Abstract: The characteristics of a sample body fluid are determined in a chemical analyzer by sensing the transmittance of light by the sample fluid and reagents during a reaction period. A beam of light is directed onto a cuvette containing the sample body fluid and reagent. A portion of the light is absorbed by the cuvette, the sample fluid and reagent. The remainder of the light is transmitted to a sensor which provides an analog electrical transmittance signal proportional thereto. The analog signal is logarithmically amplified, and is applied to a peak detector. A structure adjacent the cuvette provides a strobe signal such that the analog signal always has a peak amplitude during the strobe signal. The peak detector senses the peak amplitude of the analog signal during the strobe signal and the peak amplitude is converted to a digital value representing absorbance.

Abstract: An improved drive is provided for a syringe having a barrel and a plunger. The drive utilizes an electric motor which has an axial shaft that moves back and forth axially when the shaft is prevented from rotating. A syringe barrel holder is fixed relative to the electric motor housing and a plunger holder is rigidly fixed to the shaft. When the electric motor is energized, the plunger holder will move back and forth relative to the syringe barrel holder. A plurality of switches for controlling the electric motor are positioned in fixed locations relative to the motor housing. The plunger holder is operative to actuate and deactuate the switches during axial travel of the shaft.

Abstract: The blood processing method, and the apparatus for performing the steps of the method are utilized in separating whole blood into its components and include the steps of, or component parts of the apparatus for carrying out these steps of: pumping whole blood from a donor; passing the whole blood through a first chamber in a centrifuge device: centrifuging the whole blood in the centrifuge device to cause sedimentation of red blood cells from the whole blood in, and separation of platelet rich plasma from the whole blood in, the first chamber; pumping the separated platelet rich plasma from the first chamber and out of the centrifuge device where it is monitored and then back into the centrifuge device and through a second chamber in the centrifuge device where the platelet rich plasma is centrifuged to cause sedimentation of the platelets therein while passing the remaining blood fluid though the first chamber and back to the donor; recombining the plasma passed through the second chamber with the blood flui

Abstract: A conductivity monitoring system including a temperature sensing means for sensing the temperature of a fluid and also providing a temperature compensated conductivity signal. Electronic circuitry is provided for detecting and indicating the inoperability of the temperature sensor.