Abstract: A process and apparatus for calibrating a particle counter is described. The process comprises the steps of forming a vector gas flow by an aerosol of particles of the same grain size, developing ions in the vector gas with both sign by a bipolar charger, certain particles being electrically charged to a stationary charge state in which the distribution of the number of charges fixed to each particle follows a Gaussian law (Gunn or Boltzmann), passing the charge aerosol into a mobility selector to attract the charged particles to electrodes therein and classify them as a function of the numbers p of their elementary electrical charges e and allowing the electically neutral particles to escape, collecting the neutral particles and passing the neutral particles into the particle counter to be calibrated, the particles counter displaying a value N'.sub.o ; counting the values of N.sub.p and N.sub.

Abstract: A colony counting apparatus includes a reading unit with a visual sensor incorporated therein. The presence of a colony is detected at the end of that colony by moving the reading unit along lines selected at an appropriate pitch and by reading data on the individual points set along each line as logical high or low signals. The values obtained in the above-described counting operation are added and stored in an addition/storage device in a CPU, and the results of addition which are stored in the addition/storage device are output to a suitable display by an outputting device when the counting operation is completed.

Abstract: A method for labelling polygons of a geometric layout which includes the steps of scanning a geometric layout during a first scan line pass to detect objects which form a polygon, processing the scan line at each occurrence of an event to detect the objects which contact the scan line, assigning temporary numbers and root designators to the objects which contact the scan line in accordance with a sorting criterion, updating the temporary numbers assigned to the objects to keep the temporary number associated with the earliest root designator of each separately detected polygon, and renaming each object which forms a part of the same polygon with a common label. The step of updating includes the steps of numbering each object in a polygon with a temporary number assigned to a root object of the polygon, and storing, in a sorted order, the root objects which lose their status as root objects during the step of updating.

Abstract: An event counter has dual counting channels, each employing a ripple counter, and a timing generator supplying square wave switching signals of opposite phases to gates at the inputs of the two counters, the switching signals having a much greater periodicity than that of events to be counted, so that one, and only one, of the counters is counting at any one time. The timing generator also generates control signals to transfer a count from whichever counter is inactive to an associated latch and then reset the counter. When a counter is again enabled, the switching signal is also used to enable output from the latch of the previously stored count. This arrangement enables ripple counters to be used in an arrangement providing both continuous counting and continuous output availability.

Abstract: The processing time for identifying discrete objects in a visual field composed of pixels is reduced by establishing indirect links between points of occurrence in the array and object names in an object designation list.

Abstract: A test chamber is disclosed that permits standardized measurement of particles in the chamber environment. A device or structure that is suspected of the emitting particles and which is desired to be tested is located within the chamber. The chamber environment is then controlled by the introduction of filtered air thereby permitting both static measurements of particle emissions from the device or structure and flow through measurements of particle emissions from the device or structure.

Abstract: A system is disclosed for counting particles/cells within a counting box of precisely known volume that is completely inside a transparent section or sample. The box has a chosen height with defined upper and lower limits and appropriately selected width and depth dimensions. It resides completely within the sample and has no surface in common with an exterior surface of the sample. The system includes a compound light microscope that has a depth of focus which is small in relation to the thickness dimension of the counting box. The microscope includes adjustment means for moving the focal plane through a range which is greater than the height of the counting box. Display means are provided which show the portion of the sample that is within the depth of focus and user-operated means is provided to enable the user to mark the cells so displayed.

Abstract: A particle measurement apparatus for obtaining accurate information relating to airborne particles in a gas under vacuum from a process chamber including a sampling chamber which can be subjected to a very strong vacuum and used for obtaining a sample of the gas in the process chamber. The interior of the sampling chamber is first flushed with very clean purge gas, and subsequently opened to the process vacuum chamber which is to be sampled so that a sample of the atmosphere of gas from the process vacuum chamber is held in the sampling chamber. The sampling chamber is sealed from the process chamber and the sample is brought to atmospheric pressure by adding a particle-free purified gas. The sample is then flushed from the sampling chamber and passed through a particle counter. Calculations can then be made to determine the original particle concentration in the process vacuum chamber based on the measured particle concentration from the sample of the sampling chamber.

