Abstract: System and method for organizing information relating to polymer probe array chips including oligonucleotide array chips. A database model is provided which organizes information relating to sample preparation, chip layout, application of samples to chips, scanning of chips, expression analysis of chip results, etc. The model is readily translatable into database languages such as SQL. The database model scales to permit mass processing of probe array chips.

Abstract: A video microscopic visualization system and image processing and data extraction and processing method for in situ detailed quantification of the deposition of sub-micrometer particles onto an arbitrary surface and determination of their concentration across the bulk suspension. The extracted data includes (a) surface concentration and flux of deposited, attached and detached colloids, (b) surface concentration and flux of arriving and departing colloids, (c) distribution of colloids in the bulk suspension in the direction perpendicular to the deposition surface, and (d) spatial and temporal distributions of deposited colloids.

Abstract: A method for providing a preliminary diagnosis of skin cancer, more specifically a screening risk assessment of pigmented lesions receiving digital photographs of skin abnormalities from a plurality of consumers at a server, receiving medical information related to each of the plurality of consumers at the server, assigning an identification to at least one of the consumers and the digital photographs, reviewing the digital photographs and categorizing the digital photographs into at least three categories so as to define category information, the at least three categories including a first category of a first risk, a second category of risk lower than the first category and a third category of insufficient photograph quality, and providing the category information as a function of the identification.

Abstract: Particles in a fluid are counted as the fluid flows through an examination area of a particle analyzer. Parameters based upon the particle count are calculated. It is determined whether the at least one calculated parameter is within an allowable range for the parameter. Based on this determination, an indication is provided of uniformity of the fluid sample in the examination area.

Abstract: A self-contained system uses light reflectivity to examine intensity of a dyed spot on a device membrane surrounded by background area to discern information about the specimen that produced the spot. In a preferred embodiment, a master clock alternatively drives one LED focussed upon the spot center, and then drives two LEDS focused on the background area. Light reflected from the spot and background is detected by preferably two photodetectors (“PDs”) spaced-apart a multiple of 90° azimuthal, a configuration discovered to minimize the effects of uneven membrane topography upon light intensity measurements. The PD outputs are average-summed together and are input to a phase lock-in amplifier system that enhances detected signal/noise by measuring signal voltage without producing noise. The lock-in system simultaneously positively and negatively amplifies the average-summed PD outputs, which amplified signal is then switched in synchronism with the LED drive signals.

Abstract: A counter unit counts discrete articles that are within a predetermined size range into lots having a predetermined number of articles. The counter unit includes (1) a first conveyor that delivers a flow of articles separated at discrete intervals; and (2) at least one bin positioned to receive articles from the conveyor. The at least one bin has at least first and second outlet gates for emptying articles into separate respective first and second locations. A detector unit detects and maintains a count of articles that are received in the at least one bin and fall within said predetermined size range. The detector unit generates an out-of-size signal when an article received in the at least one bin falls outside said predetermined size range. A control unit causes the first outlet gate to open when the count of articles is equal to said predetermined number and causes the second outlet gate to open in response to receipt of an out-of-size signal.

Abstract: A spectroscopy instrument that uses spectra produced from random binary sequence modulated data. Statistical estimation techniques are used to achieve resolution enhancement, while properly accounting for the Poisson noise distribution and other artifacts introduced by a modulator or “chopper” or other system components. Indeed, a resolution similar to that of modem spectrometers can be achieved with a dramatic performance advantage over conventional, serial detection analyzers. Both static and dynamic behaviors are theoretically or measured experimentally accounted for in the model as determined. In one embodiment, the finite penetration of the field beyond the plane of the chopper leads to non-ideal chopper response, which is characterized in terms of an “energy corruption” effect and a lead or lag in the time at which the beam responds to the chopper potential.

Abstract: A system for collecting images at multiple wavelengths for image analysis of biological specimens. The process separates contrasts for images of a biological specimen prepared with a chromogen. Light wavelengths matched with each chromogen optimize separation for each image. Computing attenuation coefficients and extinction coefficients for each chromogen provides for determination of the concentration of each chromogen. A chromogen separator allows for subtracting predetermined chromogens to generate new images and aid in identification of cell morphology. The system can perform the image analysis of the new images using image processing techniques such as segmentation, feature calculation and object classification. At each stage of image processing, data from each of the new images may influence the processing of the other images.

