Abstract: Automated control methods and apparatus are provided for the separation and collection of desired blood portions for use in an extracorporeal photophoresis treatment system wherein a photoactivatable agent, in contact with leukocyte enriched blood from a patient is irradiated and then returned to said patient.

Abstract: A pulmonary monitor for measuring a complex set of variables utilizing a group of three pushbuttons arranged to operate in hierarchical a hierarchical pattern for facilitating operator control of the functions of the monitor.

Abstract: A monitoring arrangement is provided for detecting for extreme pressure conditions in blood tubing lines of a hemodialysis system. The arrangement includes a first pushbutton switch and a pivoted lever arm. A clamping means is located at a first end of the lever arm for clamping the blood tubing line against the first pushbutton switch, and the other end of the lever arm opposes a second pushbutton switch. Under low pressure conditions, the blood pressure in the tubing is no longer sufficient to hold the first pushbutton switch closed. The switch then opens to signal a low pressure condition. Under high pressure conditions, the blood tubing pressure causes the lever arm to pivot so that the far end of the lever activates the second pushbutton switch, which signals a high pressure condition.

Abstract: Methods and reagent kits for the detection of intracellular antigens such as TdT and antinuclear antibodies. The methods involve swelling the cells with a hypotonic solution for increasing the localization of large molecular weight substances such as antibodies at intracellular antigenic sites, fixing the cells and reacting them with antibodies specific for the intracellular antigen to be detected. The cells are then further reacted with labeled antibody specific for the first antibody, washed to remove unreacted antibodies and the presence of label detected whereby the presence or absence of the intracellular antigen may be determined.

Abstract: A reverse osmosis system including a high pressure pump and pump motor is enclosed in an unvented enclosure to reduce the amount of noise which would otherwise be transmitted into the surrounding environment. The pump motor is cooled by the flow of inlet water through heat-conducting tubing arranged as by wrapping to be in thermal contact with the pump motor. The absorption of thermal energy by the inlet water provides an additional benefit in that product water flow during reverse osmosis is a function of temperature, with the higher temperature water yielding an increased product water flow. In a preferred embodiment of the present invention, the tubing coil is secured to the pump motor housing by a clamshell-like clamping assembly. The purity of the product water is monitored by a conductivity cell including first and second electrodes arranged to detect the conductivity of the water.

Abstract: Method for discriminating unstained cells from stained cells in a heterogeneous population. Specified cell types are stained with an absorbing stain and all cells are passed through the class of flow cytometry instrumentation employing focused collimated light sources. Detection of low angle and wide angle light scatter permits differentiation between the cell types on the basis that cells stained with an absorbing stain produce comparatively less low angle light scatter and comparatively more wide angle light scatter than do unstained cells.

Abstract: A two-pump single needle hemodialysis system is provided in which a flexible blood accumulator bag is located between the dialyzer and the second, venous blood pump. The accumulator bag is filled as the first, arterial blood pump is operated. Blood is pumped through the dialyzer and into the bag until the bag is full and taut. At this time, a rise in pressure is detected and the venous blood pump is activated to withdraw blood from the accumulator bag. The use of the accumulator bag assures that low blood pressures are maintained in the system.

Abstract: A blood flow system for processing blood has two phases of operation, an arterial phase and a venous phase. During the arterial phase, the system is filled with blood through operation of an arterial blood pump. When a predetermined blood pressure level in the system has been attained, the arterial blood pump is inactivated and a venous blood pump removes blood from the system for a given number of pump turns.

Abstract: A bubble detector system is provided which dynamically responds to changes in energy transmission efficiency. The output of a detector is coupled to a dynamic reference level circuit, which develops a reference level that changes slowly in a time-varying manner with changes in the energy level received by the detector. The output of the detector is also coupled to a bubble detector circuit which produces a detection signal that changes rapidly when gas is present between an energy source and the detector. The detection and reference levels are compared to detect the presence of gas in the flow of fluid between the energy source and the detector.

Abstract: Methods for determining the presence of antigens or antibodies in an aqueous sample or presence of antigens on the surface of cells. A preferred embodiment employs fluorescent antigens which compete with the sample antigens for antibody binding sites. The antibodies are deposited on a support surface means in alternating patterns. The surface means and fluorescence detector are translocated with respect to each other and a signal generated by the detection of the repeating pattern of fluorescence. The signal is analyzed by means of a gated integrator responsive to a gate track control means also located on the surface means. Immunoassay methods having increased sensitivity are thereby obtained.

Abstract: A hemodialysis system capable of operation in either a single needle mode or a double needle mode includes an arterial blood pump which is the sole blood pump in the system during the double needle mode. For single needle mode operation a venous blood pump is employed to return blood to the patient. A pump speed control adjusts the speed of the arterial pump in the double needle mode, and the speeds of both blood pumps in the single needle mode. A controller continuously operates the arterial pump in the double needle mode, and alternately activates the two pumps in the single needle mode. A module for modifying a commercially available double needle system for operation in either of the two modes is also described.

