Abstract: A heat exchanger (38) is provided which may be used in a mass transfer device (20), such asn an oxygenator or a dialyzer. The heat exchanger comprises a core (40) formed of a corrugated metal having a high thermal conductivity. Each of the corrugations of the core comprises substantially parallel side walls (70, 72). A first fluid, such as blood, is introduced onto the outside of the core. A second fluid, such as water, is introduced into the inside of the core. The first and second fluids will be in heat exchange relationship with each other and the flow of the fluids is substantially uniform resulting from the substantially parallel side walls of the corrugations. The core is formed by providing a flexible metalhose, annealing the flexible metal hose, compressing the annealed hose and expanding the compressed hose to a length that is substantially less than its original length but greater than its length during compression.

Abstract: A container such as a nursing container, and packaging arrangement are disclosed of the type employing a rigid outer sleeve or holder and a flexible inner container. The inner container is pre-filled and sterilized and attached to an access assembly such as a nipple assembly for dispensing the contents. The access assembly, in one embodiment, is attached to and closes one end of the sleeve. In another embodiment, the access assembly is enclosed by the outer sleeve, one end of which is frangibly removable to access the access assembly. A flexible sheet may also be provided to simultaneously seal the ends of a plurality of containers and join them together in an integral packaging arrangement.

Abstract: A flexible tubing occluding device is provided for releasably occluding flexible tubing. The tubing occluding device includes housing that is adapted to receive the tubing and defines a tubing occluding surface against which a transverse section of the tubing is transversely urged and compressed when in an occluded position. A wedge-shaped tongue member is provided for urging the transverse section of the tubing against the tubing occluding surface. The geometry of the tubing occluding surface and the wedge-shaped tongue member cooperate to distribute a relatively low amount of force at the center portion of the occluded tubing and a relatively large force at the distal ends of the occluded tubing, utilizing the mechanical advantage of the wedge-shaped tongue member.

Abstract: A medical fluid administration set and a drip chamber (10) for use on the administration set are disclosed. The drip chamber (10) may be used with conventionally available drop counters whereby fluid flow can be monitored. The drip chamber (10) is intended for incorporation into a medical fluid administration set. At least a portion of the inside surface of the drip chamber (10) has a matte or satin finish (20) as distinguished from a glossy finish. The matte finish (20) alters the surface characteristics between solution residing in the drip chamber (10) and the drip chamber (10) itself, thereby preventing substantial upward splash back or bounce back of liquid drops impacting the surface of the fluid in the drip chamber (10) which splash back or bounce back can result in erroneous flow rate indications.

Abstract: A system is disclosed for priming an ultrafiltration unit (10) connected to a blood source, without requiring a pump in the blood line. An ultrafiltration unit (10) is provided having an ultrafiltration membrane which separates a blood compartment from an ultrafiltrate compartment, a blood inlet port (12), a blood outlet port (14), a second inlet port (16) communicating with the ultrafiltrate compartment, and an ultrafiltrate outlet port (18). A feedback tube (38) connects the blood outlet port (14) to the second input port (16). Priming solution (36) is introduced to the blood inlet port (12) and a vacuum is applied to the ultrafiltrate outlet port (18). The priming solution (36) is drawn through the blood compartment, through the ultrafiltrate compartment, out the ultrafiltrate outlet port, and to drain.

Abstract: A novel roller clamp is described for controlling flow of fluids in flexible tubing used for intravenous fluid administration to a patient. The roller clamp includes a unique placement means to enhance placement of a roller within a clamp body or frame. The novel placement means includes angular portions disposed in an infeed section of the frame. The angular portions form an angle greater than 90 degrees with a side wall portion of the frame to encourage upward movement of the roller during insertion onto guide surfaces in the frame of the clamp.

Abstract: The present invention provides a fast, efficient and precise method and apparatus for compounding a large number of solutions for use in hyperalimentation therapy. The apparatus includes a host computer which maintains a data base of prescriptions to be compounded, and a high speed compounding apparatus connected to the host computer for compounding mixtures of base solutions in response to information supplied by the host computer from the prescription data base.Information can be entered concerning patients or prescriptions through a video display tube into the host computer data base. The host computer also includes provisions for a library of prestored standard prescriptions which can be recalled and associated with a given patient. A group of prescriptions to be compounded is first sorted in accordance with the types of specified base solutions and optionally sorted again based on the concentration of base solutions.

Abstract: A method and apparatus of collecting a desired end-point weight amount of material first conveys the material into the collection container until a predetermined weight amount is collected. The predetermined weight amount is less than the desired end-point weight amount by a selected initial weight offset amount. An additional incremental amount of material is next conveyed into the container for a predetermined fixed time period. In doing so, the method and apparatus gauge the particular flow characteristics of the associated flow system. A further additional incremental amount of material is conveyed into the collection container for another time period, the length of which reflects the anticipated flow characteristics of the system, based upon the performance of the system during the preceding period. The method and apparatus repeat this sequence until the then-existing weight amount equals or exceeds the desired end-point weight amount.

Abstract: A process is provided for detecting if a temperature sensor (18) is correctly located in a heating conduit at a point that is remote from the heater (28). Power is applied to the heater (28) in a predetermined manner. The change in the temperature sensed by the temperature sensor (18) is observed. If the temperature sensed by the temperature sensor (18) has changed in a certain manner, a signal is provided indicating that the temperature sensor (18) is located correctly. If, during observation, the temperature sensed has not changed in the certain manner, an alarm signal is provided.

