Abstract: A volumetric infusion pump useful in intravenous feeding includes a detector which provides an alarm when the supply bag or reservoir becomes empty or an occlusion occurs between the supply bag and the pump. The pump includes a first pumping chamber having a cylinder, a piston, a first flexible diaphragm and first and second valves. The piston is driven by a first cam through a first cam follower which is connected to the piston. The empty supply bag detector senses contact between the first cam and the first cam follower. During normal operation, when the first valve opens and the second valve closes the first pumping chamber fills due to the head pressure of fluid from the bag, and the cam follower remains in contact with the cam.

Abstract: A new Braille writing slate has a front frame with a parapet on its back side, forming a template in which a blind person can quickly, easily and accurately insert a sheet of Braille writing paper. At the front of the writing slate is a cell plate of conventional design for guiding the writer's stylus appropriately into the paper below. At the back of the cell plate and the writing paper is a hinged receiving plate, also of conventional design. When the receiving plate is forced against the paper, the parapet assures the correct position and pins are engaged through holes, piercing the paper and locking it in the desired position. A back cover is hinged to the writing slate, and the engagement of the receiving plate with the paper is effected simply by a firm closing of this back cover.

Abstract: A warning device for breathing apparatus which has a respiratory gas conduit through which respiratory gases are passed and which includes three interconnected chambers. Two of the chambers include diaphragm valves operable, responsive to pressure conditions therein, to actuate a piston in the third chamber which moves a signaling element into the gas conduit to signal a low pressure condition.

Abstract: A single enclosed chamber includes a lower destabilizing area, a central filtering and coalescence area containing coalescence material, and an upper flotation and separation area. Emulsion is introduced into the lower destabilizing area and is destabilized therein. The emulsion is then passed upwardly into the central filtering and coalescence area. The dispersed phase of the emulsion is attracted to the coalescence material in the form of droplets, and as the emulsion continues to pass upwardly therethrough the droplets grow in size. During passage of the emulsion through the filtering and coalescence material, matter in suspension is filtered from the emulsion. Within the flotation and separation area is located a separation device including a lower convergent portion and an upper divergent portion.

Abstract: A medical infusion system is described employing a pump for conducting fluid or semi-solids from an upstream portion to a downstream portion of the system. The pump includes upstream and downstream conduit means and a removable cassette communicating between the two. The cassette has a window therein and a diaphragm spans the window. The cassette has inlet and outlet openings valvelessly communicating with the pumping chamber or cavity of the cassette. Fluid in the conduit is pumped by restricting and opening the conduit means at upstream and downstream locations, and displacing the contents of the cassette pumping chamber appropriately.

Abstract: Production of a polyurethane embedding material from an aromatic diisocyanate in stoichiometric excess with a polyol mixture consisting essentially of castor oil and trimethylolpropane to first form a prepolymer containing unreacted isocyanate groups and being sufficiently flowable to permit coating onto membrane surfaces in all types of coating methods, and subsequently hardening the prepolymer by addition of a cross-linking agent consisting essentially of castor oil alone or another mixture of castor oil with trimethylolpropane in an amount sufficient to cross-link the prepolymer through at least a majority of its unreacted isocyanate groups. The products obtained in the invention are the embedding materials or the resulting hardened or cured embedded products or more simply "bedded" final products which have excellent properties particularly adapted to the mounting of semipermeable membranes in dialysis equipment to give an improved and more useful construction.

Abstract: Apparatus for the transfer of substances between two fluids with the simultaneous tempering of at least one of the fluids. The apparatus includes at least one heat permeable membrane having first and second opposing surfaces for the transfer of heat therethrough. First and second fluid conducting means are provided for conducting a first and second fluid, respectively. Transfer means are provided for transferring substances between the first and second fluids. The second fluid conducting means conducts the second fluid along the first surface of the heat permeable membrane and third fluid conducting means are providing for conducting a third fluid along the second surface of the heat permeable membrane for tempering the second fluid. According to the preferred embodiment, the transfer means may comprise either means for directly mixing the first fluid into the second fluid or may comprise a semipermeable membrane for diffusing substances therethrough between the first and second fluids.