Abstract: A particle washing system and method of use provides for the placement of the fluid containing the desired particles within an inner tube having near the bottom thereof an orifice plugged with a material for sealing the particulate containing fluid from a wash fluid under forces substantially equal to 1G. The inner tube is positioned within an outer tube which contains a wash fluid having a density at least equal to that of the particle containing solution but less than that of the particles. Application of centrifugal force, substantially greater than 1G, and directed toward the bottom of the outer tube, causes the sealing material to be dislodged thereby permitting the particles to move through the orifice and through the outer solution. Thus the particles are collected from the inner solution, washed by the outer solution, and pelleted at the bottom of the outer tube.

Abstract: A sample having a mixture of unknown stained cells and known cells having different staining characteristics is analyzed rapidly, a cell at a time, in a flow cytometry system having a sample stream dimension in the range of expected cell dimensions. The cells are illuminated with focused illumination and fluorescence is detected and related to the number of cells. The resulting histogram of the mixture sample may be analyzed by counting the cells in a controlled population below a relatively low threshold value of fluorescence intensity to form a first fraction and relating this fraction to the fraction of cells in the sample mixture below the threshold value of fluorescence intensity to determine the number of unknown cells in the sample mixture.

Abstract: Blood flowrate in a hemodialysis system is controlled in accordance with the relative speeds of two periodically operated blood pumps. Information as to the speeds of the two pumps is converted to flowrate information, which is used to determine the mean flowrate of blood through the system. The mean blood flowrate may be altered by changing the speeds of the blood pumps in a control system which maintains a constant ratio of pump speeds.

Abstract: The method assesses the level of general and specific cellular immunocompetence by measuring the responses of individuals to antigens in vitro employing the phenomenon of Leukocyte Migration Inhibition (LMI). The present invention differs from the previously described LMI technique in that antigens are individually incorporated into the agarose of assay plates, requiring no preincubation of antigens with patient blood cell (leukocyte) suspensions. The LMI assay method described herein is a practical alternative to delayed hypersensitivity skin testing to identify cellular immune deficiency and avoids the risk and inconvenience of the skin test procedure. The method also allows in vitro diagnosis of Tuberculosis and monitoring of tumor therapy.

Abstract: A particle washing system and method of use is described wherein in a preferred embodiment the fluid containing the desired particles is placed within an inner tube having near the bottom thereof an orifice with a diameter at least equal to that of the diameter of the particles, and wherein the inner tube is positioned within an outer tube having a fluid with a density at least equal to that of the solution containing the particles to be separated but less than that of the particles. The application of centrifugal force to the particles directed toward the bottom of the outer tube causes the particles to move through the orifice and through the outer solution contained within the outer tube so that the particles are collected from the inner solution, washed by the outer solution, and subsequently sedimented at the bottom of the outer tube.

Abstract: A particle washing system and method of use is described wherein in a preferred embodiment the fluid containing the desired particles is placed within an inner tube having near the bottom thereof an orifice with a diameter at least equal to that of the diameter of the particles, an air vent and, wherein the inner tube is positioned within an outer tube having a fluid with a density at least equal to that of the solution containing the particles to be separated within the inner tube but less than that of the particles. The application of centrifugal force to the particles directed toward the bottom of the outer tube causes the particles to move through orifice and through the outer solution contained within the outer tube so that the particles are collected from the inner solution, washed by the outer solution, and subsequently sedimented at the bottom of the outer tube.

Abstract: Methods for producing from human serum, human gamma globulin essentially free of HB.sub.s Ag and products resulting therefrom. Specifically provided are ion exchange resin/buffer systems capable of effectively removing HB.sub.s Ag thought to be closely correlated with viral hepatitis type B infectivity. Additional steps can include ultrafiltration to increase reduction of any virus not removed in the column passage as well as the addition of anti-HB.sub.g to substantially eliminate all infectivity.

Abstract: Reagents and methods are described for an immunoassay test of increased sensitivity and decreased complexity employing an immunoglobulin specific for an antigen naturally or artificially placed upon the surface of an indicator particle coupled through the use of a hetero-bifunctional coupling reagent to a second antibody of differing specificity and specific for the antigen to be detected. In a preferred embodiment, a hetero-bifunctional coupling agent couples via a sulfhydryl group, a univalent immunoglobulin specific for the surface antigens on erythrocytes to a second multivalent immunoglobulin through an amide linkage with the latter immunoglobulin wherein said second immunoglobulin is specific for hepatitis-B surface antigen.