Abstract: A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

Abstract: A digital image analysis system is disclosed in which a digital input image formed by a raster scan method is so modified as to fill up a hole in a clump and a recess at the bottom of a clump viewed in the sub-scanning direction of the raster scan method, for the purpose of forming a control image, the state of a clump at two consecutive scanning lines of the control image (that is, the generation and termination of the clump at one of the scanning lines or the continuity of the clump at the scanning lines) is detected from the values of adjacent pixels on the two consecutive scanning lines, and a feature value of the clump is calculated on the basis of the detected state of the clump.

Abstract: An apparatus for automatic identification and couting of a large number of returned or collected used linens at once by recognizing the shapes of markers that are opaque to X-rays and attached thereto. By numerically processing the shadow images of the markers projected onto an X-ray detector, a many kinds of linens can be identified and counted according to classification instantaneously.

Abstract: A liquid scintillation counter system utilizes multiplexing to monitor scintillation events in a continuously flowing effluent, using relatively few sensors, such as photomultiplier tubes, each such photomultiplier tube, in a specific embodiment, receiving light generated by scintillation events at a plurality of predetermined monitoring points along the flow path of the effluent. Each monitoring point, is coupled by means of light guides to at least two of the photomultiplier tubes. Some background noise is eliminated by use of discriminators which establish a predetermined threshold level for the magnitude of the outputs of the photomultiplier tube, above which the pulses are countable. Coincident circuitry is used to determine the presence of a scintillation event, and thereby issue a coincidence pulse which is counted. In accordance with the invention, n photomultiplier tubes can be used to monitor (n/2)(n-1) monitoring points along the flow path.

Abstract: A method of determining the rate of change of frequency of a plurality of randomly occurring events begins by counting the number of random events which occur within a plurality of predetermined sampling intervals to obtain a plurality of count values, each corresponding to one of the sampling intervals. These count values are stored in a memory table and the count values which correspond to the most recent set of N of the sampling intervals is summed to obtain a first accumulated count. A second accumulated count is obtained by summing the count values which correspond to a second set of N of the sampling intervals, preceding the most recent set. The rate of change of event frequency is then calculated by dividing the logarithm of (S.sub.1 /S.sub.2) by the number N. The value of the number N is dynamically adjusted for subsequent calculations based on the incoming frequency of random events.

Abstract: A method of counting a plurality of pulses representative of randomly occurring events includes the steps of counting the number of pulses, having an amplitude exceeding a first threshold amplitude, which occur during a predetermined sampling period to obtain a first count and counting the number of pulses, having an amplitude exceeding a second threshold amplitude, which occur during the sampling period to obtain a second count. The second count is compared to a predetermined number and the counts for that sampling period are rejected if the second count is too large. If the second count is not too large, the true count is calculated by subtracting the second count from the first count. This counting procedure is repeated for a preselected number of successive sampling periods. After the final sampling period, all of the true counts are added to obtain an accumulated count and the accumulated count is multiplied by a scaling factor to obtain an output count.

Abstract: A condensation nucleus counter (1) for measuring particulate concentration within a gaseous environment, including an inlet orifice (3) leading to a flow path (5) within saturator (4). The resultant vapor (10) enters a condenser section (11) wherein the particulate matter suspended within serves as the nucleus for condensation. The enlarged droplets (23) thus formed enter a conventional optical particle counter section (15).

Abstract: A method and an apparatus for counting uniform objects passing a row of sensors over a conveyor for the objects, in which counting of each object by activating a sensor is ensured by proper spacing of the sensors, prevents double counting of any object by scanning the control circuit respectively for the sensors. An activated sensor then inhibits the control circuit for the sensor or sensors adjacent that activated, which might be activated by the same object.