Abstract: Particles in a fluid are counted as the fluid flows through an examination area of a particle analyzer. Parameters based upon the particle count are calculated. It is determined whether the at least one calculated parameter is within an allowable range for the parameter. Based on this determination, an indication is provided of uniformity of the fluid sample in the examination area.

Abstract: A method for counting substantially uniformly sized objects includes the steps of obtaining an image of substantially uniformly sized objects; analyzing the image to determine total object area in the image and average object size of the objects; and determining a count of the objects from the total object area and the average object size.

Abstract: A filter on which living bacteria are captured is processed with an extraction reagent and a luminescence reagent. The state of luminescence of the filter is photographed by a television camera 1 including an optical system and an image acquisition means such as a charge coupled device. The number of luminous points is counted from data for the image of the luminous points of fluorescence originating in microbes through an image processing device 3 and a data-analyzing device 4. The result of the count is shown on a display 5. In the analysis of the data, when there exists a first luminous point adjacent to a second luminous point, the first and second luminous points are grouped and counted as one luminous point. A process for eliminating the effect of the diffusion of light from a luminous point of great luminance is performed.

Abstract: A method and system for detecting a presence of more than one item at a point along a conveyance path, comprising steps of (A) generating a light beam and directing the beam through the path such that a presence of the item will cause the beam to be attenuated; (B) detecting the beam after it is attenuated by the presence of the item; and (C) determining from the amount of attenuation how many items are simultaneously present. In the preferred embodiment the item is an item of currency, and the step of generating a light beam includes a step of operating an optical source, such as an LED or a laser, to generate a beam having a wavelength in the range of about 400 nm to about 1 micrometer or longer.

Abstract: A method and apparatus are disclosed for use in an area digital imaging system for assays to extract targets on a specimen containing an array of targets that may not be arranged in perfect regularity. A matrix is defined of nominal target locations including a probe template of predefined, two-dimensional size and shape at each of a plurality of fixed, predefined grid points on the specimen, and a determination is made of the most probable location of the probe template corresponding to a specific target by sensing both pixel intensity and the spatial distribution of pixel intensities in an image of the specimen at a plurality of locations in the vicinity of a nominal target location.

Abstract: This invention relates to a method and apparatus for improving the precision of at least one of neutron coincidence counting and neutron multiplicity counting. The method includes the steps of: (1) sampling the real and accidental coincident pulses at the incoming pulse rate; and (b) sampling the accidental coincidences at a clock rate, wherein the clock rate is much faster than the pulse rate. The clock rate is faster than the pulse rate by a factor of 5 to 10 (in the preferred embodiment, approximately 4 MHz).

Abstract: The invention relates to dust/particle monitors, and particularly but not necessarily exclusively to a method of monitoring fine particles harmful to humans in working environments. Equipment and methods of detection are known but which have several disadvantages such as no instantaneous warnings of excessive exposure, bulky sampling equipment, prone to errors due to poor handling of particles, and fluctuating flow rates of air borne particles. The object of the invention is to provide a method and equipment that avoids those disadvantages mentioned above, an objective met by a method of monitoring dust/particulate material concentrations in air, comprising drawing air through a monitor at a predetermined rate to enable particles to pass through a measurement section one at a time, whereby they may be individually detected and counted.

Abstract: System and method for organizing information relating to polymer probe array chips including oligonucleotide array chips. A database model is provided which organizes information relating to sample preparation, chip layout, application of samples to chips, scanning of chips, expression analysis of chip results, etc. The model is readily translatable into database languages such as SQL. The database model scales to permit mass processing of probe array chips.

Abstract: Substrate beads for combinatorial synthesis are selected individually from a mixture by suspending the mixture in an electrically conductive liquid, in a bead selection vessel, causing the liquid to flow at a controlled rate through an aperture in the side wall of a pipette extending through the vessel, and detecting the passage of a bead through the aperture by monitoring an electrical resistance across the aperture. In an alternative embodiment, beads are passed through a tube into a collection passage in which a continuous laminar flow takes place. Detection takes place at the tip of the tube, and, in response to the detection of a bead, the flow through the collection passage is diverted to cause the bead to be deposited. In both cases, the selected bead is deposited into a well of a plate having rows and columns of wells in a rectangular array, while a vacuum is drawn through a filter in the bottom of the well.

Abstract: Particles in a fluid are counted as the fluid flows through an examination area of a particle analyzer. Parameters based upon the particle count are calculated. It is determined whether the at least one calculated parameter is within an allowable range for the parameter. Based on this determination, an indication is provided of uniformity of the fluid sample in the examination area.

