Abstract: A method and device for the continuous real-time monitoring of relative blood volume change, based on registration of blood hemoglobin concentration, during long periods of time, such as dialysis session. A method and device for cardiac output measurement during dialysis, surgeries, intensive care procedure is provided. Calibration of a sensor in response to a change in a measureable blood property is determined from a coefficient corresponding to a change in the measured blood property.

Abstract: The measurement of blood flow in a dialysis shunt is obtained by injection of an indicator material into a venous line leading from dialysis equipment to the shunt. The blood flow in an arterial line leading from the shunt at a location downstream of the venous line to the dialysis equipment is monitored by an arterial line sensor for the presence of the indicator material. A detector connected to the sensor provides a dilution curve in response to the presence of the indicator material and the blood flow in the shunt is calculated from the area under the dilution curve. The locations of the arterial and venous lines in the shunt can be reversed to obtain a measurement of blood recirculation from the venous line into the arterial line.

Abstract: A method and apparatus for monitoring and measuring the filter blood volume by dilution techniques in real time, wherein the filter may be in use or off line during the measurements. The system includes a method and apparatus for measuring or monitoring the volume of a blood side of a filter by employing one of a bolus in the blood side upstream of the filter; a change of the filtration rate in the filter; and a bolus on the dialysate side, wherein the filter blood volume is calculated from the obtained data.

Abstract: The measurement of blood flow in a dialysis shunt is obtained by injection of an indicator material into a venous line leading from dialysis equipment to the shunt. The blood flow in an arterial line leading from the shunt at a location downstream of the venous line to the dialysis equipment is monitored by an arterial line sensor for the presence of the indicator material. A detector connected to the sensor provides a dilution curve in response to the presence of the indicator material and the blood flow in the shunt is calculated from the area under the dilution curve. The locations of the arterial and venous lines in the shunt can be reversed to obtain a measurement of blood recirculation from the venous line into the arterial line.

Abstract: A method and device for the continuous real-time monitoring of relative blood volume change, based on registration of blood hemoglobin concentration, during long periods of time, such as dialysis session. A method and device for cardiac output measurement, based on optical dilution technique, during dialysis, surgeries, intensive care procedure. The effects of blood electrolyte composition change which result in a change of light beam geometry are eliminated by the relative orientation between a light source and a single light or photodetector. An illumination axis and a detection axis are oriented in an offset, non collinear configuration at a sufficient angle to substantially eliminate the scattering properties of the blood. A primary implementation of the device is extracorporeal paths, such as hemodialysis tubing systems, artery-vein extracorporeal artificial shunts, other extracorporeal systems. It also may be applied to vessels, tissues or to body parts being capable of transillumination.

Abstract: The present invention provides a method and apparatus for measuring the blood flow rate within an A-V shunt via indicator dilution techniques. Unknown flow resistance within the A-V shunt are addressed by adjusting a measured flow rate to provide a flow rate within a predetermined margin of error. The calculated flow rate can be rejected based upon flow conditions of the introduced indicator. Different indicator introduction rates can be used to enhance accuracy of the measured flow. The indicator flow path can include a flow restrictor to limit the flow rate of the indicator to below a predetermined value.

Abstract: A method and apparatus for monitoring and measuring the filter blood volume by dilution techniques in real time, wherein the filter may be in use or off line during the measurements. The system includes a method and apparatus for measuring or monitoring the volume of a blood side of a filter by employing one of a bolus in the blood side upstream of the filter; a change of the filtration rate in the filter; and a bolus on the dialysate side, wherein the filter blood volume is calculated from the obtained data.

Abstract: The measurement of blood flow in a dialysis shunt is obtained by injection of an indicator material into a venous line leading from dialysis equipment to the shunt. The blood flow in an arterial line leading from the shunt at a location downstream of the venous line to the dialysis equipment is monitored by an arterial line sensor for the presence of the indicator material. A detector connected to the sensor provides a dilution curve in response to the presence of the indicator material and the blood flow in the shunt is calculated from the area under the dilution curve. The locations of the arterial and venous lines in the shunt can be reversed to obtain a measurement of blood recirculation from the venous line into the arterial line.

Abstract: A diverter for selectively providing fluid communication between ports to a common chamber is disclosed. The diverter includes a resilient deformable common chamber having a plurality of ports. Upon deforming the common chamber along a given line, fluid communication between selected ports is precluded, which flow preclusion is used to effectively reverse a flow direction in a circuit connected to the diverter.