Abstract: A liquid scintillation counter system utilizes multiplexing to achieve monitoring of a plurality of scintillation samples using relatively few sensors, such as photomultiplier tubes, each such photomultiplier tube, in a specific embodiment, receiving light generated by scintillation events in a plurality of the scintillation samples. Each scintillation sample, which may be contained in a vial, is coupled by means of light guides to at least two of the photomultipler tube. Some background noise is eliminated by use of discriminators which establish a predetermined threshold level for the magnitude of the outputs of the photomultiplier tube, above which the pulses are countable. Coincident circuitry is used to determine the presence of a scintillation event, and thereby issue a coincidence pulse which is counted. In accordance with the invention, n photomultiplier tubes can be used to monitor (n/2)(n-1) samples.

Abstract: A pattern recognition system is disclosed with working area detection which automatically positions a field in a proper position with respect to an optical scanning means to optimize the pattern recognition and to automatically enable examination of the field in a good working area. The system has particular application to the examination of blood smears on a slide by enabling the positioning of the slide to enable examination of the blood smear in a good working area without operator intervention.

Abstract: The present invention relates to a method for examining the content of a volume of biological sample containing particles to determine the diagnostic significance of that volume of biological sample. A number of aliquots of the sample are distributed and are examined under low power field magnification. The total number of aliquots examined under low power field magnification if a first fraction of the volume of biological sample. The percentage of particles detected in the first fraction is counted. The percentage of particles detected is compared to a first known percentage. In the event the comparison yields the result that the sample contains diagnostically insignificant number of particles, than the method is terminated. Otherwise the method is continued. A second fraction of volume of the biological sample, comprising a plurality of aliquots, is examined under high power field magnification. The percentage of particles detected under high power magnification is totalled.

Abstract: A method of counting red blood cells suspended in a blood sample is disclosed which can judge the presence or absence of clogging in the sample passage system of a blood cell counting apparatus. In this method, for example, the counting of red blood cells for a period of 200 msec is repeated 50 times, the means value X and standard deviation SD of 50 red blood cell counts each indicating the number of red blood cells per unit time (equal to 200 msec) are calculated, and when one of the red blood cell counts deviates from the mean value X by more than 3SD, such deviation is judged to presage clogging in the sample passage system. Further, each of the red blood cell counts can be displayed on the fluorescent screen of a CRT display.

Abstract: A Geiger-Mueller tube-based radiation measurement device includes circuitry for the correction of the dead time losses associated with the Geiger-Mueller tube. As the event count rate rises, the transfer function (e.g., the closed loop voltage gain) of an operational amplifier responding to an event count rate signal is modified to compensate for dead time losses experienced at high count rates. Preferably, an analog switch controlled by the event count rate signal automatically sets the voltage gain of the operational amplifier at a level corresponding to the desired amount of dead time compensation required to provide an accurate measurement of actual events. The dead time correction circuitry disclosed herein finds practical application in the use of well-known analog rate meter circuits of the charge pump type.

Abstract: Apparatus and method are provided for analyzing sub-micron-sized features of microscopic particles. Two central features of the invention are (1) constraining microscopic particles to flow with substantially constant orientation through a predetermined interference fringe pattern, and (2) estimating particle structure by analyzing its fringe profile. The invention allows nearly an order of magnitude higher resolution of chromosome structure than possible with currently available flow system techniques. The invention allows rapid and accurate flow karyotyping of chromosomes.

Abstract: A blood counter comprising a sheathed flow cell; a light source including what has the wavelengths causing absorption of light by hemoglobin in the blood; means for receiving transmitted light; means for receiving the scattered light; a decision assembly for judging, based on the output signals detected by means for receiving the transmitted light and scattered light, (i) the flowing cells therein to be a red blood cell if the degree of absorption is larger than the preselected level and (ii) the other to be a blood platelet if the intensity of the scattered light is larger than a certain level and if the degree of absorption is smaller than said preselected level; and a counter assembly for counting out the red blood cells and blood platelets.

