Abstract: A reagent for classifying leukocytes with a flow cytometer by means of optical measurements on fluorochrome-stained blood cells is included. The reagent is useful in the practice of clinical testing and includes a Neutral Red fluorochrome and either an Astrazon Organe G or an Auramine O fluorochrome to enable differentiation of leukocytes.

Abstract: A flow cell for a fluid particle analyzer comprises a narrow measuring liquid path, liquid introducing paths continuous to this measuring liquid path, liquid specimen nozzles disposed so that the front ends may be opposite to each other across the measuring liquid path, and sheath liquid inlets and waste liquid outlets disposed in the liquid introducing paths, respectively.The particle analyzer is designed to emit light to the liquid specimen flowing as a sheath flow in the measuring liquid path in the flow cell and detect the light from the particles individually. Since two liquid specimen nozzles are disposed opposite to each other, measurements from the liquid specimen discharging from one of the liquid specimen nozzles can take place while preparation of the other liquid specimen takes place, so that the analysis processing time can be notably shortened.

Abstract: In an apparatus for extracting individual cell images in an original imaged frame by means of windows and storing the extracted individual cell images in an editing memory, a window setting memory is constituted by a plurality of bits corresponding to respective ones of a plurality of the cell images. Coordinates of each pixel in the imaged frame are used as addressed of the window setting memory.

Abstract: An imaging flow cytometer is provided with a continuous-emission light source for continuously monitoring cells passing through the image capturing area of a video camera for cell-image capturing, and with an excitation light source for picking up a fluorescent image of a cell. When a line sensor monitoring cell passage through the cytometer senses such cell passage, the cell is irradiated with strobe light and then, after waiting for the cell to move a fixed distance, with the excitation light. Thus, a particle analyzer is provided in which an image by white light resulting from the strobe light and a fluorescent image resulting from the excitation light can be captured simultaneously by a single video camera in either upper and lower halves or right and left halves of one imaged frame.

Abstract: A particle image analyzer includes a first light source for applying strobe light to a sample solution flowing through a flow cell, first image pick-up means for taking a still picture of a particle in the sample solution irradiated by the first light source, a second light source for constantly irradiating the sample solution in the flow cell, and second image pick-up means for picking up an image of the sample solution in the flow cell irradiated by the second light source. When a particle is detected from the image pick-up data from the second image pick-up means, the first light source is flashed, based upon detection of the particle, in a predetermined image pick-up interval of the first image pick-up means.

Abstract: A flow imaging cytomer for imaging the dimensions and shapes of particle components in a flow of a specimen solution has a slender filament serving as a focusing reference provided in a flat imaging zone through which the specimen solution flows in order for the particle components to be imaged. By imaging the filament-shaped focusing reference and adjusting position in accordance with the sharpness of an image of the reference, the particle components in the specimen solution can be brought into sharp focus.

Abstract: A white-light image and a fluorescent image are capable of being captured by a single video camera, and a single light source for producing exciting light is used to pick up the fluorescent image and monitor arrival of particles to the image capturing area. Specifically, besides a strobe light source, a light source, the output of which normally is low, is provided for exciting fluorescence and for monitoring cell flow-through. An image intensifier is used in the light-receiving system of the fluorescent image and is supplied with a voltage the size and timing of which are controlled in such a manner that the irradiation of a cell with the strobe light when the white-light image is captured will not have an adverse effect upon the aforementioned light-receiving system. This makes it possible to pick up two images each in a different zone on the light-receiving surface of image capturing means.

Abstract: A particle detector is designed to detect particles such as cells and blood corpuscles, and this particle detector includes means for passing and recovering a multilayer flow consisting of an inner layer A of conductive liquid specimen, a middle layer B of conductive first sheath liquid, and an outer layer C of nonconductive second sheath liquid surrounding them, in an orifice 12, and a pair of electrodes disposed on both sides of the orifice so as to contact the conductive liquid respectively. A detector circuit 44 is connected to the pair of electrodes so as to detect a particle signal on the basis of difference of electric impedance between the electrodes. The diameter of the orifice 12 is substantially the diameter of the middle layer. By varying the flow rate balance of the conductive liquids and nonconductive liquid, the diameter of the middle layer may be freely changed. Accordingly, the diameter of the orifice may be apparently changed as desired.

Abstract: A standard substance for optical calibration is produced by mixing a proportion of a scattering substance with a first silicone liquid. The optical properties of the first liquid are measured and a further amount of the first liquid is added to the original mixture to provide a desired optical property. Then, the mixture is further mixed with a second silicone liquid which initiates a curing process. The final mixture is poured into a transparent vessel for curing. The transparent vessel, with the cured final mixture inside, is useful as a standard substance for calibration of an optical equipment. A technique for calculating the proportions of the mixtures is disclosed.

Abstract: A method for demarcating a reticulocyte particle group from a red blood cell particle group in a one-dimensional frequency distribution assumes a normal distribution on one side of the distribution. Various positions Xs.sub.1, Xs.sub.2, . . . , Xs.sub.n, which respectively indicate frequencies that are p.sub.1, p.sub.2, . . . p.sub.n percent (where n is an integer of 3 or greater) of a peak frequency of the distribution, on the normal side of the distribution, are determined. An average value and standard deviation of the normal distribution is determined from these values. A threshold value is next obtained from the average value and standard deviation, the threshold value being used to separate the reticulocyte group from the red blood cell group. The average value and standard deviation may be obtained using a least square method or by computing the mean of several average values and standard deviations.