Abstract: A system for counting a series of progressively moving articles using one or more sidewardly positioned and angularly oriented ultrasonic transducers which bathe the articles with ultrasonic waves and receive echoes reflected backwardly therefrom. Distances to the articles are determined by measuring round-trip sonic travel times. Count adjustment signals are generated when articles pass through the fields of view of the transducers and are replaced by other articles at measurably different distances.

Abstract: The invention includes a particle sensor with a particle counter. A regenerative blower pulls ambient air into a flow within the particle counter, and a laser illuminates the flow to generate laser radiation indicative of particles within the flow. A detector detects the laser radiation; and particle sensing electronics counts particles within the flow at a preselected volumetric flow rate, e.g., 1 CFM. Preferably, the particle counter includes a plurality of pressure sensors; and a blower speed voltage controller adjusts the speed of the blower according to signals from the pressure sensors to achieve the preselected volumetric flow rate. The regenerative blower permits use of a high efficiency exhaust filter to filter air exhausted from the blower. An airflow path between the particle counter and the regenerative blower preferably has at least one bend between the particle counter and the blower to increase compactness of the system.

Abstract: A method and apparatus for determining the number of particles or cells in a liquid sample. The method comprises a) determining the number of particles or cells in a first volume of the liquid sample, b) determining the statistical uncertainty of the determined number of particles in said first volume, c) if the determined uncertainty is larger than a pre-determined value, determining the number of particles or cells in a further volume of the liquid sample, d) adding the numbers of cells or particles determined in steps a) and c), e) determining the statistical uncertainty of the number of particles determined in step d), f) repeating steps d) and e) with a further volumes of the liquid sample, until the uncertainty determined in step e) is lower than said pre-determined value or until a pre-determined total volume of the liquid sample in which the number of cells or particles has been determined exceeds a pre-determined volume being larger than said first volume.

Abstract: A specimen preview and inspection system is disclosed. The system beneficially includes a preview stage, which provides a set of biasing-information for preview by a technician before the technician formally screens the specimen. The preview stage enables the technician to conveniently review information pertinent to the specimen at issue. The preview stage may thereby bias, or channel, the technician's attention during screening toward diagnostically significant aspects of the specimen. The invention is particularly useful in the context of Pap smear screening, although the invention may extend to inspection of other types of specimens or samples as well.

Abstract: The track counter circuit of the present invention is for counting tracks. The circuit indicates a circuit for generating a first signal indicating a first track has been crossed and a second signal indicating a second track has been crossed after the first track, a circuit for determining when a third track should have been crossed and generating a missing signal to indicate the third track, a circuit for determining a valid track period based on the first signal and the second signal, and a circuit for maintaining the valid track period when said missing signal is generated. The track counter circuit for counting tracks may use the first signal as a MIRR signal. Additionally, the second signal may be a MIRR signal.

Abstract: A process and device for continuously measuring the quantity of particles spended in a liquid, which exist in at least two different physical states, such as detached or attached within the paper pulp. A separation assembly separates the particles into divisions depending on their size, and the separation assembly is continuously fed with liquid via an input pipe. A measuring and processing assembly has two channels or ducts coming from the separation assembly and are provided with translucent windows. A measurement and capture unit illuminates the windows, and at least two cameras located opposite each of the respective windows are synchronized with the illumination unit to capture, at regular intervals, an image of the windows. A system for digitizing the captured images and processing them to determine the quantity of particles for each physical states is forwarded to an output unit in a digital or analog form.

Abstract: A method and apparatus for determining the number of particles or cells in a liquid sample. The method comprises a) determining the number of particles or cells in a first volume of the liquid sample, b) determining the statistical uncertainty of the determined number of particles in said first volume, c) if the determined uncertainty is larger than a pre-determined value, determining the number of particles or cells in a further volume of the liquid sample, d) adding the numbers of cells or particles determined in steps a) and c), e) determining the statistical uncertainty of the number of particles determined in step d), f) repeating steps d) and e) with a further volumes of the liquid sample, until the uncertainty determined in step e) is lower than said pre-determined value or until a pre-determined total volume of the liquid sample in which the number of cells or particles has been determined exceeds a pre-determined volume being larger than said first volume.

