotor plate which includes a center and a plurality of cartridge ports which are located in spaced relation radially outward from the center of the plate. The cartridge ports include a cartridge dock which is shaped to receive the cartridges and a balance weight dock which is located radially inward from the cartridge dock. The cartridge dock is shaped to receive a balance weight. A locking mechanism is provided which holds the cartridge in the cartridge dock during rotation of the cartridge rotor plate. A balancing mechanism is provided which includes a balance weight which is movable to the balance weight dock when a cartridge is inserted into the cartridge dock.

Abstract: An analytical instrument for analyzing fluids. The instrument includes a cartridge carousel assembly which receives analytical cartridges. The analytical cartridges include a centrifugal force-operated sample metering/separation system, a pressure-operated sample transport system, and a test element which provides a detectable analytical property of a fluid sample. The cartridge carousel assembly includes a cartridge rotor plate which has a plurality of cartridge ports which receive the cartridges. A rotary drive mechanism rotates the cartridge rotor plate to provide rotation of the plate which activates the centrifugal force-operated sample metering/separation system of the cartridge. The instrument includes a sample transport actuator which activates the pressure-operated sample transport system of the cartridge. In addition, the instrument includes a detector which measures the detectable analytical property of the fluid sample after the sample metering and transport systems have been activated.

Abstract: The present invention relates to a dry control cartridge for providing a plurality of voltage and impedance inputs to an electrochemical analysis instrument for verification of its proper functioning. The dry control cartridge includes a battery and a plurality of electrical circuits for providing a plurality of predetermined voltage and impedance outputs. The dry control cartridge is adapted for insertion into an electrochemical analysis device using probe electrodes to measure microvolt-range potential differences, appropriate to the input ranges inherent in the instrument. By comparing the measured voltage and impedance inputs to the predetermined outputs of the cartridge, verification of the instrument's proper functioning and accuracy may be made.

Abstract: The present invention relates to an electrical switch including an arcuate cavity partially filled with an electrically conducting fluid. The fluid is adapted to move into electrical contact with a pair of electrodes positioned within the cavity in response to a rotational force acting thereupon. The switch is electrically connectable to a rotatable platter. When connected to the platter, the switch is positioned radially outward from the platter's axis of rotation, such that the forces generated by the platter upon rotation urge the electrically conducting fluid into contact with the electrodes and thus complete a circuit.

Abstract: A method and apparatus for detecting proper strip insertion into an optical reflectance meter. An electrical or electromagnetic device within the optical reflectance meter launches a signal when a test strip is inserted therein. The test strip which is designed for use in such a meter contains a material which enhances the coupling of the signal to a receiver within the meter. The meter then receives the signal and will not produce reading until a signal of a proper level is received. Use of the meter and special test strip of the present invention comprises a more cost effective system for detection of proper test strip insertion which is not dependent upon clean optics as in prior art devices. The present invention therefore ensures reliable protection of strip insertion with the ability to distinguish not only whether the test strip has been inserted incorrectly by the user, but also whether the test strip was designed for use with the meter into which it has been inserted.

Abstract: An instrument for determining a characteristic of a biological fluid or a control includes a heater and a heater control. The heater comprises a heater element, supported in heat conducting relationship to the biological fluid or control when the instrument is in use. A temperature sensitive element monitors the temperature of the heater element support. The heater control comprises a first temperature setpoint control for controlling the heater to maintain the temperature of the biological fluid or control at about a first temperature and a second temperature setpoint control for overriding the first temperature setpoint control to heat the biological fluid or control toward a second temperature.

Abstract: A method and apparatus for detecting proper strip insertion into an optical reflectance meter. An electrical or electromagnetic device within the optical reflectance meter launches a signal when a test strip is inserted therein. The test strip which is designed for use in such a meter contains a material which enhances the coupling of the signal to a receiver within the meter. The meter then receives the signal and will not produce a reading until a signal of a proper level is received. Use of the meter and special test strip of the present invention comprises a more cost effective system for detection of proper test strip insertion which is not dependent upon clean optics as in prior art devices. The present invention therefore ensures reliable protection of strip insertion with the ability to distinguish not only whether the test strip has been inserted incorrectly by the user, but also whether the test strip was designed for use with the meter into which it has been inserted.

Abstract: An apparatus for patient safety protection in a medical device with a heater. A heater configuration for a medical device, such as a haemodialysis machine, is disclosed in which a shock hazard to the patient from the heater elements due to a single fault condition is eliminated. The invention comprises an insulation layer formed between the heater elements and a grounded metal plate. A single fault condition is prevented from creating a shock hazard to the patient (which is considered to be the dialyser fluid) because any break down of the insulation layer which brings the heater elements 14 into contact with the grounded metal plate will result in a large current flowing to ground (rather than to the patient), thereby causing a fuse in the circuit to trip. Tripping of the fuse removes power from the heating elements, thereby preventing any further possibility of contact between the live electrical heater element and the dialyser fluid (i.e. the patient).

