Abstract: The present invention comprises a miniature pump which can be implanted in the eye for controllably removing excess fluid from the eye to treat glaucoma. The pump, in accordance with the inventive method, may be placed beneath the conjunctiva and/or extraocular muscles. In order to ensure that the right amount of fluid is removed from the eye the pump has a variable pumping rate, which results in a variable rate of removal of fluid from the eye. The pumping rate can be manually adjusted or automatically controlled in response to sensed ocular pressure. In the automatic mode, serious complications such as hypotony are avoided by reducing fluid flow when ocular pressure is low.

Abstract: Access recirculation in a shunt is determined quantitatively by a method in which a standard solution, such as a saline, is injected into a patient's bloodstream upstream of the shunt. At a point in the access line, a photometric measurement is conducted of the change in hematocrit (.DELTA.H) with respect to time. Electronic circuitry receives signals from the detector and compares the integrated area of .DELTA.H with respect to time of the standard solution initially flowing through the access and of the recirculated solution and provides display of access recirculation. In another aspect, access recirculation and access blood flow are quantitatively determined without injecting a solution into the bloodstream. In this aspect the extent of access recirculation and/or access blood flow is determined quantitatively by a method in which the dialyzer blood flow rate or the ultrafiltration rate (UFR) is changed and the corresponding change in concentration of a blood constituent is measured.

Abstract: A compact blood oxygenator has a minimal priming volume and is particularly advantageous for pediatric cardiac surgery. A generally rectangular housing has longitudinally spaced and interspersed heat exchanger conduit groups and oxygenator fiber bundles. The conduits and oxygenator fibers extend transversely across the interior of the housing in criss-cross fashion. Cured potting compound and flanges on the interior surfaces of the housing define hermetically sealed heat transfer fluid, blood and gas mixture flow paths. The inlet and outlet ends of the heat exchanger conduits communicate with first and second chambers formed on opposite sides of the housing. The inlet and outlet ends of the oxygenator fibers communicate with third and fourth chambers on the other opposite sides of the housing.

Abstract: The delivered dose of hemodialysis in large patients is often less the adequate. The present invention provides a method and apparatus for dialysis which increases the clearance of urea in patients weighing 80 kilograms or more. The apparatus is comprised of two dialyzers which may be connected to a patient in parallel configuration. The present invention can be practiced with any commercially available dialyzers and dialysis machines without requiring expensive modifications which negate manufacturers warranties and inherent safety features. The present invention provides a safe, cost effective way to increase the delivered dose of hemodialysis in patients weighing 80 kilograms or more.

Abstract: A blood membrane oxygenator has a housing defining a blood flow path, a rotor hub in the form of a double lumen shaft, and a plurality of distributor disks each having a plurality of hollow fibers which extend across the housing blood flow path. The plurality of distributor disks rotate within the housing to mix the blood resulting in three-dimensional mixing, disruption of the blood boundary layer and efficient blood oxygenation.

Abstract: A hemodialysis and vascular access system comprises a subcutaneous composite PTFE silastic arteriovenous fistula having an indwelling silastic venous end which is inserted percutaneously into a vein and a PTFE arterial end which is anastomosed to an artery. Access to a blood stream within the system is gained by direct puncture of needle(s) into a needle receiving site having a tubular passage within a metal or plastic frame and a silicone upper surface through which needle(s) are inserted. In an alternate embodiment of the invention, percutaneous access to a blood stream may be gained by placing needles directly into the system (i.e. into the PTFE arterial end). The invention also proposes an additional embodiment having an arterialized indwelling venous catheter where blood flows from an artery through a tube and a port into an arterial reservoir and is returned to a vein via a port and a venous outlet tube distinct and distant from the area where the blood from the artery enters the arterial reservoir.

