Cobe Laboratories, Inc.

Gambro, Inc.

Vasca, Inc.

Vasco, Inc.

George W Buffaloe, Iv

James M Brugger

Francis T Ogawa

Jeffrey H Burbank

Charles David Finch

Gerald Beathard

Methods and apparatuses for determining a fluid parameter in a vessel by altering a property of the fluid, sensing the difference in the property after the fluid is altered, particularly as related to the property in an unaltered portion of the fluid.

Differential fluid parameter determination

Method and apparatus for quantitatively determining a degree of recirculalion flow in a vessel of a fluid by altering the electrical conductivity of the fluid, sensing the difference in electromagnetic field after the fluid is altered, and integrating the sensed difference over a period of time including any time of potential recirculation of any altered conductivity fluid.

Differential conductivity hemodynamic monitor

A body lumen access system comprises a distal access cannula and a proximal access cannula. The distal access cannula is attached to or within the body lumen and the proximal access cannula is attached to an implantable port or is transcutaneously positioned and attached to a luer or other external connector. The distal and proximal access cannulas are usually implanted separately, cut to length, and attached at a subcutaneous junction location. Preferably, the proximal access cannula has a larger lumen diameter than that of the distal access cannula in order to reduce flow resistance within the cannula system. In some cases the distal and proximal access cannulas may be formed integrally. Replacement of a proximal portion or distal end may be performed by accessing the cannula, removing either the proximal portion or distal end, and reattaching a replacement portion of the cannula.

Method and systems for establishing vascular access

A body lumen access system comprises a distal access cannula and a proximal access cannula. The distal access cannula is attached to or within the body lumen and the proximal access cannula is attached to an implantable port or is transcutaneously positioned and attached to a luer or other external connector. The distal and proximal access cannulas are usually implanted separately, cut to length, and attached at a subcutaneous junction location. Preferably, the proximal access cannula has a larger lumen diameter than that of the distal access cannula in order to reduce flow resistance within the cannula system. In some cases the distal and proximal access cannulas may be formed integrally.

Methods and systems for establishing vascular access

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.

A differential conductivity recirculation monitor quantitatively determines the degree of recirculation in a fistula by comparing the conductivity of blood entering the fistula to the conductivity of blood being withdrawn from the fistula. A discrete quantity of a high conductivity marker fluid is injected into the blood entering the fistula, altering the conductivity of the blood entering the fistula. The altered conductivity blood enters the fistula and, if recirculation is present, co-mingles with blood in the fistula, altering the conductivity of the blood in the fistula in proportion to the degree of recirculation. Blood withdrawn from the fistula has an altered conductivity related to the degree of recirculation. Quantitative values of the conductivity of the altered conductivity blood entering the fistula and the conductivity of the blood being withdrawn from the fistula are measured and a difference determined. The determined difference between the conductivities is used to determine a quantitative measurement of the degree of recirculation in the fistula.

Altered fluid conductivity monitor

A differential conductivity recirculation monitor quantitatively determines the degree of recirculation in a fistula by comparing the conductivity of blood entering the fistula to the conductivity of blood being withdrawn from the fistula. A discrete quantity of a high conductivity marker fluid is injected into the blood entering the fistula, altering the conductivity of the blood entering the fistula. The altered conductivity blood enters the fistula and, if recirculation is present, co-mingles with blood in the fistula, altering the conductivity of the blood ion the fistula in proportion to the degree of recirculation. Blood withdrawn from the fistula has an altered conductivity related to the degree of recirculation. Quantitative values of the conductivity of the altered conductivity blood entering the fistula and the conductivity of the blood being withdrawn from the fistula are measured and a difference determined. The determined difference between the conductivities is used to determine a quantitative measurement of the degree of recirculation in the fistula.

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Arvada, CO, United States of America

George W Buffaloe, Iv