Abstract: A tubing occluder pump is provided that includes a structure for occluding flexible tubing that distributes a relatively low amount of force at the transverse center portion of the tubing during occlusion and a relatively large force at the distal transverse ends of the occluded tubing, utilizing a mechanical advantage. The occluding structure includes a recessed first occluding surface and a projecting occluding surface. The tubing occluding surface is configured so that one-half of a transverse section of occluded tubing generally conforms to its original shape and so that most of the strain energy stored within the occluded tubing is utilized to return the other half of the tubing to an open position. The occluding structure may form part of either a peristaltic pump or a linear pump.

Abstract: A monitor and control system for water purification apparatus includes first and second conductivity cells located in the input water path and the purified product water path of the apparatus, respectively. The conductivity cells produce output signals exhibiting amplitudes representative of the impurity concentrations in the respective water paths. These signals are detected and modified by circuitry which imposes logarithmic characteristics upon the two signals. The two logarithmically variable signals are differentially combined to produce a signal for display which is representative of the percent of impurity rejection of the water purification apparatus. The detected signal are also individually combined with signals representative of the temperature of the water being processed. The temperature-corrected signals are then displayed to provide an indication of the impurity concentrations of the input and purified water paths in parts per million.

Abstract: Automated peritoneal dialysis apparatus for providing dialysis solution to a patient and including bracket means for receiving and holding a multiple junction connector of a flexible conduit set member carried by the apparatus. The bracket means is adapted to hold the multiple junction connector in only a single position of orientation whereby flexible conduits of the set member extending from the connector are naturally directed toward their intended destination stations.

Abstract: The present invention provides an accurate method and apparatus for monitoring the drop flow rate from a fluid source. The drops are indirectly sensed by piezoelectric means mounted on a drip chamber when the drops impinge on a fluid surface in the chamber. The chamber can include a second differential piezoelectric sensing element, which provides a noise reference signal which can be subtracted from the drop sensing signal. The volume of the fluid drops sensed can be determined. The sensing element can be incorporated in open and closed loop disposable chamber modules which can include both monitoring and occlusion valving functions integral therewith.

Abstract: An apparatus for separating and collecting plasma from whole blood includes a ratio control system which enables replacement fluid to be added by a replacement fluid pump within the apparatus to processed plasma-deficient blood at a predetermined ratio to the volume of plasma collected in a collection container. A transducer within the system develops an electrical signal frequency-dependent on the weight of the collected plasma. This signal is applied through a first rate multiplier circuit to the up-count input of a bidirectional counter. A second signal derived from a tachometer on the replacement fluid pump is supplied through a second rate multiplier circuit to the down-count input of the counter. A digital-to-analog converter converts the count in the counter to an analog control signal which controls the operation of the replacement pump motor. The multiplication factors of the rate multipliers are set by a user-operated switch to obtain a desired replacement ratio.

Abstract: A container is disclosed for maintaining its contents at a desired temperature for an extended period of time such as for use in shipping contents in a frozen condition. The container includes an outer shell which is substantially airtight and which has an inner surface; a passive heat exchange medium; a support structure for the heat exchange medium; and means for maintaining an air space between the contents of the container and substantially the entire inner surface of the outer shell of the container and between the contents of the container and the support structure for the heat exchange medium for allowing convection current to develop in the air space which circulates past the heat exchange medium and maintains a substantially uniform temperature around the contents of the container.

Abstract: A cannula support assembly comprises a hub subassembly, which supports the cannula, and a cover subassembly, which attaches to the hub subassembly to sealingly enclose the cannula prior to use and which can be easily removed from and subsequently reattached to the hub subassembly, if desired. Each subassembly is itself preferably fabricated from one or more individually extruded component parts which can be assembled together in a manner lending itself to cost efficient, automated production techniques and which thereby obviates the use of substantially more costly injection molded or compression molded plastic parts. The resulting support assembly is durable, easily attachable to flexible tubing, and readily adaptable to diverse uses, such as a hub and cover for a phlebotomy needle or an inline sampling needle.

Abstract: A medical liquid administration set is disclosed for the sequential administration of two medical liquid sources which can be delivered at different liquid flow rates without readjustment of the administration set. The set includes first and second conduits for connection to first and second medical liquid sources, respectively. A cross-over branch places the second conduit in communication with the distal end of the first conduit. A common conduit extends downstream of the first conduit and cross-over branch. The common and second conduits are in communication at their downstream ends, just upstream of the set outlet. Separately adjustable liquid delivery rate control means are disposed on the common and second conduits to allow for separate delivery rates of the first and second liquid sources. One-way valves are disposed in the cross-over branch and the first conduit to permit liquid flow only in the downstream direction.

