Abstract: A blood analyzer is provided with means to automatically pierce the sealed closure of a vacuum container or to aspirate through an aspirator tip blood samples to be analyzed. The samples are drawn serially through a repositionable valve structure, preferably of rotary form, and having three members in layers with aligned ports in one position to receive the blood that is drawn through the valve by a syringe type aspirator. Another position of the valve connects diluent supplies providing measured amounts of diluent to wash out the bores of the middle member of the valve containing amounts of blood measured by the size of the bores. In the case of the red blood cell measurement, where the bore is extremely small, a larger by-pass port is provided in parallel with the sample containing bore to allow more rapid flow simultaneously through both.Blood analysis is performed by separate conventional cell counter arrangements for each of the red and white counts.

Abstract: An apparatus for making blood counts is provided with computer and instrument control to optimize performance of the apparatus. Means for counting blood cells such as platelets, white blood and red blood cells enables a plot of the number of particles counted in each of the adjacent bands or channels inclusive within a selected range of particle size so that a plot of count against particle size may be made. The computer enables analyses of plots thus obtained by system algorithms in order to correct errors of various types which may occur in the plot. For example, by calculating the logarithms of the counts of particles and of mean particle size for each particle size channel, a further plot of log count against log of blood particle size of generally symmetrical bell shape may be generated. The computer further calculates change of logarithm (.DELTA. log) of counts in adjacent channels.

Abstract: In particle counting apparatus such as a hematology parameter measurement apparatus for performing multiple measurements on one blood sample, first and second impedance transducers, each including inner and outer electrodes, are provided for selective hydraulic connection to a probe head including one set of pressure ports and a further inner electrode. The first and second transducers are respectively immersed in first and second dilutions of the sample. Measurements on each dilution are made in a conventional manner. The inner electrodes are connected in parallel as are the outer electrodes so that small liquid passageways may be provided between the transducers and the probe head while maintaining a low impedance in the liquid path. Means are provided for selecting the sequence of operations and are provided to increase the throughput of samples for which multiple measurements are made.

Abstract: In a hematology parameter measuring apparatus, signals indicative of measured parameters are obtained and loaded into first digital registers. Calculated parameter values are generated through use of the values stored in the digital registers. A first parameter value is circulated from a register into a digital divider through a digital data line to set a divisor in the divider. A control circuit circulates a value from another register to the divider for utilization as a signal indicative of a dividend. The output of the divider is coupled to a result register to store a value indicative of the calculated parameter. In this manner, calculated parameter values are obtained, and the first registers retain values indicative of the measured parameter values. The control means may selectively couple signals to a display from any of the registers or to a printing unit.

Abstract: A method and apparatus for correcting the output count of an electronic particle counting system in which additional correction pulses are added to the pulses generated by the electronic counting system as a result of detecting particles flowing through an orifice. The correction pulses are added in accordance with a curve which is generated by statistical computation determined by the size of the orifice and the character of the particles being detected therein and their quantity per unit volume. The improved apparatus comprises the addition of a second counter chain to the system which includes digital counters having outputs at various frequencies which are dividends of the frequency of the input pulses. The various-frequency outputs are combined through logic circuitry to generate individual correction pulses at frequencies such that when the pulses are added to the detected pulses, the total of the pulses corresponds to the actual number of particles flowing through the orifice.

Abstract: A system for counting electrical pulses representing red and white blood cells and for determining hematocrit, mean corpuscular volume and hemoglobin in association with the blood cell counts. The system includes a blood cell transducer through which a blood sample is caused to flow and operative to produce electrical pulses in response to the passage of cells through a metering aperture. Red and white blood cell counts are electronically accumulated during respective analytical runs and logic circuitry is provided for determining, during a red blood cell counting run, mean corpuscular volume and hematocrit. The system can also include correction circuitry to correct for the coincident passage of cells through the metering aperture.