Hematocrit measurement in an automatic hematology analyzer
First Claim
1. In a blood cell analyzer in which a cell signal is provided in response to the detection of blood cells in a precise volume of blood, said cell signal including a plurality of pulses, with each pulse representing the detection of one cell and with the magnitude of each pulse relating to the size of each detected cells, hematocrit measuring means for providing a voltage relating to the hematocrit of the blood comprising:
- integration means for summing signals applied thereto;
controlled switching means for coupling said pulses to integration means; and
detecting means for detecting the maximum of magnitude of each pulse of said cell signal and for producing a gate signal indicative of said detected maximum magnitude and having a fixed, preselected width which is narrow compared to a typical pulse width, said detecting means being coupled to said controlled switching means for rendering said controlled switching means conductive in response to said gate signal, whereby said integrator is incremented by a voltage indicative of a peak portion of each pulse and the voltage stored in said integration means at the completion of said cell signal comprises the voltage relating to the hematocrit of the blood.
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Abstract
In a hematology analyzer, peaks of pulses indicative of red blood cells in a sample during a count are detected. Peak detecting means produce a gate signal connected to gate means which couple a portion of each pulse in the time vicinity of its peak to integration means. The level accumulated in the integration means is indicative of total cell volume, and hence indicative of hematocrit for a known sample volume.
52 Citations
5 Claims
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1. In a blood cell analyzer in which a cell signal is provided in response to the detection of blood cells in a precise volume of blood, said cell signal including a plurality of pulses, with each pulse representing the detection of one cell and with the magnitude of each pulse relating to the size of each detected cells, hematocrit measuring means for providing a voltage relating to the hematocrit of the blood comprising:
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integration means for summing signals applied thereto; controlled switching means for coupling said pulses to integration means; and detecting means for detecting the maximum of magnitude of each pulse of said cell signal and for producing a gate signal indicative of said detected maximum magnitude and having a fixed, preselected width which is narrow compared to a typical pulse width, said detecting means being coupled to said controlled switching means for rendering said controlled switching means conductive in response to said gate signal, whereby said integrator is incremented by a voltage indicative of a peak portion of each pulse and the voltage stored in said integration means at the completion of said cell signal comprises the voltage relating to the hematocrit of the blood. - View Dependent Claims (2, 3, 4, 5)
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Specification