Abstract: The intensity of initial agitation of blood and an activating reagent affects the contribution of platelets to clotting in an activated clotting time (ACT) test. An improved ACT test accommodates the effects of platelet activation by incorporating a platelet activation phase. In the platelet activation phase an activating reagent is mixed with a sample of blood to be tested at a controlled point in time followed by gently agitating the mixture in such a manner and for a period of time sufficient to establish a predetermined and predictable contribution to the ACT from platelet activation. The platelet activation phase is followed by a clotting test phase of the ACT test. A platelet functionality test provides information regarding the functionality of platelets in a sample of blood.

Abstract: Coagulation related activities are detected in a fluid sample in a plunger sensor cartridge. The cartridge includes a test cell with a reagent chamber and a reaction chamber and a plunger assembly. A reagent drive subassembly forces the contents of the reagent chamber into the reaction chamber. The plunger assembly is raised and released by a plunger lifting subassembly to allow it to descend through the sample of liquid in the bottom of the reaction chamber. A dispenser subassembly automatically meters precise quantities of fluid into the test cells. The plunger lifting subassembly and the reagent drive subassembly are mechanically separate and are controlled separately. Stepper motors are used to provide precise control over the degree, rate and sensitivity of movement of the plunger lifting subassembly, the reagent drive subassembly and the dispensing subassembly.

Abstract: An inhibitor of platelet-related procoagulant activity is included in a collection medium into which a whole blood sample is collected. The inhibitor prevents an initial drop in the recalcified activated clotting time measured during an assay test conducted on the whole blood sample collected in citrate in the medium. The discovery of the problem of the initial drop in the activated clotting time and the solution of including the inhibitor of the procoagulant activity is of considerable importance in heparin therapy, since the initial drop in the activated clotting time of heparinized blood is substantial. The inhibitor can be included with a calcium chelating agent in the collection medium. Prostacylin and imidazole, which is an inhibitor of platelet thromboxane A2 synthesis, are effective inhibitors of this platelet-related procoagulant activity.

Abstract: An inhibitor of Platelet Factor 3 activity is included in a collection medium into which a whole blood sample is a collected. The inhibitor of Platelet Factor 3 activity, it has been discovered, prevents an initial drop in the activated clotting time measured during an assay test conducted on the whole blood sample collected in the medium. The discovery of the problem of the initial drop in the activated clotting time and the solution of including the inhibitor of Platelet Factor 3 activity is of considerable importance in heparin therapy, since the initial drop in the activated clotting time of heparinized blood is substantial. The inhibitor of Platelet Factor 3 activity can be included with a calcium chelating agent in the collection medium. Prostacylin and imidazole, which is an inhibitor of platelet thromboxane A2 synthesis, are effective inhibitors of Platelet Factor 3 activity.

Abstract: Coagulation is detected in a fluid sample such as blood which has been inserted into a cartridge and operated on by an actuator mechanism. The cartridge may be of either of two types: a plunger sensor cartridge wherein a plunger assembly is reciprocated in a predetermined manner within the fluid sample and the descent of the plunger assembly is sensed to determine coagulation conditions, and a gas flow cartridge wherein gas is passed through the fluid sample to transmit liquid in bubbles and the accumulation of the coagulating liquid from the bubbles is sensed to detect coagulation. An actuator mechanism operates with either one or both types of cartridges to create the conditions under which coagulation can be detected and to sense the coagulation detection conditions. The actuator mechanism reciprocates the plunger assembly and forces gas through the liquid sample to create the bubbles.

Abstract: A gas flow cartridge in which to conduct analytical coagulation tests on a sample of fluid such as blood includes a tube-like member and a resilient flexible membrane having a slit formed therethrough to divide the tube-like member into an upper reaction chamber in which the test takes place and into a lower reagent chamber which initially contains reagent to be mixed with the sample of liquid upon which the test is to be conducted. The contents of the reagent chamber are forced through the slit in the resilient flexible membrane due to the flexing of the membrane around the slit when pressure is applied. Once the reagent is in the reaction chamber with the sample of fluid, a flow of gas is forced upward through the slit in the membrane during the analytical test.