Abstract: A valve assembly for a fluid filter includes a rotatable valve spindle movable with respect to the value housing and having first and second channels communicating with the filter, the channels also communicating with first and second bores of the housing when the spindle is in a first position in which fluid flows through the filter. The valve spindle further includes a third channel to provide a bypass around the fluid filter when the spindle has been rotated to a second position. The valve spindle also includes seal means for sealing the first and second bores when in the second or filter bypass position, which means includes a pair of chambers arranged to be aligned with the bores and a seal member within each chamber arranged to seal the respective bores. Each seal member has an aperture providing communication between its chamber and its respective bore to allow fluid to enter and charge the chambers for forcing the seal members against the bores in fluid tight sealing engagement therewith.

Abstract: An improved dialyzing and ultrafiltering device is disclosed, for extracorporeal blood dialysis, the main improvement comprising a more efficient connection means, a net for supporting the dialyzing membrane having a rectangular mesh-pattern with the weft threads of the net having an undulated arrangement. Improved means are disclosed for the assemblage of the apparatus and for ensuring reliable sealtightness.

Abstract: An improved electroplating apparatus comprises a nonlinear array of treating tanks having a central rinse tank. A hoist motor is located on a fixed support structure above the rinse tank. A traversing guide engages a hoist cable to move the cable around the array of treating tanks. An insulating canopy surrounds the array to conserve waste heat given off by any heated treating tanks. A plurality of shower nozzles is located around the rinse tank for rinsing off any articles carried thereto by the hoist cable. The rinse water is heated by the waste heat conserved by the insulating canopy. The rinse discharge from the rinse tank can be conducted to a concentrating device for concentrating any contaminants contained in the rinse discharge.

Abstract: An intravenous needle assembly and an associated manufacturing method, wherein the needle assembly comprises a hypodermic needle attached to a hub at its trailing end, a transparent blood detection chamber integral with the hub, a catheter disposed around the needle and the needle hub and a plug closing the blood detection chamber, the plug having air breathing capacity so that upon venipuncture blood from a vein may flow through the needle into the blood detection chamber without substantial air resistance to such flow to visually confirm the accuracy of the introduction of the needle into a vein. The plug is centrally hollow and has an axially directed leading projection connected to an annular shoulder or flange. The projection comprises a symmetrical hollow truncated conical extension with a hollow interior and walls having pairs of longitudinally directed ribs insuring ready passage of air from the flashback chamber along the outside of the projection under pressure of the heart.

Abstract: A process is disclosed for recovering re-usable bitumen from waste bituminous roofing felt and the like. The waste material is cooled, preferably to 0.degree. C. to 5.degree. C., and then comminuted to a particle size less than 5 mm, for example using a flail. The comminuted material is added to water and the material which floats is collected, melted and then filtered to remove particulate or fibrous impurities. Additives may be added to the molten material to adjust its melting point, according to the eventual use of the recovered bitumen. Any fibrous impurities filtered out may be treated with white spirit or kerosene to extract further bitumen, which is then recovered from the solvent.

Abstract: Portable hemodialysis apparatus which can be used for dialysis and/or ultrafiltration, or hemoperfusion. Separate circuits are provided for blood and for the ultrafiltrate and the dialysis solution. The blood circuit includes a pump in which the flexible tube is periodically throttled, causing blood to be drawn from the patient and advanced under pressure through the blood circuit. A similar pump is included in the circuit for the dialysis solution. The output side of the latter pump is selectively connectable either with the inlet of the dialyzer or with an ultrafiltrate collection station, while the input side of the latter pump is selectively connectable with the outlet of the dialyzer either through the dialysis liquid supply tank or directly via a shunt line. A lighter auxiliary tank is also provided for temporary freedom of movement with respect to the normal supply tank.

