Abstract: An implantable device for providing communication between interior structures of the body and the exterior of the body, the device comprising a rigid tubular member of biologically compatible material including a transcutaneous stem portion defining a stem cavity therein and a plurality of subcutaneous arm portions in fluid communication with the stem portion. A septum closure in the stem cavity provides an interruptable seal between the stem cavity and each of the arms, permitting the arms to be separately accessed by a cannulae or needle.

Abstract: Septum retaining means for an implantable tubular percutaneous device. The retaining means is a tubular stem insert having an integral pressure plate across an intermediate portion thereof. A modified septum fits into the insert below the pressure plate. Tabs extending outwardly from the upper edge of the insert cooperate with a grooved portion of a body exterior cavity in the T-stem to provide means for holding the insert in the T-stem cavity. Notches in the walls of the insert on either side of the tabs allow the wall portions containing the tabs to be flexed inwardly so as to permit the insert to be passed into and out of the T-stem. The insert is designed to permit a forceps or other crimping tool to obtain access to the tab containing insert wall portions for removal of the insert and septum.

Abstract: An implantable blood access device has a matte titanium finish on the exterior subcutaneous surfaces thereof providing sites for tissue ingrowth. A preferred finish is a coating of porous titanium which may be manufactured by fusing titanium powder to the device.

Abstract: A proportioning system for preparing hemodialysis or hemofiltration solutions. The apparatus of the system is a specially plumbed tank containing a flexible plastic container which holds solution concentrate. Introduction of pressurized water into the tank outside the bag discharges concentrate and water through separate paths into a mixing chamber at a rate determined by the size ratio of narrow orifices in the respective paths.

Abstract: A blood pump system in which a roller pump is provided for pumping blood through a flexible tube. A low voltage D.C. motor is provided having an output shaft. An electrical control circuit is connected to the motor for applying the necessary voltage to drive the motor at a predetermined speed. Gearing means are provided connecting the motor's output shaft to drive the roller pump. Means are optically coupled to the motor for controlling the speed of the motor. Means are connected to the optically coupled means to determine the blood flow rate being pumped though the tube by the pump. Means are provided which display a digital readout of the flow rate. The roller pump is provided with an arcuate bearing surface, which carries the flexible tube, the bearing surface defining an arc of approximately 168.degree.. Lead ramps extend from each end of the bearing surface and are substantially tangent to the end of the surface from which the respective ramp extends.

Abstract: A blood pump system in which a roller pump is provided for pumping blood through a flexible tube. A low voltage D.C. motor is provided having an output shaft. An electrical control circuit is connected to the motor for applying the necessary voltage to drive the motor at a predetermined speed. Gearing means are provided connecting the motor's output shaft to drive the roller pump. Means are optically coupled to the motor for controlling the speed of the motor. Means are connected to the optically coupled means to determine the blood flow rate being pumped through the tube by the pump. Means are provided which display a digital readout of the flow rate. The roller pump is provided with an arcuate bearing surface, which carries the flexible tube, the bearing surface defining an arc of approximately 168.degree.. Lead ramps extend from each end of the bearing surface and are substantially tangent to the end of the surface from which the respective ramp extends.

Abstract: A universal dialyzer end cap which provides a connection between a kidney dialyzer and a blood tubing line. The end cap is constructed of a material which allows a firm connection to the dialyzer while at the same time is of a configuration which does not allow blood to contact the surface of the end cap when properly attached to a kidney dialyzer.

Abstract: This invention relates to an ultrasonic flow meter utilizing a conventional tubular member with an inlet and outlet. An ultrasonic transducer is located in the member to transmit and receive ultrasonic energy through liquid flowing through the member. An energizing means is connected to the transducer so that ultrasonic energy can be transmitted through the liquid in the member. Reflector means variably positionable within the member are provided for establishing a position for the reflector means which is proportional to liquid flow rate through the member and for reflecting ultrasonic energy from the transducer back to the transducer. Control means are provided for producing at least a single pulse of ultrasonic energy from the transducer to be transmitted through the liquid and for detecting an echo pulse reflected from the reflector means.

