Abstract: The new instrument for taking readings of the hematocrit value from a blood sample has two electrodes with which the conductivity of the sample may be measured. The sample contacting faces of the electrodes are placed in a horizontal plane with an accurately fixed spacing therebetween so that a blood column of a given size may be formed from the sample. The sample is acted upon by ac. From a reading representative of the change in impedance the hematocrit value may be read off from a calibration curve.

Abstract: For measuring the deformation capacity of erythrocytes use is made of a sample vessel that is walled off into two spaces by a piece of foil with a pore therein. One such space is filled with buffer solution with erythrocytes and the other is filled with buffer solution without erythrocytes. A pressure head is produced acting across the foil for causing transit or passage of the erythrocytes through the opening, whose diameter is less than the major quiescent diameter of an erythrocyte so that information on the deformation capacity may be produced by measuring the transit time. This is done by electrodes placed on the two sides of the opening so that changes in the resistance to alternating current by an erythrocyte in transit may be sensed and the transit time taken. After about 200 transits the readings are processed in a processing unit.

Abstract: The present invention relates to a method of circulating organo-biological liquids, preferably blood, wherein a liquid contained in a reservoir is released to a pressure (head) level below its original fluid pressure (head) level, thereafter raised periodically or in steps to a pressure (head) level above the original level, then transferred from such level to a reservoir positioned at a predetermined, relatively lower pressure (head) level, and thereupon drained to an outlet positioned approximately at the level of the original pressure (head) level.

Abstract: A test value corresponding to blood subsidence from a syllectogram is determined as a result of the effect of shearing forces on a blood sample, by ascertaining the slope of the test curve representing the syllectogram at a predetermined time beginning with or after the onset of the blood aggregation phase as the test value after:(a) sudden stoppage of the shearing; or(b) a transition to a continuous minor residual shearing.