Abstract: A self-arming, prescaling frequency counter system comprises an armable frequency counter, an envelope detector, a prescaling pulse-shaper, and a delaying means. The envelope detector detects occurrence of an oscillating signal to be frequency measured and transmits an arming signal to arm the frequency counter for the duration of the oscillating signal. The prescaling pulse-shaper is coupled to receive the oscillating signal burst and generate a pulsed test signal of frequency an integer fraction of the oscillating signal frequency. The delaying means couples the test signal to the armable frequency counter input, delaying receipt of the pulsed signal burst until after the counter is armed, and delaying termination of the pulsed signal until after counter is disarmed.

Abstract: Offset-error included data normally is output from a single ramp analog to digital converter in response to input information applied thereto during light or cuvette sample intervals. During dark sample intervals between the cuvette sample intervals, the input information is blocked from the converter and the converter is operated with the output counter counting down to a dark count representing the offset error of the counter. During the next cuvette sample interval the counter counts up from the dark count effectively subtracting out the offset error introduced by the converter.

Abstract: A method for determining the percentage T-cell content of lymphocyte, which comprises scanning a test specimen with a pickup device, discriminating a lymphocyte from other cells contained in said specimen from the output level and regional information of the image signals transmitted from said pickup device, searching the data marginal to those of the cell discriminated as lymphocyte, to detect pixels corresponding to the image signal output level different from that corresponding to the lymphocytes or background, and discriminating a T-cell from other lymphocytes from the number of detected pixels.

Abstract: An apparatus for counting numbers of microscopic corpuscles such as blood cells, comprising an optical system, a driving mechanism, a photoelectrical convertor means and a counter means. The optical means is adapted to illuminate a sample containing the corpuscles so as to irradiate magnified images onto a charge coupled device (CCD) as the convertor means having elements lined up in a row in an X-direction perpendicular to a Y-direction in which the sample is moved by the driving mechanism whereby X-directional scanning is automatically executed by the CCD without moving the sample while Y-directional scanning is conducted with a sample holder continuously moved by said mechanism comprising a drive motor and a cooperating spring. The CCD is adapted to detect the number of corpuscle images contained in each scanning line in the X-direction and thereby to produce electric signals fed to the counter means, which comprises electronic circuits for summing up these signals in respect of Y-direction.

Abstract: The specification discloses an electronic manually operated blood cell counter including continuous count capability in response to a single key depression for recording large number of similar cells during a differential count. More specifically, the counter includes microprocessor control for periodically incrementing a counter in response to sustained depression of a manually actuated counting switch. The control is adjustable to vary the speed at which the counter is periodically incremented to accommodate individual laboratory technicians.

Abstract: Apparatus for counting articles traveling in a random pattern along a predetermined path in a selected direction comprising an article counting stage which is positioned along the predetermined path, a source positioned relative to the article counting stage for producing in a scan pattern a plurality of pulsed, spaced parallel beams of radiation such that each article is adapted to independently intercept at least two beams of radiation and to produce therefrom at least two pulses of radiation, each of said beams being directed along a scan path into the article counting stage wherein selected beams of radiation are adapted to be intercepted by a selected portion of the article passing through the article counting stage, a radiation pulse receiver for receiving the at least two pulses of radiation intercepted by and the article and which produces therefrom output signals in a time spatial sequence representing the radiation level of the at least two received pulses of radiation exceeding a threshold level wi

Abstract: The present invention relates to a method for examining the content of a volume of biological sample containing particles to determine the diagnostic significance of that volume of biological sample. A number of aliquots of the sample are distributed and are examined under low power field magnification. The total number of aliquots examined under low power field magnification is a first fraction of the volume of biological sample. The number of particles detected in the first fraction is counted. The number of particles detected is compared to a first known total. In the event the comparison yields the result that the sample contains diagnostically insignificant number of particles, then the method is terminated. Otherwise the method is continued. A second fraction of volume of the biological sample, comprising a plurality of aliquots, is examined under high power field magnification. The number of particles detected under high power magnification is totalled. This is then compared to a second known total.

