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: 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 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: 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: 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: A drip chamber includes a cap that extends the field of view of a droplet in a vertical direction above the plane of the droplet, as well as horizontally in the plane of the droplet. The drip chamber has a deformable body and an interior volume to accommodate manual air purging and priming by squeezing the body.

Abstract: A system and method for treating a fluid carrying a contaminant to which a photoactive material has been bound include a treatment device that defines a flow passage with a gap. The system and method operate to establish a flow of fluid from the inlet end of the gap to the outlet end of the gap. The system and method also channel the flow of fluid in the gap in succession through one or more flow paths. The system and method establish at least two discrete sources of radiation in the flow path at spaced apart locations along the direction of fluid flow. At least one of the radiation sources comprises a photodiode. The system and method further include a control for operating each discrete source of radiation at a selected wavelength within the prescribed range to activate the photoactive material bound to the contaminant. Upon activation, the material eradicates the contaminant.

Abstract: A peristaltic pump tube holder includes a body that supports a flexible tubing loop in an erect, outwardly bowed position extending from the body for engagement with a peristaltic pump rotor. The holder also includes a receptacle carrying the body. The receptacle includes a wall forming a chamber that covers the flexible tubing loop and at least partially shields it from contact. The chamber further serves, during engagement between the tubing loop and a peristaltic pump rotor, as a cover for the peristaltic pump rotor.

Abstract: A vessel holds a liquid content for exposure to prescribed light energy. The vessel has a region transparent to the prescribed light energy. The liquid content of the vessel includes a solution comprising a material undergoing reduction oxidation as a result of exposure to the prescribed light energy, and a reducing agent for the photoactive material. A device measures optical absorbance of the vessel and the liquid content. The device operates in a first instance to measure a first optical absorbance value before exposing the vessel and the liquid content to the prescribed light energy. The device also operates in a second instance to measure a second optical absorbance value after exposing the vessel and the liquid content to the prescribed light energy, to obtain a difference between the first and second optical absorbance values. The difference comprises an illumination characteristic for the vessel with respect to the prescribed light energy.

Abstract: Blood processing systems and methods establish on line communication between a container and a source of blood containing leukocytes and platelets, such as a human donor. The systems and methods create a centrifugal field between the source of blood and the container that separates from the blood an unfinished suspension of platelets having a first physiologic characteristic different than the desired physiologic characteristic. The systems and methods pump the unfinished platelet suspension outside the centrifugal field through a finishing device. The finishing device changes the first physiologic characteristic to the desired physiological characteristic, thereby creating the finished platelet suspension. The systems and methods convey the finished platelet suspension from the finishing device directly into the container. The systems and methods function without interrupting the on line communication between the container and the source of blood.