Sitkovsky-Egorov Apparatus

Sitkovsky-Egorov Apparatus serves for determining the time of blood coagulation. The Sitkovsky apparatus consists of 2 glass test tubes and a scale. The outer test tube serves as a water bath. Into this test tube is inserted the second test tube, and into the latter a scale, on which are attached a thermometer, manometer, and capillary. The capillary is removable. A rubber stopper tightly closes the inner test tube (air bath). Through this stopper pass two tubes. One tube is equipped with a stopcock. By means of rubber drain tubes, these tubes are connected on one side inside the test tube with the capillary and manometer, and on the other side with a glass cylinder (air reservoir) having an outlet tube, to which a three-way stopcock is attached. The latter is connected to a rubber bulb. The bulb can be compressed by a special, immovably fixed screw, which changes the pressure inside the apparatus. In Egorov's apparatus, a number of technical shortcomings present in Sitkovsky's design have been eliminated. For example, the thermometer and manometer with scale have been removed from the air bath. This makes it possible to avoid cooling of the water bath and facilitates use of the capillary into which blood is drawn. The air bath is a narrow test tube having a short outlet tube in its upper part. By means of a T-connector, the air bath is connected to the manometer and rubber bulb. The manometer is placed in front at the upper part of the stand; the water bath is attached to a horizontal board. The thermometer passes through the stopper into the water bath. The rubber bulb is fitted onto a glass T-connector, connecting it on one side with the rest of the apparatus, and on the other side by means of a rubber tube with atmospheric air. When working with the apparatus, a Mor clamp is placed on this tube, which disconnects the inner part of the apparatus from the atmosphere and serves as a safety valve for the entire apparatus in case of excessive pressure increase. The data obtained with this apparatus regarding normal blood coagulation time vary within relatively narrow limits—2-4 minutes.