Abstract: A method for determining cardiac output in conjunction with flow through an extracorporeal circuit, wherein flow through an arterial line of the extracorporeal circuit is temporarily reversed and an indicator is passed through the cardiopulmonary circuit. A dilution curve is measured in the arterial line of the extracorporeal circuit during the reversed flow, and cardiac output is determined corresponding to the measured dilution curve.

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 determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

Abstract: A method and apparatus for determining cardiac output in conjunction with flow through an extracorporeal circuit, wherein flow through an arterial line of the extracorporeal circuit is temporarily reversed and an indicator is passed through the cardiopulmonary circuit. A dilution curve is measured in the arterial line of the extracorporeal circuit during the reversed flow, and cardiac output is determined corresponding to the measured dilution curve.

Abstract: A method and apparatus for determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

Abstract: A method and apparatus for determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

Abstract: A transit time ultrasound sensor is employed for the measurement of liquid flow in a conduit, the sensor having an acoustic path formed of materials matched in ultrasound properties to the flow under test, and designed to conform to the shape of the conduit. The sensor can be configured as a clamp on device, wherein the conduit walls are constructed from such an ultrasonically-matched material. Alternately, in a perivascular configuration, the ultrasonically-matched material is operably intermediate the blood vessel and the sensor.

Abstract: A method and apparatus for determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

Abstract: A method and apparatus for determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

Abstract: A catheter for retrograde orientation in a blood flow is used to determine the blood flow rate by thermodilution measurements. The determination of the blood flow rate accommodates injectate induced thermal influences on a dilution thermal sensor, wherein the thermal influences can occur prior to introduction of the injectate into the blood flow.

Abstract: A catheter for retrograde orientation in a blood flow is used to determine the blood flow rate by thermodilution measurements. The determination of the blood flow rate accommodates injectate induced thermal influences on a dilution thermal sensor, wherein the thermal influences can occur prior to introduction of the injectate into the blood flow.

Abstract: A sensor probe provides a pair of unique signal paths through a test material, wherein one configuration of the probe provides identical external portions of the signal paths such that a selected parameter of a measuring signal passing along at least two of the unique signal paths is measured. From these measurements, a method is provided for calculating at least one parameter of the test material, wherein the parameter can include an intrinsic parameter as well as a condition of state.

Abstract: A method and apparatus for determining cardiac output in conjunction with flow through an extracorporeal circuit, wherein flow through an arterial line of the extracorporeal circuit is temporarily reversed and an indicator is passed through the cardiopulmonary circuit. A dilution curve is measured in the arterial line of the extracorporeal circuit during the reversed flow, and cardiac output is determined corresponding to the measured dilution curve.

Abstract: A method and apparatus for determining an angioplasty induced blood flow changes, wherein the apparatus includes the catheter having a port for introducing a blood property change in a downstream sensor. The downstream sensor and the catheter are configured to space the sensor from an adjacent vessel wall so as to minimize effects of the vessel wall during sensing of the blood property change.

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: 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 determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

Abstract: A method and apparatus for determining an angioplasty induced blood flow changes, wherein the apparatus includes the catheter having a port for introducing a blood property change in a downstream sensor. The downstream sensor and the catheter are configured to space the sensor from an adjacent vessel wall so as to minimize effects of the vessel wall during sensing of the blood property change.

Abstract: A method and apparatus for determining an initial flow rate in a conduit is disclosed. A known change is made to the flow to be measured, resulting changes (or values corresponding to these changes), or relative changes in the flow to be measured are monitored and the initial flow in the conduit is calculated from the value of the known change and monitored changes. Devices to practice the method include catheters having one or two sensors and one or two sites for introducing the volume change.

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.