Abstract: One embodiment of the invention is an apparatus for counting parts. The apparatus includes a tray having at least one location for containing a part; a plate having at least one hole positioned above the at least one location; a pneumatic device coupled to the at least one hole; and a sensing element for determining the presence of a tray part in the at least one location when the pneumatic device is active.

Abstract: One embodiment of the invention is an automated method for counting parts. The method includes positioning a tray having an array of part locations; aligning a complementary array of holes in a plate with the part locations; activating air flow through the holes such that the parts will move to alter the air flow; and determining from the altered air flow the number of parts.

Abstract: The present invention comprises an apparatus for counting a plurality of objects, wherein the objects are aligned such that the objects form a linear array oriented in an X-Y plane, comprising a sensor for detecting a discriminating characteristic of an object, and for locating the orientation of the linear array formed by the objects, a sensor moving means for moving the sensor in an X-Y plane, and a processor for determining the orientation of the linear array formed by the objects, wherein the sensor scans the orientation of the linear array formed by the objects when counting the objects.

Abstract: The present invention comprises a method for counting a plurality of objects, wherein the objects have a discriminating aspect and are aligned such that the objects form a linear array, comprising determining the orientation of the linear array, scanning the linear array and detecting individual objects within the linear array as the linear array is scanned.

Abstract: A device for measuring the number of persons without any affection by overlap of persons in any direction, sunlight variations, shadows, or the like includes a plurality of cameras arranged in parallel with respect to their optical axes for taking an image in a measuring area to measure the number of persons, an extraction unit for extracting a person based on image data taken by said plurality of cameras, a trace unit for tracing the person extracted by the extraction unit, and a decision unit for deciding whether or not a decision line is passed based on the data produced by the trace unit and to increase the number of passing persons when the line is passed. In the extraction unit, the persons overlapping in a depth direction can be precisely separated by employing space coordinate data by correspondence in a plurality of images taken by the plurality of cameras at the same timing.

Abstract: The present invention relates to a procedure for counting faintly luminescent particles, and relates specifically to a procedure for counting cells and microorganisms marked with a colored or fluorescent stain or marker that selectively marks the microorganisms and cells to be counted, characterized by the fact that the said procedure is implemented with the aid of a photon-accumulator camera and includes the acquisition of at least one low-resolution image I, the threshold processing of the said low-resolution image in order to obtain at least one digital image Ib, at least one dimensional filtration stage, and the counting of the number N of objects belonging to a given class of sizes in the digital image Ib.

Abstract: To evaluate cleanliness of wafer accommodating members used for storing or transporting of silicon, gallium arsenide or like semiconductor wafers, pure water is poured into a vessel-like wafer accommodating member, such as a wafer case body, a top cover, etc., capable of containing liquid therein, and then low frequency vibrations or supersonic wave is applied to the member. Alternatively, inner wafer accommodating members accommodated in the wafer case body, such as a wafer basket, a wafer retainer, etc., are accommodated in a vessel containing poured pure water, and the low frequency vibrations or supersonic wave is applied to the members. Then, the quantity of particles in the water is counted. Particles that have been attached to the wafer case or to inner wafer accommodating members accommodated therein, such as a wafer basket, a wafer retainer, etc., are made readily separable into the water, thus permitting quantitative detection of generation of particles from the inner wafer accommodating members.

Abstract: An object counter includes a feeding funnel having a frustroconical section, the narrow end of which is coupled to a substantially vertical feeding channel having a substantially rectangular cross section. A pair of linear optical sensor arrays are arranged along adjacent orthogonal sides of the feeding channel and a corresponding pair of collimated light sources are arranged along the opposite adjacent sides of the feeding channel such that each sensor in each array receives light the corresponding light source. Objects which are placed in the feeding funnel fall into the feeding channel and cast shadows on sensors in the arrays as they pass through the feeding channel. Outputs from each of the two linear optical arrays are processed separately, preferably according to various conservative criteria, and two object counts are thereby obtained. The higher of the two conservative counts is accepted as the accurate count and is displayed on a numeric display.

Abstract: Apparatus and process capable of rapid detection and counting of rarely occuring mammalian cells in blood and other tissues which have been labeled with a fluorescent dye.The process includes: scanning a solid support on which a specimen potentially containing fluorescent cells has been deposited, with an incident beam from a laser, forming a laser spot on the solid support, the laser spot being substantially greater than the cells to be detected, the laser spot size being between 15 and 30 .mu.m; and simultaneously: detecting the resultant fluorescent light at least at one wavelength; establishing a set of correlated-features by a line-to-line correlation of individual features; comparing the correlated-features on each pair of adjacent lines in time synchrony, at least at two different wavelengths .lambda..sub.1 and .lambda..sub.