Abstract: A filter apparatus comprising a gravitional extraction section 1 and a high pressure section 3. In the high pressure section 3 there is a rotatable drum 35 around which a pair of filter bands 4,5 on carrier belts 6,7 are advanced with means for applying pressure to the belts to squeeze the bands and belts together to expel water from the sludge 13 through open-topped channels formed in the carrier belts. An intermediate section 2 for applying medium pressure to the sludge may be provided and the bands and belts are continuous. Various special features like cleaning, different pressure loading systems, and driving means and other modifications are described but the principle is to progressively increase the pressure by advancing the sludge between the belt and carrier assembly and to arrange for the water expelled to be diverted through the channels 8,9 in the carrier belts with no frictional drag between the respective bands and belts as they advance at the same speed.

Abstract: A water filter, in particular for aquarium water, comprises a filter chamber having a water inlet and a water outlet and being filled with exchangable filter material, as well as a boost pump arranged downstream of the water outlet. The filter chamber is defined by an annular space between two concentric tubes of different diameters, the outer tube having as water inlet a perforation arranged spaced around its entire circumference and its entire length and the inner tube likewise being provided with a perforation around its entire circumference and its entire length. At one end of the inner tube, a water outlet line is connected, while the other end of the inner tube is closed. With this structure, the entire filter material employed may be completely utilized, and also, the exchanging of the filter material is simpler.

Abstract: The ultra-filtration in a hemodialysis operation is controlled by a control apparatus which is connected to a balancing device (1) and to a dosing device (9) to form a closed loop control circuit for the metered supply of dialysis concentrate into the balancing device and for the metered supply of fresh dialysis solution into the dialyzer. The closed loop control circuit controls the alternating supply of fresh dialysis solution into one chamber of a balancing device and the withdrawal of used-up dialysis solution from the other chamber of the balancing device. The closed loop control circuit also controls a pump for the metered withdrawal of used-up dialysis solution out of the dialysis circulatory system. The dosing device operates as a proportionality device to produce fresh dialysis solution from water and dialysis concentrate whereby the concentrate is dosed and the dialysis solution is also dosed or metered.

Abstract: An apparatus for controlling the ultra-filtration in connection with a hemodialysis treatment comprises a plurality of storage containers for the dialysis liquid. These containers are connected in parallel to each other and to the circulatory system of the dialysis liquid by groups of valves which are controlled by an automatic timer mechanism in such a manner that these containers are operatively connected to the circulatory system in a timed sequence. The groups of valves are operatively connected to the inlet and outlet ports of these containers. In addition to the main pump for circulating the dialysis liquid, there is a branching pump for withdrawing a dialysis liquid proportion from the system and a pump for filling the containers with a fresh dialysis liquid.

Abstract: A dialyzing membrane, especially for hemodialysis, formed as a hollow fiber, tubular foil or flat sheet by regeneration of cellulose from a cuprammonium solution, the membrane comprising at least two firmly adhered cellulosic layers including at least one dialyzing layer consisting essentially of a semipermeable regenerated cellulose and at least one adsorbent layer consisting of said regenerated cellulose containing embedded therein fine particles of an adsorbent material in an amount of up to 95% by weight with reference to the dry weight of the adsorbent layer, preferably 1 to 90% and especially 20 to 70% by weight, when the adsorbent layer is part of a hollow fiber structure.

Abstract: A filter assembly (10) for use in the filtration of medical treatment liquids is disclosed. The filter assembly (10) includes a strip of porous filter media (12), first enclosure means (14), and a second enclosure means (16). An inlet connector (18) is connected to inlet end (20) of the filter assembly (10) and an outlet connector member (22) is connected to an outlet end of the filter assembly (10). The first and second enclosure means (14), (16) are formed of strips of flexible plastic material having longitudinal edges (30), (40) which are ultrasonically welded to the filter media (12). Dimples (36), (42) are formed in the first and second enclosure means (14), (16), respectively, and are ultrasonically welded to the filter media (12).

Abstract: A device for separating a mixture of, for example, oil and water consists of a number of elements treating the mixture in stages, said elements being arranged in overlying position in order to manufacture a compact device.