Abstract: A method and apparatus for verifying the operating accuracy of an instrument (10) for detecting the concentration of a medically significant component of a body fluid. The instrument (10) operates by determining the remission of a reacted chemistry contained on a substrate (106) after the chemistry has reacted with the medically significant component of the body fluid. The instrument (10) includes a radiation source (182), a radiation detector (300) and a pathway (164) from the radiation source (182) to the chemistry (106) and from the chemistry (106) to the radiation detector (300) when the substrate (106) is properly inserted into the instrument (10). The remission of the chemistry (106) determines the radiation detected by the radiation detector (300).

Abstract: A method and apparatus (10) for determining the remission of a chemistry (106) which reacts with a medically significant component of a body fluid. The remission of the chemistry (106) changes as it reacts. The method and apparatus (10) include irradiating the chemistry (106) with a radiation source (182), detecting remissions of radiation from the chemistry (106) with a radiation detector (300), providing a radiation pathway (164) between the source (182) and the chemistry (106), providing a remission pathway (164) between the chemistry (106) and the detector (300), and detecting the rate of change of remission of the chemistry (106) with respect to time.

Abstract: A reflectance meter having improved noise immunity for measuring photometric quantities is disclosed. The device includes noise reduction techniques for eliminating the effects of ambient and artificial light upon the measurement signal. A gated modulator provides frequency shifting of desired information to a carrier frequency so that undesired signals may be filtered out. A gated demodulator provides a means to demodulate the information contained in frequency spectrum near the gate or chopping frequency.

Abstract: Computationally complex primitive operations of an algorithm are executed concurrently in a plurality of functional units under the control of an assignment manager. The algorithm is preferably defined as a computationally marked graph contianing data status edges (paths) corresponding to each of the data flow edges. The assignment manager assigns primitive operations to the functional units and monitors completion of the primitive operations to determine data availability using the computational marked graph of the algorithm. All data accessing of the primitive operations is performed by the functional units independently of the assignment manager.

Abstract: In a television receiver, an output signal from a binary rate multiplier (BRM) is used to control the amplitude of a video signal and thereby the contrast of a displayed image. Contrast control in response to ambient lighting conditions is accomplished by means of a light dependent resistor which modifies the output pull-up voltage of the BRM.

Abstract: A laser velocimeter signal processor for measuring the signal frequency within a signal burst. The input signal is converted to digital by an ADC 16 and then shifted into shift registers 30 and 31. An automatic gain circuit 15 controls the gain of the input signal. A signal integration circuit 32 determines when a signal burst has been captured by the shift registers and and then transfers the contents of the registers to data latches 33 and 34. The data in data latches 33 and 34 is processed by digital bandpass filters 57-63, square law detectors 64-70, burst counters 71-77 and signal processor 78 to determine the frequency of the signal within the captured signal burst.

Abstract: In a television receiver, a contrast control signal for controlling the amplitude of a video signal is a function of a manual contrast control component provided by a viewer, and an automatic contrast control component provided by a light sensitive circuit responsive to ambient light conditions. A "soft" limiter limits the value of the extinguished due to excessive video signal attenuation in response to the control signal. The manual control component is provided by means including a duty cycle control device such as a binary rate multiplier or pulse width modulator.

Abstract: Arc-over in the cathode ray tube of a digital television receiver produces a large current pulse which, when it discharges via the chassis ground, disrupts the reference ground potentials of other circuitry coupled to the chassis ground. The affected circuitry includes digital data storage elements which may experience random state changes caused by the fluctuating ground potential. The CRT arc-over condition is detected by circuitry which applies a pulse to the reset terminal of the microprocessor, causing it to restore the potentially corrupted data in the data storage elements using preset data stored in a less volatile programmable read only memory.

Abstract: A beam current limiting (BCL) control apparatus for a digital television system includes a control unit for controlling the reference voltage for the analog-to-digital converter (ADC), which converts the analog composite video signal, including both luminance and chrominance components, to corresponding digital samples, so as to reduce excessive beam currents. A switching circuit prevents the reference voltage from being changed in response to the beam current during horizontal blanking intervals so as to inhibit interference with digital synchronization component detection and automatic chrominance control. A clamping circuit is coupled to the ADC to inhibit the conversion of portions of the composite video signal extending from the black level (0 IRE units) to the sync tips from being affected by the BCL operation. This inhibits the BCL operation from adversely affecting the reproduction of details in dark portions of an image.