Abstract: A system which precisely arrays small objects into a plurality of containers which comprises a vessel containing the objects in a fluid suspension; a tube, the proximal end of which is positioned substantially at the bottom of the vessel and the distal end of which is connected to a member which directs gravitationally-formed fluid drops from the distal end downward into a container positioned below said distal end; a small-objects detector, for detecting the objects in the fluid in the tube, disposed near the distal end; a drop detector connected to the member below the distal end; a device for controlling flow of the suspension through the tube by pressurizing the vessel; or device for discriminating between those signals from the small-objects detector caused by the small objects and those signals caused by other events, i.e.

Abstract: A scheme for directional counting of moving objects capable of counting moving objects stably while determining passing directions of the moving objects accurately. In this scheme, a counting line is set in an image field of the sequential images, and a dynamic image formed by pixels forming the counting line is obtained for each frame and while a succesively updated background image is obtained. Then, a subtraction and binarization processing are applied to the dynamic image and the background image to extract a moving object region, and a moving object image is formed by sequentially labeling the moving object region in time order.

Abstract: A method of providing particle deposition on a semiconductor wafer or other surface first provides a flow of clean gas into a deposition chamber that purges the chamber prior to introduction of the wafer, and after introduction, continues the flow of clean gas. An aerosol is mixed into the clean gas flow for a desired length of time, so that as the combined flow passes through the deposition chamber particles are deposited on the wafer supported in the chamber. After the deposition has continued for either a desired particle count or a length of time, the flow of aerosol is discontinued, and a clean gas flow sheath is provided over the wafer as it is removed from the chamber. The apparatus carries out this method by providing a source of a clean gas, valves for controlling aerosol introduction into the clean gas, and a support for the wafer in the path of gas introduced into the chamber.

Abstract: Changes in specified indicia of colony growth in the early stages of incubation are monitored to provide the early detection and enumeration of colonies in the growth medium. Data from images collected at different times is processed to enhance the detection of subtle changes in the specified indicia of colony growth and provide an early indication of the number of colonies present in the growth medium.

Abstract: A high speed, high accuracy parts counting system is disclosed. The new system utilizes known types of centrifugal feeder devices with novel modifications relating to the sensing and control of individual workpieces, enabling workpieces to be counted and processed at much greater speeds than before, while equaling or improving accuracy. The new system makes no attempt to separate individual workpieces for counting purposes, enabling operations to be carried out at greater speeds. Counting of workpieces in an unseparated group of such workpieces is accomplished by electronic measurement of movement of the centrifugal feeder between the leading and trailing edges of a group of unseparated workpieces. The counting of a predetermined number of workpieces is thus a function of the counting of pulses and is independent of the separation or non-separation of workpieces during counting. Provision is also made for high speed collection and discharge of counted groups of workpieces.

Abstract: A zigzag scanning address generator includes a row address generator for generating a row address signal which stops, increases or decreases a present state in response to an enabling signal, and a column address generator for generating a column address signal which stops, increases or decreases a present state in response to the enabling signal. Therefore, the zigzag scanning address generator can generate zigzag scanning addresses according to a zigzag scanning method, simplifying the circuit configuration needed for generating the address signals corresponding to the zigzag scanning pattern.

Abstract: A method and apparatus for automatically and rapidly, retrieving, counting and/or analyzing at least one selected white blood cell population and/or subset thereof of a whole blood sample or portion thereof. A volume of a biological sample containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. The opacity and/or volume parameter of the cells can be modified and the mixture is then counted and analyzed in one or more steps to obtain the desired white blood cell population analysis.The biological sample can be a whole blood sample and the reactant can include or be a lyse or a monoclonal antibody bound to microspheres, which will bind to specific ones of the cells or a combination of lyse and microspheres with antibody bound thereto.

Abstract: Particles in a fluid are counted by passing the fluid through an optical cell and an image of said particles is projected onto an array of charge coupled devices such that the area of the image of each particle at the said array is approximately the same as the area of at least a single charge coupled device, and signals from the individual charge coupled devices are processed to provide information concerning at least the number of said particles passing through the optical cell. A particle counter disclosed comprising an optical cell (1) through which is passed a fluid containing particles to be counted, means (2) for illuminating the particles in the optical cell and optical means (3) for providing an image of the particles on an array of charge coupled devices (5) such that the area of the image of each particle at the said array is approximately the same as the area of at least a single charge coupled device. The particles may fluoresce and a transmittance filter (4) may be provided.

