Abstract: In order to investigate particles in a fluid, a flow cell causes the fluid to flow past a sensor which receives light from a continuous light emission system. When the sensor detects a change in light, a particle detector is triggered, which in turn triggers a pulse generator and hence an intermittent light emission system. Light then illuminates the flow cell to allow a CCD camera to photograph the particle. The photographs taken by the CCD camera are analyzed by an image processor. In order to obtain an accurate particle concentration measurement, it is necessary to modify the initial concentration measurement derived from the analysis of particle images by the image processor by a compensation coefficient. This operation is carried out by a concentration compensator. The result may then be displayed. Additional analysis may be carried out by changing the magnification of the CCD camera, or by selecting for analysis only those particles of a selected size or type.

Abstract: A flow cell apparatus, useful in an apparatus for measuring particles suspended in a liquid, comprises a sample liquid, supply device, a sheath liquid supply device, a flow cell which has a flow passage passing through a transparent measuring portion, and a nozzle for causing the sample liquid, from the supply device to flow in the flow passage of the flow cell. The nozzle has at least one discharge port which is disposed in the flow passage in a spaced relation from the inner wall of the flow cell flow passage. The sheath liquid supply device causes the sheath liquid to flow around the nozzle discharge port and surround the sample liquid flow to form a sheath flow. The flow passage of the flow cell and the nozzle are so formed as to ensure a sample liquid flow of a fixed width through the measuring portion.

Abstract: In a stained particle analyzing method and apparatus for staining a test sample containing suspended particles, shooting an image of the stained sample, and classifying the particles and computing the density from the shot image of the sample, the sample, which may not be analyzed precisely, is detected before the start of an image analyzing process. Only the sample, which will be analyzed precisely, is stained and subjected to the image analysis. Color information of the sample before the staining is detected and stored. Color information of an image of the sample shot after the staining is compensated based on the color information of the sample detected before the staining. The sort and density of the particles are classified and computed on the basis of the image after the color compensation.

Abstract: This invention relates to an apparatus for analyzing cells in a biological liquid sample, such as blood, in which apparatus a flow passage in a sample pretreatment system can be shortened with a simple construction. A sample metering chamber, a mixing chamber and a measurement liquid extracting chamber are formed in a rotary sliding member of a pretreatment portion. The rotary sliding member is intermittently rotated so as to shift a sample from one chamber to another to perform a necessary treatment. Fluorescence or scattering light with respect to the sample, mixed with a reagent in the pretreatment portion, is detected by a flow cell.

Abstract: Particles contained in a liquid sample are analyzed by moving the particles along a detection passage past a detector using a liquid flow in the detection passage. To reduce the time required for analysis of each sample, the sample is delivered at an input location at the upstream end of the detection passage by movement of a movable container carrying the sample to the input location. Immediately after the commencement of the delivery of the liquid sample, liquid flow is caused to occur in the detection passage. Washing liquid is supplied to the input location by a liquid supplier different from the movable container which carries the sample.

Abstract: A stain discriminating apparatus in which light rays having at least light component having a wavelength in a predetermined range are projected to a cell sample to discriminate the staining method by which the cell sample has been stained on the basis of the light intensity of the light component transmitted through the sample and having the wavelength (530 nm) in the predetermined range. An automatic cell sample classifying apparatus in which a plurality of cell sample slides are sequentially fed to the stain discriminating apparatus is used to determine the staining method by which the cell samples have been stained, respectively. One of the examination/classification programs previously stored in a memory is read out according to the staining method as discriminated and the cell samples are processed in accordance with the program as read out.

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.