Abstract: Analysis of images or specimens which exhibit visually distinguishable component areas of a plurality of different types, to determine the relative abundances, average sizes or other characteristics of such areas, is facilitated by a semi-automatic scanning system which includes an on-line data processor. The apparatus combines the superior area recognition ability of the human operator with the speed and ease of operation of fully automatic systems. A keyboard control unit has a plurality of manually operable keys any one of which may be actuated to drive the stage motor of a microscope through which the operator views the specimen and each of which generates a distinctive signal identifying a different specific type of area in the specimen. The data processor receives stage translation signals and the area classification signals and computes the desired data which may be visually displayed following a period of scanning.

Abstract: A sample having a mixture of unknown stained cells and known cells having different staining characteristics is analyzed rapidly, a cell at a time, in a flow cytometry system having a sample stream dimension in the range of expected cell dimensions. The cells are illuminated with focused illumination and fluorescence is detected and related to the number of cells. The resulting histogram of the mixture sample may be analyzed by counting the cells in a controlled population below a relatively low threshold value of fluorescence intensity to form a first fraction and relating this fraction to the fraction of cells in the sample mixture below the threshold value of fluorescence intensity to determine the number of unknown cells in the sample mixture.

Abstract: An apparatus for detecting or otherwise monitoring, e.g. counting, each passage of a succession of conductive objects (especially graphite-sheathed ball-shaped nuclear fuel or breeder elements for the core of a nuclear reactor) through a pipe or tube having a conductive wall juxtaposed with the tip of an electrode. A high-voltage direct-current (d-c) generator is connected across the wall and the electrode in series with a high-ohmic resistor. A voltage divider is also connected across this gap and has a low-voltage portion across which a voltage drop of the order of up to 100 volts is detected as the signal which is applied to the monitoring circuit. Thus the electronic detector and counter circuit are connected across the low-voltage resistor of the voltage divider and this resistor is connected to the side of the electrode-pipe system opposite that to which the high-ohmic resistor is connected.

Abstract: For the detection of accumulations of particles, for instance metaphase plates, in an image converted by a raster process into electrical signals, there is first effected an electronic dilation in several directions, the parameters of the dilation being so selected that images of the chromosomes of the metaphase plates agglomerate to form unitary structures. Thereupon, an electronic erosion of images is effected in several directions, the parameters of the erosion being so selected that images of cells and impurities disappear but the agglomerated metaphase-plate images are retained. A circuit is described which consists essentially of length discriminators, decision-logic devices, delay-storage devices with provision for establishing input digital preset values, in which circuit the entire evaluation process takes place with the speed of the scanning process.

Abstract: A particle analyzer for a sample suspension of particles originating in a container in which: a flow director is mounted between the container and a first chamber, a particle sensing aperture is mounted between the first chamber and a second chamber, a liquid sheath is introduced into the first chamber for hydrodynamically focusing the particles through the sensing aperture, an electrical current passes through the sensing aperture for generating impedance signals, the pressure drop is regulated across the flow director to assure a constant flow of the suspension through the flow director and the aperture, and the flow director is formed into an optical element for viewing the sensing aperture.

Abstract: An apparatus for analyzing unknown microstructures in samples with known microstructure configurations, both biological and non-biological, by optically correlating the unknown with the known. The apparatus employs a microscope to produce images of unknown microstructures in a sample, a laser for illuminating the sample, a Vander Lugt correlator, including a preselected matched filter for particular known microstructures of interest, for optically correlating the image of the unknown microstructures with preexisting images of known microstructures, a CCD array to detect correlation indicia, and a microcomputer to control positioning of the sample for imaging, orienting the matched filter, and scanning by the CCD array of the indicia resulting from the correlation for reading and counting the same.