Abstract: A cuvette having a pedestal for transmitting light through a relatively thin layer of blood. While the pedestal enables the use of a small path length it also permits the use of a high volume and/or high flow rate conduit. The pedestal further enables methods of determining various blood parameters in which the path length, d, is fixed; i.e., there are little or no pulsatile variations. Hence, the flow-through cuvette accommodates a large range of blood flow rates without any reduction in accuracy of the hematocrit measurement. The pedestal, because of its elliptical shape, does not damage or hemolyze the individual red blood cells as they pass through. A quantitative method for determining changes in blood volume in view of the path length is provided along with a method for measuring a patient's cardiac output and oxygen consumption rate. Cardiac output is obtained by injecting a saline arterial bolus and a saline venous bolus into a patient and measuring the change in hematocrit caused by each bolus.

Abstract: A softshell blood reservoir for heart-lung machines is symmetrical about a central vertical axis and is divided into two chambers: a small main chamber accessed by the blood inlet and outlet connectors, and a larger storage chamber accessed from the main chamber through a selectably closable passage. This arrangement greatly reduces the priming volume of the reservoir without substantially affecting its total capacity, and enhances the mixing of venous and cardiotomy blood.

Abstract: A method and device for accurately determining the volume of and replacing ultrafiltrate in hemodiafiltration using an ultrafiltrate balance chamber that is subdivided by a movable partition into two balance chamber halves. The two balance-chamber halves being alternately filled, one with ultrafiltrate and the other with substituate, such that the volume of ultrafiltrate is balanced against the volume of substituate. The filling of one chamber with ultrafiltrate or substituate displaces an equal volume of substituate or ultrafiltrate from the other chamber half and diverts the displaced ultrafiltrate or substituate from the balance chamber. The filling volume of the ultrafiltrate balance chamber is used to determine the ultrafiltrate volume or the volume of substituate.

Abstract: A polysulfone hollow fiber membrane for blood purification which has no danger that any component of the membrane dissolves out, and which can be used suitably or hemodialysis and blood filtration and remove selectively and efficiently low-molecular-weight proteins having molecular weight of 10,000 to 30,000 contained in blood, as well as a blood purifier which can be used suitably as a hemodialyzer, a filter for hemodiafiltration and a blood filter are provided. The hollow fiber membrane comprises a polysulfone resin, wherein there are slit-shaped micropores having an average width of 0.02 to 0.15 .mu.m on the inner surface thereof; there are micropores having an average pore size of 0.1 to 1 .mu.m on the outer surface thereof; the inside thereof has a sponge-like structure; there are no large voids having a diameter of more than 10 .mu.m on the inner and outer surface thereof and inside the membrane; water permeability thereof is 400 to 2,500 ml/m.sup.2 .multidot.hr.multidot.

Abstract: A method for making a medical device having a biomolecule immobilized on a substrate surface is provided. The method includes coating the substrate surface with an amino-functional polysiloxane; and contacting the amino-functional polysiloxane coated surface with a biomolecule under conditions effective to immobilize the biomolecule.

Abstract: A vacuum-assisted venous drainage reservoir for cardiopulmonary bypass surgery with both hard and soft shell reservoirs. The system utilizes a wall vacuum or other source of negative pressure to create a negative pressure via a regulator within a sealed hard shell reservoir, or within a sealed housing surrounding a soft shell reservoir. The addition of a negative pressure in the venous return line enables the use of smaller cannulas suitable for minimally invasive surgery. The reservoir need not be positioned well below the patient as in conventional gravity venous drainage configurations, thus adding flexibility to the operating room layout and enabling a reduction in the extracorporeal blood prime volume needed. In one embodiment, a flexible membrane in the hard shell reservoir expands to contact the blood surface and reduce blood/air interactions. In another embodiment, a moisture trap is provided between the source of vacuum and hard shell reservoir to reduce environmental contamination.

Abstract: An apparatus for the treatment of blood or plasma by extracorporeal circulation includes a compartment for the circulation of blood. The compartment is provided with two accesses and has at least one inner surface intended to be coated, after sterilization, with at least one molecular layer of a substance soluble in an aqueous solution. The aqueous solution is capable of increasing the bicompatibility of the inner surface of the compartment. A determined quantity of the substance is deposited inside the blood compartment, at one of the accesses, in a form such that the substance is capable of undergoing, substantially without deterioration, an irradiation capable of sterilizing the apparatus.

