Abstract: A power supply apparatus which includes at least one switching power supply disposed in a chassis connected to earth ground and at least one D.C. to D.C. converter whose inputs float with respect to system ground. To reduce transmission of high-frequency electrical switching energy from the switching power supply to the load, the invention contemplates a tuned reactive circuit connected between the system ground and the earth ground. Electrical switching energy is shunted to earth ground by way of bypass capacitors located at various stages of the power supply apparatus. A further aspect of the apparatus contemplates the interposition of low-pass filters between the switching power supply and one or more D.C. to D.C. converters connected to the power supply and/or between the D.C. to D.C. converters and their respective loads to effectively eliminate radiated electromagnetic energy.

Abstract: A stable colloidal particle comprises a colloidal-sized core substrate having amine-reactive functional groups thereon with an aminodextran coating over its peripheral surface and a layer of colloidal-sized metallic solid overlaying the aminodextran coating. A linker comprising aminotrithiolate attached to the metallic solid has a free amino group to which a protein is attached by covalent bonding to the free amino group. Such novel particles are useful in flow cytometry, particularly useful in the simultaneous analyses of subpopulations of leukocytes. Methods of preparation of such particles, as well as methods of use are provided. These conjugates enable the simultaneous analyses of at least two different mutually exclusive subsets of white blood cells, based on the binding affinity of the conjugated protein.

Abstract: An oro/nasopharyngeal airway comprises an arcuately shaped tubular member adapted for insertion into a patient's pharynx, either through the mouth or nasal passage, to prevent obstruction during the administration of anesthesia. According to a preferred embodiment, an inhalant gas, typically oxygen (O.sub.2), is delivered to the airway via a gas line connected to the proximal end of the tubular member, while expired carbon dioxide (CO.sub.2) is sampled in the patient's pharynx via a second gas line connected to the tubular member in the vicinity of its distal end. Preferably, the respective inhalant and expired gas lines are positioned within the interior of the tubular member and are integral parts thereof Alternatively, the airway defines two discrete and parallel lumens or conduits, one being adapted to be connected to an inhalant gas supply, and the other being adapted to be connected to a gas level-sensing device.

Abstract: A poppet valve apparatus is structured to reduce the rate of build-up of fluid-borne debris within its internal architecture. The inlet and outlet ports are arranged tangential to the internal cylindrical walls defining the valve's flow chambers, whereby a circular flow pattern is produced within the valve interior, and a specially contoured flow director efficiently redirects the circular flow pattern through a circular annulus defined by a valve seat and a sealing ring.

Abstract: The present application discloses dextran crosslinked, antibody-phycobiliprotein conjugates containing up to twenty phycobiliprotein per dextran molecule which conjugates are able to achieve amplification of fluorescence intensity over direct antibody-phycobiliprotein labeled cells of two fold or greater.

Abstract: Snow-making apparatus comprises the combination of a bulk water nozzle for projecting a spray of water particles into the air, and a plurality of nucleators for injecting ice particles (nuclei) into the spray to provide nucleation sites about the water particles freeze and form snow particles or crystals. Each nucleator comprises discrete nozzles for respectively projecting air and water particles to a location at which they collide in the open air to form ice particles. Because the ice particles are formed "externally" of any housing, the "freeze-up" problem associated with the "internal-mix" nucleators of the prior art is avoided. Preferably, each of the water nozzles of the external mix nucleators projects a relatively thin "sheet" of water which collides with a similar pattern of compressed air which acts (a) to break-up the water into relatively tiny droplets (e.g.

Abstract: A cassette for blood smear slides has a holder portion for supporting slides in a stack and an alignment surface for orienting a bottom slide with respect to a slide egress window. A force plate member is urged against the top slide in the stack with a constant force spring to align the bottom slide and to retain the slide stack. A slide extraction device is constructed to enter the cassette and has follower pins which ride on cam surfaces of the cassette to precisely position detent edges vis a vis an edge of a bottom slide of the stack. The cassette also has structure for signaling an empty condition.

Abstract: An apparatus for automatically drawing a blood sample from a sealed container having an internal pressure below that of atmospheric pressure comprises an aspirating needle which serves to pierce the sealed container to aspirate liquid from the container, and to vent the interior of the container to the surrounding atmosphere through a suitable vent line connected to the needle. Such apparatus further comprises a vacuum pump connected to the needle through an aspiration line for aspirating blood from the sealed container. To warn the user of the possibility that fluid (e.g. cleansing diluent) in the aspirating needle has been drawn into the sealed container in the event of a vent line failure, apparatus is provided for detecting the pressure in the container immediately after the aspirating needle has pierced the container seal, and for comparing this pressure with a predetermined nominal value (typically, the negative pressure rating of the vacuum pump).

Abstract: An improved method and apparatus for making blood smears on microscope slides are disclosed. The method is characterized by the step of temporarily deforming the normally planar surface of a slide on which the smear is being made, rendering it slightly concave in shape. This step has been found to substantially reduce streaking and other artifacts which interfere with the formation of an uninterrupted, substantially uniform monolayer of blood cells on the slide. Preferably, the movement of a blood-smearing member across the slide is controlled as a function of various predetermined physical parameters of the blood.

