Blood cell counter having dual testing heads

Claim 1

A semi-automatic instrument for analyzing prediluted blood samples, said instrument having at least two independent heads and associated circuitry for simultaneously determining red blood cell and white blood cell counts, comprising: a. a red blood cell counting (RBC) head having at least two electrodes therein, and an RBC aperture between at least two of the electrodes, means for receiving and releasably coupling with a first reservoir containing a first conductive liquid dilution having a blood sample with red blood cells and diluent in predetermined ratio for (RBC) counting; b. an RBC conduit for passing the first conductive liquid dilution containing red blood cells past the electrodes and through the RBC aperture, said RBC conduit extending into a reservoir containing the red blood cell dilution; c. means for applying an electrical signal through the aperture; d. RBC circuitry for producing pulses as cells suspended in the first dilution pass through the red blood cell aperture, said RBC circuitry being connected to electrodes located on opposite sides of the aperture; e. a white blood cell counting (WBC) head having at least two electrodes therein and a WBC aperture between at least two of said electrodes, means for receiving and releasably coupling a second reservoir containing a second conductive liquid dilution having the blood sample with white blood cells and diluent in a different predetermined ratio for (WBC) counting; f. a WBC conduit for passing the second conductive liquid dilution containing white blood cells past the electrode and through the WBC aperture, said WBC conduit extending into a reservoir containing the white blood cell dilution; g. means for applying an electrical signal through the WBC aperture; h. WBC circuitry for producing pulses as cell suspended in the second dilution pass through the WBC aperture, said WBC circuitry being connected to electrodes located on opposite sides of the aperture; i. means for detecting the pulses produced in both heads and for providing output indications corresponding to the number of particles pass through the apertures, respectively.