Abstract: A diverter for selectively providing fluid communication between ports to a common chamber is disclosed. The diverter includes a resilient deformable common chamber having a plurality of ports. Upon deforming the common chamber along a given line, fluid communication between selected ports is precluded, which flow preclusion is used to effectively reverse a flow direction in a circuit connected to the diverter.

Abstract: The invention provides a method of determining a shunt flow and particularly for hemodialysis shunts. The method includes determining a shunt flow in a shunt connected between a first point and a second point in a circulating system, wherein a first flow rate is established in the circulating system; a first flow time, or flow velocity is determined between spaced locations in the shunt during the first flow rate in the circulating system; a second flow rate is established in the circulating system; a second flow time, or flow velocity is determined between spaced locations in the shunt during the second flow rate in the circulating system; and a shunt flow is calculated from the first flow time or velocity, the second flow time or velocity, the first flow rate and the second flow rate.

Abstract: The invention includes a dilution sensor for determining a blood property in a peripheral artery distal to the heart and lungs, wherein the dilution sensor may be exposed to the blood flow by passing through a pressure arterial catheter.

Abstract: A method and apparatus for identifying a central blood volume and monitoring changes in the central blood volume during hemodialysis to assist in predicting an onset of intradialytic morbid events. A method of determining a central blood volume mean transit time in a patient system having the central volume and a tubing portion includes measuring a system mean transit time through the tubing portion and the central volume; calculating a tubing portion mean transit time corresponding to passage of an indicator through the tubing portion; adjusting the measured system mean transit time in response to the calculated tubing portion mean transit time to produce the central volume mean transit time and calculating a central volume by multiplying the central volume mean transit time by the cardiac output. This technology can be used not only in hemodialysis, but in intensive care units or during the surgery with extracorporeal circulation systems.

Abstract: A method and device for the continuous real-time monitoring of relative blood volume change, based on registration of blood hemoglobin concentration, during long periods of time, such as dialysis session. A method and device for cardiac output measurement, based on optical dilution technique, during dialysis, surgeries, intensive care procedure. The effects of blood electrolyte composition change which result in a change of light beam geometry are eliminated by the relative orientation between a light source and a single light or photodetector. An illumination axis and a detection axis are oriented in an offset, non colinear configuration at a sufficient angle to substantially eliminate the scattering properties of the blood. A primary implementation of the device is extracorporeal paths, such as hemodialysis tubing systems, artery-vein extracorporeal artificial shunts, other extracorporeal systems. It also may be applied to vessels, tissues or to body parts being capable of transillumination.

Abstract: A method and apparatus for monitoring and measuring the filter blood volume by dilution techniques in real time, wherein the filter may be in use or off line during the measurements. The system includes a method and apparatus for measuring or monitoring the volume of a blood side of a filter by employing one of a bolus in the blood side upstream of the filter; a change of the filtration rate in the filter; and a bolus on the dialysate side, wherein the filter blood volume is calculated from the obtained data.

Abstract: The measurement of blood flow in a dialysis shunt is obtained by injection of an indicator material into a venous line leading from dialysis equipment to the shunt. The blood flow in an arterial line leading from the shunt at a location downstream of the venous line to the dialysis equipment is monitored by an arterial line sensor for the presence of the indicator material. A detector connected to the sensor provides a dilution curve in response to the presence of the indicator material and the blood flow in the shunt is calculated from the area under the dilution curve. The locations of the arterial and venous lines in the shunt can be reversed to obtain a measurement of blood recirculation from the venous line into the arterial line.

Abstract: An apparatus and method for measuring hemodynamic parameters includes a sound velocity sensor coupled to at least one of an arterial or venous portion of a blood system. An indicator medium is injected into the blood system upstream of the sensor to dilute the bloodstream, and the sensor detects the dilution through changes in measured sound velocity. The changes are recorded and used to determine hemodynamic parameters.

Abstract: An apparatus and method for measuring hemodynamic parameters includes a sound velocity sensor coupled to at least one of an arterial or venous portion of a blood system. An indicator medium is injected into the blood system upstream of the sensor to dilute the bloodstream, and the sensor detects the dilution through changes in measured sound velocity. The changes are recorded and used to determine hemodynamic parameters.