Abstract: A reagent for and method of measuring leukocytes or hemoglobin or both in blood using a reagent which is water-soluble mixture containing:(a) a polyoxyethylene-based nonionic surfactant represented by the formula:R.sub.1 --R.sub.2 (CH.sub.2 CH.sub.2 O).sub.n --Hwhere R.sub.1 is an alkyl, alkenyl or alkynyl group having 6 to 24 carbon atoms, R.sub.2 is --O--, ##STR1## or --COO--, and n is an integer of 6 to 50, and (b) a buffer to adjust the pH of the solution within the range of 3-11 is disclosed. Measurements of hemoglobin in blood samples are of extreme importance to clinical diagnosis of such diseases as leukemia and anemia. Measurements of eosinophils, which are in the category of leukocytes, are important to the diagnosis of allergic conditions.

Abstract: A device of measuring a blood coagulating time, the device being constructed such that when the specimen is placed in a detecting section in which it is maintained at a desired temperature, the measuring initiation time is set, followed by the transmission of a series of measuring data to a memory through an arithmetic circuit until a saturation is reached in response to which the measuring operation is stopped. On presumption that the saturating value is 100%, arithmetic operation is conducted, the results of which are stored in the remaining space of the memory. The device includes a keyboard switch whereby a time corresponding to particular percentages, such as 20%, 50%, and 80%, is previously set so as to enable the time to be easily recognized and accurately reproduced.

Abstract: Cells are imaged, digitized and binarized pixel by pixel, after which cell identification codes for each of the cells in the image field are derived from information indicative of the edges of the cells. Various cell image parameters such as cumulative chromaticity information, chromaticity histograms, cumulative gradient information and gradient histograms relates to a large number of cells are calculated from the cell identification codes. These parameters make it possible to classify the cells.

Abstract: A cell analyzing system flows a liquid to be tested and a sheath liquid through a flattened flow passage. An image of the flattened flow passage is formed at two different magnifications. The thickness of the liquid to be tested in the flattened flow passage is changed between the two different magnifications to maintain this thickness at a value smaller than a depth of field of the apparatus forming the image. The thickness of the liquid to be tested is changed by changing its flow relationship to the sheath liquid.

Abstract: A flow imaging cytometer for imaging the dimensions and shapes of particle components in a flow of a specimen solution employs a separate control solution, which is for managing precision, containing standard particles. A method of adjusting focal point with respect to the specimen flow includes steps of imaging the standard particles in the control solution, calculating an evaluation parameter which represents the definition of the image, and moving the flow cell or associated optical system so as to maximize the value of this parameter.

Abstract: A control system for a particle detector for detecting particles of blood components in an electrolyte employs sets of cams mounted on one-way clutches, which are positioned on a shaft of a motor. When the shaft is rotated by the motor in a clockwise direction, one set of cams moves together with the shaft, and when the shaft is rotated in the counterclockwise direction, another set of cams rotates in the counterclockwise direction. The rotation of cams controls movement of pistons which, together with cavities, form syringes and valves interconnected with passages. The valves and syringes are operated in sequence to prepare a specimen for measurement, to perform the measurement, and to clean up and purge the system between measurements.

Abstract: In an apparatus for extracting individual cell images in an original imaged frame by means of windows and storing the extracted individual cell images in an editing memory, a window setting memory is constituted by a plurality of bits corresponding to respective ones of a plurality of the cell images. Coordinates of each pixel in the imaged frame are used as addressed of the window setting memory.

Abstract: In particle analysis applied to blood cells, use is made of a distinguishing parameter which is the ratio of pulse height to pulse width derived from individual pulses generated in response to detection of corresponding individual particles. The distribution of the distinguishing parameter is plotted on a distribution of pulse height and pulse width, and a three-dimensional display of pulse height, pulse width and the distinguishing parameter is used in analyzing the particles.

Abstract: A particle suspension is irradiated with a laser beam, and scattered light from a single particle irradiated in an irradiating zone is detected as a plurality of particle signals. The laser beam in the irradiating zone is formed to be narrower than the diameter of a particle nucleus in the direction of particle flow and wider than the diameter of the particle in a direction perpendicular to the particle flow. The degree of complexity of the particle nucleus is determined from high-frequency signal components contained in one type of particle signal based on side-scattered light from one particle, and the degree of symmetry of the particle nucleus is determined from the magnitude of a difference between two types of particle signals based on side-scattered light from one particle. The degrees of complexity and symmetry of the particle nucleus serve as data for particle analysis.

Abstract: A particle suspension is irradiated with a laser beam, and side-scattered light from a single particle irradiated in an irradiating zone is detected as one or a plurality of particle signals. The degree of complexity of the particle nucleus is determined by extracting high-frequency signal components contained in the particle signal, and the degree of symmetry of the particle nucleus is determined by extracting the magnitude of a difference between this single particle signal and a signal obtained by flipping over the particle signal in terms of time. The degrees of complexity and symmetry of the particle nucleus serve as data for particle analysis.