Abstract: A self-adjusting pick-up tube assembly for aspirating liquid from containers of varying heights. Such assembly comprises (a) a platform member adapted to be positioned in contact with the bottom of a container when the pick-up tube is being used to aspirate liquid from such container; (b) a disk-shaped member adapted to be retained in a position proximate the container's liquid filling aperture when the pick-up tube is in use; (c) a flexible conduit interconnecting respective liquid passageways in the platform and disk-shaped members, and (d) a telescopic mount for enabling relative movement between the platform and disk-shaped members to accommodate containers of different height.

Abstract: Apparatus for drying a succession of microscope slides having wet blood specimen smears on a first major surface, including a belt transport for moving slides along a longitudinal drying path with their wet surfaces facing in a common direction and means for directing low velocity, heated air flows toward the non-smeared, major slide surfaces. Air flow proximate the slides preferably is about 15.degree. C. above ambient and at a velocity of about 10 to 30 feet per minute for a drying period of about 75 to 135 seconds, per slide.

Abstract: Preparation of non-infectious control cells from normal, non-infectious, non-disease altered blood by depletion or augmentation of one or more cell types found in normal blood to reflect a specific disease state. The control cells so produced are preserved and thereafter reconstituted for use in immunological assays.

Abstract: A fanless snow gun for producing man-made snow comprises one or more water nozzles for projecting a substantially conical spray of water particles into the air, and a plurality of nucleating nozzles arranged rearwardly of and at spaced locations surrounding the water nozzles for injecting ice nuclei into the water spray to effect conversion of the water particles to snow prior to descending to the ground. To compensate for the absence of an independent source of air (e.g. a motorized fan) for cooling the water particles provided by the water nozzles, the snow gun is adapted to be supported at least 20 feet above ground level to increase the particle flight time and, hence cooling time, the water particle size is limited to about 300 microns or smaller to facilitate particle cooling and conversion to ice crystals, and the ratio of ice nuclei-to-water particles in the spray is increased by at least a factor of at least two compared to the same ratio in conventional fan guns.

Abstract: A system and method of diagnosis provides that data from a hematopathology analyzer, e.g., hematology analyzer and/or other blood testing instrument or test, is input and compared with patterns corresponding to specific patient conditions. The matched patterns are arranged in a hierarchy in accordance with predetermined rules. Initially the patterns matched are displayed, optionally with recommendations for additional testing. If additional testing is done, a comparison of the original test data and new data is done, the patterns matched and at least one highest ranked pattern is identified, optionally with a differential diagnosis.

Abstract: A cassette for supporting a plurality of cylindrically-shaped containers (e.g., test tubes) of randomly varying diameters in spaced parallel relationship includes a frame supporting a plurality of tube centering assemblies in side-by-side relationship. Each tube-centering assembly comprises a housing defining a through opening for receiving a container, and a pair of cooperating collar members slidably mounted on the housing for movement towards and away from each other. Each of the collar members has an arcuate surface adapted to contact a side wall of a received container during the sliding movement thereof. A spring is provided to bias the collar members towards each other and towards engagement with the side wall of a received container, whereby the collar members cooperate in supporting a received container therebetween.

Abstract: Pumping apparatus for dispensing or otherwise metering precise and minute volumes (measured in microliters) of fluid (e.g. human blood) from a flexible conduit containing such fluid. According to a preferred embodiment, such apparatus includes a pinch valve for selectively captivating a certain volume of fluid in the conduit between the pinch valve and the conduit's outlet end, and a pinch pump for selectively expelling a predetermined portion of the captivated fluid through the conduit's outlet end. The pinch pump is located and adapted to pinch closed a predetermined length of the conduit's fluid passageway. Preferably, such length is adjustable to adjust the volume of fluid dispensed or metered, and the pinch pump is structured to assure that, during activation of the pinch pump, the captivated fluid is advanced towards the outlet end of the conduit.

Abstract: A blood analyzer system is provided with improved slide making capability by coupling a blood analyzer apparatus to an automatic slidemaking apparatus by means of a clinically effective blood specimen transport assembly, which includes a blood conduit forming a curvilinear flow path that imparts a substantial angular velocity component to blood moving therein. The system enables a blood analyzer portion and a smear slide portion of a given sample to be aspirated with physical and temporal proximity.

Abstract: An improved method and apparatus for making blood smears on microscope slides are disclosed. The method is characterized by the step of temporarily deforming the normally planar surface of a slide on which the smear is being made, rendering it slightly concave in shape. This step has been found to substantially reduce streaking and other artifacts which interfere with the formation of an uninterrupted, substantially uniform monolayer of blood cells on the slide. Preferably, the movement of a blood-smearing member across the slide is controlled as a function of various predetermined physical parameters of the blood.

Abstract: A method and apparatus provide a system for measuring a measurable component in a sample. A sample is introduced into a chamber. A permeable membrane to the measurable component allows the component to pass into a second chamber. In the second chamber the component is measured directly or reacted in the presence of an enzyme to generate a detectable product detected by a detector therein. The second chamber is then flushed. The second chamber is only of a size sufficient to contain enough liquid to wet the detector therein.

Abstract: A separation procedure for separating a selected desired or undesired population from a biological sample utilizing relatively heavy, dense particles and gravity sedimentation. The particles have one or more reactants bound thereto which are specific to and will bind with the selected population. The particles preferably are mixed with the sample by repeatedly causing the particles to settle through a substantial portion of the sample to bind to the selected population. The particles with the bound selected population then are allowed to preferentially settle in the sample and the supernatant including the non-selected population is separated from the particles with the selected population bound thereto. The particles can be heated for sterilization and endotoxin removal.