Blood analysis system

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. A novel configuration involves a bore through a block generally tangential to a bore which engages a cylindrical chamber in the sidewall of which is a jewel orifice. A foil electrode is used in the tangential passage and a larger tapered electrode with the smaller end near the orifice in the cylindrical output chamber. A discontinuity in the form of an air bubble in a passage feeding the counter apparatus enables the position of the bubble to be sensed at one place to turn on the counter and in another place in the passage to turn off the counter. The three-layer valve structure has various special indexing features and cleaning features, and the intake devices have features associated with cleaning as well.