Abstract: A system for preparation of variable hemodialysate in which a controllable pump meters multiple fluid sources of dialysate concentrates and water in controlled proportion. The system includes a plurality of cylinder and piston pump assemblies linked together for simultaneous operation. Individual valves connect the separate pump assemblies to the individual fluid sources to be proportioned. A position sensor provides signals indicative of the position of the pistons throughout their stroke cycle, and with a control operates the control valves associated with the individual pump assemblies in accord with functions of piston position and preselected proportioning control inputs, so as to control the volume of fluid metered by each of the pumps during the pump stroke.

Abstract: A flow-through or fluid coupling connector assembly possessing positive locking connect and ready disconnect comprising two connector bodies; one having a male tubular member, and the other having a female tubular member for receiving the male member upon connection of the two bodies together. The male tubular member of the one connector body has resilient arm members spaced from and extending along opposite sides of the tubular member's axis with the free remote ends of the arms flaring outwardly therefrom. The arm members are each provided with an inwardly projecting flange member for locking the two connector bodies together by fitting into a recessed collar on the other connector body.

Abstract: An ultrasonic air and blood foam detector for use in medical procedures involving extracorporeal handling of blood. A sensor assembly is adapted for positioning about a blood drip chamber and contains ultrasonic transducer means. The blood tube downstream from the drip chamber is preferably placed through the controllable clamp. Electronic circuitry provides excitation to the ultrasonic transducer means and signals transmitted through the chamber are received, amplified and processed by a level detector which provides an output signal for actuating the clamp when a predetermined low signal level occurs, indicating excessive air or foam in the drip chamber. In the preferred embodiment, a clip-on sensor assembly having epoxy lenses is provided.

Abstract: An improved hemodialysis ultrafiltration system. Dialysate input and output pumps are linked to maintain their volume flows substantially equal. A pressure attenuator and a pressure amplifier on the dialyzer dialysate inlet and outlet, respectively, are employed to control dialyzer pressure on the dialysate side. Dialysate output in excess of dialysate input is separated through the action of the dialysate output pump for measurement. The ultrafiltration rate may be controlled through the pressure transformers and the instantaneous ultrafiltration rate and total ultrafiltration volume may be continuously monitored.

Abstract: An improved portable conductivity meter for automatically and rapidly drawing an electrolyte sample and for measuring and providing an accurate output indication of its electrical conductivity, which is independent of temperature variations of the electrolyte. A pen-like dip probe, housing an electrode pair and a thermistor in unique configuration, is designed to rapidly draw an electrolytic dialysate sample whenever the probe is immersed within the electrolyte. A high frequency AC source drives a balanced active measurement circuit, having a reference leg and a measurement leg which contains the electrode pair and the temperature compensating thermistor. The balanced circuit provides measurement and reference output signals of opposite polarity to a summing amplifier which drives a visual conductivity indicator.

Abstract: A blood pressure monitoring system is disclosed as comprising a pressure transducer coupled as by a catheter inserted into the blood vessels of a patient whose blood pressure is to be measured, for providing an output signal indicative of the patient's blood pressure, a filter for removing undesired high frequency components imposed upon the transducer output, a maximum peak detector, a minimum peak detector and a mean detector for providing outputs indicative respectively of the systolic blood pressure, the diastolic blood pressure and the mean blood pressure of the patient. Depending upon the desired indication, the output of one of the aforementioned detectors is coupled by a switch to a processing circuit for applying an output indicative of the patient's blood pressure for a selected period of time to a digital display.

Abstract: A device for detecting the presence of air bubbles within a fluid-carrying tube, for example a blood tube used in medical procedures. The tube is placed between a light source and an optical sensor which produces signals when bubbles pass through the tube. These signals are integrated and a switch changes state when the integration reaches a predetermined value. The detector thus responds to a predetermined quantity of air, either by a large air bubble or an accumulation of small air bubbles. In a preferred embodiment, the switch releases a springloaded clamp which pinches off the tube when an excessive amount of air is detected.