Abstract: A method correlates average fiber diameter with performance for a complex filtration media comprising a matrix of fibers having a fibrillated component with a diameter so small (e.g., less than 0.01 microns), that cannot be physically measured with accuracy. The method manufactures a selected matrix, derives the number average diameter of the fibers according to prescribed steps, some of which do not require actual physical measurements, and observes a performance characteristic. The method repeats the foregoing steps for different matrixes, yielding different number average diameters. The method expresses change in the selected performance characteristic as a function of change in number average diameter of the matrices.

Abstract: An extracorporeal blood processing method and system wherein blood is extracted from a mammalian subject through a blood withdrawal tube having a blood pump, such as a peristaltic pump, positioned thereon. A "distal segment" of the blood withdrawal tube extends from the mammalian subject to the inlet side or withdrawal pump. A "proximal segment" of the blood withdrawal tube extends from the outlet side of the blood pump to an extracorporeal blood processing apparatus. An anticoagulant feed tube is connected to the "proximal segment" of the blood withdrawal tube such that a flow of anticoagulant solution may be combined with blood exiting the outlet of said blood pump and passing through the "proximal segment" of said blood withdrawal tubing.

Abstract: Blood processing systems and methods rotate a processing chamber on a rotating element. The processing chamber includes a first compartment and a second compartment. Blood is conveyed into the first compartment for centrifugal separation into components. A liquid free of blood occupies the second compartment to counter-balance the first compartment during rotation on the rotating element. In one embodiment, the second compartment is served by a single fluid flow access. Prior to use, the single access is coupled to tubing, through which a vacuum is drawn to remove air from the second compartment. While the vacuum exists, communication is opened between the tubing and a source of liquid. The vacuum draws the liquid into the second compartment through the single access, thereby priming the second compartment for use.

Abstract: Systems and methods rotate a chamber, in which whole blood is centrifugally separated into packed red blood cells, a plasma constituent, and an interface between the packed red blood cells and the plasma constituent. The interface carries platelets and mononuclear cells. The systems and methods include an interface control unit. The interface control unit is operative in a first state to enable removal of platelet-poor plasma in a first container for use as a diluting liquid. In a second state, the interface control unit retains mononuclear cells in the chamber, while removing platelet-rich plasma from the chamber, bypassing the platelet-poor collection container, thereby maintaining its platelet-poor character. In a third state, the interface control unit enables the removal of mononuclear cells from the chamber in a path that leads to a second container, where the mononuclear cells are collected.

Abstract: Systems and methods convey anticoagulated blood suspension from a donor into a separation device for component separation. One or more components are retained for therapeutic use, while one or more are returned to the donor. The systems and methods monitor the rate at which anticoagulant carried in the returned components is being returned. The rate, expressed in terms of milligram (mg) of anticoagulant per kilogram (kg) of donor body weight per unit of time of blood processing, is compared to a nominal rate that is correlated with donor comfort.

Abstract: A stress-bearing umbilicus for conveying fluid between a stationary body and a rotating body comprises an umbilicus body made from an extruded first polyester elastomer material having flexibility. A support block, made from a second polyester elastomer material, is over-molded about at least one region of the umbilicus body. The second polyester elastomer material has flexibility that is greater than the flexibility of the first polyester elastomer material. Surface energy of the region between the support block and the umbilicus body is increased before over-molding to prevent delamination and peeling.

Abstract: A separation zone for separating platelets from a platelet-rich suspension establishes a relationship between its radial thickness (h) and axial height (Z) that, taking into account the given angular velocity of rotation and the given kinematic viscosity of the platelet-rich suspension introduced through the inlet, represents a (.lambda.) value that is less than 700,where ##EQU1## where: .OMEGA. is the angular velocity (in rad/sec);h is the radial depth (or thickness) of the chamber (in cm);.upsilon. is the kinematic viscosity of the fluid being separated (in cm.sup.2 /sec); andZ is the axial height of the chamber (in cm).

Abstract: A blood processing centrifuge includes a disposable fluid processing assembly having a fluid processing chamber. Fluid is communicated to and from the fluid processing chamber through a flexible umbilicus. The fluid processing chamber spins while the centrifuge pulls the umbilicus around an axis of centrifugation. The centrifuge engages the umbilicus through a thrust bearing received in a gimbal assembly carried on a rotating wing plate. The gimbal assembly allows the umbilicus to pivot relative to the wing plate under the forces developed during centrifugation. The gimbal assembly includes a bearing retainer adapted to securely retain umbilicus thrust bearings of differing sizes a gimbal that loosely but securely retains the bearing retainer. Clearance between the gimbal and the bearing retainer enable the bearing retainer to accommodate thrust bearings of differing sizes without causing gimbal binding.