Abstract: A dialysis solution, typically a peritoneal dialysis solution, comprises a water solution of physiological pH, having physiological salts and glycerine present in concentrations sufficient to safely effect the removal of solutes and water from a patient by peritoneal dialysis.

Abstract: An elastic port protector closing the end of a tubular port, typically on a peritoneal dialysis solution or parenteral solution bag. The port protector defines an outer tubular section having inner and outer ends, and with an inner diameter which is less than the outer diameter of the tubular port on which it is intended to reside. An inner tubular section is connected to the outer tubular section at the outer end and is capable of occupying the bore of the outer tubular end in telescoping relation thereto. The inner tubular section has an outer diameter greater than the inner diameter of the tubular port, to fit into the bore of the tubular port in sealing relation. Handle means is carried on the outer tubular section to aid in removal of the port protector.

Abstract: A container for pooling plasma and the like has an integral cap. The cap includes an air vent with an inline bacterial filter. The cap also includes a fluid passage to which a length of tubing is integrally connected. The tubing includes at its unattached end one or more connector members which can be coupled to a fluid source to enable fluid to be transferred into the container via the tubing. The connector members are releasably secured to the cap prior to use. After fluid transfer is complete, the transfer tubing is sealed and severed close to the cap. The cap includes a pocket which receives the remaining sealed end portion of the tubing to protect the sealed end portion from inadvertent contact and damage during subsequent handling. The cover includes a plug which can be moved into a position which hermetically seals the vent and, thus, the entire container.

Abstract: An automatic cycler for performing Continuous Cycling Peritoneal Dialysis (CCPD) and Intermittent Peritoneal Dialysis (IPD) is provided. The apparatus of the present invention is a safe and convenient cycler apparatus for performing peritoneal dialysis in either home or clinical environment. The apparatus provides a stable base by storing dialysate at a relatively low position. Tubing administration set length is reduced to a minimum by the use of individual, separated valves and by the elimination of redundant, duplicate tube sections. Administration set complexity is reduced by the use of a conventional design dialysate container for heating and weighing of an infusing dialysate dosage. The apparatus allows for gravity feed to a patient with an optional capability of adjusting the pressure head for the gravity feed.

Abstract: A container is disclosed having a semi-rigid or rigid shell, a co-extensive flexible liner weakly or temporarily adhered to the shell and an access site defined in the container wall to which an access assembly may be attached. The access site is preferably defined by an annular fold in the container wall which tightly captures the liner to provide a mechanical peripheral seal between the shell and liner around the access site to prevent leakage of liquid, into the area between the shell and liner. The container is particularly useful as a nursing container, including a nipple access site with an attached nipple assembly.

Abstract: A system is provided for increasing the control accuracy of a motor 12 which feeds back a signal to a motor control circuit 14. The motor control circuit output 20 provides a command voltage to the motor winding. The motor control circuit 14 has an input 18 for receiving an input command from a source external of the motor 12. The actual speed of the motor shaft 26 is sensed and data representative of this actual speed is transmitted through a frequency to voltage converter 36 and an analog to digital converter 40 to a microprocessor 46 which calculates an input command based upon the received actual motor speed data. The input command is transmitted from the microprocessor 46 through a digital to analog converter 58 to the motor control circuit input 18. The command voltage from the output 20 of the motor control circuit 14 is adjusted in response to variations in the input command transmitted from the microprocessor 46.

Abstract: A transmembrane pressure regulator especially useful in artificial kidney systems. The regulator will maintain a pre-selected dialysate pressure at a substantially constant value despite changes in dialysate flow. The regulator of the invention will adjust dialysate pressure in response to changes in a patient's venous blood pressure so as to maintain a transmembrane pressure substantially constant at a preselected value.

Abstract: A connection may be formed between sealed conduits in which each conduit carries an opaque, thermoplastic wall portion preferably having a melting range above essentially 200.degree. C., preferably with the opaque thermoplastic wall portions being carried on the conduit about their periphery by transparent wall portions of the conduit. The opaque wall portions of the conduits are brought together into facing contact, and then exposed to sufficient .Iadd.electromagnetic .Iaddend.radiant energy to cause the opaque wall portions to fuse together, and to open an aperture through the fused wall portions. This provides sealed communication between the interiors of the conduits.

Abstract: A molded collapsible solution container, which is made from a tubular, plastic parison, defines a body portion having an integral neck portion and shoulder portion at one end thereof. The container is sealed at its opposite end. The body portion defines, in as-molded configuration, a generally oval cross-section taken perpendicular to the axis of the container, adjacent the neck and shoulder portion. The cross-section tapers progressively to a flat configuration at the end of the container opposite to the neck and shoulder portion, which facilitates a uniform manner of flat collapsing of the container progressively from the opposite end toward the end adjacent the neck and shoulder portion as the contents thereof are withdrawn through the neck portion, when the container is disposed in neck downward position.