Abstract: A venous reservoir is provided in which a blood inlet (42) is located at an inlet end (70) of the container (48) which extends upwardly with a fast rise and for a sufficient distance to allow the blood entering the inlet to enter a large volume and to expand rapidly. The top (74) of the inlet end wall (70) of the container communicates with a vent outlet (46) whereby a sharp decrease in the velocity of the blood flow resulting from its rapid expansion provides buoyancy to air in the blood causing air bubbles to rise to the top of the container and be vented through the vent opening. A top wall (76) of the container extends from the vent opening and toward a blood outlet (44), with the top wall being curved in a manner to prevent the velocity of blood from increasing until the blood is substantially at the blood outlet.

Abstract: A heater-scale having a curved supporting member upon which a bag of fluid to be heated can be placed, has a distributed two-dimensional heating element affixed to a lower surface thereof. The curved member is supported by a load cell for generating an electrical signal proportional to the weight of the bag on the heater member, a thermistor is in contact with the fluid whose temperature is to be maintained, a thermistor is affixed to the heater member, and a control system senses the weight and temperature of the bag of fluid as well as the temperature of the heater member for the purpose of nonlinearly adjusting the electrical current supplied to the heater element as fluid is removed from or variable temperature fluid is added to the bag so as to maintain the bag at a predetermined temperature.

Abstract: A self-checking timer usable with a host system includes a clock and a plurality of interconnected counters. During a power-up phase the timer generates a system reset signal and counts the counters in a predetermined sequence. A flip-flop is set and reset during the power-up phase and inhibits generation of the system reset signal. During a normal operating phase, the timer generates a test signal that must be responded to by the host system to continuously inhibit generation of the system reset signal.

Abstract: A flexible tubing occluding device is provided for releasably occluding flexible tubing. The tubing occluding device includes housing that is adapted to receive the tubing and defines a tubing occluding surface against which a transverse section of the tubing is transversely urged and compressed when in an occluded position. A wedge-shaped tongue member is provided for urging the transverse section of the tubing against the tubing occluding surface.The geometry of the tubing occluding surface and the wedge-shaped tongue member cooperate to distribute a relatively low amount of force at the center portion of the occluded tubing and a relatively large force at the distal ends of the occluded tubing, utilizing the mechanical advantage of the wedge-shaped tongue member.

Abstract: A switch and decoder circuit and method of reading same includes a 4 to 16 line decoder latch for selectively enabling up to 14 manually settable switches, each of which generates a BCD code in response to a switch setting, a plurality of thumb wheel switches each of which is selectively enabled by the decoder latch are connected in parallel to a data bus which can then be sensed by associated circuitry. Two pseudoswitches are provided which may be selectively enabled by the decoder latch and which gate onto the address bus two known, non-BCD codes for hardware checking purposes. A control program in an associated processing unit through input/output circuitry can select a switch whose outputs are to be sensed, read asserted and negated values for the switch, compare the values to a predetermined range of allowable values, and cycle the pseudoswitches to determine whether or not the hardware is functioning properly.

Abstract: A humidifier (10) used in respiratory therapy is disclosed where the surface tension of a light probe (32) used therewith is maintained greater than the surface tension of the aqueous liquid used in the humidifier (10). Maintaining the surface tension of the light probe (32) greater than the surface tension of the aqueous liquid generally avoids erroneous indication of aqueous liquid level in the humidifier (10). Erroneous indications of liquid level can be caused by gas bubbles adhering to submerged portions of the light probe (32) or liquid droplets adhering to unsubmerged portions of the light probe (32).

Abstract: Antimicrobial compositions finding particular utility for coating access systems, lead devices including shunts, cannulae, catheters, catheter adapters, wires and other solid or hollow tubular devices used for a variety of medical purposes is provided. The composition comprises a material selected from the group consisting of acrylonitrile-butadiene-styrene copolymers, polyvinyl chloride, mixtures thereof, polyesters, polyurethanes, styrene-block copolymers, natural and synthetic rubbers, polycarbonates, nylon and silicone rubber mixed with an oligodynamic material consisting essentially of compounds of physiological, antimicrobial metals.

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. By accurately monitoring both arterial and venous pumps operating cycles, ultrafiltration volume and rate may be determined.

Abstract: An occluder valve for closing off the flow of fluid in a flexible plastic tube includes a linearly movable pinch member coupled to a rotatable shaft through a nut. The shaft is coupled to an electric motor through an electrically energizable clutch. The output shaft of the motor is mechanically constrained to rotate in only one direction. The motor, coupled through the clutch, rotates the shaft causing the pinch member to move linearly away from the tubing. A torsion spring opposes this rotation. Once opened the valve will stay opened as long as the clutch is energized as the shaft of the motor will not rotate in a closing direction. To close the valve, the clutch is deenergized and the torsion spring moves the pinch member linearly against the flexible tubing closing it off.

Abstract: A nebulizer is provided which includes a liquid container and a cap attachable thereto. The cap includes a outlet port for delivery of a nebulized liquid/gas mixture to a patient, a gas inlet, a venturi in communication with the gas inlet, a conduit through which liquid may be circulated in the cap and heated by an external heater, a liquid outlet adjacent the end of the venturi, so that the gas flowing through the venturi draws out the liquid, and a dial rotatable on the cap. The dial has windows which may be positioned over openings in the cap to allow air from the environment to enter the cap and dilute the gas to a desired concentration. The dial engages the cap securely once its position is set on the cap, so the gas concentration is not inadvertently changed during use of the nebulizer.