Abstract: A blood separation system operates in a first mode to convey whole blood into the inlet region of a blood processing chamber for centrifugal separation into packed red blood cells, a plasma constituent, and an interface, which carries mononuclear cells, between the packed red blood cells and the plasma constituent. The system removes packed red blood cells and the plasma constituent from the chamber, while maintaining the interface within the chamber. The system operates in a second mode to remove the interface from the chamber by conveying packed red blood cells into the inlet region. An outlet path conveys the removed interface from the chamber. The outlet path includes a first sensing element to locate mononuclear cells in the removed interface and provide a sensed output upon locating mononuclear cells.

Abstract: A viewing area in a blood separation chamber is monitored for the presence of an interface region between plasma and cellular blood components. Sensed optical density values for the viewing area are compared to a calibrated threshold value to generate a time pulse output. A calibration element derives the calibrated threshold value based upon either (i) a comparison of a sensed reference optical density value in the viewing area to an expected optical density value for the reference material, or (ii) a sensed optical density value of plasma exiting the blood separation chamber, or both.

Abstract: Systems and methods treat biological fluids carrying contaminants by photoactivating materials mixed with the fluids. The systems and methods quantify the photoreactions that occur in a manner that permits correlation with clinical results.

Abstract: Blood filtration devices and methods of filtering are disclosed. In part, a blood filtration device is provided comprising a housing defining an interior periphery. The device includes a rotating structure mounted within the interior periphery and defining with the housing an annular gap within the interior periphery, an inlet fluid path for allowing a blood product to flow into the annular gap, and the rotating structure including an exterior surface that includes a filter membrane. The filter membrane has a coating thereon comprising an insitu condensation product of a first electrophilically active, high molecular weight polyalkylene oxide and a second high molecular weight bifunctional diamino-polyoxyalkylene oxide derivative.

Abstract: Blood separation systems and methods employ a rotating chamber. The chamber includes an inlet region where whole blood enters for centrifugal separation into packed red blood cells, a plasma constituent, and an interface carrying mononuclear cells between the packed red blood cells and the plasma constituent. The packed red blood cells in the chamber have a hematocrit value H.sub.PRBC. A controller operates in a first mode to convey whole blood into the inlet region while removing packed red blood cells and the plasma constituent from the chamber and while maintaining the interface within the chamber. The controller also operates in the first mode to maintain a set H.sub.PRBC by conveying packed red blood cells into the inlet region.

Abstract: Blood processing systems and methods separate blood into constituents including a plasma constituent that includes a platelet volume. The systems and methods detect the optical density of the plasma constituent and generate a first output indicative of the optical density. A processing element integrates the first output relative to the volume of plasma constituent and generates an integrated output. The integrated output correlates to the platelet volume. A second processing element generates a third output based, at least in part, upon the integrated output, which comprises parameters for storing the platelet volume.

Abstract: Viral, bacterial and parasitic contaminants in blood and cell culture containing compositions are inactivated by adding a photosensitizer and a blocking agent to the composition and irradiating the resulting mixture with electromagnetic radiation. Blocking agents reduce photolysis of the photosensitizer by mechanisms not involving the quenching of reactive oxygen species. The blocking agents reduce photolysis which occurs by ring opening. Preferred photosensitizers are quinoline or quinolone.

Abstract: A medical fluid processing device for processing blood or other fluids includes a plurality of hardware elements that perform specific functions. Different processing procedures are achieved by performing the specific functions in appropriately arranged sequences and combinations. A user accessible menu permits user selection of the desired processing procedure. A dual region, user accessible screen provides user interaction with the processing device.

Abstract: Plastic compositions, containers useful in the storage of red blood cells, and methods for providing such red blood cell storage containers and for storing red blood cells are disclosed. The plastic composition includes a polyolefin copolymer and a plasticizer. The flexibility of such plastic compositions and containers made thereof is substantially unchanged upon heating to a high temperature relative to its flexibility before such heating.

Abstract: A controller for a peristaltic pump receives as an input pressure P.sub.i sensed at the inlet of the pump. The controller derives a nonlinear scale factor S.sub.Pi that varies as a step function with P.sub.i. The scale factor S.sub.Pi equals a first nonvariable value when P.sub.i lays in a first defined zone of inlet pressures, and equals a second nonvariable value, different than the first nonvariable value, when P.sub.i lays in a second defined zone of inlet pressures different than the first defined zone of inlet pressures. The controller generates a pump speed command based, at least in part, upon S.sub.Pi.

Abstract: Systems and methods treat plasma carrying contaminants and leukocytes that are capable of entraining contaminants. The systems and methods separate leukocytes from the plasma by filtration, thereby removing contaminants entrained within leukocytes. The systems and methods also add to the plasma a photoactive material and emit radiation at a selected wavelength into the plasma to activate the photoactive material and thereby eradicate the contaminant that is free of entrainment by leukocytes.

Abstract: Apparatus and methods for treating a biological fluid with light and for inactivating contaminants in biological fluid. The biological fluid is contacted with a light source providing a high intensity light to the biological fluid. The biological fluid may include a quantity of a photochemical agent that when activated by light is operable to cause inactivation of at least some of the contaminants.