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AssigneeHema Metrics, Inc.
InventorsRobert R. Steuer, David R. Miller
Estimating the term…
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. The oxygen consumption rate is then determined using the cardiac output and measuring the degree of oxygen saturation. Finally, an improved cuvette and corresponding method of measuring microemboli is provided. The cuvette contains multiple mini-lenses that focus narrow beams of light through the blood. These narrow beams of light are individually monitored by detectors.
A noninvasive method of measuring cardiac output in a dialysis system having arterial and venous tubing lines using a first extracorporeal cuvette located at an input to a dialyzer in said dialysis system and a second extracorporeal cuvette located at an output of said dialyzer, each extracorporeal cuvette having an inlet, an outlet, and a conduit in fluid communication therebetween, said conduit having first and second opposed walls allowing electromagnetic radiation therethrough with inner surfaces thereof having a first predetermined separation therebetween, outer surfaces and said inner surfaces of said first and second opposed walls being planar, said inner surface of said first wall including a pedestal emanating outwardly toward the inner surface of said second wall, said pedestal having a planar end surface defining a second predetermined separation from said second wall, said first predetermined separation being greater than said second predetermined separation so that a shorter radiation path length is created across said second predetermined separation, said method comprising the steps of:
A method for detecting blood emboli using an extracorporeal cuvette having an inlet, an outlet, and a conduit in fluid communication therebetween, said conduit having first and second opposed walls with inner surfaces thereof having a first predetermined separation therebetween, said method comprising the steps of:
A method for monitoring blood constituents using an extracorporeal cuvette having an inlet, an outlet, and a conduit in fluid communication therebetween, said conduit having first and second opposed walls allowing electromagnetic radiation therethrough with inner surfaces thereof having a first predetermined separation therebetween, outer surfaces and said inner surfaces of said first and second opposed walls being planar, said inner surface of said first wall including a pedestal emanating outwardly toward the inner surface of said second wall, said pedestal having a planar end surface defining a second predetermined separation from said second wall, said first predetermined separation being greater than said second predetermined separation, said method comprising the steps of:
Dependencies are inferred from the claim text.