Abstract: A system compact enough to be located entirely beside the donor's chair, and able to process the blood while the donor is still resting in the chair after having donated the blood. The separated blood components (plasma and red blood cells) may be stored in their individual optimum environments immediately after the whole blood is drawn, and the blood does not need to be transported back to a separation laboratory for processing. The system includes a needle (72) (or other cannula-like device) for insertion into a vein of the donor and drawing whole blood therethrough, a rotor (2a) for holding the blood after it is drawn, and a motor (50) for spinning the rotor so as to cause the blood to separate into components, for example, plasma and red blood cells.

Abstract: A method for treating conditions associated with ischemia or infarct is disclosed which includes the steps of administering a biocompatible non-blood oxygen carrier while monitoring one or more oxygenation indices to maintain oxygenation of the patient's tissues at or above a predetermined level.

Abstract: A hollow fiber oxygenator includes a housing defining a blood chamber between an inner core wall and an outer wall. The chamber includes at least one blood inlet and at least one blood outlet. A plurality of hollow semi-permeable fibers extend through the chamber. Each fiber has an open inlet and and an open outlet end, the ends being sealed from the chamber by sealings. The oxygenator further includes a gas inlet on one end of the chamber in communication with the inlet ends of the fibers, and a gas outlet on the other end of the chamber in communication with the outlet ends of the fibers. Blood flows into the chamber and across the exterior surfaces of the fibers to effectuate gas transfer therebetween. A partitioning wall divides the chamber into at least two sections. In one of the sections, the blood flow is co-current with the gas flow, while in another section the blood flow is counter-current with respect to the gas flow.

Abstract: Improved apparatus and method for the dialysis of blood. The improved apparatus comprises a subcutaneous port and catheter assembly comprising a connector portion comprising a subcutaneous port element, and a catheter portion comprising a catheter element. The improved apparatus also comprises a novel percutaneous catheter assembly comprising a catheter portion comprising a catheter element, and a connector portion comprising an extracorporeal connector element.

Abstract: An apparatus for treatment of acute and chronic renal disease by continuous passive plasma ultrafiltration includes a plasmapheresis element comprising a catheter and a plasmapheresis filter element secured to the end of the catheter for being implanted in a patient's vena cava or jugular vein, a tube secured to the catheter for receiving and directing blood plasma, a one-way valve for preventing fluid flow from the tube to the catheter, and a container for receiving and collecting the blood plasma. The treatment of the patient is performed by implanting the catheter and plasmapheresis filter element in a patient's vena cava, passing of blood plasma containing the toxins to be removed from the patient's blood supply through the filter element and along the catheter, and collecting and discarding the collected blood plasma.

Abstract: An assembly for being implanted in a blood vessel for carrying out in vivo plasma separation incorporates a plasma extraction capsule formed of a microporous polymeric membrane sheet having a pore size capable of allowing diffusion of plasma, the capsule having one or more interior plasma flow channels and a catheter secured to the capsule and having at least one lumen in fluid communication with the one or more interior capsule channels.

Abstract: A method for providing at least partial bypass of the heart to supplement the pumping function of the heart to thereby enable the surgeon to perform various surgical procedures thereon includes providing a circulatory assist system having a portable extracorporeal axial flow pump with a pump housing, a rotating pumping member disposed in the pump housing and inlet and outlet cannulated tubes respectively connected to inlet and outlet ports of the pump housing, accessing the patient's left atrium of the heart with the inlet cannulated tube, accessing the aorta with the outlet cannulated tube, actuating the rotating pumping member to draw oxygenated blood from the left atrium of the heart through the lumen of the inlet cannulated tube and into the inlet port of the pump housing whereby the pumping member imparts mechanical energy to the oxygenated blood passing through the pump housing and directs the oxygenated blood through the outlet port and through the lumen of the outlet cannulated tube to be transferred