Abstract: The measurement of gray scale or color composition integrated densities of irregularly shaped areas of a subject specimen is accomplished by using a video camera to derive an analog video image signal representative of the optical intensity of light associated with the specimen. A modified low cost high speed video digitizer converts the video image signal into a digital format which an interactive computer program converts into digital optical density values that are used to determine the net integrated density of each irregularly shaped area within the specimen.

Abstract: A particle counting apparatus for counting a total particle counting value contained in a liquid sample comprising, a flow cell in which the liquid sample flows, a light source for irradiating a light beam to the sample liquid in the flow cell, a detector for detecting pulse-wise signal scattered from the particles by the irradiating of the light beam, and a computer for obtaining the total particle counting value contained in the liquid sample as a counting value measured when the top end of the liquid sample is irradiated with the light beam and the plural particles in the top end does not overlapped in the light beam, multiplied by a coefficient.

Abstract: An apparatus for counting discrete objects of various sizes and shapes as they travel through the apparatus in a disorderly flow. The apparatus includes a sensor array which comprises a plurality of photodetectors arranged in a linear fashion. The discrete objects are passed over the sensor array. By utilizing the sensor array as a means for obtaining information about the discrete objects, the apparatus samples the sensor array at predetermined time intervals, examines the various contours of the images produced through the sampling and based upon predetermined criteria determines whether an image represents one or more objects.

Abstract: The particle counting apparatus is intended to count the number of particles such as blood corpuscles, by passing through a minute aperture, and detecting the particles electrically. In this particle counting apparatus, the liquid specimen is passed into the minute aperture at a specific flow rate by means of a liquid specimen discharge device, and the particles are counted preliminarily, and the dilution proportion of the liquid specimen is determined when the value of this preceding counting is over a specific value. According to this dilution proportion, the liquid specimen discharge device and diluent discharge device discharge so that the flow rates may be as specified, and the mixture is passed through the minute aperture for main counting. In this way, if there are many particles, simultaneous passes do not occur in the detecting region.

Abstract: A device and method for counting particles on a sample surface. The device includes a scanner having a surface for interfacing with the sample surface. The scanner is connected to one end of a tube which has two canals. The other end of the tube is connected to the particle counter. One of the tube canals supplies air from the particle counter through holes in the scanner surface for dislodging and fluidizing particles on the sample surface. The other tube canal returns air with the sample surface particles to the particle counter. After the particles are counted they are removed from the air stream by a filter. The air is then recycled back through the supply canal of the tube to facilitate additional particle counting. The method for using the device involves passing the scanner over the sample surface for predetermined periods, and collecting, counting and computing the average relative number of particles per unit area.

Abstract: A method and an apparatus for synchronizing particle counts to process events provide a trigger signal related to the process events in lieu of a time-based trigger signal. In one embodiment, the controller to a particle counter further subdivides a process event into sub-intervals to allow profiling of particle counts during the process event. In one embodiment, the controller of the particle counter receives multiple trigger signals corresponding to multiple trigger signal sources, each trigger signal source being identified by a source tag. Particle counts and time-stamps are maintained for each source of the trigger signals.

Abstract: A system for sorting particles is arranged such that the presence or absence of multiple parameters is determined for each particle in a flow of particles, and a logic condition is determined based on the multiple parameters. Thereafter, particles are outputted from the system when the logic condition is present. Accordingly, multiparameter high-speed measurements of a rare subpopulation of particles (e.g. biological cells) can be made amidst a larger population of particles with differing characteristics. When attached to a multiparameter flow cytometer/cell sorter and microcomputer, the system allows multiparameter analysis of cells at rates in excess of 100,000 cells/sec. This system can be an outboard module attached to a commercially available or home-built flow cytometer.

Abstract: The measurement of integrated densities of irregularly shaped areas of a subject specimen is accomplished by using a video camera to derive an analog video image signal representative of the optical intensity of light associated with the specimen. A modified low cost high speed video digitizer converts the video image signal into a digital format which an interactive computer program converts into digital optical density values that are used to determine the net integrated density of each irregularly shaped area within the specimen.