Abstract: Coagulation is detected in a fluid sample contained in either a gas flow cartridge or a plunger sensor cartridge, either one of which may be inserted in an actuator mechanism which has the capability of acting on either type of cartridge. Coagulation is detected in the gas flow cartridge by optically sensing the accumulation of coagulating liquid in a foam member at the top of the reaction chamber. In the plunger sensor cartridge, a plunger assembly is raised and released to descend through the sample of liquid in the bottom of the reaction chamber. The plunger assembly descends more slowly upon an increase in the viscosity of the fluid sample due to coagulation. Both cartridges include a lower reagent chamber, an upper reaction chamber, and means initially sealing and thereafter communicating the contents from the reagent chamber to the reaction chamber.

Abstract: A gas flow cartridge includes a tube-like member which defines a reaction chamber in which a pool of liquid is subjected to an analytical test. A coating of debubbling agent is applied to an area of the tube-like member above the reaction chamber. The debubbling agent collapses bubbles of noncoagulated fluid but allows bubbles of coagulated fluid to continue an upward movement above the area where the coating is applied. Coagulation is detected by sensing the coagulated bubbles moving upward in the tube-like member. A quantity of activator agent is initially confined with the reaction chamber, preferably within a structure defined by a segment of paper-like material formed into an activator retaining form. The paper-like material unrolls or unfolds during the analytical test.

Abstract: A gas flow cartridge in which to conduct a coagulation-related test uses an elongated pin member movably positioned within a communication opening which separates a reagent chamber from a reaction chamber. A first portion of the pin member has an operative configuration for sealing the communication opening when the first portion is positioned in the communication opening. A second longitudinally displaced portion of the pin member opens the communication opening to further communication therethrough upon longitudinal movement of the pin member. At the commencement of an analytical test, a plug member is moved upwardly to contact the pin member and move the first portion out of the communication opening and the second portion into the communication opening. The upward movement of the lower plug member forces the contents of the reagent chamber through the opened communication opening and into the reaction chamber.

Abstract: An apparatus and method for accelerating the coagulation of blood and the components thereof uses the injection of an additive and gas to trigger coagulation. The appartus is designed to include a disposable multi-cell pack for minimizing manual handling of the blood and for minimizing exposure thereof to foreign surfaces with each cell containing a specimen of blood disposed above, but separated from, a predetermined amount of additive by means of a releasable cap. The cell pack containing the multiplicity of cells is inserted over a corresponding multiplicity of gas injection nozzles which effect the release of the caps in each cell for injecting the additive and the gas into the blood. As the gas passes through the blood, bubbles that are continually formed in the space above the blood burst and blood transported therein refluxes back into the blood below until coagulation occurs.

Abstract: A system for determining the coagulation time of blood and components thereof, the amount of anticoagulant to be injected before and during surgery, and the amount of additive required to neutralize the anticoagulated blood during and after surgery. With collected samples of anticoagulated blood inserted into the system coagulation of the blood is accelerated through the controlled injection of a neutralizing additive by a corresponding injection of regulated gas. Failsafe means determine if gas is being injected into the sample and detection means detect the event of coagulation and indicate the elapsed time for coagulation. Before surgery, an anticoagulant is added to the patient's blood in a quantity necessary to avoid coagulation during surgery. The system responsive to the parameters of the patient's sex, height, and weight and/or pump volume and blood volume determines the amount of anticoagulant to be injected.

Abstract: A method and means for the repair of severed peripheral nerves utilizing a porous, thin walled, bridge conduit or tube and an applicator instrument therefor. The instrument is connected to a vacuum source and has means for supporting the tube in the region of the transverse hole therein. When supported by the instrument the interior of the tube is operatively connected to the vacuum source through the transverse hole and a pressure differential is created between the interior of the tube and the ambient atmosphere by means of the vacuum source. This pressure differential is used to draw one end of the severed nerve into one end of the tube and then the other end of the severed nerve into the other end of the tube, the nerve ends being in abutment within the tube. Additional means may be provided to maintain the nerve ends in abutment within the tube when required and means may also be provided facilitating removal of the tube upon repair of the nerve if desired.