Abstract:
An apparatus and method are disclosed for filtering or separating particles. The apparatus has a centrifuge rotor rotatable about an axis of rotation. A fluid chamber rotates with the rotor. A substance is supplied to the inlet of the chamber. A saturated fluidized bed of first particles forms within the fluid chamber and obstructs flow of second particles through the chamber. Additive substances alter sedimentation velocity of the first particles to modify the filtration characteristics of the saturated fluidized bed.
Abstract:
A pivotable cover secures a pump header or tubing to a peristaltic pump of a dialysis machine. The cover includes an integral raceway for engaging the pump header as a rotor of the peristaltic pump rotates along the integral raceway. The cover is pivoted away from the dialysis machine to separate the raceway from the rotor and provide substantial access for loading the pump header about the rotor. The cover is then closed to secure the pump header in place and properly position the integral raceway in relation to the pump rotor. If the pump header is connected to a blood tubing set, the cover also secures the blood tubing set in position against the dialysis machine. A detachable hinge connects the cover to the dialysis machine to allow the cover to be completely detached from the dialysis machine. The detachable cover provides complete access for cleaning the area surrounding the peristaltic pump rotor and the location where the blood tubing set is located.
Abstract:
A flow rate of a fluid flowing in a tube is quantitatively determined by altering the electrical conductivity of the fluid by injection of a bolus of saline. The electrical conductivity of the altered conductivity is measured over the time it takes the altered conductivity fluid to pass a conductivity measuring location. The measured conductivity is integrated over the time it takes to pass the conductivity measuring location. The integral is interpreted to determine the flow rate.
Abstract:
A process is provided for freezing, including freeze-drying of cells, cell-membranes or cell-like materials using a cryoprotectant medium which stabilizes the cells or membranes for freezing or freeze-drying and allows for freezing or freeze-drying to be performed at -60.degree. C. or higher.
Abstract:
Blood from a patient is treated extracorporeally by any selected one of a plurality of predetermined treatments. Each of the treatments involves the flow of blood from the patient into a primary chamber of a filtration unit, past a semipermeable membrane located in the filtration unit which separates the primary chamber from a secondary chamber of the filtration unit, out the filtration unit and back to the patient. A replacement fluid is selectively and controllably added to the blood, as required for the selected treatment. A secondary fluid is controllably and selectively introduced into the secondary chamber of the filtration unit for controllably collecting material passing across the semipermeable membrane from the blood or for supplying material to pass across the semipermeable membrane into the blood as required for the selected treatment. Materials are removed from the secondary chamber and collected in accordance with the selected treatment. Blood leaks into the secondary chamber are automatically detected and the rates of blood and fluid flow automatically adjusted in response thereto. An apparatus which automatically performs and monitors the selected treatment is also described.
Abstract:
A blood component collection system with optimization capabilities. In one embodiment, the blood component collection system includes a central input station (e.g., computer) and a plurality of blood component collection assemblies. These blood component collection assemblies include a blood component collection device and an operator interface module (e.g., computer). Various types of data are maintained on the collection procedures performed in the blood component collection system and are utilized to generate various types of reports for optimizing system operations.
Abstract:
A method and system are disclosed for more accurate administration of a composition being infused into a body fluid having formed elements. The improved accuracy is due to a correction factor that corrects for the relative impermeability of the formed elements to the infused composition. In one embodiment, the infusion system is a cardioplegia system in which a controller receives information pertaining to the hematocrit and initial blood potassium concentration and adjusts blood flow rate and crystalloid (KCl) solution flow rate so as to obtain the desired resulting potassium concentration in the cardioplegia. The invention further includes an infusion system that comprises a controller which uses an equation that relates the correction factor to an index of formed elements in the body fluid, such as the hematocrit. The equation is determined empirically from a series of experiments in which the resulting concentration of the substance infused into the body fluid is correlated to a formed element index of the body fluid, such as hematocrit.
Abstract:
A technique for automatically priming and recirculating sterile fluid through an extracorporeal circuit of a dialysis machine having a blood pump, a dialyzer, and a blood tubing set including an arterial line for drawing blood from a patient and a venous line for returning the blood to the patient. The dialysis machine selectively opens and closes clamps on the arterial and venous lines and further operates a waste valve for selectively opening and closing a waste line leading to a waste drain. A connector attaches both the arterial and venous lines to the waste line downstream of the arterial and venous clamps and upstream of the waste valve. The dialysis machine automatically operating the blood pump, the clamps and the waste valve to flush the dialyzer and the blood tubing set with the sterile fluid and direct the used fluid down the waste drain. The dialysis machine then operating the blood pump and the clamps to again fill the dialyzer and the blood tubing set with additional sterile fluid and recirculate the sterile fluid through the extracorporeal circuit without the assistance of a dialysis machine operator. The dialysis machine further providing the operator with an indication when the recirculation process is complete. The connector being either one component of the disposable blood tubing set or a permanent component fixed to the dialysis machine.
Abstract:
The biocompatibility of polymeric and metallic articles used in contact with blood can be substantially improved by coating the articles as described. The coating materials are triblock copolymers of the polylactone-polysiloxane-polylactone type. Optimum biocompatibility is provided by a coating of optimum surface concentration. Porous membranes can be coated as described, providing improved biocompatibility of blood oxygenators, hemodialyzers and the like.
Abstract:
The wear on components in a dialysis machine is analyzed for the purpose of making repair and maintenance decisions. The actual performance of components is used to establish a test value. The test value is compared to a threshold value which represents the limits of normal performance of the component. Each instance where the test value exceeds the threshold value is counted and a maintenance count value is developed. The maintenance count value represents the number of abnormal performance events, and the maintenance count value is used to make maintenance and repair decisions. The test value developed for each component varies according to the type of component. The maintenance count values may be displayed for use by service personnel.